Chemical Effluents Research Articles

Effects of pollutants on freshwater organisms

Pollutants from point and nonpoint sources are continually entering aquatic systems. This review focuses on the effects of toxic chemical pollutants, conventional pollutants, and effluents on freshwater organisms.

Simulation of reverse osmosis processes concentrating industrial wastes

Abstract The process parameters of a reverse osmosis system concentrating industrial wastewater in a closed‐loop operation have been studied. The model describes system solute concentration as a function of operating time and can be used to predict separation efficiency and permeate flux. The model uses seven parameters that are obtained from membrane and solution data. Simulation of a simple salt system was compared to the experimental data of an inorganic chemical effluent composed of typical plating metals. The results indicate variance from predicted mass transfer and overall membrane performance. The model is useful in predicting performance when membrane fouling is not a major problem.

Social movements, technology and development: A query and an instructive case from the Third World

I believe that the KSSP's claim that all technological issues should be evaluated and assessed only in the context of their impact on the people are borne out by the case studies. Apart from the Silent Valley and the Mothi Chemicals controversies, the KSSP had a positive role to play in other technological and environmental controversies, such as those over river pollution from untreated chemical effluent being dumped in several rivers of the State by chemical and paper companies, nuclear power plant siting, and drug policy. The KSSP's position paper on industries indicates that Kerala has a high concentration of chemical industries, and urges the government to issue no more new licenses for chemical companies. Instead they urge the government to bring in more engineering and electonics industries into the State. The State government has been generally responsive to such calls by actively promoting electronics industry in the State. K.K. Subramanian and K.J. Joseph demonstrate how a “capital-deficient” State like Kerala can stimulate economic growth and employment opportunities in the electronics sector by taking advantage of the considerably well-educated “human resources” of the State. K.K. Subramanian and K.J. Joseph, \ldElectronics in Kerala's Industrialisation,\rd 23 (1988), pp. 1233\2-1240. The KSSP is in the thick of a debate about the advisability of the establishment of a nuclear power plant in the State as a long range plan to alleviate the acute power shortage predicted for the year 2000. The consensus seems to be that since Kerala is a densely populated State, a continuum of villages and towns and cities from one end to the other situated on the coastal belt, there is no proper site on which a nuclear power plant can be built. However, given the fact that the power availability should be increased and diversified and also that the statistical probability of a nuclear accident is remote, a strong minority in the KSSP is picking up support for a nuclear power plant among the media and the people. Mani, \ldPopularising Science, Fighting Pollution.\rd It appears that KSSP's campaign to reach out to the people to make science and technology instruments of change is quite successful. It is not clear how much their efforts are influencing scientists and technologists at large, who are not associated with the KSSP, to help unleash the potential inherent in science and technology to improve the quality of life of the people. Even though there are no quantitative studies to measure KSSP's contributions to the high literacy rate, low infant mortality rate, and similar indicators of social progress in the State, it is safe to assume that the KSSP's campaign of “Science for Social Revolution” has made a positive contribution to these achievements. Though the KSSP claims to be a non-political voluntary organization, its objective is to raise the consciousness of the people in order to harness the benefits of technology to socio-economic development. The measure of success they have had in educating and raising the consciousness of the people, who might have otherwise remained ignorant or indifferent to technological issues and controversies, is evident. Given the fact that the KSSP is a totally non-governmental and voluntary organization surviving on its own resources, its success in achieving its set goals are remarkable. It is an encouraging sign that similar people's science and technology (S&T) movements are springing up in several States in India, following the foot-steps of the KSSP. After the killing of thousands of people by the Union Carbide chemical plant in Bhopal, the need for many more such people's S&T movements for democratic control of technology has become ever more urgent.

