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The plating process typically involves, alkaline cleaning, acid pickling, plating and rinsing. Copious amounts of waste water are generated through these steps, especially during rinsing. Additionally, batch dumping, spent acid and cleaning solutions contributes to the complexity of waste treatment. With greater quantities of waste water produced and discharge standards becoming more stringent, there is a need for more efficient and cost effective methods for removing heavy metals. Membrane processes are capable of removing many materials from water that are typically treated using unit processes ranging from sand filtration to carbon adsorption to ion exchange. Membrane technology is one option for a nonpolluting process. In order to increase the removal efficiency and reduce the operating cost, membrane technology can also be used together with other treatment processes (Srisuwan, G. et al., 2002). Studying the heavy metals removal from water using membrane, Kosarek found that efficiencies of removal of As, Cd, Cu, Pb, Hg, Ni, Se and Zn were 75-98%. The results also showed that for water treatment with polymer prior to chemical treatment, the percentage removal increased to 90-99 %( Kosarek, L.J. 1981). For the fractional separation of heavy metals from electroplating waste streams, the coupling of two or more techniques may result in better performance than using either unit operation individually. By combining the membrane techniques with other physical and chemical processes the effectiveness of the operation can be improved. Precipitation of sparingly soluble metal compounds and micro-or ultra filtration is the suitable and economical hybrid operation for the removal and recovery of heavy metals from waste streams. For selective removal and recovery of the metals like Cd, Cu, Fe in cadmium electroplating bath (containing high amounts of Cd, Zn, Cu, Fe and small amounts of Ni, Co, Mn), hybrid precipitation- polymer enhanced ultra filtration based separation scheme was developed and effective separation of heavy metals from industrial wastes was achieved (Sezin Islamoglu et al., 2001). The present paper draws attention towards effective technologies involved and of use in successfully removing heavy metal in waste water, recommends natural, cheap adsorbents for removing each of heavy metal (Cu, Fe, Ni and Zn) analyzed 398 in waste water from four electroplating sites (AB 1 , AB 2 , AB 3 and AB 4 ) of Agra city, apart from determination of pH, BOD, COD and heavy metal concentration for analyzing the waste water quality discharged from such units. Material and Method Waste water from four electroplating sites AB 1 , AB 2 , AB 3 and AB 4 of Agra city were assessed for heavy metals Cu (II), Fe (II), Ni (II), Zn (II) concentrations and other physico-chemical parameters (pH, BOD& COD). One major electroplating industry was also among the sampling site, which is believed to contribute largely in electroplating waste of Agra. Two sites were small electroplating shops in main city and one electroplating site was medium scale industry in the exterior of the city. pH was measured within two hours from collection on laboratory arrival. Chemical and physical analysis of sample water was done following the procedure recommended by APHA, pH is measured with the help of pH meter after calibration of the respective instrument. BOD (biological oxygen demand), COD (chemical oxygen demand) is determined by titration method. The metal analysis was performed on an Atomic Absorption Spectrometer (Perkin-Elmer A. Analyst 100), following the condition of operation for the instrument. For the metals analysis Atomic Absorption Spectrometer uses acetylene and air as fuel and oxidant respectively. The standard solution of each metal (Cu, Fe, Ni and Zn) was made using analytical grade reagents for calibration purpose, samples were filtered and digested with nitric acid before determination of the metal concentration. Wavelengths used for particular metals were as follows: Copper (324.8 nm), Iron (248.3 nm), Nickel (232.0 nm) and Zinc (213.9 nm). Result and Discussion Physico-chemical characteristics (pH, BOD and COD) of waste water collected from different electroplating sites are given in Table 1. pH, varies differently in all the four sites. Waste water sample of site AB 1 has the pH value of 12.02, and was the most alkaline sample water, pH above 7 is due to presence of sufficient quantity of carbonates. Site AB 2 waste water was acidic among value of pH
