Introduction: As we all know that water is essential for existence of human on this earth. It is also important for agriculture and industries. The life of human and its ecosystem is dependent on the physico-chemical and biological characteristics of water bodies[1]. Various human activities like industrialization, urbanization, agriculture activity increases the pollution of surface water as well as ground water [2]. Water-borne diseases is still a major threat to health in many parts of the world and reported to cause at least 4 billion clinical cases of diarrhoea every year, representing 5.7 % of the global disease burden in the year 2000 [3] Water may be contaminated by careless disposal of hazardous household wastes, agricultural wastes and chemicals, and leaking of underground storage tanks. Water bodies can also be contaminated by disease causing pathogens from landfills and septic systems. It is pertinent to mention that food and poor sanitation are the main sources for contamination with pathogen of gastrointestinal tract, drinking water is the major source of microbial pathogens in developing regions [4]. Water is a most important component of public health, and failure to supply safe drinking water will be a major threat to humanity [5].
Prior to 2004, unhygienic practices related to food, water and personal hygiene in Ethopia, the majority of Ethiopia’s population does not have access to safe and reliable sanitation facilities. Accordingly, more than 75 % of Ethiopia’s health problems were due to water borne diseases attributed to unhealthy and inadequate water supply, and unhygienic waste management, with human excreta being the major problem [6].
Besides microbial contaminants, heavy metals contaminations of water resources is a major concern because of their high toxicity even at lower concentration [7,8]. Furthermore, it has been found that heavy metals are not biologically and easily assimilated and can be bio-accumulated in the protoplasm of aquatic organisms [9]. The common heavy metals include mercury, iron, lead, arsenic, cadmium, vanadium, chromium, nickel, cobalt, zinc, and copper [10,11]. Through food chain, these heavy metals can reach to every member and then human posing health risk to the consumer.
People on earth are under a threat due to undesired changes in the physical, chemical and biological changes in water, soil and air. Being a basic need of human development, health and well being, safe and readily available water is important for public health, whether for drinking, domestic use, food production or recreational activities. In 2010, the UN General Assembly explicitly recognized “The Human Rights To Water And Sanitation”, which says that everyone has the right to have sufficient , continuous, safe, acceptable, physically accessible, and affordable water for personal and domestic use.
According to WHO, “Improved water supply and sanitation, and better management of water resources, can boos countries’ economic growth and can contribute greatly to poverty reduction.”
Drinking water standards describes the quality parameters set for drinking water. Good quality drinking water is necessary for improving the lives of people and prevent them from diseases.
Need of water Quality Analysis
Water analysis is a chemical analysis of the dissolved materials in water, including a determination of the amount of suspended solids and pH value. It is required mainly for monitoring purposes. It is carried out to identify and quantify the chemical components and properties of water samples. Some importance of such assessment include:
- To check whether the water quality is in compliance with rules and regulations.
- To check whether the water quality is in obedience with the standard limits set and thus checking its efficiency or sustainability to be used.
- To check whether the machines or systems need to be changed or up gradation is required.
- To check the efficiency of systems working for water quality maintenance.
Water quality analysis is extremely necessary in sectors of:
- Public health ( especially drinking purposes, agriculture, irrigation, livestock etc.)
- Industrial activities.
Contamination of Natural Water
“The Safe Drinking Water Act” defines the term “contamination” as meaning any physical, chemical, biological, or radiological substance or matter in water.
Drinking water may reasonably be expected to contain small amounts of some contaminants. Some drinking water contaminants may be harmful if consumed at a certain level while others may be harmless.
The potential source of contamination can b geological conditions, industrial and agricultural activities, and water treatment plants. Moreover, due to increased population, industrialization, use of fertilizers in agricultural and man-made activities, water is highly polluted with contaminants. Different types of impurities are introduced in to aquatic system by different ways such as weathering of rocks and leaching of soils, dissolution of aerosol particles from the atmosphere and from several human activities, including mining, processing and the use of metal based materials. Contaminants can be categorized as microorganisms, inorganics, organics, disinfectants and radionuclide. General categorization of drinking water contaminants are:
- Physical Contaminants :
They primarily impact the physical appearance or other physical properties of water. E.g. sediments or organic material suspended in water of lakes, rivers and streams from soil erosion.
