Science topic

Drinking Water Quality - Science topic

Explore the latest questions and answers in Drinking Water Quality, and find Drinking Water Quality experts.
Questions related to Drinking Water Quality
  • asked a question related to Drinking Water Quality
Question
24 answers
There are many quality index for water quality assessment, 2012 edition of the drinking water standards?
Relevant answer
Answer
The best quality
  • asked a question related to Drinking Water Quality
Question
5 answers
Permissible limit of arsenic in drinking water was 50 μg/l by WHO which was later reduced to 10 μg/l. Currently many countries like Bangladesh and China have not updated their own Permissible limits. However, this is been observed that on the event of long term exposure of arsenic at low concentration that is less then 10 μg/l in drinking water, health complication arises.
Relevant answer
  • asked a question related to Drinking Water Quality
Question
4 answers
Please discuss the role 'rain water harvesting' can play in addressing the issue of drinking/ useable water worldwide. What are different 'rain water harvesting' methodologies/ technologies? And other technological alternatives to 'rain water harvesting'.
Relevant answer
Answer
Collecting and using rainwater can be a superb way to solve problem of water crisis. Some people use rainwater for watering plants, cleaning, bathing, or drinking. However, it is important that the rainwater system is maintained properly and the water quality is appropriate for addressing the issue of drinking/ useable water worldwide .
Generally, there are two ways of harvesting rainwater, namely; surface runoff harvesting and rooftop rainwater harvesting.
  • asked a question related to Drinking Water Quality
Question
7 answers
It is often alleged that the roofing material may introduce some contaminants into the collected water after a prolonged use. Such communities using this facility may not have the resources to periodically change the roof and this can be a challenge.
Relevant answer
Answer
organic roofs or those that accumulate organic matter over time have lower water quality
  • asked a question related to Drinking Water Quality
Question
8 answers
I am very interested in perception by residents of communities of the quality of the air in their communities and their drinking water.
Relevant answer
Answer
this project is very important
  • asked a question related to Drinking Water Quality
Question
3 answers
I am looking for any studies on effect of biological ion exchange method in reducing THMs precursors in high DOC (15 ppm) and cold water?
Relevant answer
Answer
you can see the research
  • asked a question related to Drinking Water Quality
Question
27 answers
Membrane fouling is a process whereby a solution or a particles are deposited on a membrane surface or in membrane pores in a processes such as in a membrane bioreactor, reverse osmosis, forward osmosis, membrane distillation, ultrafiltration, microfiltration, or nanofiltration so that the membrane's performance is degraded. Membrane fouling is thea major obstacle to the widespread use of this technology.
Relevant answer
Answer
Dear Ronei De Almeida thanks for your detailed answer and contribution in the discussion.
  • asked a question related to Drinking Water Quality
Question
13 answers
Dear Researchers!
It is known that methods such as: GOD (Foster) and DRASTIC (Aller et al) and others are widely used. But are there new methods developed to evaluate the intrinsic vulnerability of the physical environment to loads or pollutants? and with easy application (accessible parameters)?
Relevant answer
Answer
There is no method that can fit every case of study. DRASTIC request several factors that are not available in many countries; the spatial resolution of data is another problem. GOD is made for aquifers that have a large extension; it is not the best solution for small aquifers or where lateral and vertical lithological variations are frequent. SINTACS is the italian little brother of DRASTIS; it has thus the same shortcomings. AVI is based on permeability which is generally not available or the measurement points are poorly distributed...
Since geophysical data are mostly available or surveys could be done, we suggest a geophysical method for countries where data are lacking.
Please check this recent paper:
Regards
  • asked a question related to Drinking Water Quality
Question
26 answers
What is the most economical and efficient method of analyzing surface and underground water quality?
Especially nitrate, thermotolerant coliforms, Total Dissolved Solids TDS.
Relevant answer
I think that the EPA National Service Center for Environmental Publications: nepis.epa.gov is a good choice on economic methods
  • asked a question related to Drinking Water Quality
Question
15 answers
Trihalomethanes (THMs) were discovered in the early 1970s and regulated in the USA in 1979 and later included in the WHO Guidelines for Drinking Water Quality. They are byproducts of chlorine reacting with organic carbon. Chloroform was carcinogenic in rats and mice tested by corn oil gavage, but later testing in drinking water was essentially negative. Later it was shown to be a threshold carcinogen at much higher doses than occur in drinking water, Both USEPA and WHO have revised their risk assessments. I am curious whether drinking water researchers and other drinking water and regulatory professionals consider THMs to be carcinogens in drinking water and use them to limit chlorine applications.
Relevant answer
Answer
Thanks for the comments. The risk, if any, issue is not clear at all. 2 of the THMs are not carcinogens in drinking water (EPA) and 3 are not according to WHO and the 4th (BDCM) will likely be determined to not be carcinogenic based upon published high dose animal tests. The THMs were carcinogenic in corn oil gavage dosing but not when dosed in drinking water. Probably a combination of dose rate and corn oil effects in the rodents.It appears that the animal test design are flawed relative to drinking water exposures.A few DBPs found at ppb or less are possibly carcinogens. The other large group is HAAs which are much more interesting than THMs. The trace iodos are cytotoxic, which means that they are chemically reactive to naked cells. However, their reactivity means that they probably disappear in the GI tract. Iodoform is not carcinogenic in whole animal tests.
Bladder cancer is the only cancer that had some correlation with THMs is some epi studies (about 10% of the 75+ publications).
You might be interested in this paper.
National Trends of Bladder Cancer and Trihalomethanes in Drinking Water:A Review and Multicountry Ecological Study. Joseph A. Cotruvo and Heather Amato.
Dose Response Journal January 23 17(1) Open Access.
ABSTRACT We examined trends in incidence of bladder cancer in 8 countries in the 45 years since trihalomethanes (THMs) were detected in chlorinated drinking water. Total trihalomethanes (TTHMs) are the principal regulated disinfection by-products (DBPs) along with halogenated acetic acids (HAAs). Numerous epidemiological studies have examined exposure to TTHMs and associations with bladder cancer. Concentrations of TTHM have declined in most of the 8 countries that were studied as has smoking prevalence. Incidences of bladder cancer have usually stayed relatively flat, especially for females, with some variations. SinceTHMs are not carcinogens in whole animal tests, they may not be appropriate surrogates for studying potential cancer risks in drinking water. Etiology of bladder cancer is complex; incidence correlates with age. Previously identified risk factors include smoking, type 2 diabetes, sex, ethnicity, arsenic, aromatic amines, and occupations. As a predominant risk factor, smoking trends may dominate incidence rates, but additional time might be required to determine whether a DBP risk exists due to long latency periods. Causal drinking water-related bladder cancer risks remain questionable and likely small compared to other factors,although surrogate-based DBP management is an appropriate strategy for maintaining drinking water quality as long as it does not compromise microbial disinfection.