eing 6.08, pH value of AB 3 and AB 4 site were close to each other values being 5.02 and 4.15 respectively. Thus pH values in decreasing order were as follows: AB 1 > AB 2 >AB 3 >AB 4 . Digital pH meter NIG 333 was used for the determination of pH of sample water. Tolerance limits of pH for industrial effluents discharge in to inland surface waters (IS: 2490-1974) is 5.5 - 9.0. AB 1 pH value is above 9.0 and two site AB 3 and AB 4 pH value is below 5.5. Biological oxygen demand (BOD) is an index of organic pollution in water, it is the rate of removal of oxygen by microorganisms in aerobic degradation of dissolved or even particulate organic matter in water. All the four site’s waste water sample, have different BOD values. Site AB 1 has the highest BOD, value being 118 mg/l. Site AB 2 BOD value being 104 mg/l, AB 3 and AB 4 site sample BOD values were 46 mg/l and 54 mg/l respectively. BOD values in decreasing order were as follows: AB 1 >AB 2 >AB 4 > AB 3. Tolerance limit of BOD for industrial effluents discharged in to inland surface waters (IS:2490-1974) is 30 mg/l and in all the site samples BOD value crosses this value of 30 mg/l prescribed by Indian standard for discharge in to inland surface waters. Chemical oxygen demand (COD), the measure of oxygen required in oxidizing the organic compounds present in water by means of chemical reactions involving oxidizing substances such as potassium dichromate and potassium permanganate showed different values in all the waste water samples, site AB 2 COD value was the highest among the four site its value being 225 mg/l which crossed the tolerance limit for industrial effluents discharged in to inland surface waters (IS: 2490-1974) which is 250 mg/l , site AB 1 COD value(85 mg/l) was second highest, AB 3 and AB 4 COD values were 92 mg/l and 80 mg/l respectively. All Site average COD values were below the ISI standards for discharge of industrial effluents in to inland surface waters. COD values in decreasing order were as follows: AB 2 >AB 1 >AB 3 >AB 4. All metals copper, iron, nickel and zinc analyzed are present at different level of concentrations in all the sites samples, Table3. Copper is industrial health hazard, excess of copper in human body is toxic and causes hypertension, sporadic fever, uremia, coma and even death. Copper also produces pathological changes 399 in brain tissue, copper concentration was highest in site AB 3 value being 12.04 mg/l , least in site AB 1 4.24 mg/l , 7.2 mg/l and 9.4 mg/l in site AB 2 and AB 4 respectively, copper in decreasing order of concentration was as follows: AB 3 >AB 4 >AB 2 >AB 1 . All site samples value exceeded the tolerance limit for industrial effluents discharged in to inland surface waters (IS: 2490-1974) which is 3.0 mg/l . Membrane technology by which copper is removed efficiently up to 98 % is reverse osmosis and by nano filtration removal achieved is 90%. Suggested natural and cheap adsorbent for copper removal are fly ash, china clay, saw dust, jute, cow dung and coconut coir dust. More than 10 mg/kg level of iron causes rapid increase in pulse rates, congestion of blood vessels, hyper tension and drowsiness. 3.0 mg/l is the waste water discharge standard for iron prescribed by IS: 2490-1974 and EPA. Highest concentration of iron was found in site AB 3 (8.82 mg/l), least in site AB 1 (2.82 mg/l) .Concentration in site AB 2 and AB 4 was 3.6 mg/l and 5.24 mg/l respectively. Concentration in decreasing order of concentration was as follows: AB 3 >AB 4 >AB 2 >AB 1 . Application of ultrafiltration membranes for treating waste water laden with iron concentration is effective, it does not require pretreatment, by using a combined treatment process and also provide a positive barrier to pathogens, such as cryptosporidium and giardia, and both organic and inorganic solids. Suggested natural and cheap adsorbent for iron removal are modified acacia bark, raw rice husk, and fly ash. Nickel concentration more than 30 mg causes change in muscle, lung, liver, brain and kidney and also can result in cancer. It also causes tremor, paralysis and even death. Nickel concentration was highest in site AB 3 (27 mg/l) and concentration in site AB 1 , AB2 and AB 4 was 5.64 mg/l , 12.2 mg/l and 18.6 mg/l respectively. Nickel in decreasing order of concentration was as follows: AB 3 >AB 4 >AB 2 >AB 1 . The nickel concentration in all the sites exceeded the tolerance limits for industrial effluent discharge in to inland surface waters which is 3.0 mg/l (IS: 2490-1974) and EPA. Surfactant-added powdered activated carbon/ microfiltration (PAC/MF) hybrid process in the removal of nickel from water and wastewater is the latest, efficient, promising technology. Suggested natural and cheap adsorbent for nickel removal are
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National Seminar on Rainwater Harve
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once subsoil water starts draining
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The plantation process starts with
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DOLASANE , SANGAMNER RANGE I, SANGA
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Table 1. Present land use of waters
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the determination of specification
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Hydrological Parameters (mm) 140 12
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end uses and the intentional manage
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INTRODUCTION Indian water sector is
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