- Chemical Contaminants :
These are elements or compounds and they can be naturally occurring or manmade. E.g. Nitrogen bleach, salts, pesticides, metals, toxins produced by bacteria.
- Biological Contaminants :
These are organisms in water are referred as microbes or microbiological contaminants. e.g. bacteria, viruses, protozoan and parasites.
- Radiological Contaminants :
These are the chemical elements with an unbalanced number of protons and neutrons resulting in unstable atoms that can emit ionizing radiations. E.g. Cesium, Plutonium and Uranium.
Contaminants and Major health issues:
The inorganic chemicals hold a greater portion as contaminants in drinking water . e.g. minerals in form of heavy metals. Heavy metals accumulate in human organs and nervous system, interfering with normal functions. In recent years, heavy metals such as Lead (Pb), Arsenic(As), Magnesium(Mg), Nickel(Ni), Copper(Cu) and Zinc(Zn) have received significant attention due to causing health problems.
1.Cardiovascular diseases, kidney related problems, Neuro-cognitive diseases, and cancer are related to the traces of metals such as Cadmium(Cd) and Chromium(Cr).
2. The Lead(Pb) is known to delay the physical and mental growth of the infants.
3. Arsenic (As) and Mercury(Hg) can cause serious poisoning with skin pathology and cancer and further damage to kidney and liver, respectively.
4. The presence of toxic and radioactive element like Uranium in the groundwater is another serious concern I many parts of the world .
Table- Different parameters ,their source and health problems caused by them
| S. no. | Parameter | Source of occurrence | Potential health effect |
| 01 | Turbidity | Soil runoff | Higher level of turbidity are associated with disease causing bacteria’s. |
| 02 | Color | Due to presence of dissolved salts | – |
| 03 | Odour | Due to biological degradation | Bad odor unpleasant |
| 04 | Electrical conductivity | Due to different dissolved solids. | Conductivity due to ionizable ions. High conductivity increases corrosive nature of water. |
| 05 | pH | pH is changed due to different dissolved gases and solids. | Affects mucous membrane; bitter taste; corrosion |
| 06 | Dissolved oxygen | Presence due to dissolved oxygen. | D. O. corrode water lines, boilers and heat exchangers, at low level marine animals cannot survive. |
| 07 | Total hardness | Presence of calcium (Ca2+) and magnesium (Mg2+) ions in a water supply. It is expressed. Hardness minerals exist to some degree in every water supply. | Poor lathering with soap; deterioration of the quality of clothes; scale forming |
| 08 | Total alkalinity | Due to dissolved gases (CO2) | Embrittlement of boiler steel. Boiled rice turns yellowish |
| 09 | TDS | Presence all dissolved salts | Undesirable taste; gastro-intestinal irritation; corrosion or incrustation |
| 10 | Calcium | Precipitate soaps, anionic | Interference in dyeing, textile, |
| 11 | Magnesium | surfactants, anionic emulsifiers, | paper industry etc. |
| 12 | Ammonia | Due to dissolved gases and degradation of organics | Corrosion of Cu and Zn alloys by formation of complex ions. |
| 13 | Barium | Discharge of drilling wastes; discharge from metal refineries; erosion of natural deposits | Increase in blood pressure |
| 14 | Biochemical oxygen demand (BOD) | Organic material contamination in water | High BOD decreases level of dissolved oxygen. |
| 15 | Carbonate | Due to dissolution of CO2 | Product imbalance Unsatisfactory production Short product life |
| 16 | Chloride | Water additive used to control microbes, disinfect. | Eye/nose irritation; stomach discomfort. Increase corrosive character of water. |
| 17 | Nitrate | Runoff from fertilizer use; leaking from septic tanks, sewage; erosion of natural deposits | Effect on Infants below the age of six months Symptoms include shortness of breath and blue-baby syndrome. |
| 18 | Phosphate | stimulate microbial growth, Rancidity Mold growth | |
| 19 | Sodium | Natural component of water | |
| 20 | Sulphate | Due to dissolved Ca/Mg/Fe sulphates | Taste affected; gastro-intestinal irritation. Calcium sulphate scale. |
Parameters to assess water contaminants
A number of scientific procedures and tools have been developed to assess the water contaminants. These procedures include the analysis of different parameter such as pH, turbidity, conductivity, total suspended solids (TSS), total dissolved solids (TDS), total organic carbon (TOC), heavy metals, biological oxygen demand (BOD), chemical oxygen demand (COD) etc.
