I. INTRODUCTION

INTRODUCTION

Water is one of the most priceless gifts of nature. It is also regarded as

the lifeline on earth because evolution of life and development of human civilization

could not have been possible without it. Throughout the history, social and economic

development, and the stability of the culture and civilization were closely connected

with the availability of water. The world population was 1 billion about 2 centuries

ago. It is projected to be 17.9 to 19.1 billion by 2015. The volume of water remaining

the same, this increase in population will lead to over exploitation of water resources.

Moreover, due to the impact of human activity, environmental disturbances on the

water cycle are also increasing.

Recently for the first time in history, man has faced one of the most

horrible ecological crises - the problem of pollution of his environment, which some

time in the pastwas pure, virgin, undisturbed and uncontaminated. In the last two

decades, most of the industrially and technologically advanced countries of the

west and east alike, felt an urgent need to combat the environmental pollution, with

all their might. Many factors such as population explosion, unplanned urbanization

and deforestation, profit oriented capitalism and technological advancement have

caused pollution crisis on earth (Odum, 1971; Southwick, 1976 and Smith, 1977).

Industrialisation is believed to cause inevitable problem of pollution to water, soil

and air based on the type of industry, the nature of raw materials, processes involved

and types of equipment used (Billings and De Hass, 1971; Hodges, 1973).

Most of the Indian rivers and freshwater streams are seriously polluted

by industrial water, which come out of different factories. Although volume wise,

the domestic sewage constitutes about 75% of the total effluent generated, it is the

industrial effluent which contains high concentrations of pollutants, either toxic or

non-toxic, that is of greater concern (Bhavanisankar, 1994). All the chemicals of

the industrial water are toxic to phytoplankters and animals and may cause their

death or sublethal pathology of the liver, kidneys, reproductive system, respiratory

system or nervous system of both invertebrate and vertebrate aquatic animals.

The fight against the water pollution has become a major issue in terms

of health, environment and economy. During the past 50 years, the country has

made tremendous progress in the sphere of industrialization. The major steps to

pollution control in industries are : -

Efficient process control on modification to minimize the strength of water.

Water minimization by proper handling of raw materials and finished products,

and

Optimising resource initialisation.

The lnternal control measures will only reduce the pollutant generation,

but will not eliminate its generation. Therefore, the external measures such as the

treatment of the effluents form an inevitable part in pollution control. The various

processes in pollution control are pre-treatment, primary treatment, secondary

treatment and tertiary treatment (Sax, 1974).

Pre-treatment usually includes preliminary process to remove large

aggregates of floating and suspended solid matter, grit and much of oil and grease

content and the equalization and storage of the effluent from different water streams.

The primary treatment consists of both physical and chemical methods including

floatation, sedimentation, neutralization, chemical addition and coagulation. Primary

treatment removes settable solids, suspended solids and biochemical oxygen

demand. Following primary treatment, the waste water is processed in secondary

treatment phases, which include activated sludge process, trickling filtration, contact

stabilization, rotatrng discs, fluidised beds and lagoons of various types. Biological

process is employed in secondary treatment where organic wastes are metabolised

by living organrsms

Water stabilization ponds are low cost, low technology, but high efficient

method of wastewater treatment (Mara and Parson, 1988). Stabilization ponds have

employed for wastewater treatment for many years. The first recorded construction

of a pond system was at San Antonio, Texas, U S . in 1901. Today, large number of

pond systems are used throughout the world (Reed eta/., 1995). There are three

main types of ponds: anaerobic, facultative and aerobic. Anaerobic ponds are

several meters deep, free of oxygen and have high BOD rates. Facultative ponds

have aerobic conditions on the top and anaerobic conditions un the bottom layers.

Aerobic ponds are shallow, completely oxygenated and are best for algal growth

(Venkataraman et a1.,1994).