  • asked a question related to Drinking Water Quality
Question
13 answers
  • pH
  • Conductivity
  • Nitrate
  • Chloride
  • Sulphate
  • Fluoride
  • Sodium
  • Magnesium
  • Iron
Relevant answer
Answer
Hello Lazola,
I also recommend the following text. Good Luck!
Gray, N.F., 2008. Drinking water quality: problems and solutions. Cambridge University Press.
  • asked a question related to Drinking Water Quality
Question
13 answers
Just wanted to throw this question out there, if anyone know about any country, municipality or other entity that has adopted water quality standard for hygiene use (in contrast to potable water, or drinking water quality standard)?
Relevant answer
Answer
Ah, by the way, if we consider, river/sea bath as hygiene activity, then there are different guidelines (standards) in many countries.
  • asked a question related to Drinking Water Quality
Question
11 answers
Which water quality index is the best index for drinking water quality and irrigation water quality?
Relevant answer
Answer
Candia WQI
  • asked a question related to Drinking Water Quality
Question
2 answers
Drinking water quality is critically important for animal production. Cattle in feedlots can foul drinking water troughs. Addition of water purifying agents can reduce concentrations of coliform bacteria. However will residual bacteriacide significantly and detrimentally effect rumen fermentation patterns?
Relevant answer
Answer
Please refer to this publication:
Good luck.
  • asked a question related to Drinking Water Quality
Question
20 answers
Ground water, surface water and wastewater always contain dissolved solids. Most of researchers used electrical conductivity (EC) meter for measuring dissolved solids. But the results are always different from that measures with gravimetrically. Question arises, how to testify, which one is authentic.
Gravimetric method is time consuming. If we use EC meter, what cares may be taken?
Is ion-balancing is of some use?
Relevant answer
Answer
The answer is clear: only the gravimetrically determined method provides reliable results. The EC/TDS method is a calculation using a conversion factor which ranges from 0.25 to 1.34 [µS/cm and mg/L] . If – and only if – you predetermined the conversion factor for a given site THEN you can use the EC/TDS ratio and it will also be reliable. Please see my paper
Hubert, E. & Wolkersdorfer, C. (2015): Establishing a conversion factor between electrical conductivity and total dissolved solids in South African mine waters. – Water SA, 41(4):490-500, 6 fig., 8 tab.; doi:10.4314/wsa.v41i4.08.
for details and more references.
So, to answer the last part of your question: determine the EC (at 25 °C = κ / TDS ratio for several samples of your site(s) using the gravimetrical method (ensure you calibrate your EC meter) and then use this factor f to calculate TDS as follows:
TDS [mg/L] = f × κ [µS/cm]
  • asked a question related to Drinking Water Quality
Question
13 answers
Can someone suggest me some specific clay minerals such as zeolites, kaolinite etc that can be the lead to release of high fluoride in groundwater.
The study area is an alluvial deposits and there is no role of geological formations in release fluoride in groundwater?
Relevant answer
Answer
Hello
The mineralogy of the alluvial deposits may be important, and also is there a possibility that the groundwater may be a discharge area for a more regional flow system?
Attached is a copy of a study from the 1970's where high fluoride (over 10 mg/L in some wells) was found. The report can also be downloaded from:
Search this page for the word Plymouth for the report.
Hope this is helpful.
  • asked a question related to Drinking Water Quality
Question
52 answers
Does anyone want to become a collaborator of an interdisciplinary group to perform research within the project: Systems for Sustainable a Planet? Are you interested or experienced in any of the following global issues?
  • Availability of clean drinking water
  • Reusability and treatment of water
  • Sustainable agriculture
  • Reduction of carbon emissions
  • Renewable energy systems
  • Natural hazard risk assessment
  • Natural hazard remediation
  • Organizing healthcare in developing countries
  • Renewable energy in developing countries
I am looking for motivated individuals who would like to contribute to the greater purposes and goals of the project in any way they can. We can use ResearchGate.com and e-mail to communicate and combine our ideas, wherever you are in the world, and with whatever free time you have available outside of your current jobs and busy schedules.
Reply with "yes", a little bit about yourself, ideas for collaboration.
***You just follow me to become a collaborator on the project.***
Thanks for looking! I hope you'll join us.
Relevant answer
Answer
YES. I am PhD in Environmental Engineering, Law and Management (c) and Dean of Gujarat Technological University India. Let me know how to go ahead.
I am interested in following areas:
  • Availability of clean drinking water
  • Re usability and treatment of water
  • asked a question related to Drinking Water Quality
Question
17 answers
Specifically arsenic bearing liquid discards. I have the information on solid wastes.
Relevant answer
Answer
Hi Harold,
I am not sure what are you asking but I wanna know the arsenic present in liquid discards from any drinking water treatment plant.
  • asked a question related to Drinking Water Quality
Question
9 answers
Just wondering, how to add HCO3 without raising sodium to the irrigation system ? what is best source of HCO3 for irrigation? 
Relevant answer
Answer
Lithium carbonate or magnesium carbonate are the closest matches. I think you will find the easiest to dose is magnesium oxide (MgO) which dissolves well and convert to hydrogencarbonate in water in contact with air.
  • asked a question related to Drinking Water Quality
Question
12 answers
Hey, I would appreciate if somebody help me “what is the Max permissible limit for Na+, Ca2+, Mg2+, K+, Ca2+, Cl−, HCO3−, in drinking and irrigation water according to WHO standard. Thanks
Relevant answer
Answer
  • asked a question related to Drinking Water Quality
Question
3 answers
If someone is having data related to anti-nutritional factor associated with various agriculture by-product and their concentration & permissible limit to be used as safe feed for fish, please share. 
Relevant answer
Answer
I think NRC (2011) could be a good tool to answer your question for plant and animal by-product produced from agriculture sector
  • asked a question related to Drinking Water Quality
Question
20 answers
I have a 350 ft borewell in my home. Physio- chemical parameters were analysed for the same. Almost all the parameters are above the permissible limits. I have attached the analysis report for more details. TDS  is 3220 ppm, Total Hardness 1350 ppm, also facing with odor problem . I want to make this water safe for daily utilities bathing, dish-washing and clothes washing. can we use any chemicals or Is there any alternate solutions?
Relevant answer
Answer
Hi Jaya,
Coagulation is key. I would prefer you conduct a Jar test to know the amount of coagulant (Alum, Ferric chloride)  that is necessary. This is a cheap process compare to the more technical and fairly expensive membrane process. I would also advise you check the breakpoint chlorination to prevent unnecessary contamination with excess chlorine.
  • asked a question related to Drinking Water Quality
Question
4 answers
What are the minimum parameters we have to maintain in the drinking water, and what is the limit ??
Relevant answer
Answer
Dear Saravanan,
Here is an interesting document concerning health risks from drinking demineralised water. You will also find the quality standards required. This document is from WHO.