Parameters of water quality can be categorized for specific studies:
1. Biological parameters
2. Physical parameters
3. Chemical parameters
4. In-situ parameters
These parameters even affect the drinking water quality; if their values are in higher concentrations then the safe limits set by WHO or local standards such as National Drinking Water Quality Standard (NDWQS).
Physico-Chemical Properties of water
It is important to test the water quality before it is used for drinking purposes, agricultural activities or in domestic or industrial fields. It must be tested with different physical and chemical parameters. These parameters depend on what purpose the water is being tested and to which extent we need quality to be pure. Water contains different content depending on the source it is taken from and contain floating particles, suspended particles, microbiological and even bacteriological impurities. The tests can be divided into physical and chemical methods. The physical tests can be performed to check water’s pH, color, odor, temperature, turbidity etc. and can be performed on site while chemical tests are performed in the laboratory and include tests to note BOD, COD, dissolved oxygen, hardness etc. For further quality analysis, tests for heavy metals and trace elements can be performed. These parameters are inter dependent on each other and their values vary accordingly. Drinking water must pass all these tests and contain minerals and metals in a certain quantity to be in the safe range set by local standards. Following are different physical and chemical parameters which are monitored to check water quality for drinking purposes:
Temperature :
Temperature exerts a major influence on biological activity and growth. It also governs the kind of organisms that can live in rivers and lakes. As temperature goes too far or below preferred range, the number of animals living in it eventually decrease until finally they are none. Temperature of water controls rate of chemical reactions going on which majorly impacts other parameters like pH, alkalinity, dissolved oxygen etc. which further impacts the aquatic life and indirectly ecosystem as a whole. Water, particularly groundwater, with higher temperature can dissolve more minerals from surrounding rocks and will therefore have higher electrical conductivity. Whereas warm water holds less dissolved oxygen it in than the cold water , and thus may not contain much oxygen for survival of aquatic life in it.
Hydrogen ion activity (pH) :
Mathematically, it can be said that pH is the negative logarithm of the activity of the hydrogen ion.
pH is the term used to express the acidic or alkaline conditions. It is an important parameter to check for the quality analysis. Lower the pH, more acidic the water is causing corrosive nature while higher the pH of water , higher the alkalinity. It is positively correlated with the electrical conductance and total alkalinity. Lower the rate of photosynthesis , higher the assimilation of carbon dioxide and bicarbonates and thus higher the alkalinity and lower the oxygen values in summers.
Primary pH standard values are found out by using a concentration cell with transference, simply by measuring the potential difference between a standard electrode such as the silver chloride electrode & hydrogen electrode. Measurement of pH for aqueous solutions can be done with a pH meter or a glass electrode. We can also find the value of pH by using indicators.
pH measurements have significant importance in the field of biology, environmental science, chemistry, medicine, oceanography, food science, agriculture, nutrition ,civil engineering, chemical engineering, forestry, water treatment & water purification and many other applications.
The solubility (amount that can be dissolved in the water) and biological availability (amount that can be utilized by aquatic life) of chemical constituents such as nutrients (phosphorus, nitrogen, and carbon) and heavy metals (lead, copper, cadmium, etc.) can be determined by pH of water.
According to [12], pH of ground water can also be lowered by organic acids from decaying vegetation, or the dissolution of sulfide minerals. The slight basic nature of the bore well water may be mainly due to the limestone basin of the all the locations.
