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A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
We have set up a test field for highway stormwater monitoring on Rijeka city bypass as a start of our stormwater monitoring program. ADT on this bypass is between 15000 and 50000. We are in the process of creating our monitoring plan and I would appreciate if anyone could share their experiences in sampling, sample volume and which elements should be included in analysis.
Our test field is on an intersection with a closed, watertight drainage system and there are 3 small watersheds from which stormwater goes to an oil and grit separator. we plan to take samples form 5 locations - 1 from each watershed, 1 before and 1 after the separator.
I think the point was mostly that the load and the flow is not always coincident. Your post provides an example different than mine but the solution is the same: you have to monitor concentrations of pollutants over the course of storm water flow events, not at a single point during a storm event, if one is to estimate total loading.
I am interested in the water intake, consumption and discharge of power plants, iron and steel plants, refineries and chemical facilities in the EU. Please indicate if you know of existing databases that hold this information or if you know of institutes or organizations that collect this data in the EU.
There are many methods for analysis of organic contaminants in drinking water. Most of organochlorine pesticides, acidic herbicides, carbamates and PAHs are mostly not detected. I already analyzed chlorine disinfection by-products like THMs, HAAs and HANs. So i want to know if there are any other organic compounds known to be detected in drinking water?
These include Persistent organic pollutants (POPs), they are toxic chemicals that adversely affect human health and the environment around the world. Because they can be transported by wind and water, most POPs generated in one country can and do affect people and wildlife far from where they are used and released. They persist for long periods of time in the environment and can accumulate and pass from one species to the next through the food chain.Many people are familiar with some of the most well-known POPs, such as PCBs, DDT, and dioxins. POPs include a range of substances that include:
Intentionally produced chemicals currently or once used in agriculture, disease control, manufacturing, or industrial processes. Examples include PCBs, which have been useful in a variety of industrial applications (e.g., in electrical transformers and large capacitors, as hydraulic and heat exchange fluids, and as additives to paints and lubricants) and DDT, which is still used to control mosquitoes that carry malaria in some parts of the world.
Unintentionally produced chemicals, such as dioxins, that result from some industrial processes and from combustion (for example, municipal and medical waste incineration and backyard burning of trash).
POPs work their way through the food chain by accumulating in the body fat of living organisms and becoming more concentrated as they move from one creature to another. This process is known as "biomagnification." When contaminants found in small amounts at the bottom of the food chain biomagnify, they can pose a significant hazard to predators that feed at the top of the food chain. This means that even small releases of POPs can have significant impacts.
Thank you Scott. Are you interested in papers where a closely related chemical, tetradecyltrimethyl ammonium bromide was tested on bivalve mollusks? See: http://5bio5.blogspot.com/2013/05/inhibition-of-mussel-suspension-feeding.html
I think the most suitable formulea to calculate the no.of H+ ions evolved during the water electrolysis, that you get by combining Faraday’ s Law of electrolysis and Ideal Gas Law, and the final equation would be
Where n is the no.of H+ ions, I is the current that you applied, t= time for passage of current, T = temperature, R= Universal gas constant, F=faraday’s constant, P=atmospheric pressure and V=Volume of hydrogen evolved.
Yes, there is a relation between the pH and the electrical current flow [the conductivity] of a solution, but there are other factors that affect the conductivity. This topic, the conductivity of solutions, takes up a full chapter in a textbook on physical chemistry with many graphs and numerical tables. But I will try to keep it simple, basic, non-mathematical, - and short. When an electrical current passes through a wire, what actually moves and carries the curent is ELECTRONS. But in solutions, the current is carried by IONS: positively charged CATIONS [+]such as H+ , Na+, Mg+, etc. and negative ANIONS [-]such as OH-, Cl-, Acetate-, etc. [The + and - should be superscripts, but this computer cant show this [maybe it can, but I cant]. The conductivity of a solution depends on the concentration of ALL the ions present, the greater their concentrations, the greater the conductivity, These ions all have the electrical unit charges shown by their symbols, but they move at different velocities [mobilities] through the solution, so they contribute differently to the conductivity. An analogy would be a line of persons carrying water to a tank, they all have the same size bucket, but some walk faster than others [i.e. have greater mobility]so they contribute more. These relative mobilities have been measured and are listed in many chemistry texts and reference books. Of the common ions, the most mobile CATION is the Hydrogen ion [H+] with a value of 350 units, and the most mobile ANION is the Hydroxyl ion [OH-], 199 units. The other common ions have values ranging between 40 and 80 units. So you se that strongly acidic [or strongly basic] solution will have high conductivity Since the pH is a measure of the concentration of the Hydrogen [and the Hydroxyl] ions, for an acidic solutin, the lower the pH [i.e. the higher the H+ concentration,] the greater the conductivity will be. Remember, the conductivity is the sum of the contribution of ALL the ions present in the solution I hope this brief discussion helps you. For more detailed information, I suggest bellow reference for further detail information.
I have gathered data on the free water content in beef (with the same protocol) in more than 400 samples from different breeds and breeding methods. Data are about thawing loss, drip loss, cooking loss, cooling loss, whc and whc trend, water content at consumption. I also have other qualitative data such as meat cooking shrinkage, tenderness, etc. I have the opportunity of a grant of 3 months in Germany and I would love to be able to analyze this data with a German colleague expert on the subject. Objective is to produce a paper that describes the behavior of free water at the different moments of the beef supply chain. For processing data I'm using SAS for over 20 years.
Simulation of water treatment processes constitutes an important research theme. In comparison with real works at the industrial scale, where is the real place of simulation in developing water treatment technology?