The effluent after the secondary treatment may contain suspended and

colloidal solids, organic materials which are resistant to or have escaped from

biological treatment and which are by products of bacterial metabolism, nutrients,

primary nitrogen and phosphorus, dissolved solids such as chlorides and other

mineral salts, bacteria and viruses (Pavoni and Perrich, 1977). The secondary

effluent loaded with inorganic nitrogen and phosphorus causes eutrophication and

long-term problems arise because of refractory organics and heavy metals that are

discharged (De la Noue eta/. ,1992). The presence of toxic substances in wastewater

has always been a matter of concern. Microalgae are envisaged to provide a tertiary

biotreatment system for the treatment of urban, industrial and agricultural effluents

(De la Noue et al., 1992). The benefits of algae in treatment system are oxygenation

and liberalization, in addition to their role as producers in trophic systems

(Elnabarawy and Welter, 1984). The microalgae have the ability to use inorganic

nitrogen and phosphorus for their growth (Oswald, 1988). They have also the

capacity to remove heavy metals (Ray, 1961 ; Becker, 1994) as well as some of the

toxic organic compounds (Redalje et a!.. 1989). Algae can specifically accumulate

and thereby remove toxic compounds from industrial wastes (Cannell, 1990).

The effect of pollutants on the biological community can be considered

as an early warning system for potential pollutants (Walsh et a1.,1980). Many algae

are considered as indicators of water pollution (Palmer, 1957; Shotriya and Dubuey,

1987; Gunak, 1991). The bioaccumulation of chemicals and their concentration in

certain organisms reflect the environmental pollution over time ((Mason, 1990). The

algae being the primary producers can indicate the trophic status of effluent

treatment system and receiving streams. Algal growth is either inhibited or stimulated

depending on the toxicity of effluents. Algae appear to act directly in the degradation

of organic chemicals or mediate proteolysis. The mitigation of contaminant effects

by these oganisms is provided through rendering the toxic chemicals unavailable

by degradation to harmless form (Boyle, 1984).

Algae are photosynthetic non-vascular plants, which contain chlorophyll

and have simple reproductive structures. Microalgae are the microscopic

photosynthetic plant components in the aquatic ecosystem. They incorporate solar

energy into biomass and produce oxygen that gets dissolved in water. Thus they

function in cycling and mineralization of chemical elements and serve as food for

herbivorous and omnivorous animals. When died, they sink to the bottom where

their chemical constituents are transformed, solubilized and recycled into the water.

These functions depend on the phytoplankton population dynamics, which in turn

depend upon seasonal variability in temperature. Microalgae serve as the most

sensitive indicators of environmental quality because they have a larger period of

exposure there by detecting the very minute effects much before other living forms.

Algal communities have served as ideal test systems in the study of ecological

impacts of pollutants and in toxicity evaluations. Palmer (1980) compiled 269

different works of 165 authors and made a list of more than 850 species of algae,

which are commonly found in water containing high concentrations of wastes. Among

these, diatoms ranked first, followed by green algae. The species diversity of algae

is found to be affected by physical, chemical and biological factors of the aquatic

environment.

Relative fertility and potential resources of an aquatic ecosystem are

governed by its bioproductivity at primary trophic level, where microalgae are the

major producers. Production of organic matter by microalgae is of utmost importance,

because it initiates the aquatic food chain. A quantitative measurement of primary

production is therefore of great significance. Studies showed that the algal biomass

could be used as animal feed, fertilizer, as live food in aquaculture and in the

biological purification of wastewater. Microalgal composition, their biomass and

changes in the ratio between carotenoid and chlorophyll can be used to assess the

water quality. The biomass of phytoplankton can be estimated in terms of

photosynthetic pigments and this will be useful to predict the productive potential

of the ecosystem Studies on phytoplankton pigments indicate that the pigments

have a direct relationship with phytoplankton production (Harvey, 1934; and Fei

et a/. , 1 990).

Natural and anthropogenic alterations of water quality can bring about

changes in the species composition of algal community, rate of production of biomass

and water chemistry. If water quality is altered by toxicants or growth stimulants

from industrial, agricultural or municipal sources, normal algal function may be upset

causing gross changes in structure and function of the receiving aquatic ecosystem.

Owing to the rapid industrialization and urbanization, large volume of

untreated industrial, agricultural, domestic and other wastes are frequently

discharged into water. This indiscriminate discharge of the waste materials may

endanger the safety of the aquatic life and may cause even irreparable damage to

: 6 .

the otherwise very delicately balanced ecosystem. Most of the surface water

including the coastal waters is polluted to varying degree and practically all rivers

receive pollutants due to industrial and human activities.

lnorganic pollutants such as alkalies, acids, inorganic salts, other

chemicals, etc. are discharged mainly from industries like paper and pulp, tanneries,

textiles, coke ovens and many others. lnorganic chemicals like free chlorine,

ammonia and hydrogen sulphide and other sulphides, salts of metals like Ag, Cd,

Cu, Cr, Ni, Zn etc. are usually found in metal plating liquid wastes, alkali producing

units, polyvinyl chloride, coke oven and fertilizer industries. Large quantities of

free acids and neutralized chemicals are produced by pharmaceutical industries.