Electrical Conductivity (EC) :
It is measured by EC meter which is standardized with known value of conductance with standard KCl solution. It determines the resistance offered by water between two platinized electrodes.
The measure of the ability of an electrolyte solution to conduct electricity is called its conductivity. Conductivity is also referred to as specific conductance. The SI unit of conductivity is siemens per meter (S/m). Underground drinking water quality can be effectively measured by controlling the conductivity of water. Conductivity is directly linked to the total dissolved solids (T.D.S.) in various cases. The electrical conductivity shows correlation with ten parameters: temperature , pH value , alkalinity , total hardness , calcium , total solids, total dissolved solids , chemical oxygen demand , chloride and iron concentration of water. The presence of inorganic dissolved solids such as chloride, nitrate, sulfate, and phosphate anions (ions that carry a negative charge) or sodium, magnesium, calcium, iron, and aluminum cations (ions that carry a positive charge) affect the value of conductivity in water. Various organic compounds like phenol, oil, sugar and alcohol do not conduct electrical current well and therefore possess a low conductivity in water. Temperature affects the conductivity as well: the warmer the water, the higher the conductivity. Discharges to streams have the potential to change the conductivity depending on their make-up. A failing sewage system would raise the conductivity because of the presence of chloride, phosphate, and nitrate; an oil spill tends to lower the conductivity.
Carbon Dioxide :
It is the end product of the degradation of organic carbon and thus determines the net ecosystem metabolism which makes it an important parameter . There are methods to measure carbon dioxide based on the their role in the environment like pH (pCO2) can be measured by photometric methods , total dissolved inorganic carbon (DIC) can be measured by coulometer or can be measured by IR carbon dioxide analyzer and Total alkalinity (TA) can be measured by HCl titration of water sample to CO2 equivalent point.
Alkalinity :
It is measure of the quantity of carbonates and bicarbonates present in water. It acts as a stabilizer for pH, Alkalinity , pH and hardness affects the toxicity o many substances in water. To high causticity can cause other problems like, foaming . It is determined by a simple dilute HCL titration in presence of phenolphthalein or methyl orange as an indicator. Hydroxyl alkalinity in boiler water is necessary to protect the boiler against corrosion
Dissolved Oxygen :
It is one of the most important parameter as it gives direct and indirect information like bacterial activity , photosynthesis , availability of nutrients , stratification etc.
In summers, dissolved oxygen decreases due to rise in temperature and thereby increase in the microbial activity. Duration of the sunlight has a direct influence on the soluble gases like oxygen and carbon dioxide. It is measured by Winkler’s Method after five days incubation at 293K. The difference between the initial and final dissolved oxygen gives the amount of oxygen consumed by bacteria.
fIt is measured when the pH reaches above 8.3. it is measured by the titration of the standard titration of the HCl using phenolphthalein as an indicator. Below 8.3 pH , carbonates convert to equal amount of bicarbonates.
Bicarbonates :
It is also measured by the titration with standardized HCl using methyl orange as an indicator. The solution turns to yellow from orange below pH 4.
Biochemical oxygen demand (BOD) :
It is a measure of the organic contamination in water and is specifies in mg/L. It is the amount of dissolved oxygen required for biochemical decomposition of the organic compounds and oxidation of the inorganic materials like ferrous and sulphites. The test is conducted over a five day period.
Chemical Oxygen Demand (COD) :
It is a measure of the organic material contamination in water specifies in mg/L. It is the amount of the oxygen required to cause chemical oxidation of organic material.
Both BOD and COD are used in waste water treatment.