Nov 14, 2013
Simulation provides a convenient platform for us to change the condition and observe the results. As such, you could change the process conditions such as pH and see how treatment efficiency changes. This will help you to identify the process conditions that are best for an efficient treatment. Otherwise, you may have to conduct large number of experiments to find out the best conditions for efficient treatment.
But, there is a risk. Because, the accuracy of the simulation outcomes depends on the accuracy of your model that you have used to simulate. There are ways to create models and to check the accuracy of the model, i.e. how accurate the model replicates the process. Any standard text book on modelling should explain the fundamentals.
You could initially use simulation technique to identify the best conditions, test it an industrial level and see whether it works. As I mentioned before, you could avoid tedious and sometimes expensive experiments. Hope this helps :)
Distilled water is known to be acidic due to atmospheric CO2 absorption. how can one measure the degree of acidity in water due to CO2 absorption ? Distilled water in our labratory has pH ~ 5.8-6.4. How can I know that this change in pH is due to CO2 absorption ? Might I be measuring the concentration of HCO3- ion in water?
The pH can be measured by a standard (well calibrated) pH electrode. Pure water at 25 Celsius in equilibrium with the standard atmosphere (air) has a pH of 5.67, say 5.70 according hydro chemical equilibrium calculations (e.g. using Phreeqc model). Of course, cooling, heating, shaking water, can modify some gas equilibria and induce some fluctuations, as indicated by you. Pure distilled water is in fact rather unstable, and a few micromol change of CO2 gas absorption from e.g. air or depletion, change the bicarbonate equilibrium and pH. You can measure bicarbonate or the alkalinity (TIC or total inorganic carbon) using a titration. For pure water, a special accurate titration method (as described in Stumm and Morgan , Aquatic Chemistry) is recommended.
All analytical work on aqueous solutions in contact with the air, will have to deal with CO2 from atmosphere, although it are micro-molar transfers, and not that important (in general). Most other electrolytes (dissolved salts) or soluble organic compounds (with acid-base action) will override the atmospheric CO2 effect quickly. Therefore, I wouldn't bother that much.
For a project I'm looking at the cost and benefits of water retention in the soil versus water retention directly on the land. Is there a relation between soil water content and organic matter? If yes, what is that relation and what can be the minimum en maximum water content of a sandy and clay soil per ha or m3 of soil?
Please use the latest version of the Soil Texture Triangle Hydraulic Properties Calculator which can be downloaded from the following website: http://hydrolab.arsusda.gov/soilwater/Index.htm. This calculator allows you to dial or choose organic matter content and then asks you to input %sand, %silt and %clay. It will calculate the hydraulic properies for you. I think this will a good beginning....
wiki/Fuel : "Fuels are any materials that store potential energy in forms that can be practicably released and used as heat energy."
H2O is the highest oxidation achievable by Hydrogen and cannot be oxidized further. Hence, water as such, cannot be used as a fuel, be it from sea water or DDW. One can break the O--H bonds to get Hydrogen which then can be used as a fuel. When Hydrogen is used as a fuel, the product one gets is water. So, essentially what we are doing is taking water, splitting it, get the hydrogen thus derived, oxidize it back to water. There is no net energy gain from the process and hence water cannot be used as a fuel like petrol or diesel or CNG (As Barry indicated).
Splitting water using solar energy and using the Hydrogen is just a method of harvesting solar energy indirectly. The major limitation being faced is not in the water splitting reaction but in the efficiency of solar energy panels which is much less than the conventional fuel oxidation. This is not a viable solution at this moment from commercial point of view. Improving solar energy capture efficiency is the way to do it. It it were the case, one can directly use the solar energy rather than the roundabout way through water.
In conclusion, water cannot be used directly as a fuel in any method whatsoever, but can be used as an intermediate to convert one form of energy to the other.
We are very keen to obtain estimates of the costs to water companies of treating water to change concentrations of nitrates, phosphates and also to improve ecological status. Note that our focus is on costs of treatments by water companies rather than say quality changes from land use change. Ideally we would like estimate for the UK but we are intersted in any available information. Ideally this should link the monetary cost to the concentration (before and after treatment) and the volume of water treated. So the costs mmight be a constant monetary amount per (say) cubic metre (or millions thereof); or it might be a cost function relating all of the above factors together. We have tried to obtain this information from water companies without success and are getting fairly desperate (its for a report deadline) so any information would be greatly appreciated. Thank you. Ian
Generally your levels for any added ions are in the ppm to ppb levels, so not much material is needed. The settling tanks and mixing areas are costly to build. Anything with nitrites will need to be under nitrogen... there are a lot of variables in there. My company works a LOT with water treatment and may have some good people to contact.
In the 1985, I collaborated with Peter Borgesen and W.Moeller at the Max-Plank Institute for Plasma Physics in Garching (Germany), as to use their ion implanter equipped with a on-line mass spectrometer, to estimate the water desorption yield of lunar silicates and glasses, when they are subjected to implantation of solar wind hydrogen. Note that we did use a deuteron (D) beam rather than H, as to avoid contamination by terrestrial H2O. We were amazed about the excellent yield of desorb water of about 10-4 D2O molecule for each incident D . Sure enough we had a new source of exotic water on the Moon (i.e., both solar, by H, and lunar, by O).
These molecules are ejected in ballistic motions in the ultra-thin lunar atmosphere, with a fraction being collected in the permanently shadowed and frozen regions of the Moon, such as the lunar poles --See: Blandford, Borgesen, Maurette, Moller, Monnart, On-line analysis of simulated solar wind implantation of terrestrial analogues of lunar materials (1986) JGR, 91, 467), and Blandford et al (1985) Hydrogen and water desorption on the Moon: Approximate on-line simulations, in Lunar Bases and Space Activities in the 21st Century, Ed. W.W.Mendel (NASA Book).