Aquatic hazard assessment of the toxic fraction from the effluent of a petrochemical plant

AbstractEffluent hazard assessment guidelines were applied to determine the environmental safety of discharged chloroether fractions from a chemical plant effluent. The chloroether fraction was identified as a mixture of pentachloroethers (2,5,6‐trichlorohexyl 1′,3′‐dichloroisopropyl ether [PCE 1,3] and 2,5,6‐trichlorohexyl 2′,3′‐dichloropropyl ether [PCE 2,3]), tetrachloropropyl ethers (TCPE; a mixture of l,3,1′,3′‐tetrachloroisopropyl ether, 1,3‐dichloroisopropyl 2′3′‐dichloropropyl ether, and 2,3,2′,3′‐tetrachloropropyl ether), 1,2,5,6 tetrachlorohexane (TCH), and related components. The fractions were identified in a toxicity identification evaluation (TIE). The chloroether mixture was acutely toxic between 1.5 and 20 mg/L and had no observed effect concentrations (NOEC) for chronic toxicity from 1 to 3.2 mg/L. Individual chloroether components showed acute toxicity (LC50) from 1.5 to 56 mg/L. Acute toxicity predictions from U.S. Environmental Protection Agency (U.S. EPA) structure‐activity relationships (SAR) were within a factor of four. Acute to chronic ratios for specific chloroether components were between 3 and 14. Sediment studies showed moderate sorption of TCPE with a log Koc between 2.7 and 2.9. The log Kow was 3.2 for TCPE, and the bioconcentration potential (logBCF) for the mixture was < 2.7. Laboratory and field stream experiments confirmed laboratory predictions for toxicity, with NOEC for trout growth > 0.26 mg/L and effects on Gammarus feeding at 0.44 mg/L of the mixture.

Evaluation of Purification Efficiency of Activated Sludge Treatment Plants for Pulp and Paper Industry Wastewaters in Finland

Since 1984, when the first activated sludge treatment plant (ASTP) was built to treat pulp and paper industry wastewaters in Finland, twenty more plants have been introduced by 1989. An evaluation was undertaken to find out the actual performance of the ASTPs in BOD7, CODc r and phosphorus removal. The evaluation included all the 12 ASTPs in operation in the pulp and paper industry at the beginning of 1987. The highest average BOD7 removals were about 90 % at pulp mills as well as paper and board mills. CODc r removal was generally higher at paper and board mills (about 40-70 %) than at pulp mills (about 25-55 %). Phosphorus was added to wastewater in most plants. In some ASTPs, phosphorus concentrations were lowered by 20-40 % compared with wastewater from the mill. In some plants phosphorus load on the recipient was higher than the load coming from the mill. In treated wastewater, correlations between suspended solids and BOD7, CODc r, phosphorus and nitrogen were significant in most plants. This indicated that low removal efficiencies resulted from poor suspended solids removal in the secondary clarification. Volumetric and sludge CODc r loading rates could not explain removal efficiencies when all plants were included in the comparison. In plants treating chemical pulping effluents, higher removal efficiencies were normally achieved with lower loading rates. When the plants were studied separately, the influence of loading rate was generally significant.

Acute toxicity of cadmium, copper, zinc, ammonia, 3,3′-dichlorobenzidine, 2,6-dichloro-4-nitroaniline, methylene chloride, and 2,4,6-trichlorophenol to juvenile grass shrimp and killifish

The acute toxicity of several compounds was investigated while performing a toxicity evaluation of a complex chemical effluent. The tests were conducted for one or more of the following reasons: (1) data were not available for the chemical; (2) data were not available for the species; or (3) data were not available for the juvenile life stage of the species. Forty-eight hour acute toxicity tests were run on juvenile grass shrimp (Palaemonetes pugio) and juvenile killifish (Fundulus heteroclitus) exposed to the following compounds: cadmium, copper, zinc, ammonia, 3,3{prime}-dichlorobenzidine, 2,6-dichloro-4-nitroaniline, methylene chloride (dichloromethane) and 2,4,6-trichlorophenol.

Biological decomposition of dichloromethane from a chemical process effluent.