Total Dissolved Salts (TDS) :
It is the amount of the inorganic salts and small amount of organic matter dissolved in the water solution. The major constituents are Calcium , Magnesium , Sodium , Potassium ions and carbonates, hydrogen bicarbonates , sulfate , chlorides , nitrates etc. A measure of the combined content of all inorganic and organic substances contained in a liquid in molecular, ionized or micro-granular suspended form is called Total Dissolved Solids (TDS). We generally discuss TDS for freshwater systems only, as salinity consists of some of the ions contributing in the definition of TDS. The Study of water quality for streams, rivers and lakes is the most important application of TDS, although TDS is not a primary pollutant, but TDS is used as an indication of aesthetic characteristics of drinking water and as an indicator of the presence of a broad array of chemical contaminants. Electrical conductivity depends on TDS. Agricultural and residential runoff are primary sources for TDS in receiving waters, and so are leaching of soil contamination and point source water pollution discharge from industrial plants. Calcium, phosphates, nitrates, sodium, potassium, sulphates and chloride comprise few of the important chemical constituents. The chemicals might be cations, anions, molecules or agglomerations on the order of one thousand or fewer molecules, so long as a soluble micro-granule is formed. Pesticides arising from surface runoff are more exotic and harmful elements of TDS. Certain naturally occurring total dissolved solids arise from the weathering and dissolution of rocks and soils.
Total Dissolved Solids is determined by filtering a measured volume of sample through a standard glass fiber filter. Gravimetry and conductivity are the two important methods of measuring total dissolved solids. Gravimetric methods are the more accurate methods and they involve evaporating the liquid solvent and taking the mass of residues left. This is the best method generally, but it is time-consuming. If inorganic salts are there as the great majority of TDS, gravimetric methods are more appropriate.
TDS is generally monitored in order to create a water quality environment which is favorable for organism productivity in the case of hydroponics and aquaculture. For freshwater oysters, trouts, and other high value seafood, highest productivity and economic returns are achieved by mimicking the pH and TDS levels of native environment of each & every species. Total dissolved solids is considered one of the best indices of nutrient availability for the aquatic plants being grown for hydroponic uses.
According to [13], potable water should not contain more than 1000 mg/l of total dissolved solids (TDS).
Total Hardness :
It is the measurement of the hardness of water caused due to the bicarbonate , carbonate , sulfate , and chlorides of Calcium and Magnesium. These can be measured by the complexometric titration of water sample against EDTA using Eriochrome Black- T as an indicator.
Sulphate (Turbidity) :
The haziness or cloudiness of a fluid due to various individual particles ( TSS or TDS) that can be seen with naked eyes (like smoke in air) is known as turbidity. The determination of value of turbidity might be termed as one of the most important tests of water quality. Turbidity (or haze) is considered in the case of transparent solids such as glass as well. In plastic production, the percentage of light that is deflected more than 2.5° from the incoming light direction is known as haze. Turbidity can also be termed as the measure of a liquid’s relative clarity. Turbidity is an optical characteristic of water and is also an expression of the amount of light scattered by material in the water when a light shines through the water sample. The higher the intensity of scattered light, the higher the turbidity. Material causing water to be turbid include silt, clay, finely divided inorganic and organic matter, soluble colored organic compounds, algae, plankton and various other microscopic organisms.
High concentrations of particulate matter affect light penetration and productivity, recreational values, and habitat quality, and cause lakes to fill in faster. In streams, increased sedimentation and siltation can take place, which might result in harming the habitat areas for fish and other aquatic life. Particles also provide attachment places for some other pollutants, especially bacteria and metals. That’s why, turbidity readings are used as an indicator of potential pollution in a water body.
Turbidity can provide shelter and food for pathogens. Regrowth of pathogens in the distribution system is promoted if the turbidity is not removed, leading to waterborne disease outbreaks, which have caused significant cases of gastroenteritis throughout the world.
It is measured by Nephelometric method( based on the concept that particles in solution will scatter light passing through solution rather than absorbing light) in which concentration of turbidity is measured against known concentration of synthetically prepared sulfate solution. Barium chloride is used for producing turbidity and NaCl is used to prevent setting of turbidity.
Ammonia (Nitrogen):
It causes overstimulation of aqueous plants and algae and thereby using dissolved oxygen. It is measured by spectroscopic ally at 425 nm radiation by making a color complex with Nessler’s reagent [potassium tetraiodomercurate(II)] .