With my best regards
Prof. Bachir ACHOUR
  • asked a question related to Drinking Water Quality
Question
6 answers
In Hospital, specifically Kidney hospital,  RO water was used for the cleaning of many equipment that could be reuse after cleaning. The RO water line would be sanitize with formalin to prevent microbial contamination. After disinfecting by formalin it should be necessary to identify whether formalin was removed or not. So, How to check the formalin residue with very short time.
Relevant answer
Answer
Thanks for providing information, Furthermore, some strips are available into the market to check the content of formalin,
So, Is that product is reliable? and By which principle the strip can detect the formalin?
  • asked a question related to Drinking Water Quality
Question
15 answers
What parameters should be included?
Relevant answer
Answer
Computation of WQI of groundwater - Please see the attached paper.
  • asked a question related to Drinking Water Quality
Question
25 answers
I would like to know what are the implications of heating up wastewater (or sludge) with the purpose of capturing the humidity in a surface through condensation and use that water as potable? I've seen people doing that with river water or not so heavy polluted waters, however I couldn't find anything with wastewater so far..
Is the vapor capable of carrying any pathogens / contaminants? Are the low-temperature volatile solids harmful and what are the most common ones that has evaporation point below the water temperature?
Thanks in advance, much appreciated.
Regards, Jose
Relevant answer
Answer
You could make an anaerobic reactor upflow sludge blanket (UASB) according to the number of residences. They are easy to build. The fall of water could be a source of energy and in addition the production of methane would give another source of energy. The water produced can lead to the settling ponds and then filtered with activated carbon or microfiltration membranes adding disinfectant. You must evaluate water quality parameters that are drinkable and safe for human consumption.
There is no drinking water at low cost. Current pollutants are a real challenge to remove from the water and wastewater. Success in your research.
  • asked a question related to Drinking Water Quality
Question
6 answers
what is safest method of drinking water disinfection
Relevant answer
Answer
If your question is directed strictly to disinfection, I recommend copper ionization which is effective, economical and convenient.  Many systems are currently in operation throughout Mexico.  See:  http://www.agri-ions.com/  for agricultural applications of this method that easily adapts to solving microbiological problems related to ensuring safe drinking water.  Think of it as providing farms with control of waterborne diseases that might affect their crops and people.  
  • asked a question related to Drinking Water Quality
Question
20 answers
There are several methods proposed claiming to have maximum efficiency in water purification, These methods include sensor method and filtration techniques. Do you have any idea which the best?
Relevant answer
Answer
Dear Jestin,
Today , Reverse osmosis and Plasma water Sanitation system  frequently used for the purification of water. 
  • asked a question related to Drinking Water Quality
Question
19 answers
I am studying the treatment on drinking water from an undergound water source. It is high in Fe2+ and Fe3+ content. The drinking water that is supplied to residents is full of Ferric chloride that leaves significant stains on clothes and other items.
  • asked a question related to Drinking Water Quality
Question
4 answers
In Europe there is a global limit including each pesticide(+metabolites) and limit them to 0.1µg/L per compound and 0.5µg/L for total of compounds. So AMPA is regulated by this policy even if Europe doesn't knew it's existence when the policy was written.
Did you know if north america has a policy of that kind or anything else to regulates AMPA in drinking water?
thank you!
Relevant answer
Answer
Dear Alexis,
In the US, glyphosate and the related acid and salt compounds are currently undergoing registration review by the United States Environmental Protection Agency, which is required for all registered pesticides every 15 years. The assessment is expected to be completed by the end of 2016, at which time a decision will be made regarding the use of glyphosate in the US.
With my best regards
Prof. Bachir ACHOUR
  • asked a question related to Drinking Water Quality
Question
5 answers
Fluorine is a common element that does not occur in the elemental state in nature
because of its high reactivity. It accounts for about 0.3 g/kg of the Earth’s crust and
exists in the form of fluorides in a number of minerals, of which fluorspar, cryolite
and fluorapatite are the most common.
Exposure to excessive consumption of fluoride over a lifetime may lead to increased likelihood of bone fractures in adults, and may result in effects on bone leading to pain and tenderness. Children aged 8 years and younger exposed to excessive amounts of fluoride have an increased chance of developing pits in the tooth enamel, along with a range of cosmetic effects to teeth.
Relevant answer
Answer
Dear Dr. Prakash,
I have shared the following write-up to some researchers. You can go through the same.
 A brief account on fluoride removal (based on literatures):  
Various techniques and materials were explored throughout the world for defluoridation of groundwater. The techniques can broadly be classified into four categories:
Adsorption technique, Ion-exchange technique, Precipitation technique, and Other techniques, which include electro chemical defluoridation and reverse osmosis.
Materials used as defluoridation agents in these four techniques are:
Adsorption: Carbon materials, Activated Alumina, Magnesia, Tricalcium phosphate, Calcite, Hydroxy apatite, Wood, Lignite, Activated char coal, Fish bone char, Processed bone, Nut shells, Avaram bark, Paddy husk, Coffee husk, Tea waste, Jute waste, Coir pitch, Fly ash, Bauxite, Serpentine
Ion-exchange : a) Anion exchange resins-  NCL poly anion resin, Tulsion A27, Lewatit-MIH-59, Amberlite IRA-400, Deacedodite FF-IP, Waso resin-14, Polystyrene. b) Cation exchange resins: Defluoron-1, Defluoron-2, Carbion.
Precipitation: Lime, Alum, Lime & Alum (Nalgonda technique), Alum flock blanket method, Poly Aluminium Chloride (PAC), Poly Aluminium Hydroxy Sulphate (PAHS), Brushite.
Others:  Electrochemical method (Aluminium electrode), Electro dialysis, Electrolysis, Reverse Osmosis.
The basic characteristics of an ideal defluoridation process are the following:
o   Cost-effective
o   Independent of input fluoride concentration, alkalinity, pH, temperature
o   Easy to handle/operate by rural population - the major sufferer
o   Not affect the taste of water
o   Not add other undesirable substances (eg. Aluminum) to treated water
Defluoridation can be introduced at two organizational levels; as household defluoridation for consumption of single household members and as community defluoridation  for the public use in a village.
The defluoridation processes available today are not totally successful. Nalgonda and  Krass processes for defluoridation have some merits.
This is for your kind information that at CSIR-CMERI, Durgapur we are working on the defluoridation of groundwater. We have already developed a process (adsorption technique) for defluoridation and filed a patent in April, 2016.
We have also designed and developed a 'Domestic Defluoridation Unit' for reducing the fluoride content in water. In addition to the removal of fluoride, the unit also arrests other common contaminants found in the groundwater. This unit is suitable for domestic purposes in the fluoride affected rural areas.
Specifications
·         No electricity
·         No chlorine, no bromine, no iodine used
·         No running water required
·         Flow rate: 5 L / hour
·         Adsorbent life (proposed): ~2000 L
·         Storage capacity: 18 L
 Techno- Socio-Economic analysis
·         Adsorbent replacement cost: Rs. 600/-
·         Maintenance cost/month: 150/- (~500 L p.m.)