The effluents from fertilizer factories contain chemicals likechromates, phosphates,

ammonia and urea.

High molecular weight compounds like sugars, oils, fats and protein

obtained from distillery, canning, sugar and other food processing industries

contribute to organic pollution. They impart a high BOD load to the liquid waste

because a large quantity of dissolved oxygen is necessary to degrade these organic

substances. When dissolved oxygen is reduced below a certain limit aquatic life

becomes threatened. Oil, oil spillage and liquid effluents from industries

manufacturing drugs, dyestuff, pesticides and detergents also can be toxic.

The ceramic, paper and pulp mill industry effluents, fine clay particles,

milk waste, sewage, free perox~des from iron and other metal salts impart turbidity

to water. Turbidity inhibits light penetration and will adversely affect photosynthetic

rate of aquatic flora, consequently the aquatic fauna too. The liquid effluents from

paper and pulp, dyestuff, tanning and textik industries cause colour pollution. Colour

7 ::

too cuts off the sunlight required for photosynthesis. Thermal pollution of water is

also dangerous as the hot effluents discharged into the water cause a rise in

temperature, decreasing the content of dissolved oxygen even below the critical level.

Various types of biocides too cause serious environmental pollution. The alarming

fact is that they are capable of undergoing biological magnification. (Sodergren,

1968; Vance and Drummond, 1969; Cox, 1977, Miyamoto etal., 1979; Venketararnan

etal., 1994).

The nitrate in the polluted water causes many serious problems. The

main source of nitrate pollution is nitrogenous fertilizers, garbage, industrial effluents,

etc. When the nitrate in the drinking water becomes excess, a disease called

methaemoglobinaemia or "blue baby" will be caused in children. Another

environmental nuisance is phosphorus. High levels of phosphorus increases

phytoplankton density and productivity of aquatic ecosystem (Gopinathan et al.,

1984; Axier etal.. 1991; Foellimi. 1994 and Gemza, 1995). Phosphorus and nlrogen

cause algal blooms, by acting as nutrients for a luxuriant algal growth which raises

the BOD and destroy the aesthetic beauty of water bodies imparting foul smell and

odour. The water pollution problems become more prevalent during dry season,

when the water bodies get saturated with the wastewater. Pollution effects due to

the discharge of industrial effluents into the Indian rivers have been studied by

many workers. Bhimachar and David (1946) reported the effects of factory effluents

on the Bhadra river fisheries at Bhadravati.

Ganapatr and Alikunhi (1950) investigated the pollution effects caused

by the factory effluents of Mettur Chemicals and Industrial Corporation Ltd, Mettur

Dam, Madras on the fisheries of Cauvery river. Ganapati and Chacko (1951 a)

studied the physical, chemical and biological conditions of Pamban, Kodiathanar

and Gundur rivers. The effects of pollution on Godavari river due to waste of paper

mills at Rajah mundry were studied by Ganapati and Chacko (1951 b). The impact

of industrial waste on river water in U.P and Bihar was assessed by Bhaskaran

(1959). Qasim and Siddiqui (1960) made some preliminary observations of river

Kali affected by industrial effluents. The ecology of algal flora of Moosi river,

Hyderabad, with special reference to water pollution was documented by

Venkateswaralu (1969 a, b, c). He also reported the physico-chemical characteristics

affecting the distr~bution and periodicity of algae. Pollution studies of Chambal river

and tributaries at Kota were conducted by Olaniya et a/., (1976). Agarwal et a/.

(1976) observed the physico-chemical characteristics of the Ganga river at Varanasi.