The application of specialized microorganisms to treat dichloromethane (DM) containing process effluents was studied. An aerobic fluidized bed reactor with a working volume of 801 filled with sand particles as carriers for the bacteria was used. Oxygen was introduced into the recycle stream by an injector device. DM was monitored semi-continuously. A processor controlled the feed volume according to the DM effluent concentration. Mineralization rates of 12 kg DM/m3bioreactor.d were reached within about three weeks using synthetic wastewater containing 2000 mg/l DM as single carbon compound. DM from process water of a pharmaceutical plant was reduced from about 2000 mg/l in the feed to below 1 mg/l in the effluent at volumetric loading rates of 3 to 4 kg DM/m3bioreactor.d. Degradation of wastewater components like acetone and isopropanol were favoured, thus making the process less attractive for waste streams containing high amounts of DOC other than of DM. DM concentrations of up to 1000 mg/l were tolerated by the immobilized microorganisms and did not influence their DM degradation capacity. The ability to mineralize DM was lost when no DM was fed to the reactor for 10 days.

Influence of industrial wastes on physico-chemical properties of soil and germination and mineral composition of wheat

The effect of chemical effluents discharged from a chemical and fertilizer factory on physicochemical properties of soil and germination and mineral composition of wheat was studied at Varanasi, India. Forty times higher concentration of Na was observed in the effluent than that of the nearby well water. It showed a positive (significant) correlation with Na and a negative (significant) with K and Ca of the soil. Cation exchange capacity (CEC), porosity and water holding capacity were reduced by effluent affected soil. the germination percentage of wheat was negatively correlated with the Na of effluent and Na+Mg/Ca of the soil. A significant (positive) correlation existed between Na of effluent and Na content of the plants. Calcium percentage on the other hand, exhibited a reverse trend.

Requirements for the Treatment of Effluents from Chemical Pulp Mills in the F.R.G.

In 1986, the 11 chemical pulp mills in the F.R.G. produced 350,00 t of bleached sulfite pulp. With the enactment of the so-called minimum requirements in 1982, general standards for the treatment of effluents were promulgated for this branch of industry. They comprise various measures, such as high-grade recovery of spent liquor including its evaporation and incineration, partial or total reuse of condensates from evaporation or reduction of their load by stripping, and mechanical treatment of total waste water. In view of the persisting high pollution levels of German rivers caused by pulp mills, more stringent standards reflecting the present state of the art will be implemented in 1991. This paper deals with these standards, covering the applicable in-plant and external abatement measures, such as extended cooking, substitution of elemental chlorine and biological treatment for decisive improvement of the chemical pulp mill effluent situation.

Physical model study of thermal and chemical pollution in the Shuaiba offshore area of Kuwait

Abstract The cooling and process waters of the industrial plants located in the Shuaiba Industrial Area in Kuwait are supplied by a complex system of seawater outlets and intakes. Discharge of heated water from the industrial plants is considered a major problem since it may recirculate directly through the intake towers, and the cooling water withdrawn may be at a higher temperature than is desirable. Higher cooling water temperature reduces the efficiency of industrial plants and causes thermal pollution, which adversely affects the water of the Arabian Gulf. In addition, the discharged process water may cause chemical pollution in the offshore area. An undistorted physical model with a scale of 1:50 was constructed and tested with the basic objectives of determining the temperature field in the Shuaiba offshore area identifying possible recirculation patterns and temperature increase at the intake, examining the flow and mixing characteristics of chemical effluents discharged, and investigated alternative remedial measures. The model test results showed that, in line with the field tests, the temperature of the sea water at the intakes was about 1.7–2.5°C higher than the ambient temperature. When heated water from the larger outlets was allowed to discharge into a channel running parallel to the shoreline and curved to stay parallel to the outside of the southern breakwater of the Shuaiba harbor, the temperature increase at the intakes was limited to 0.8–1.0°C and tests showed that the concentration of conservative chemical pollutants at the intakes was reduced by about 50%.