·         The commercial filtration unit addressing the defluoridation of water for domestic purposes is not  available in the market. The developed filtration unit could be promising for commercialization.
·         Unit can be deployed in the fluoride rich regions of India through Govt./ NGO support 
We are conducting a research project entitled “Geochemical modelling of fluoride contamination in groundwater of the Birbhum District, West Bengal” which primarily aims to explore the origin and enrichment mechanism of fluoride in groundwater. This study has encouraged us to undertake the work on defluoridation of groundwater.
We have a plan to deploy some working models of the ‘Defluoridation Unit’ in the fluoride affected villages of Birbhum district, West Bengal.
Please give your feedback.
  • asked a question related to Drinking Water Quality
Question
4 answers
follow up question from my previous one. 
Relevant answer
Answer
Dear Millenus,
I suggest you to refer to the following link.
With my best regards
Prof. Bachir ACHOUR
  • asked a question related to Drinking Water Quality
Question
6 answers
I am trying to link the presence of heavy metals in drinking water sources or the biomagnification of these metals up the food chains for example when waste waters are used in irrigation and the plants take the metals up or when waste water mixes with aquatic ecosystems like rivers and lakes and fish take them up..and then there is the risk of humans consuming the contaminated fish or plants. could these processes be linked to the rising cases of cancer? how can such a research be designed?
Relevant answer
Answer
You can measure the dose of heavy metals in tissues of plants, fish and animals that drink the water or who eat that water plants and that fish.
If you study the water from the tap, you can give it to some animals (lab mice) and look at their tissues.
I'm not sure about human level (human tissues). Using medical statistics is a good idea.
  • asked a question related to Drinking Water Quality
Question
4 answers
When compared to Eureka Forbes & Kent , Unilever's advertisement strategy is different. They have mentioned about EPA but other companies have told about the elimination of bacteria and virus.Why is it?
Relevant answer
Answer
Manoj very clearly mentioned that IS 14543 for Packaged drinking water and IS 10500 for bottled drinking water.   These are the Indian standard for drinking water. The Chemical, Physical and Biological parameters in water have to be within the permissible limits. In addition to this,  desirable limits have been taken into consideration after examining  EU, USEPA, WHO,   Thus  Bureau of Indian Standards  made  guide line, which every company who make water purification instrument or market drinking water bottle or packet have to be followed. 
  • asked a question related to Drinking Water Quality
Question
10 answers
chemical engineer
Relevant answer
Answer
The US EPA doesn't regulate TOC directly. When water is being treated and later disinfected, organic compounds can become precursors to disinfection by-products, so there are rules on TOC levels in that case, but measurement of the specific THM compounds that are the concern, so the previous answer with 4 mg/L and 2 mg/L applies there and can by misconstrued as a TOC limit. Refer to US EPA Stage 2 DBPR.
Specific VOCs are regulated. Many states in the USA add a layer of regulations on top of EPA though and since we have 50 states, I can't speak for all of them. Some may regulate TOC but California does not. All of these regulations in official form are publicly available on the web.
Different governments worldwide will have their regulations that vary widely, and different industries will have regulations and guidelines as well. For example, in the US, purified water for pharmaceutical use must meet USP 23 and TOC maximum is 0.05 mg/L as previously stated.
There isn't a single answer to your question and the effect on safety of TOC presence in drinking water could depend on how the water is being used, if it is surface water or ground water, if it is membrane permeate, evaporator condensate or sieve filtrate, how or if it will be disinfected, etc.
Perhaps you could re-phrase your question because the way you have written it, there are many answers. My advice is to ascertain the organic compounds that make up the TOC measurement and understand their source and best available technology for removal.
  • asked a question related to Drinking Water Quality
Question
10 answers
Water is being drilled from underground and pumped to tank reservoirs at relatively high elevation and is distributed by gravity feed to the residential areas in the village. The water is crystal clear and even looks better that the river water we drink. But it has a very bad smell? what are the reasons for the smell? so now people don't drink it except using it for secondary purposes like washing. Please share your thoughts. 
Relevant answer
Answer
The cause of the bad smell depends upon what the water smell like.  It could be low (ppb) levels of hydrogen sulfide.  This would leave the water very clear but would smell bad to most people.  Other sources of bad smells would be things such as amines or organic sulfides.  So it sounds like you need to do a thorough water analysis that is capable of detecting these types of compounds.
  • asked a question related to Drinking Water Quality
Question
10 answers
We have to conduct water pathogen tests in remote places in Bangladesh. Is their any easy cost effective way to do e-coli test ?
Relevant answer
Answer
Maybe I was not clear, I did not typically do ecoli, but I know the Millipore filter company has these tests, equipment and supplies.  For the water bath, we installed a water heater element that looked like what you might see in a dish washer, added a thermistor control to regulate temperature. The heater was installed into a relatively inexpensive water cooler like you use for picnics and we used silicone to seal up the drill holes.  I held water just fine, no leaks.  We may have had a thermometer to read without opening the cooler when it was operating at 35 degrees C or 44.5 degrees C for total or fecal coliform.  We installed some plastic over wire racks in the bottom to hold the petridishes down.  I used whirlpacks as an inexpensive way to keep the water out of the petridishes during the incubation period.  The black light(s) was installed into a box with enough capacity to hold instruments that needed sterilization and would produce ozone if I am remembering right, for sterilization of equipment.  The methods I followed were after review of Standard Methods for Analysis of Water and Wastewater and also reviewing the methods provided by Millipore Filter company.  We just could not afford their high price for instruments, so we made our own.  If you have a good electronics technician, you should have no problem designing instruments that might not look as pretty but will do the job.  However, if you are not electronically inclined or have some help, I would not suggest you try to do this without some help.
  • asked a question related to Drinking Water Quality
Question
15 answers
Currently, peoples are using the lengthy spectrophotometric method and the ISE method.
Relevant answer
Answer
Dear Singanan Malairajan, 
The Best Method for Fluoride determinations at Low cost 
1) Ion Selective electrode method 
With the help Of TISAB Buffer Solution We can Check  0.1 to 100 ppm fluorides 
2) Alizarine-Red (Visual Color Comparison) Method 
As per IS: 3025(P-60) 2008
Note : This test Can also perform By  UV-Vis Spectrophotometer @510nm  with DM Water as a Reference Solution 
3) Spadns Method 
By using UV-Vis Spectrophotometer Zirconium-Spands Reagent 
APHA 22nd Edn 2012
  • asked a question related to Drinking Water Quality
Question
7 answers
I mean the highest which is harmful for the drinking water or living microorganism..
Relevant answer
Answer
It depends on guideline in your country. Different country, then different requirement.
Thank you.