The resulting ice would next react ( in a complex way) with lunar material during micrometeorite impacts. In brief, your problem has still not been solved. Possibly, clays minerals might be present at the lunar poles. And related processes effective on the first wall of fusion reactors might perturb their functioning.
Life as we know it yes, as water is quite unique (see article below from NOVA), but we can of course think outside that box. Alcohols are a fairly good class of solvents, as is liquid methane or ethane, as are acetic acid and acetone(all miscible in water) or even liquid ammonia which seem to be readily available in the cosmos. However, most of these also have a very small liquid range (without additives), and thus a creature with say ammonia in its system, could walk outside in 10-degree warmer weather and its "blood" would literally boil, or even just by over exerting itself! Water in contrast stays liquid over almost 100 degrees (C), depending on pressure. [Where I live water boils at 94 C. :-) ] But this also presupposes life based on organic chemistry. What about Boron or Silicon, both of these elements can support very complex chemistry with hydrogen or halogens, but my guess is Earth would be very hostile to these beings. (Borane for example is very flammable!) But under the right conditions who knows what is truly possible for life, and given the fact that we have discovered life like Archea growing deep in the Earth and in other "unlivable conditions" we have know idea what extremes Earth life can adapt too let alone alien life!
The only way to know is to perform all the analysis. Deep well water can be very good drinking water.
In Denmark there is no use of surface water at all - we don't like the taste and disinfection byproducts - and our typical wells are in sandy aquifers below a clay layer. They are typically 20-50 m deep and the age of water is 10 to >100 years. All wells are analysed several times a year.
Why don’t we directly add CuSO4 and Ag2SO4 into water?
Jan 15, 2014
People use copper-silver ionization through electrolysis to disinfect water. Relatively adding CuSO4 and Ag2SO4 should have lower cost than electrolysis facility.
Copper and silver salts are used in water treatment. In my experience copper is used for algal control and silver has been used in potable water disinfection. However it seems to me that the generation of these ions by electrolysis would be easier to automate and less demanding of human intervention than a dosing plant. The silver and copper electrode would also probably be less subject to spoilage during storage.
i'm just starting my thesis for my MSc in sustainability and environmental management. i'm aiming to understand why collaboration is important in creating the change needed within the water stewardship strategies of corporates.
I found the following articles quite helpful for my research:
Grimble, R., & Wellard, K. (1997). Stakeholder methodologies in natural resource management: A review of principles, contexts, experiences and opportunities. Agricultural Systems, 55(2), 173-193.
Margles, S., Peterson, R., Ervin, J., & Kaplin, B. (2010). Conservation Without Borders: Building Communication and Action Across Disciplinary Boundaries for Effective Conservation. Environmental Management, 45(1), 1-4.
Tam, C. L. (2006). Harmony hurts: Participation and silent conflict at an Indonesian fish pond. [Article]. Environmental Management, 38(1), 1-15. doi: 10.1007/s00267-004-8851-4
I\m writing a paper based on a 2 year research project where institutional entrepreneurs were involved initiating and implementing recycled water schemes in Australia and I haven't seemed to be able to find anyone else writing on this phenomena.
I'm not sure if you have seen research in institutional bricolage and water usage . Not exactly the same, but similar. Bricolage has nice links to "making do, through using resources on hand, to create novel solutions to challenges and opportunities" including distressed "cheap" resources (see Baker & Nelson, 2005). So this notion of reuse, recycling fits nicely with the theory at both levels: the firm level and the institutional level. good luck. :)
Baker, T., & Nelson, R. E. (2005). Creating something from nothing: Resource construction through entrepreneurial bricolage. Administrative science quarterly, 50(3), 329-366.
Cleaver, F. (2002). Reinventing institutions: Bricolage and the social embeddedness of natural resource management. The European Journal of Development Research, 14(2), 11-30.
Merrey, D. J., & Cook, S. (2012). Fostering Institutional Creativity at Multiple Levels: Towards Facilitated Institutional Bricolage. Water Alternatives, 5(1).
Dear Khaled, separate your samples into training (106 Sample) and Test (34 Sample). Then you need to choose an ANFIS structure with less number of parameters (premise+consequent) than your training sample. For example, choose Gaussian-shaped with three MFs for one input, two MFs for two inputs and one MF for four input. By this structure you have 106 unknown parameters and 106 training data.
Thank you so much for the wonderful question; corporation sector worked on water, sanitation and health etc., but lack of publication works; doesn't take them in to the unknown. several materials or reports are available in PWD sections of all district head quarters; please if you can go through the things, which were unpublished so far ; some of the materials were published in CPCB portal, NEERI portal, etc.
I am trying to assess the contribution of benthic communities to the whole system metabolism (oxygen signal) measured through the dissolved oxygen loggers, within 100 m length of a creek for which I would like to get an estimate of the littoral zone, to scale up the contribution per square meter to the whole littoral zone. Is there a particular technique to estimate the area of littoral zone within a specified section of creek/lake/river?
If you defined the littoral zone as some specified depth, such as one meter or the photic zone, etc. it could be pretty easy to calculate the area of the littoral zone (assuming spatial homogeneity of littoral zone). Basically, you first construct a bathymetric map of the system, which is fairly straightforward in ArcMap. I construct my bathymetric maps using triangular irregular networks (TINs) in ArcMap and then calculate surface area or volume using the spatial analyst toolbox. First, determine the total surface area/volume from the TIN and then calculate the surface are/volume after removing say the first one meter from the entire surface (or whatever distance that you defined as the specified depth of the littoral zone). The difference between these two would give you the surface area (m2) or volume (m3) of the littoral zone as you defined it.