The effect of pollution on biological community of the river Khan (Indore) was

assessed by Rama Rao etal. (1978). Govindan and Sundaresan (1979) carried

out works on the pollution aspects of Adayar river in Madras and its effects on

aquatic life with special reference to algae and their seasonal succession over a

period of one year. The impact of industrial and urban wastes on river Cauvery was

analysed by Sreenivasan et a/. (1980). Prasad and Saxena (1980) extended their

work on blue green algae in relation to industrial pollution of the river Gomati at

Lucknow. The change in algal flora in the Cauvery river due to industrial and domestic

pollution was detected by Paramasivam and Sreenivasan (1981). Bilgrami and

Siddiqui (1980) investigated the effect of industrial effluent on phytoplankton

communities of the river Ganga at Barawni. Boralker et a/. (1982) reported about

the pollution in Krishna river. The effect of pulp and paper mill effluents on the

water quality of Muvattupuzha river emptying into Cochin backwaters was studied

by Balachand and Nambisan (1986). Jayraj etal. (1992) reported the consequences

of heavy metal pollution on the productivity of water bodies. Nutrient and physico-

chemical characterization of Rishikulya estuary during pre-monsoon was conducted

by Mahapatro and Padhy (2001).

Many scholars have worked on the impact of industrial wastes on aquatic

flora (Palmer, 1980; Rishi and Kachroo, 1981 ; Re Boredo et a/. 1984; Ahluwalia et a/. ,

1979; Ambros et a/., 1994) and fauna (Ray, 1961; Sprague and Mc Lease, 1968;

Blinkski and Jonas, 1973; Shumway and Palensky, 1973; Thomas, 1973; Verma

and Delela, 1975; Johnson, 1977; Misra eta/., 1985). When the industrialeffluents are

discharged into the aquatic system, the oxygen content of the water will be depleted

and this will interfere with the respiratory metabolism of animals (Qasim and Siddiqui,

1960; David and Ray, 1966; Venkataraman, 1966; Chockalingam and Balaji, 1991).

The selection of the location of an industry is based on both the availability

of reasonably good water for industrial processes and the facility for discharging

the wastewater. The rivers, estuaries etc. which supply fresh water and receive

effluents from most of the industries, constitute the major pathways of natural and

anthropogenic materials from land to sea. Compared to other geological agents

such as wind, glaciers, ground water etc., the total amount of material carried by

the river is remarkably high. Concentration of industries on the banks of rivers and

estuaries, along with large-scale urbanization and agricultural activities have been

proved detrimental to the riverine and estuarine ecosystem.

Paper industry plays a significant role in the economic development of a

nation. At the same time it discharges effluents with higher organic and inorganic

pollution potential (Chakravarti ef a/., 1996). Owing to high BOD and COD values it

becomes a major source of pollution for the water resources

a. . . .,. _ ... *... -.---.~ .. i4 (8 3-

The pulp and paper industry is one of the

India. There are 123 paper mills in the country and

producing countries of the world (Mahajan, 1989). Most of the paper-producing

units in lndia are integrated pulp and paper mills. Paper mills are believed to consume

230-500 m3 of water per tonne of paper produced (Waghmare etal., 1986). The

volume and characteristics of pulp and paper mill effluents depend on the type of

manufacturing process adopted and the extent of resource of water employed in

the plant.

The pulp mill effluents contain high concentration of suspended solids.

Based on the figures given by WaMichuk (1962) and Webber (1969) a typical sulphite

process mill may discharge effluent with total solid concentration of about 6000 pprn.

They accumulate at the bottom and destroy the benthic community.

A survey of Ghosh et a/. (1973) revealed that 96 industries discharge

their effluents into the Hoogly estuary. Of these, 41 include pulp and paper mills

employing sulphite, sulphate and soda process. According to them pulp and paper

industry contributes 28.59 tonnes of BOD (43.2%), 547.40 tonnes of total solids

(61.2%), 299.20 tonnes of suspended solids (72.5%) and 24.20 tonnes of dissolved

solids (51.5%). Extensive studies on the impact of pulp-paper mill effluent on Hoogly

estuary have been done by various workers, viz. Basu (1966), Elasu etal. (1973),

Ghosh et al. (1977 and 1980), Ray etal. (1977), Ray (1980), and Ray and Mitra

(1980). Various scientists have worked out the hazardous impacts of paper and

pulp mill effluents on the biological world. Among them those who need special

mention are Sputnik (1940), Verma and Delela (1975), Rajannan and Oblisamy

(1979), Balchand and Nambisan (1986), Ghosh and Konar (1980), Reddy and

Venkateswarlu (1987), Misra and Behera (1991). Pritchard eta/. (1991), Sudhakar

et a/. (1991 a, b!, Rao and Rao (1992), Haupt and Folger (1993) and Pinkerton

(1993). Rajannan and Oblisamy (1 979) reported that though the paper mill effluents