  • asked a question related to Drinking Water Quality
Question
3 answers
APROPOS: Chitta Chowdhury's publication on fluorosis in Karnataka, covered by Time of India, 25th Feb 2016 (NITTE team), I would like to note the WHO prescribed limits of 1.5ppm F is not applicable to India and such hot countries with people consuming low nutritious food. Even 0.5ppm of F creates enough havoc in poor communities. We should be cautious in suggesting fluoridation of water. US and such societies are withdrawing water fluoridation. Could experts in the field respond please?
Relevant answer
Answer
The upper limit of F in India should not exceed 0.5ppm- kindly contact the researchers in the field- Dr Rajareddy, Dr Susheela, dr Arjun L Khandare. THis was discussed at UNICEF WASH meeting at Hyderabad and elswhere too.
Nutrition in fluorotic areas for children should also be to suite their special need (besides F free water) for Ca, Mg, Vit C, Vit D and protein. Supplementing with natural sources (food sources) is better as advised  by Dr Susheela.
  • asked a question related to Drinking Water Quality
Question
8 answers
Is there any water quality standards for animal drinking? My point is on captive animals at Zoo. If you think it as an absurd then comment here why? Do animals also need the one so? Do they also need to enjoy pathogen free /pollution free water? 
Greetings
Anila Ajayan
Relevant answer
Answer
This attachment has a lot of information on drinking water from forests and grasslands that might be helpful.  Their point is to seek out the best sources of water for drinking to save on treatment costs and know where the water comes from (the watershed) and that may help you determine what potential issues exist.  Forests are generally your best opportunity for natural pure water. 
I have not researched much the topic.  In a quick google search, I came up with a couple of items.  The best success I had briefly was searching on animal drinking water quality.  Whether zoos, pets, animal facilities, vet, research facilities, farms, etc., there should be some basic standards.  You have probably hit on something important and can champion the cause for proper drinking and living conditions for zoos.  These animals are essentially caged pets and we owe them as far as we can provide proper living conditions.
  • asked a question related to Drinking Water Quality
Question
27 answers
People living in Jaffna are facing a grave threat in accessing clean drinking water due to groundwater pollution caused by oil leakage. In recent days, oil waste is clearly observed in drinking-water sources (wells etc) in Chunnagam and Valigamam areas. Wells are the prime and mostly the sole source of water in Jaffna and this contamination is severely affecting the livelihood in those areas.
This issue has resulted in scarcity for clean drinking water for the people living in the areas. No satisfactory action has been taken yet by authorities. Hence, there is an imminent need to create awareness of the issue to a wider audience in order to accelerate the phase at which actions are taken to solve the issue.
Can any body give a sustainable solution fore this burning issue in Northern Sri Lanka?
Relevant answer
Answer
 Dear Dr. Saravanamuttu Subramaniam Sivakumar,
Yes, it is possible by installing costly treatment units consisting of special filters or air strippers. At low cost level through use of carbon filter or a reverse osmosis filter.
  • asked a question related to Drinking Water Quality
Question
1 answer
I'm designing a study of analysis differences for various synthetic and volatile organics in drinking water matrices, and would like to limit the scope by learning which shipping/storage extremes affect temperature and analyses most.
Relevant answer
Answer
I am sure you are familiar with the book on the Standard Methods for Analyzing Water and Wastewater.  I don't have one anymore.  But go to those tests for organics, etc. and look up the background references that they used to set up preservation and storage guides.  It may not tell you exactly who or why they decided on preservation techniques, but someone in a lab probably did due diligence in trying techniques, and determining breakdown rates under different scenarios.  The details are seldom published, but reviewing the references and authors might give you potential contacts to find out some of the lab based and chemical theory behind the procedures.  
  • asked a question related to Drinking Water Quality
Question
8 answers
Normally drinkable water is stored in tanks made out of steel or PVC. But why it's so uncommon to store the water in concrete tanks. Concrete is made out of natural resources and it's very cheap. But there aren't any papers discussing concrete as store material.
Relevant answer
Answer
To your question: reinforced concrete tanks for storage of drinking water is cheap only at first. During their explotation requires substantial expenditures for inspection, repair and elimination of leaks, many times exceeding their cost. If you are interested, in addition to info from John I can say about emerging hydrochemical, hydrophysical and ecological processes.
Regards, Aleksandr
  • asked a question related to Drinking Water Quality
Question
15 answers
The policy planners are emphasizing to increase the water use efficiency. However, I understand a minimum leaching fraction is essential even for canal water irrigation under arid climates. Arid regions are already facing shortage of good quality water, to meet this shortage poor quality irrigation waters are in use everywhere. I fear, unless magnitude of LR is not considered and met, there must be problems of soil salinity followed by sodicity that is even more difficult to reclaim and manage for crop production for food security.
Relevant answer
Answer
use modern irrigation system is first step, also, cover soil surface by polyethylene mulch, save about 20 % of water for plants, adding organic compost for soil is the third option because compost has high water holding capacity and then save water
  • asked a question related to Drinking Water Quality
Question
3 answers
What could be the possible changes to drinking water quality caused by extreme storm events and monsoon season that can cause flash floods. How can these effects be best managed to maintian the quality of drinking water supplied?
 
Relevant answer
Answer
Effect of monsoon on drinking water quality depends upon source of water supply.
If source is surface water body, following can be observed:
- increase in TSS
- increase in bacteriological contamination
-increase in presence of pesticides, fertilizers due to surface runoff, if source is surrounded by agricultural field.
- change in TDS will depend upon the characteristics of top soil and landuse in the catchment area.
- water treatment plants need more energy & resources for treatment with normally negative change in efficiency.
If source is groundwater:
- significant changes in bacteriological contamination does not take place unless groundwater table is very high.
- since high TDS in groundwater is already a problem in many areas, monsoon is mostly helpful in slight reduction in TDS.
- change in presence of pesticides and fertilizers would be not as significant as in the case of surface water.
In case of deep water table, there would be hardly any change in the treatment efficiency of the plant except some relief to the membrane if RO is used.
But, bacteriological contamination has always been a major issue as increase in water borne diseases are reported every year by various parts of the country during monsoon. 
  • asked a question related to Drinking Water Quality
Question
4 answers
What are the key advantages and disadvantages of direct potable reuse as compared to seawater desalination for municipal water supply?
Relevant answer
Answer
Each technology has advantages and disadvantages. If all things are equal with respect to supply certainty, sustainability and costs etc. seawater desalination is the correct choice as it “superdominates” (Pasacal)
  • asked a question related to Drinking Water Quality
Question
12 answers
Disinfectants obviously controls biofilm growth. But increasing dosing pose health problems as well. In addition, unpleasant taste and odour are results of increased dosing. Are there any other methods to control biofilm growth. Some studies say biofilm growth improves the efficiency of systems by reducing pipe roughness initially, however it increases when pipes are old. What is the better cheaper method to clean biofilms from older pipes?
Relevant answer
Answer
Clean the water from any impurities that could serve as nutrients for microorganisms including inorganic salts (Fe, Mn...) That would reduce biofilm formation much better than disinfectants.