Do you need to make an empirical or theoretical pdf? Would you like a cumulative distribution function (cdf) or the pdf?
Because I don't know your background knowledge, I'll answer as if were a student. I'm sorry if you find it too basic.
The empirical pdf is a curve made from your observations whereas the theoretical pdf is a mathematical function fitted to your data. The cumulative distribution function (cdf, or F(x)) is the integral, or the sum, of probabilities up to x in your pdf f(x).
This page displays the cdf in the upper plot and the corresponding pdf in the lower plot:
To produce an empirical pdf manually, sort your data. Are you using daily data for a three month period (spring) or the maximum value? Regardless of your data, the method is the same.
1) Sort your data from smallest to highest.
2) Assign an index i to each observation. The first observation is i=1, the second is i=2 etc, up to i=N.
3) Calculate the probability of non-exceedence by using Weibull's plotting formula: i/(N+1).
If you'd rather like exceedence probabilities, simply calculate 1-(i/(N+1)).
Step 3) provides the empirical cummulative distribution function for your data.
In order to find the theoretical pdf, you have to do exploratory data analysis (histograms, pp-plots, qq-plots) to determine which distribution may be appropriate. For daily discharge, the normal, gamma, or lognormal distribution are candidates. For extremes, the Gumbel, Frechet or Weibull distribution are candidates. When you have decided on which distribution to chose, use a method to determine the curve parameters. The method of moments is one such method: http://en.wikipedia.org/wiki/Method_of_moments_(statistics)
I measured total and fecal coli forms in water. I think in water fecal coli forms should be less than total coli forms. But my results didn't show this matter. I want to find a reference for the relation between fecal and total coli forms.
You give very interesting analysis, although it is difficult for me to fully accept the extraordinary importance that you attach to the very low solubility of radium in the water.
Do you have some source data, confirming the drastic changes in the concentration of radium in waters containing, for example, excessive concentrations of sulphates and carbonates?
In my view, the problem of low concentrations of radium in water is rather associated with the transport barrier of this chemical element from the Earth crust to the water. Let us remember that in spite of all radium is the chemical element with the lowest (or one of the lowest) weight content in the earth's crust.
The access of radon to the water (on the basis of equilibrium saturation) is, however, in my opinion, undisturbed, despite the unusually low content of radon in the atmosphere (about 2.3 kg of radon throughout the earth's atmosphere).
Co-production techniques like slow vacuum pyrolysis of the bagasse can result into 2 value added products; bio-oil that can be used as a fuel and biochar the residual waste which is actually pure carbon; biochar can be further used as a soil conditioner or as a soil amendment agent.
We have water samples from clean river that need to be tested for anion. However, the machine is currently not functional for a moment. Is there a technique to preserve the sample without using separate technique as I being told that separate method of preservation for each individual anion to be tested.
Do you just want to increase the calcium concentration? Or what are the constraints and why do you want to increase the Ca-concentration in the fresh water. This is important to know in order to give the right answer on your question. If you don't care about the alkalinity of your water, you can add CaCl2 or any other soluble Ca-salt.
I am going to make an apparatus for my PHD thesis about "internal erosion in soils", but one of the my important problems is the measurement of water turbidity (involves soil particles and some solution solutes) with a sensor or detector (call turbidity meter) .Also it's satisfying for me to have online data from sensor or detector. But the main problem about this, is the cost and availability of this sensors for 10-30 mm pipes. Please Help me.
Dear Vahid - There are several options in the market for you so much depends on your specific setup (e.g. closed or open system), sampling method/frequency, detection limit requirements and, of course, budget.
As such, your options range from highly accurate 'inline' sensors that measure and transmit data in real time ... to collecting 'grab' samples on glass microfibre filters (eg. Whatman GFC).
Pending your objectives, however, you may want to include a protocol that incorporates both given that values obtained using a 'turbidity meter' (aka. nephelometer) is an optical measure in units of NTU (or FTU) whilst filtered grab samples provide a physical measure in (mg/cm^2) commonly referenced as TSS (total suspended solids).
Although relevant, these two measures cannot necessarily be be directly compared. I make note of it here as many regulatory standards may use one or the other (likely not both) and whereas your in situ, electronic measures, will be in NTU/FTU virtually all numeric models that I am aware of treat turbidity as a physical particle ... ie. TSS.
In many cases it is worth considering measure of both and the development of a correlation between the two, although, the effectiveness can be somewhat limited depending the variability in the physical/optical properties of your sediment materials.
Note that there are established procedures for the measurement of TSS, however, these too can vary between laboratories. As such, use caution in your approach and be sure to standardise between samples as the method employed can, and will, influence your results. Also, be mindful that all electronic equipment needs to have calibration verified, and are subject to sensor 'fouling' and 'drift' and therefore need be checked/validated on a regular basis. The manufacturer should be able to provide this type of guidance.
These links may be of some interest/assistance. There is also much available in the literature:
Is it caused by normal to surface oriented water dipoles and/or by broken H-bonded 3d structures? Then how is this broken H-bonded net organized to produce the high surface tension of water? Has anybody estimated the number of H-bonds to unit of surface square and to the 2d structure of the water interface?
I think the best answer at the moment is that we don't know. There is a large effort on understanding this at the moment and a good deal of disagreement in the literature. Some even claim that the surface has a positive charge. I suggest you look at articles by James Beattie, Richard Saykally and Pavel Jungwirth to follow the debate. I think one of the complications is that when you are talking about the interface you need to understand the region of the interface that you are referring to. (what depth into the interface). Different experimental techniques will probe different depths and for most techniques this depth is not known. There are also challenges with the theoretical interpretation of simple measurements such as surface tension and how ions alter the surface tension, especially when you consider that concentrations near the interface are not going to be monotonic but oscillatory. Great question, but I think it will be some years yet before we have a clear answer.