are detrimental to plant growth at higher concentrations, they could promote plant

growth at lower concentrations. Reddy and Venkateswarlu (1987) opine that organic

content, nitrites, phosphates, solids etc., from the paper mill effluent will alter the ionic

composition of the river water and its flora and fauna. Pulp and paper mill effluents

are found to be toxic to many aquatic organisms, especially to primary producers

by reducing the available light, changing the pH and decreasing the nutrients due

to increased bacterial activ~ty and toxic compounds (Kuivasniemi eta/., 1986).

Hindustan Newsprint Limited, Velloor is a subsidiary of Hindustan Paper

Corporation. With an annual production capacity of 80,000 metric tonnes, it is the

largest newsprint factory in Asia. The raw materials used are bamboos, reeds and

eucalyptus trees. It is sltuated on the banks of Muvattupuzha river.

Muvattupuzha river is one of the major rivers in central Kerala. It has a

length of about 121 kilometers and a catchment area of about 1,544 square

kilometres (CESS, 1984). The river originates form Western Ghats and it flows into

the Cochin estuary near Vaikom. Two major tributaries namely, Thodupuzha and

Kaliyarjoin Muvattupuzha river near Muvattupuzha town. After flowing as a single

stream upto Vettikkattumukku, the river branches into two distributaries namely

lthipuzha and Murinjapuzha. The entire Muvattupuzha river basin lies between

latitude g045'-1O005' N and longitude 76"22'-76" 50'N.

Petrochemical industries are expanding fast and are the source of toxic

effluents entering the watercourses throughout the world. The products of industry

are categorized as aliphatic, cyclic aliphatic, aromatic and inorganic. The wastewater

characteristics include oils, solvents, high BOD, suspended solids, halogenated

and polycyclic aromatic compounds and detergents. The phenols, aldehydes and

chlorinated aromatic hydrocarbons in the effluents are biocides and are very toxic

to fish (Chivers, 1984). The phenolic compounds are highly toxic to fish and fish food

organisms because of the high oxygen demand of the compounds (Train, 1979).

Hindustan Organic Chemicals Limited (HOC) is a subsidiary unit of

Rasayani Ltd. Mumbai. It IS a major factory in the field of phenol and acetone

manufacturing. This firm is situated on the banks of Chitrapuzha. HOC is depending

on the Kochi refineries Ltd for raw materials, such as liquified petroleum gas or

benzene. Most of the industries in Kochi are clustered at two zones- one at Eloor

on the banks of Periyar and another at Ambalamughal, by the side of Chitrapuzha,

which is a tributary of Periyar.

A host of industries including a major fertilizer plant, chemical factories,

aluminium and zinc production units, and monazite processing plant are situated

along the side of Periyar. A fertilizer plant (FACT) and petroleum refinery (KRL)

and Hindustan Organic Chemicals Ltd. are the industrial units located on the banks

of Chitrapuzha river. Most of these industries depend on these rivers and streams

for their intake source of fresh water and at the same time their disposal outlets are

kept open to these rivers. Chitrapuzha river, which carries the effluents from major

industries, is delivering the water into Cochin estuary. The quantity of effluents

discharged into the river is estimated around 80 million litres per day. There are

longstanding local complaints about water pollution causing fish kills and serious

damage to paddy and other agricultural crops. Prawn farming is yet another area

that may be adversely affected by the variation in the physico-chemical parameters

of the water in Chitrapuzha river. In addition to the above socio-economic aspects,

it has a commercial dimension too, thanks to the lower reaches of this river that

form a part of national waterways,

Alterations in the physico-chemical parameters of the river water have

been reported by many investigators (Jayapalan et al., 1976; Paul and Pillai, 1978;

Sarala Devi et al., 1979; Remani etal. 1980; Sankaranarayanan etal. 1986; Joy,

1989; Joy et 1990). Occasional instances of fish kill have also been reported

(Silas and Pillai, 1976; Shynamma etal., 1981; Naha, 2003).

In general, the distillery industries are among the major polluters of

aquatic environment. The wastes generated from distilleries are highly organic in

nature. Wastewater discharge from distilleries creates problems of toxicity due to

their high BOD, COD, colour, odour etc. (Tare, 1981).