  • asked a question related to Drinking Water Quality
Question
27 answers
Our laboratory studies require 100 L/h of drinking water to study biofilm development in flow cells. We need to remove residual chlorine (0.5 mg/L) from tap water to eliminate that bacterial growth in the flow cells is hampered by a minute chlorine concentration. Dosage of sodium bisulphite is not preferred because of practical reasons. Any suggestions? Would an activated carbon filter be recommended? What type of carbon filter would be suitable?
Relevant answer
Answer
There's likely no need to replace GAC (or have filters in series) if you are only using it to remove chlorine. Chlorine is not adsorbed like NOM, it is catalyzed to chloride at the surface of the GAC. Maybe I've missed something in this discussion but I thought I'd point this out just in case. It is possible though that you might have to occasionally remove the GAC to deal with excess headloss (unless operating in upflow mode). As for carbon fines, if you initially clean the GAC properly and the hydraulic loading rate isn't terribly high you shouldn't have a problem with fines (at least in downflow mode). The carbon fines are usually only produced with the harsh conditions associated with backwashing which it seems you won't be doing. (For bench or pilot contactors/filters treating turbid waters we just remove the carbon and rinse it out in a bucket and replace it.)
  • asked a question related to Drinking Water Quality
Question
14 answers
Anyone has any suggestion for recommended dose of KMnO4 used in drinking water treatment plants?
Any cases where it has been used as pre-coagulation step and it has worked?
Thanks
Relevant answer
Answer
Dear Mehrnaz,
Potassium permanganate is not normally used in water treatment for the reduction of DBP potential. Although more expensive, Ozone is the preferred chemical.
At the normal dose rates used for iron and manganese reduction, potassium permanganate does not have a major impact on reducing DBP formation. At higher dose rates (> 2 mg/L) reductions of 30% to 40% have been achieved. This is about the same reduction as that achieved using ‘enhanced coagulation’ ie a slight excess of alum and a pH value around 5.8.
  • asked a question related to Drinking Water Quality
Question
33 answers
best removal methodology means cost effective, keep water quality, time
Relevant answer
Answer
What are the "Toxic" elements?  To be cost effective the removal technology would have to be targeted towards specific contaminants.  You should fully characterize the water, list the contaminants, then only can you devise best solution to your problem.
For instance: If toxic element is microbial you could perhaps use UV, or chlorine in various forms.  If chemical RO / or carbon filtration etc..  
  • asked a question related to Drinking Water Quality
Question
5 answers
Hello. I would like to know if I can use 3M Petrifilms (Aerobic Count, E. coli/coliform and Yeast and mold) to measure microbiological quality of drinking water in a food processing plant. If so, what are the acceptable limits? I've seen research suggesting <100 cfu/mL of HPC as the limit, but I haven't found data regarding other plate counts. Thank you in advance.
Relevant answer
Answer
A notable challenge here (at least for the fecal indicators) is that they are typically in low numbers in drinking water, and the Petrifilm process analyzes small volumes (1mL versus the traditional 100 mL sample volume for drinking water analysis).  A non-detect on Petrifilm would correspond to count of < 1 per 1 mL, or <100 per 100 mL when put in units common to drinking water reporting.  This is much too high a limit of detection, as most guidelines are 0 per 100 mL.   Therefore, if using this approach, some negative results might actually be falsely negative.  A method capable of analyzing a minimum 100 mL sample volume would be recommended.  I believe Petrifilm has methods that incorporate a membrane filtration step - which would address this issue.
  • asked a question related to Drinking Water Quality
Question
14 answers
.
Relevant answer
There must be nearby a sugar or milk product or any other industry ,which may be the main cause of high BOD / COD.In ground water. COD values found 258 mg/l in the depth of 300 ft. may be due to effluents and the permeability of the geological strata specially Sandy soils/ Alluvial are known to be highly permeable.
  • asked a question related to Drinking Water Quality
Question
5 answers
What are the main sources for "excess chlorine consumption" during disinfecting "well water"?
Relevant answer
Answer
There is no general answer to that.
It is likely that chlorine are consumed by reaction with natural dissolved organic matter.
In some cases well water contains ammonia which might convert chlorine to chloramine.
  • asked a question related to Drinking Water Quality
Question
4 answers
I need to know the advantages and disadvantages 
Relevant answer
Answer
I don't think any advantage as WHO, BIS & ICMR recommend the pH limit 6.5-8.5. Beyond 8.5 only persons suffering from acidity or other diseases may be benefecial.
  • asked a question related to Drinking Water Quality
Question
7 answers
I want to use GC-ECD to analyse and determine all the polycyclic aromatic hydrocarbons together in tap water. but I don't know is  the Electron Capture Detector capable to response to all the compounds.  for FID, I followed the EPA method 8100 but I am not sure I can use the same method for ECD.
Relevant answer
Answer
A method for determination PAH's using GC‐ECD after derivatisation with bromine is presented in a literature below. ECD is highly selective and sensitive for measuring bromo‐PAH's. The detection limits were improved up to two to three orders of magnitude compared with FID‐detection of underivatised PAH's.
  • asked a question related to Drinking Water Quality
Question
4 answers
Local communities in Southern India are resistant to the use of chlorine for decontamination primarily because of its taste and offensive odor. Most often it is the only remaining resort to decontamination water in resource-poor settings, how could we improve on this?
Relevant answer
Answer
Maybe SODIS - Solar desinfection of water can be a viable solution, especially in areas with intense solar radiation, as it should be the case in southern India. It is extremely cheap and completely decentralized. You can find more information here: http://www.sodis.ch/index_EN
  • asked a question related to Drinking Water Quality
Question
34 answers
In my study, some of the ground water samples were having Cadmium concentration higher than the drinking water quality standard (BIS)
Relevant answer
Answer
Dear Rejit, as told Prof. Pradeep Naik there are multiple sources of Cd (related to human activities and natural sources). First of all you should identify possible sources in the basin. For example if the if you found it in agricultural area, possible the source could be related to agrochemicals, some fertilizers present Cd as impurities, specially phosphate fertilizers (Mortvedt 1995). It is also used in the electric and electronic industry and as pigment. Satarug et al 2003 show a broad review of possible sources of Cd. Although it  is focused to global level it could be useful to you. Metal mining  is other possible source (active and abandoned mines and tailings), specially in Zinc deposits (example Schwartz 2000). 
J. J. Mortvedt 1995/1996 Heavy metal contaminants in inorganic and organic fertilizers. Fertilizer research Volume 43, Issue 1-3, pp 55-61
Satarug S, Baker JR, Urbenjapol S, Haswell-Elkins M, Reilly PE, Williams DJ, Moore MR. 2003. A global perspective on cadmium pollution and toxicity in non-occupationally exposed population.Toxicol Lett. ;137(1-2):65-83.
Michael O. Schwartz (2000)Cadmium in Zinc Deposits: Economic Geology of a Polluting Element. International Geology Review; 42:5, 445-469.