A Nafion tube was immersed in water with dispersed microspheres (diameter of microspheres ca. 2µm). After exposing the tube to normal light for a few minutes, a flow was initiated which kept on flowing through and around the tube for at least 20 min. The reason for the flow is still unknown (No difference in electrical potential or pressure was applied in this experiment just a Nafion Tube, visible light, water and a glass dish). Moreover, around the edges of the tube there are no microspheres. The width of this region is ca. 50µm.
In my opinion this is virtually impossible as the light penetration will be affected by many factors other than turbidity. In particular the sun angle above the horizon would affect the path length even if you corrected for light intensity at the surface.
When studying the migration behaviour of trace elements or radionuclides in argillaceous rocks, one assumes that the thermodynamics underlying the speciation of radionuclides in the confined pore water is the same as one for bulk water. This might be not the case at all. Therefore it is necessary to learn more about thermodynamics in confined solutions.
As to water itself, both dynamics and thermodynamics in confined geometries are significantly different from their bulk analogues and strongly dependent on dimensionality.
Two good (though not exhaustive - this field keeps evolving, and rapidly) references you could examine are 1) the 2003 monograph by Buch and Devlin ('Water in Confined Geometries') and 2) the 2008 computational review by Brovchenko and Oleinikova ('Interfacial and Confined Water').
As to experimental techniques involved, take a serious look at works performed in high- and low-resolution NMR, as well as as to neutron and dielectric spectroscopy.
I completely agree with Dear Prof. and Dear colleagueMillôr Sabará that, This is possible by adding crushed (< 0.5 micrometer) commercial limestone without Mg or Calcite limestone. It will depend upon P levels. In oligotrophic (0.01 mg P/L) freshwater it will works. Start using 10 umol Ca / L.
Especially in the case of shallow pond having maximum depth of not more than 20-25 meters. Would there be any changes in the depth of thermocline layer due to varying concentrations of hardness and TDS?
Strictly speaking pH is a simplified way to numerically quantify the H+ ion concentration of a given solution. So whatever affects the [H+] of a given solution, pH of that soultion will also experience an inverse change. Now talking of corelation of pH and temperature, since a rise in temperature is associated with incresed molecular vibrations,upon increasing the tempreature, the observable [H+] also increases due to a decreased tendency of forming Hyderogen bonds, thus leading to a reduction in the pH.
This fact is clearly evident when we measure the pH of water @ 0 deg C we find it to be 7.47, but the same water at 100 deg C will have a pH of 6.14 ! so there a definate corelation of pH and temperature .
I think it is necessary to include another issues than only market. Indigenous peoples have been in their territories and have rights over their natural resources. Some cultural indicators can be important to measure, as well as the institutional arrangement and local to national agreements.
Can onyone suggest a simple and accurate measurement method for lignin presence in black liquor?
Mar 3, 2013
Black liquor is the waste water produced during pulping process (Kraft, Soda method). Due to structural variations in lignin from one plant species to another, it is very difficult to know the exact chemical structure of lignin. But I am sure there would be some structural base unit in lignin molecule, irrespective of sources.
Recent article from my group:
Gassara, F., Ajila, C. M., Brar, S. K., Tyagi, R. D., Verma, M. et Valero, J. R. (2012). Lignin analysis using microwave digestion. Biotechnol. Lett., 34 (10) : 1811-1815.
DOI : 10.1007/s10529-012-0991-7
What are the most effective methods for remotely detecting and mapping coastal freshwater springs? The water temperature of these springs changes rapidly to an intermediate temperature between the temperatures of the background water and the air temperature.
I want to analyze water 2,4-D in HPLC. Can anyone tell me about reference methods, like USEPA methods? Currently I am following the method in GC-ECD but in HPLC the sample preparation is very simple. So I want the reference method only. Is there anyone who can help me?
I have collected data from a number of papers regarding the absorption coefficients and refractive indices of pure water. I have attached an Excel file containing this data. Is anyone aware of other papers that I should include? Also I would appreciate comments re my 'recommended' set of data.
Röttgers, R., Doerfer, R., McKee, D., Schönfeld, W., 2010. The Water Optical Properties Processor (WOPP): Pure water spectral absorbtion, scattering, and real part of refractive index model, Algorithm Technical Basis Document, report number, WR D6.
We are using MNDWI, NDWI, VIUPD and several indices to delineate water boundary from non-water features. We try to implement these methods for floods or lakes and try to choose some best threshold methods.
The turbidity, organic and inorganic matter content of the water, and the nature of the atmospheric layer between the sensors and the water body (often influenced by time of the year) and the nature of the surface at the boundary between water and land could introduce challenges. These variables would affect the albedo of the water body and make it more difficult to distinguish. There have been a number of studies utilising bio-optical and radiation transport models to enhance mapping accuracy.
How can we calculate the water productivity of fodder? We are using a jet type water sprinkler to irrigate fodder plots. The scientists or researchers working in this area may be able to help me with this. Is there any instrument which can directly assess the amount of water delivered from a sprinkler jet?
I think that it is important to specify the biome wherein this will be taking place, because different water evaporation coefficients will occur according to temperature, humidity, elevation above sea level(which also leads to alternating levels of air pressure). Also the different climatic zones will also affect how the plat grows.
How to separate volatile oil from a mixture of oil-water after extraction of oil using clevenger apparatus?
Mar 7, 2013
I have recently extracted volatile oil from some plant material and now I have a mixture of both oil and water. Could you please suggest what is the best method to separate pure oil from this mixture of water and oil. From the literature I know that I need to use propane but I don't have a concrete reference for that.