Mc Dowells Distilleries Ltd. of the UB group of distilleries is manufacturing

alcohol and beer and is discharging the effluents directly to Cochin estuary. Cochin

estuary is the highest back water system in the west coast of India, extending parallel

to the coast from Alappuzha in the south to Munambam in the North (Latitude Y28'-

1O010'N and Longitude 76"13'-76"25'E). It has a length of about 113Kms and breadth

varies from few hundred meters to 14.5 Kms covering an area about 233 sq. Kms.

The estuarine system has two openings with the sea, one at Fort Cochin and the

other at Munambam. On the southern side of the estuary, very near to Mc Dowells

Distillery, a barrage has been constructed near Thanneermukkam to prevent the

salt-water intrusion during extreme drought (pre-monsoon). The construction of

Thanneermukkam bund led to the deterioration and stagnation of water in the

agricultural Kuttanadu region resulting in large changes in the quality of Cochin

backwaters. The Inter basin transfer of river Periyar to river Muvattupuzha caused

changes in the pattern of water flow resulting in new management problems.

Cochln estuary is subjected to increasing human interferences and it

receives considerable amount of pollutants from industrial units, domestic sewage,

fishery industries, coconut husk retting yards and Cochin sea port which handles

large quantities of petroleum product and industrial chemicals. The influence of

industrial effluents on the general hydrography of Cochin estuary is high and it

deteriorates the quality of water by loading it with large quantities of pollutants,

which often exceed the carrying capacity of the aquatic system causing the complete

destruction of the biota. Complaints of massive fish kills and associated problems

are common in Cochin estuary.

Recently estuaries are recognized as areas of industrial, commercial

and recreational activities Even though the development of estuaries has

contributed to considerable economic development and social changes, it has also

caused severe economic problems.

A number of estuaries receive nutrient additions over 1000 times than

the fertilizer loads added to agricultural area (Nixon et a/. , 1986). The resulting

hydrogen and phosphorus inputs lead to elevated phytoplankton productivity (Ryther

and Dunston, 1971 ; Nixon and Pilson, 1983), which in turn can lead to eutrophication.

There has been an increase in the recent years in the rate of eutrophication of

rivers, lakes and estuaries due to the release of nitrates and phosphates from

excess of fertilizers and sewage effluents (O'Neill, 1985). Considerable amount of

work has been carried out on the chemo estuarine variability of nutrients in the

Cochin estuary by Qasim and Sankaranarayanan (l972), Joseph (1974), Manikoth

and Salih (1974), Rama Raju etal. (1979), Lakshmanan etal. (1987), Anirudhan

(1988) and Balachand et a/. (1 990). The degree of water pollution can be estimated

by analysing various physico-chemical parameters like temperature, pH, acidity,

alkaline hardness, total solids, BOD, COD, DO etc.

The present project was undertaken to carry out a detailed study on the

impacts of some effluents on selected microalgae. The first phase of the study was

to isolate freshwater microalgal species viz. Chlorella ellipsoidea Gerneck,

Ankistrodesmus falcatus (Corda.) Ralfs,Scenedesmus bijuga (Turp,) Lagerheim.

Haematococcus laccustris (Girod.) Rostafinski, and Chlorococcclm humicola (Naeg.)

Rabenhorst from the natural fresh water bodies. During the second phase of

investigation, the cultures of test algae were exposed to different concentrations of

the selected effluents and their impacts were analysed on different growth

parameters. The effluents selected were distillery effluent, pulp-paper mill effluent

and petrochemical factory effluent. The different growth parameters analysed were

cell count, primary production, and the contents of photosynthetic pigment , protein

and carbohydrate of the microalgae

In addition to the invitro effects of effluents on microalgae, the physico-

chemical parameters of the water resources which are receiving the effluents were

also analysed. The physico-chemical factors focussed were pH, temperature,

dissolved oxygen, free CO, biochemical oxygen demand (BOD), chemical oxygen

demand (COD), hardness, alkalinity, productivity, salinity, nitrate, nitrite, phosphate.

silicate, total suspended solids, total dissolved solids and phytoplankton. The

assessment of various physico-chemical parameters of effluent receiving water

bodies was conducted in order to estimate the extent of water pollution caused by

these industries.