  • asked a question related to Drinking Water Quality
Question
14 answers
Dear all
There is a drinking water tank with 12000 lit capacity. Tank material is 3 layer polyethylene. Tank is filled with fresh drinking water once a week and water used during the week. To prevent microbial contaminant growth, this tank should be equipped with an disinfection circle. Attached picture is the scheme of the mentioned tank and disinfection system. However, I want to know the optimum water turnover flow rate and period for a drinking water reservoir. Is there any standard or reference in this field?
Thank you in advance.
Regards.
Relevant answer
Answer
This system is not going to provide bacteria-free water at any flow rate.  This is not a "disinfection cycle" - only a site treatment.  UV only treats the water as it flows through and the poly tank as well as the rest of the system is not sterile and will suffer microbial growth.  You will have a biofilm develop in the tank and you can't effectively sanitize a poly tank.  
As Laith said, if you want bacteria-free system, you'll need to add an additional treatment and chlorine can serve that role.
  • asked a question related to Drinking Water Quality
Question
3 answers
EPA publish model to evaluate drinking water ingestion for radionuclides, but EPA does not publish model to quantify cancer risk from dermal exposure to radioactive contaminants in water. Please suggest 
Relevant answer
Answer
See Keith F. Eckerman and Jeffrey C. Ryman, External exposure to radionuclides in air, water, and soil. Federal Guidance Report No. 12. EPA-402-R-93-081, US EPA, Washington, DC, 1993:
  • asked a question related to Drinking Water Quality
Question
17 answers
Lakes are getting polluted, if same condition getting prolonging entire world in danger.
Relevant answer
Answer
Lake pollution is generally caused by various sources. Export of nutrients through drainage water from agricultural lands is one of the major ways to create eutrophic condition which is the major driver for hypoxic zone. To reduce the nutrient export in the lakes, drained water can be treated for nutrients by various management practices such as denitrifying woodchip bioreactors, constructed wetlands, and controlled drainage.
  • asked a question related to Drinking Water Quality
Question
8 answers
biotechnologists, toxicologists 
Relevant answer
Answer
 Where algae can grow in those who create risks will have systemic toxins. For more information, please see Attachments.
  • asked a question related to Drinking Water Quality
Question
15 answers
Griess method is the standard method. However it is not able to determine nitrite at low levels in drinking water.
Relevant answer
Answer
Standard Methods for the Examination of Water and Wastewater. SM-4500-NO2. Colorimetric method, the de facto method for nitrite in water. You can easily detect 5 ug/L (ppb); if you are careful and have a good UV spectrophotometer you can get detection limits between 1 and 2 ug/L. Simple, fast, precise and cheap.
  • asked a question related to Drinking Water Quality
Question
2 answers
How do you verify the results and calculate the error % of the model
Relevant answer
Answer
Thank you Babatunde for your answer.
  • asked a question related to Drinking Water Quality
Question
4 answers
I am going to do my research on the use of the palm kernel oil as a coagulant/coagulant aid.
From most of the journals I have read, I understand that the use of Moringa oleifera in coagulation requires the extraction of residual oil before use, to avoid the increase of oil and grease in treated water.
How does the residual oil threaten the coagulation process?
Relevant answer
Answer
If you are removing UV254 compounds, Moringa oil could increase the organic content
  • asked a question related to Drinking Water Quality
Question
4 answers
I need some data about water containing bacteria at natural conditions. Which fast-testing method is most suitable find out if sample of drinking water is good or bad?
Relevant answer
Answer
To determine if water is safe to drink from a microbiological just make sure it is not contaminated by pathogenic microorganisms. But the latter belong to many different genera and species that their research is long and laborious; So you prefer to search for the so-called "indicators of faecal contamination" that some species of bacteria (coliform and fecal streptococci) present in large numbers compared to pathogens in human feces and animals. The presence of these bacteria "indicators" in water indicates fecal contamination and the suspected presence of pathogens, therefore, is to consider not drinking.
Essentially be excluded the presence of:
- Helminths (worms) such as Schistosoma (larva) or other helminths as Fasciola hepatica (larva), Taenia solium (eggs), Echinococcus (eggs)
- Protozoa such Entameba histolitica and Giardia intestinalis and Cryptosporidium parvum
- Bacteria: Salmonella typhi and paratyphi A and B, other Salmonella (various species), Shigella (various species), Yersinia enterocolitica,
Escherichia coli (enteropathogenic), Campylobacter jejuni,
Vibrio cholerae
- Virus: Adenoirus, Echovirus. Norwalk virus, Hepatitis A, Hepatitis E
This set is almost complete.
  • asked a question related to Drinking Water Quality
Question
5 answers
Urban Agriculture (UA) can be implemented in various ways. For instance rooftop-based, land based, or in a closed controlled environment. Furthermore different cultivation methods are available (e.g. hydroponics, soilless- or soil-based agriculture). In addition, it can also be distinguished between community based concepts, private lots, or profit-orientated approaches, etc.
Aside from that UA can have a beneficial effect on urban infrastructures (storm water management, utilizing waste water and biomass, heat reduction, etc.).
My research focusses on the assessment of sustainable and resilient aspects of UA mainly from an ecological point of view. I would be grateful, if somebody could give me some recommendations how I can assess these values in order to provide a selection matrix as a tool for urban planners to incorporate UA in different urban structure types. Any recommendation is welcome ;)
Relevant answer
Answer
Hi. I think that within a decision matrix the decision variable should be energy gain with UA. This variable should be expressed as kW.hr-1 gained, Mega Joules, or kilocalories. The ratio between energy used by traditional agriculture per unit of area versus energy used by UA should be a good indicator of the goodness of the practice in urban areas. In this computations water plays a main role. Other way to view that is trying to answer the question: how many calories are invested for producing one calorie of some product? If the energy produced is higher than that invested then we may consider a good sustainable option.
  • asked a question related to Drinking Water Quality
Question
10 answers
Regarding adaptions of prehistoric hominins to drinking water resources, what is the maxima in brackish waters modern humans from native and indigene groups living in such environments can deal with? References regarding this question would be appreciated, thank you in advance!
Relevant answer
Answer
Hi Johannes,
I guess you found most of these papers already but these is what I found found about the topic with a quick search through google and google scholar:
- Laell et al. 1944, DESERT CLIMATE PHYSIOLOGICAL AND CLINICAL OBSERVATIONS. The Lancet 244, pp. 491-497
- Gleibermann, L. 1973, Blood pressure and dietary salt in human populations. Ecology of Food and Nitrition 2 (2) pp. 143-156
This one seems to compare the effects of salt intake in different human populations but since I can not directly asses it I don't know whether it only takes sodium into account or if chloride is also dealt with.
- Stevenson, Richard J.; Case, Trevor I.; and Oaten, Megan J. 2010, Salt-Induced Thirst Results In Increased Finickiness In Humans. The Psychological Record: 60 (3), Article 1.