Pass the oil through a bed of sodium sulphate in a funnel. Water will adsorbed by the sodium sulphte and oil will pass.
or put the oil-water mixture in -20C. Water will freeze but not oil.
What is the role of behavioural change in mitigating climate change?
Mar 6, 2013
We would like to know if its possible to change individuals' behaviour towards sustainability. And if so, if there is a real impact on mitigation climate change.
Mar 11, 2013
Behavioral and attitude change is the first step in adoption of any technology. However much a technology is well packaged to best of knowledge by the producer, it is bound to fail if in its implementation, behavioral change is not addressed first. We have had an interesting experience from a project we are currently running on mitigating climate change induced water vulnerabilities in east Africa. A water use technology was introduced into a pastoral community which was already having a less efficient water harvesting and storage technology. The technical staff packaged and implemented the technology with participation of all stake holders organized in an innovation platform (Tenywa, et al., 2011-http://mahider.ilri.org/bitstream/handle/10568/3562/AIParticle.pdf?sequence=2) . A scenario has been observed where the pastoralists even after selecting the technology, have decided to abandon it. It has prompted an instigation into the scenario to establish the exact cause of the neglect and get solutions to the problem. To my view the attitude change was not addressed first but the communities were jest excited by the presence of a project. It is worth noting that even the district level administrators have not shown participation as committed initially. It shown failure to adopt from the farmers to policy level. I think thorough advocacy for mindset change is key to solving any problem be it scientific or any interventions to society.
You can take glass test tube. Than to reduce wettability by water you can treat it for example in dimethyldichlorosilane vapour. To do this, put thoroughly cleaned testtube in a desiccator with dimethyldichlorosilane. Degree of hydrophobisation will depend upon exposure time.
I assume it should be less than in ambient conditions. Since glovebox atmosphere contains trace amounts of O2 and H2O, thermodynamically the temperature needed to evaporate H2O should be less. Do you have any experience in such kind of a treatment? I prefer a little bit of precision in the answers instead of assumptions.
I have not quite understood the intention of your trance amount argument. In principle the more you have in the gas phase, the more you drive the equilibrium towards the surfaces.
With nanoporous films, capillary forces may play a big role and while not influencing te equilibrium - the time constants for reaching equilibrium may become quite substantial. And what kind of state do you want to reach? Zero monolayers of water? That requires high temperatures even in vacuum (we have metal surfaces there).
Some years back I have occasionally worked with a tempered container for sample holders which were to enter UHV. They were kept at 50-60°C to reduce desorption of Water upon insertion to the UHV (faster pump-down). For a glove box system I would target at the same kind of temperature if transfer to UHV was the purpose of getting rid of (most of) the adsorbed water.
And probably you can use the water monitor of the glove box to appreciate the progress of desorption. You could also design the heated compartment in analogy to the SAS (make it possible to be evacuated separately) and exchange N2 gas with dry one without spoiling the glove box atmosphere.
I think the problem with this use could be that bacteriophages only kill a limited range of specific species of bacteria, but not all pathogenic bacteria species that could theoretically be in contaminated water.
From the water engineering side it is necessary to have a effective disinfection of all potential pathogens from water before it can be safe for drinking water.
There are certain websites that keep their standards online if you are good at searching. I once found a Chinese pharm company that left many freely searchable online a while ago, but we purchased the ASTM books, so I don't have that site anymore.
I like your method to ask a question. If you want to calculate the evapotranspiration during a season, you have multiple choices. You can find a number of simple methods to do this from the following review paper (It can be downloaded from reseachgate space or directly from webpage of the Journal). Most methods have reasonable auucracy in estimate seasonal evapotranspiration in spite that it is great challenge to estimate its inter-annual or decadal variability.
Wang, K., and R. E. Dickinson (2012), A review of global terrestrial evapotranspiration: Observation, modeling, climatology, and climatic variability, Rev. Geophys., 50, RG2005, doi:10.1029/2011RG000373.
I want to explore the different methods of water harvesting and the most suitable ones to harvest the water of Eastern Nile, so we can increase the water resources of the Eastern Nile Basin Countries. Who can share in this? It can be a big project and seed for funds from different sources. At least we need a partner from Ethiopia, a partner from Sudan, a partner from South Sudan, partners from Egyptian Universities and Water Research Institutes and partners from European Union or America.
If you can expect few compounds it may contain from literature, it will be easy to go for chemical tests for those compounds, otherwise GC-MS is the best option to clear spectrum of compounds that the algae secretion contain.
You should also probably add another question to it: Why does water expand while freezing at 0 C? These are very important questions but to my knowledge have not been understood microscopically. Definitely directed hydrogen bond and their dynamics play roles but no one has any quantitative explanation. I shall come back to you later.
At present I am pursuing my phd, the area under study was found to have manganese ores. I analyzed the samples of ground water and surface water (river water) for heavy metals such as Ti Mn,Ba and more. It was found that all the metals below detection limits. I wish to know to what extent the results are relaible.
i think it's possible that the heavy metals take away from that ore because it's brought by river stream, or maybe the heavy metals settles at the bottom of the rivers, heavy metal have heavier atomic mass than water so it's possible would find on the bottom of the river,, just my opinion :D
Traditional water management practices are termed as good but not practiced at present. How this knowledge can be compared with modern approaches? We cannot have data for the traditional practices other than notes/ scripts etc in traditional scripts and publications refering these scripts.