Sodium and Potassium ions :
Higher concentration of these ions cause heart problems. Both ions can be measured by flame photometer. The instrument is standardized with known concentration of sodium and potassium ions respectively.
Chlorine :
Naturally, chlorides are found as salts such as sodium chloride (NaCl), potassium chloride (KCl), and calcium chloride (CaCl2). Chlorides are leached from different rocks into soil and water due to weathering. The chloride ion is generally mobile and is shifted to oceans or closed basins. Chlorine is an effective disinfectant in water but also is a major contaminant in drinking water. Too much chlorine in drinking water causes acidity and thus become corrosive and damage body cells. Chloride increases the electrical conductivity of water and also its corrosivity. Chloride concentrations in excess of about 250 mg/l can give rise to detectable taste in water, but the threshold depends upon the associated cations. Consumers can, however, become accustomed to concentrations in excess of 250 mg/l. No health-based guideline value is proposed for chloride in drinking-water.
Chloride levels in unpolluted waters are generally below 10 mg/litre and sometimes even below 1 mg/litre. Chloride in water may be significantly increased by treatment processes in which chlorine or chloride is used. It is measured by titrating known volume of sample with standardized silver nitrate solution using potassium dichromate solution in water.
Total suspended solids (TSS) :
TSS is the dry-weight of particles which are trapped by a filter having a specified pore size. To find TSS of a water sample, measured volume of water should be passed through a pre-weighed filter having a specified pore size, then taking the weight of filter again after drying to evaporate the water in the filter paper. Filters composed of glass fibers are typically used for measuring TSS. The dry weight measure of the particulates present in the water sample is the gain in weight & it is expressed in units derived or calculated from the volume of filtered water. Turbidity also tends to measure almost the same quality of water property as TSS, TSS is more useful as it gives an actual weight of the undissolved material in the sample provided.
Total Suspended Solids consist of a huge variety of material, for example, decaying plant, silt and animal matter, sewage & industrial wastes. Water having high concentration of suspended solids might cause problems for aquatic life & stream health. Higher amount of TSS can also cause problems for industrial uses, as the solids might clog or scour pipes and machinery.
MATERIAL AND METHODS
Sample collection
In order to get most accurate results, samples need to be collected properly. And that is why, setting up of sampling standard operating procedures (SOPs) are important , there are some common best practices for collecting samples , some major particularities are needed to be given attention like bottle type , preservation techniques , holding time , sampling techniques , sampling points and documentation. The steps include :
Sample collection bottles and materials :
Before collecting samples , making sure that we have all proper bottles , field equipment and preservatives. The method followed determines the type of bottle used.eg. sample for metal analyses are collected in plastic bottles , analyses of volatile organics and pesticides are collected in glass containers. Bottles used to collect bacteria samples should be properly sterilized. Size of container is important to ensure enough sample to run the analysis. Certain analysis like volatile organics and radon require vials that are to be filled leaving no head space , which keeps analytes dissolved in water. Darker bottles are used for analytes that break down in sunlight.
Preservative and holding time :
A common preservative used is sodium thiosulphate , a dechlorinating agent , used to stop any chlorine reaction. It is used for bacteria analysis and volatile organics. Volatile organics are further preserved in field using HCl , which is used to reduce nay microbial activity. Temperature plays an important role as preservative. Most analysis requires samples to be kept cool i.e. between 4-6C. Cooler temperature helps contaminants from breaking down during transit.
Holding Time : this refers to the amount of time from collection to when analysis begins. Regulatory samples need to meet these holding times and recognized holding time vary from state to state.
Sampling techniques :
Techniques for collecting samples vary from source to source. E.g. While sampling well water, run water for several minutes so that sample collected is directly from well and not from a source that has been sitting in storage tanks and pipes.
Use onsite measurements, like pH , temperature and conductivity to determine accurate sampling. Take measurements every 2-3 minutes , till we get 3-4 consistent measurements .