Optimization of the Operating Variables of an Industrial Wastewater Treatment Process

The Complex Method of optimization has been applied to minimize the operating costs of a large (1200 m3/hr effluent with an average of 1500 gCOD/m3) chemical effluent processing plant. The process, an oxygen enriched activated sludge process, consists of 3 parallel trains of UNOX bioreactors, each of four compartments, followed by 3 settling tanks.The five most important operating variables for a given recycle and waste sludge flowrate are the amount of gas vented to the atmosphere from the last compartment of each bioreactor train and the submersion depths of the electrically driven aerators in each bioreactor compartment. Using the cost prices of oxygen and electricity these five operating variables have been incorporated into a cost function which, subject to various constraints, must be minimized. The constraints are described by a steady-state, nonlinear model in which the concentrations of the dissolved oxygen in each compartment of each reactor are expressed in terms of the operating variables. The model parameters have been estimated from steady-state measurements.The result of the optimization is a simple strategy, independent of any of the model parameters, which fixes the depths of submersion of the aerators. The amount of gas vented to the atmosphere can be calculated regularly offline by means of a numerical search procedure. Savings in the order of Hfl. 15, 000 to Hfl. 30, 000 per year can be predicted from this study.

Ratio and population density of psammolittoral meiofauna as a perturbation indicator of sandy beaches in South Africa

Since 1975, pollution surveys have been carried out along the South African south and west coasts as part of a monitoring program of unpolluted areas and known and anticipated impact areas. To evaluate these data a reference or baseline level was needed. In unpolluted beaches a close relationship between meiofauna and sediment grain size was found and granulometric analysis was found to be important. This relationship was used to evaluated perturbation effects. It was found that contamination by chemical effluent depressed numbers of the nematodes and harpacticoids drastically. Mechanical perturbation increased the number of harpacticoid copepods but did not affect nematode densities. Oil in beaches decreased the number of harpacticoids, while normal nematode densities were found. Organic enrichment increased the number of nematodes, harpacticoid numbers remained normal while the perturbation effect due to sewage increased the number of both taxa.Explanations for these effects are given, together with related chemical analyses. The application of these results to other sandy beaches elsewhere is discussed briefly.

Chemical Quality of Effluents and Their Influence on Water Quality in a Shallow Aquifer

AbstractThe chemical quality of liquid effluent released from an industrial waste treatment plant at the Los Alamos Scientific Laboratory controls the quality of water in a shallow aquifer in the alluvium of Mortandad Canyon. The dilution of the effluent with surface flow in the canyon reduces the concentrations of the chemicals as they move down gradient into the aquifer. Mass estimates of residual chemicals in solution in the aquifer average 1–6% of the total chemicals released to the canyon from 1963–1974. The average annual concentration of sodium, nitrate, chloride, and total dissolved solids in the aquifer through a 12‐year period was directly correlated with annual average concentrations in the effluent. This relationship provides a means of predicting the impact of the chemical effluents on the quality of water in the aquifer.

A COMPARISON OF RIFFLE INSECT POPULATIONS IN THE GIBBON RIVER ABOVE AND BELOW THE GEYSER BASINS, YELLOWSTONE NATIONAL PARK1

A study was made of the aquatic insect populations of two riffles, one above and one below the effluents of major geyser basins on the Gibbon River, Yellowstone National Park, from June through September 1963 and from October 1964 through September 1965. Eight 0.25‐m2 samples were taken from each riffle on each of the 21 collection dates. Water depths, current speeds, and bottom types were similar in both riffles. Maximum and mean temperatures were greater in the lower riffle. Alkalinity and concentrations of K+, Na+, Cl−, PO43−, and SO42− were markedly greater in the lower riffle. There were 50 taxa in the upper riffle, 45 in the lower. The total number of individuals and biomass was slightly greater in the lower riffle. Ephemeroptera and Coleoptera occurred in greater numbers and biomass in the upper riffle, Trichoptera and Diptera occurred in greater numbers and biomass in the lower, and Plecoptera were about the same for both. Seven of the most numerous organisms in the upper riffle and two in the lower comprised about 68% of the total numbers for each. Ephemeroptera was the dominant order in the upper riffle, and Trichoptera dominated the lower. The thermal and chemical effluents entering the Gibbon River from surrounding geyser basins changed the lower riffle so that it was less diverse, contained a greater standing crop of aquatic insects, and was more favorable to Trichoptera than the upper.