I think maybe the point is not to compare them, but how they can inform each other since the ways of knowing and the type of information conveyed in traditional vs. modern knowledge are so different. In general I would say that traditional knowledge is much more applied and relevant to people, typically learned over long periods of time and is not reductionist as modern knowledge is. I recently had this story related to me that summarizes these points:
"One of the Hawaiians told a story about a hydrologist who wanted to drill for water in an area where the scientific data indicated it could be found. The elders told the hydrologist he shouldn't waste his time. He ignored the warning, relying on the hydrological indicators. The scientist was right, he did discover water. But it was undrinkable, acidic, red and brackish. The Hawaiians informed him that the name of the hill over the aquifer was named "Red Water", and that they knew the water was there but bad. They pointed him to another hill nearby with the Hawaiian name "water for man", and suggested his luck might be better over there."
It is not an easy question by any means, but I think recognizing the relative strengths and weaknesses of the two ways of knowing and not "comparing" them but synthesizing them is one way forward.
Honestly think the majority of catastrophic forecasts about water wars naïve and poorly placed (if not erroneous).
Water conflicts always occur between neighbors, not between countries, social groups and ethnicities remote. Waterdespite vital , has a low aggregate value, any action that perpasse the contiguous borders of two groups is more expensive than existing technical solutions.
A war in the present day is extremely expensive in terms of water use (production of armaments, moving troops, maintaining occupancy), allied to this, a fight between countries or areas not adjacent would imply two solutions to the use of water resources , water transport or full occupation of the area. These two works cited, seem beyond naïve and puerile (despite been accepted by major magazines!), they forget that there is an effect on global temperature and precipitation, the "neighbors" of the injured also in a greater or lesser degree also will be adversely affected and there was no significant difference in water availability.
Let's imagine a absurd scenario: Saudi Arabia suffer water stress and the only country with significant surplus water is Brazil. It is extremely simple to Saudi Arabia to invest in desalination of seawater (or even transporting icebergs!) than try to take water from Brazil!
Now another example, if there was a drought stress in the USA was simply deviate some rivers from Canada . Such as Canada is a country with abundant sources of water, would be much simpler for the USA "buy" this water than it takes.
These scenarios are placed in jobs "pseudoscientific" seem more science fiction than science.
I identified 6 sampling stations in a village, analyzed the collected water samples for 14 parameters such as pH, EC, TDS, THW, Ca, Mg, Na, K, Cl, Fe, Nitrite, phosphate, total alkalinity... I wish to calculate correlation matrix.. It was found that out of all the six stations analyzed, the analysis values obtained for certain parameters are the same. Do I violate that parameter while calculating correlation matrix?
Having identical values for some observations is not a problem. Remember for correlation analysis that variables should be approximately normally distributed, and should be appropriately transformed if they're not. You have only six observations for each variable, which is not really enough to calculate meaningful correlations. In your dataset, I presume that "nitrite" is actually nitrate?
I measured the protein (PN), polysaccharide (PS) of surface water for drinking water analysis. But as we all know, the concentration of PN & PS are too low to be detected. Therefore, I want to use lyophilization to concentrate the water samples. However, I can not find any papers talking about using this concentrating method. I am just wondering if anyone has any experience with lyophilization or water sample concentrating. Is lyophilization a feasible method to concentrate water samples.
Deionizing systems use a mixture of cation and anion exchange resins (usually in a mixed bed). These resins exchange cations and anions in the source water for H+ and OH-, respectively. The H+ and OH- combine to form H2O, leaving only the residual H+ and OH- produced by autodissociation (autoprotolysis), H2O = H+ + OH-; the equilibrium constant of this reaction = 1 x 10^-14 at 25 °C. So the pH of deionized (DI) water is close to 7 **at delivery** and the electrolytic conductivity is about 0.055 µS/cm (corresponds to resistivity ~18 MΩ cm, hence the - technically incorrect, as the units are incorrect - term "18 megohm" water). However, this is true only if the DI water **has not** been in contact with atmospheric CO2. If it is in equilibrium with atmospheric CO2, the conductivity is on the order of 1 µS/cm (resistivity ~1 MΩ cm) and the pH is ~5,6 , both owing to dissociation of the dissolved CO2 to H+ and HCO3-. DI (or any other CO2-free-) water avidly takes up atmospheric CO2 and rapidly approaches the equilibrated values of pH and conductivity. For this reason, conductivity sensors in DI systems are located immediately following the last resin bed (column) and the water is continuously circulated, so that the conductivity value is obtained before the water has a chance to take up any CO2.
Distillation relies on phase separation to eliminate the dissolved ions (which remain in the pot). However, the steam is in contact with the atmosphere, and distilled water generally has electrolytic conductivity and pH values simliar to those of DI water that has equilibrated with the atmosphere (i.e., pH 5.6 and conductivity 1 µS/cm). Distillation systems can only remove CO2 if elaborate measures are taken to avoid contact with the atmosphere (e.g., flushing with pure N2 and blanketing the product H2O with N2).
DI systems do not remove molecular species (e.g. sugar, most other organics) from the product water. However, many commercial systems include an activated charcoal (or similar) column that removes many organics. Distillation will remove nonvolatile molecular species, but not volatile ones (they distill over with the steam).
Note that DI systems do not remove dissolved O2, as it is a molecular species.
The same dissociation reactions occur in both distilled and DI water. DI resins can "bleed" organics, although many of these will be taken up by the activated charcoal.
What are the chemical, physical and biological properties of good drinking water?
Aug 31, 2013
From tap-water to distilled water, which is the most appropriate drinking water?