Bacteria :
While collecting bacteria samples , consider wearing gloves to minimize potential contamination. Sterilized, sealed, pre preserved bottles should be used. Best way when gathering the sample is to hold the cap while filling the bottle.
Sample toolkit :
A good sample kit includes supplies and equipment to run any onsite analysis , such s meters to measure Ph , temperature and conductivity as well as standard solutions to properly calibrate equipment. Supplies such as gloves and alcohol swabs are also important part of the sampling equipment.
Sampling points :
From where the sample is to be collected depends on the objective of the analysis. This it is very important to note the objective before collecting sample.
Documentation :
It is critical to record information such as the date and time of collection of samples so that samples are run within proper holding times. It’s a good idea to note the identification , like address or a more specific location. Documentation helps in comparing the results from year to year.
Procedure
A. Study Area :
The UT of J&K is considered as a paradise on Earth with ample water sources such as lakes , rivers and glaciers besides groundwater. The main rivers that flow through the UT rae Jhelum , Chenab , Indus and Tawi and are of Himalayan origin. River Tawi flows through the city of Jammu. The Tawi is a major left bank tributary of river Chenab. Tawi river originates from the lap of Kailash Kund glacier and adjoining area south west of Bhadarwah in Doda district. Its catchment is delineated by latitude 32°35′-33°5’N and longitude 74°35′-75°45’E. The catchment area of river up to Indian border (Jammu) is 2168km2 and falls in the district of Jammu , Udhampur and a small part of Doda. Elevation in catchment varies between 400 and 4000m. it a source of drinking water for more than 700,000people in city of Jammu. Water supplied in houses for domestic use and drinking purposes is usually the groundwater.
Selection of sampling points :
The criteria of selecting sampling points are based on population density , areas of industrial or anthropogenic activities such as minerals and mining activities , and the river catchment areas.
C. Sample collection :
Drinking water samples can be collected from the tap water of residential and commercial areas. The samples can be taken from premises like restraints and private houses. Beside this , samples of bottled mineral water purchased from local shops and markets can be collected. Samples can be numbered for better identification. Quantity of sample collected has to be given attention and the bottles in which samples re collected have to pre washed with demonized water before use. Sample bottle are then be sealed and placed in a dark environment at constant temperature range of 4-10 C. to avoid contamination and effects of light and temperature.
D. Analytical Instruments :
i. On site Analysis :
On site analysis of temperature, pH, conductivity and turbidity can be carried out at the site of sample collection following standard protocols.
ii. Laboratory analysis :
The measurement of TSS and TDS in water samples can be carried out according to the standard methods by the filtration process. the analysis of heavy metals such as Cu, Zn, Mg, Fe, Cd, Pb, Cr, As, Hg and Sn can further be carried out.
Table- Various methods of parameters analysis
| s. no. | Parameters | Methods of analysis commonly used |
| 01 | Ph | Digital pH meter, pH paper |
| 02 | Turbidity | Digital Turbidity Meter, Nephelometer, Turbidity rod |
| 03 | Alkalinity | Titration |
| 04 | Acidity | Titration |
| 05 | BOD | Microbiological titration/ BOD meter |
| 06 | COD | Chemical oxidation-reduction , open reflux, Closed reflux, COD Disaster |
| 07 | Hardness | Titration |
| 08 | Chloride | Titration, potentiometric |
| 09 | Color, odor | Visual verification |
Table- Description of parameters and instrumental method for detection.