This one is about increased finickness in humans under thirst conditions.
I hope one of these proves usefull. I will probably look up more later.
  • asked a question related to Drinking Water Quality
Question
5 answers
I have searched a lot, but in different papers different values were given. Can you explain me?
Relevant answer
Answer
thanks to all.
  • asked a question related to Drinking Water Quality
Question
5 answers
Mo content in few water wells used as drinking water is higher than the standards. Is there any research deal with removal of Mo by using natural zeolites?
Relevant answer
Maybe this can be useful
Mwabi J.K. et al (2011) Household water treatment systems: A solution to the production of safe drinking water by the low-income communities of Southern Africa
  • asked a question related to Drinking Water Quality
Question
6 answers
Detection of bacteria in the drinkable tape water should be very useful for health and safety concerns, which needs a fast response sensor. It will be highly appreciated if some experts in the bacteria detection field could highlight the present status of such bacteria sensors and bacteria identification.
Relevant answer
Answer
Thanks :-) to do the paper I posted earlier took me a few months (I was already a quite senior postdoc then) but I would say it is quite straight forward. This is the only paper i did about this but after i left my group did some experiments with different bacteria. You can just use the same polymer to generate the sensor surface and then adjust the viscosity until your bacteria are about 1/3 of the diameter inside the polymer when you press them in. That just requires a few tries. We read out the sensor optically but you can also use the technique with another detection method if you happen to have one available. If you need any further practical Info's you can contact me. Best Romana
  • asked a question related to Drinking Water Quality
Question
4 answers
Dear RG Researcher,
I have learned a lot from your valuable suggestions & contribution on my previous Question about Algae Coagulation by treating with AlCl3 as a Flocculant. 
Now I have Practically approved that AlCl3 is the best option to Coagulate the Colonies of Algae.
In next stage I am looking forward to know the Threshold limit of AlCl3 for RO-Plant Feed water treatment. Please guide me about the Threshold Limits of AlCl3 for the purpose.
Regards.
Relevant answer
Answer
Hi Muhammamd,
First, aluminium chloride is a coagulant rather than being a flocculant. Second, practically since I am working in desalination field over year, I don't recommend Al & Fe coagulants in the pre-treatment processes of RO feed water, because small amounts (0.5-1.0 ppm) may leach and reach the membranes. This will reduce dramatically the efficiency of your antiscalant and enhance the fouling potential noticeably - either colloidal fouling or scaling. 
So, adding Al & Fe to your RO feed water may damage the membranes and needs very special attention. 
If you need some papers about this point, I can give you their links. 
Finally, if you want to dose AlCl3, Jar testing is the best technique to calculate the dose cause no threshold dose of coagulants/flocculants. 
Regards
  • asked a question related to Drinking Water Quality
Question
15 answers
MPL of turbidity in drinking water in USA is defined up to  0.1 to 1.0  NTU
EPA says: it could be up to 5 NTU
WHO also 5 NTU
Are there any expert in this matter who can provide me with the most acceptable number?
Thanks
Relevant answer
Answer
The answer to your question depends on the type of water you are treating; consequently, in the U.S.A turbidity is regulated as a "treatment technique", and depends on whether you are treating surface water, groundwater under the direct influence of surface water, or groundwater. Additionally, the turbidity level is further regulated within each classification of water by the type of treatment one has implemented. The type of treatment may also be regulated in and of itself. EPA's health effects language that explains the maximum contaminant level designation for turbidity states that higher turbidity levels are often associated with higher levels of disease-causing microorganisms such as viruses, parasites and some bacteria. These organisms can cause symptoms such as nausea, cramps, diarrhea, and associated headaches.
Surface Water Treatment Rule requirements: EPA’s surface water treatment rules require systems using surface water or GWUDI to (1) disinfect their water, and (2) filter their water or meet criteria for avoiding filtration so that: (i) Surface water systems and GWUDI systems that use conventional and direct filtration: (ii) At no time can turbidity (cloudiness of water) be higher than 1.0 nephelometric turbidity unit (NTU); samples for turbidity must be less than 0.3 NTU in at least 95 percent of samples in any month. (iii) Surface water systems and GWUDI that use slow sand filtration or diatomaceous earth filtration: samples for turbidity must be less than 1 NTU in at least 95 percent of samples in any month.
Surface water systems and GWUDI that use alternative filtration (technologies for filtering other than conventional, direct, slow sand, and diatomaceous earth filtration): Follow state limits, which should be at least as stringent as the following: Turbidity must not exceed 5 NTU; samples for turbidity must be less than 0.5 NTU in at least 95 percent of samples in any month.
These standards, in combination with disinfection, must ensure that the system reliably achieves required pathogen control on a continuing basis.
  • asked a question related to Drinking Water Quality
Question
23 answers
What is the relationship between altitude and water quality parameters especially in terms of dissolved oxygen in water?
Relevant answer
Answer
DO concentration in water is dependant of water temperature but also of the partial pressure of oxygen (so of air) above the water. This is the Henry's law. If the partial pressure increases, then the DO concentration in water will also increase. When the altitude is increasing, the total atmospheric pressure decreases, and then the partial pressure of oxygen is also decreasing (assuming a constant proportion of O2 in air). You will then obtain a decrease of DO concentration with altitude elevation (at constant temperature and constant water composition of course).
  • asked a question related to Drinking Water Quality
Question
11 answers
I'm conducting a research related to the effect of some physical treatment techniques on the cluster size of commercial natural mineral bottled water which contains many ions such as, Na+, K+, Mg2+, Fe3+ and OH−, HCO3− in addition to some organic and inorganic chemicals. According to the previous literature, the concentration of these ions affect the cluster size of water molecules. The same sample of water will be used in all physical treatments.
Is it required to quantify all of water ions before determining the water cluster size?
Or i can just mention about some mineral content and ions written on the bottles by the manufacturer?
Thank you
Relevant answer
Answer
Yes, I agree with Marlina, I would suggest to make your own water using pure distilled water. In non-destilled water some ions could be below detection, and they could influence the clusters. The dimensions of the clusters and composition are related to SAR.
Definitively I would suggest   to make your own water using pure distilled wáter, and add the chemicals in the experiments.
  • asked a question related to Drinking Water Quality
Question
1 answer
I am interested in water related diseases in Chennai (S. Brisset)
Relevant answer
Answer
Hi!
Yes you can do that if you use a good GPS maping.
Best Regards
  • asked a question related to Drinking Water Quality
Question
4 answers
I am currently synthesizing membranes for drinking water treatment and would like to use non-toxic solvents such as or better than Ethyl lactate. If you have done any research in this field or you know of any compound that I can use, kindly provide me with that information. 
Relevant answer
  • asked a question related to Drinking Water Quality
Question
17 answers
I need to test for Na, K, Fe, Pb, Cd, Cr, Ni, Cu, and Zn.
Relevant answer