Dear Ahed, There are some nodal and government agencies wish are present in all regions to develop standards and limitations based on their location; so it is better go with your regional standards than something else; or compare the values with WHO standards for drinking water quality criteria.
have a great day; wish you all the best for your works
Though a higher concentration of Sr in water is a potential indicator of Marine provenance. But it alone should not be considered to interpret it as a case of salt water intrusion / sea water ingress. In coastal parts of India - a lot of people engage in prawn farming and salt extraction in salt pans by pumping sea water inland through canals, pipelines etc. To substantiate the study a thorough knowledge of sub-surface aquifer disposition and geometry is also essential. The concentration of halides like - Cl, F, Br, I along with that of Na & Mg too should be considered. This is more relevant in cases of transition zones or mixing zones of fresh water and marine water systems.
Though the concentration of Sr in sea water is almost constant, its values in ground water systems varies widely based on the geology and type of water and their residence time in such systems.
The cadmium (II) ions can be chemical precipitated in shape of white crystalline precipitate, using oxalic acid o,5M as chemical reagent.I The quantity of cadmium unextractable like cadmium oxalate shape was removed by precipitation with limes stone 10%. The solution containing cadmium can be treated with a solution of oxalic acid 0,5 M at a well defined ratio, with a controlled temperature and pH, under mechanic movement, reaction time – 10 minutes.
Sources:JOURNAL OF SUSTAINABLE ENERGY VOL. 4, NO. 1, MARCH, 2013.
i did a priliminary examination of salt water intrusion in to one of the coastal villages of vizianagaram distrcit of andhra pradesh, India. I wish to study the same in all the coastal villages of the district.
It is a challenging task not only to India but also many countries in the region. Many steps can be taken but what I feel is we have to inculcate positive attitudes among children so that they will become responsible citizens. In the mean time, an integrated approach which covers the issue of waste generation, management, reuse, recycling etc. has to be implemented at all the possible levels. Therefore, all the stakeholders should be made responsible and involved. From the government side, the legal frame work which support the process needs to be strengthen, good governance need to be established, rewarding better management practices etc.. could be thought of.
If you know the main components of the facility and the amounts used, you can prep a simulated wastewater using the OECD 302,304 methods as the base. For example if PVA is the plastic, you take the OECD simulated wastewater and spike it with the PVA at the known quantities. If you know nothing about the facility, you can't do it since "plastic" can vary greatly in the treatability. Some may take a few days to start degrading while things like PVA can take a month or more.
I am going to conduct a research on simultaneous soil water and heat transfer and I am searching for the best model to estimate the coupled transfer of soil moisture and heat loss.
Jul 23, 2013
HYDRUS is a good software for water movement in vadoze zone.I've used 1 D, 2 & 3D in many rpojects with different crop, climate, soil and water application situations. It predicts the temporal and spatial water movement within reasonable errors.
I have tried to find any kind of literature that reports on stochastic applications on financial aspects of flood risk mitigation measures. I am interested in financial risk analysis / management of flood risks (NOT flood risks itself!!). If any one knows of any such works or research articles or even in grey literature, kindly advise.
Many thanks in anticipation
Aug 28, 2013
You can easily get the data set of interest rate of past 30-40 years you can put all the interest rate on the profitability staement and check the deviation using corelation coefficient.
Hi - thermal gradient is very significant factor so is isothermal temperature of the sample
there is some discussion on the subject in the following paper, you may have a look
Hanspal, N and Das, DB. Dynamic Effects on Capillary Pressure-Saturation Relationships for Two-Phase Porous Flow: Implications of Temperature. AIChE Journal, 2012: 58(6), 1951-1965, DOI: 10.1002/aic.12702.
Yes of course, many parameters influence the developing of soil water repellency and among them there are the temperatures reached and time of residence, and this last depends on the way to burning, so yes for sure influence... Kind regards, Jorge
The base of the question is that due to factors like new urbanization, intensification of existing urban environments, more intense rainfall and more often, etc.; pluvial flood risks have highly increased over the past few decades. In some cases, development pressures were so high that even watercourses were closed and backfilled. But, now, in view of high pluvial flood risks, these watercourses are being considered for redeeming. If anyone knows of such scenarios, it shall be appreciated very much.
Articular cartilage water content. Opposite to proteoglycan content. Counter-intuitive? The superficial zone of cartilage has the lowest proteoglycan content yet the highest water content and the deep zone of the cartilage has the highest proteoglycan content with the lowest water content. This seems peculiar to me as the charged GAG chains on the proteogylcans are responsible for the water content in cartilage. I'm probably missing something basic but im confused.
From my personal point of view it is a dangerous developement just to ask for quantity. The quality of the contributions should be much more considered rather than to put pressure on scientists to publish low quality papers with high redundancy in its content. All discussions of auch numbers should be strongly related to a qualitative judgement which is not only a question of the impact factor of a journal alone but much more the relevance of the article for the scientific community to follow the ideas and results that are presented.
Fresh water is a scarce commodity in many places on the planet. Several dry-arid environments have industrial operations producing excess amounts of water. That water contains excess salts, boron, ammonia, silica, and other minerals. Current operational strategy is to inject the water into below-ground natural reservoir space but that option may be limited in the future. Alternatives to disposal revolve around traditional approaches to recycle or reuse that water but I’m seeking new thinking and brainstorming of even better ways to use, recycle, and/or a novel alternative scenario for the water.
To avoid not useful water consumption and improve water saving behaviour, it should be a good practice to suggest to the water users to adopt, in their dwelling, as discharge-limiting mechanisms, as water-economizing devices (atomizers, water savings shower roses, flow reducers, etc), as mixer or thermostatic taps, and to avoid practices such as to defrost food by putting it under the tap, or to have fresh water by leaving the taps running (instead, it should be better to keep a bottle of water in the refrigerator). Further, it is possible to collect rain water taken from the roofs in order to suplly the water for flush toilets