| S. no. | Parameter | Description | Instrumental Method |
| 01 | Temperature | Temperature exerts a major influence on the biological activities and growth | Thermometer |
| 02 | Color | Term color is udes to determine te true color of water from which turbidity has been removed. | Platinum cobalt method (visual comparison) |
| 03 | odor | Odor recognized as a quality factor affecting acceptability of drinking water. | Wide mouth glass stopped bottle |
| 04 | Taste | Taste of water ranging from agreeable to disagreeable | By testing |
| 05 | pH | It is a measure of acidity (hydronium ion) in water | pH meter |
| 06 | Turbidity | It is the reduction of transparency in water. | Turbidity meter |
| 07 | TDS(total Dissolved Solids) | Measure of amount of the particular solids that are inn water. | TDS meter |
| 08 | DO (Dissolved Oxygen) | The amount of oxygen in the water. | Titrimeteric method (iodomertric) |
| 09 | Dissolved carbon dioxide | The amount of carbon dioxide in water | Titrimeteric method |
| 10 | Alkalinity | It is the quantitative capacity to react with a strong acid to a designated Ph | Titrimeteric method |
| 11 | Chloride | Measurement of the chloride amount in water | Titrimeteric method |
| 12 | Calcium | Measurement of the calcium amount in water | Titrimeteric method |
| 13 | Barium | Measurement of the barium amount in water | Titrimeteric method |
| 14 | Magnesium | Measurement of the magnesium amount in water | Titrimeteric method |
| 15 | Total hardness | Measurement of the calcium and magnesium amount in water | Titrimeteric method (complexometric) |
| 16 | Copper | Measurement of the copper amount in water | Spectrophotometer |
| 17 | sulphate | Measurement of the sulphate amount in water | Spectrophotometer |
- Results and discussions.
Values set by Indian standards and WHO are taken into consideration when checking the quality of drinking water whether it is good for drinking purpose or not. After collecting samples from different areas, it is studied through various parameters and after the analysis, the result is compared with safe standards.
Table- values of safe limits for various parameters set by Indian Standard and WHO.
| S.No. | Parameters | Technique used | Indian standard | WHO standard |
| 01 | Temperature | Thermometer | – | – |
| 02 | Color | Visual color kit | – | – |
| 03 | Odor | Physiological sense | – | – |
| 04 | Electrical conductivity | Conductivity meter | ||
| 05 | pH | pH meter | 6.5-8.5 | 6.5-9.5 |
| 06 | Dissolved oxygen | Redox titration | 3 | |
| 07 | Alkalinity | Acid-base titration | 200ppm | |
| 08 | Acidity | Acid-base titration | ||
| 09 | Bicarbonate | Titration | 125-350 | |
| 10 | BOD (biochemical oxygen demand) | Incubation followed by titration | 30-100 | 6 |
| 11 | COD (Chemical oxygen demand) | COD digester | 10 | 10 |
| 12 | Magnesium | Complexometeric titration | 30ppm | 150ppm |
| 13 | Chloride | Argentometeric titration | 250ppm | 250ppm |
| 14 | Sulphate | Nephelometer / Turbidimeter | 200ppm | 250ppm |
| 15 | Hardness | titration | 500mg/L | |
| 16 | TDS (total dissolved solids) | 500-2000mg/L | 500-1000mg/L |
Conclusion
To assess the quality of safe drinking water, the parameters are compared with the safe limits set by WHO and Indian standards. The parameters which fall between the safe range set are considered to be in safe zone while the parameters which are far from the safe range are considered bad for drinking proposes. The water then can be treated desirably as soon as the quantity of certain toxic substances are found. It is very essential and important to test the water before it is used for drinking, domestic, agricultural or industrial purpose. Water must be tested with different physic-chemical parameters. Selection of parameters for testing of water is solely depends upon for what purpose we going to use that water and what extent we need its quality and purity. Water does content different types of floating, dissolved, suspended and microbiological as well as bacteriological impurities. Groundwater is the most important source of water supply for drinking, irrigation and industrial purposes. Increasing population and its necessities have lead to the deterioration of surface and sub surface water. The modern civilization and urbanization frequently discharging industrial effluent, domestic sewage and solid waste dump. The cause of ground water gets pollute and create health problems. Once the groundwater is contaminated, its quality cannot be restored by stopping the pollutants from the source it therefore becomes imperative to regularly monitor the quality of groundwater and to device ways and means to protect it. So before using of water we should investigate qualitative analysis of some physicochemical parameters of groundwater. This may be considered as reference for the society to get cautious about the impending deterioration of their environment and health.
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