CONFISCATION OF CHEMICAL OXYGEN DEMAND FROM GROUNDWATER SAMPLES COLLECTED FROM NEAR TANNERIES USING ACTIVATED CARBON OF RICINUS COMMUNIS BLENDED WITH COCONUT SHELL A. KISTAN* Assistant Professor, Panimalar Institute of technology, Chennai-123, Tamilnadu*Email: [email protected]*ABSTRACTThe confiscation of chemical oxygen demand (COD)of groundwater samples collected from near tannery regions carried out using low cost adsorbent like Ricinus Communis blended coconut shell carbon. The COD adsorption efficiency of Ricinus Communisleaves (LAC) stems (SAC) and roots (RAC) blended with coconut shell were examined.
The plant Ricinus Communis mixed with coconut shellwere carbonized as at 300 ± 50°C then was activated in an electric hot-air oven at very high temperature around 400°C with steam in nonappearance of air. The significant COD removal efficiency rates of Stem activated carbon 11%, leaves activated carbon 6% and root activated carbon 12% were achieved by using little quantity of adsorbent (5 g/100mL). The effectiveness of the activated carbon produced from Ricinus Communis and coconut shells for the removal of organic contaminant has been established.
This study also showed that natural adsorbent, very low cost adsorbent such as activated carbon of Ricinus Communis is an alternative option for COD removal from water and wastewater.Key words:Groundwater, Activated carbon, Ricinus Communis, Coconut shell, COD, low cost adsorbent1. INTRODUCTIONTannery is one of the foremost industries which produce polluteddischarges. The tannery waste contains huge number of organics,inorganic pollutants and heavy metals. Hence the treatment of tannery waste before its removalmust be done. The COD of the tannery effluents are higher in nature, because it has high organic and inorganic loads. Therefore the treatment of tannery effluents is challenging one. Generally, many treatment techniques are available. Among them, activated carbon adsorbent treatment of such heavy metal was already explored in many studies. Hence in this study the COD removal efficiency of activated carbon and the optimum condition for maximum removal was studied .The release of tannery effluents into surface water is the serious environmental problem. Tannery effluents contain large amount of Chromium, organic and inorganic chemicals having stable compounds like nitrate, phosphate, chloride, sulphate etc., which their removal from polluted source is difficult[4-6]. The confiscation of pollutants from aqueous leftoverdischarges by adsorption using activated carbon in fixed beds is an main industrial waste water treatment practice. Activated carbon wasused to removeextremely odorous dissolved organic substances from tannery industrial waste water[8 & 9]. Activated carbon produced from jack fruit peel, (carbonized by chemical method) to treat and eliminate malachite green from wastewater released by tanneries and dye industries. For phenol, the former exhibited a slightly higher adsorption than latter. The usage of locally prepared activated carbon from palm date pits results revealed that it is highly efficient than the commercial samples. The phenol confiscation efficiency was investigated at several pH values, carbon dosages and contact times.Freundlich adsorption isotherm was used to survey the adsorption efficiencies of activated carbon is the mainly used as an adsorbent in the treatment of contaminated water, due to its surprising adsorption ability and rate. Activated carbon are prepared and used in dissimilar shapes including powered activated carbon and granular activated carbon and activated carbon fiber. Activate carbon with surface area of 110.35 ” 146.06 m2g-1 from sunflower seed were applied to removal of acid blue . Among them adsorption process found to be the most effective method. Adsorption as a water treatment process has aroused considerable interest during recent years.The complete result displays that the activated carbon of combination of Ricinus Communiswith coconut shell activated carbon can be effectively used for the removal of COD from groundwater rather than other plant adsorbents.In this research work we observed that the confiscation of chemical oxygen demand (COD)of groundwater samples collected from near tannery regions of Vaniyambadi, Vellore district has been carried out using Ricinus Communis blended coconut shell carbonas an adsorbent. The COD adsorption efficiency of Ricinus Communisleaves (LAC) stems (SAC) and roots (RAC) blended with coconut shell were examined. This study revealed that the significant COD removal efficiency rates of Stem activated carbon 11%, leaves activated carbon 6% and root activated carbon 12% were achieved by using little quantity of adsorbent (5 g/100mL). The effectiveness of the activated carbon produced from Ricinus Communis and coconut shells for the removal of organic contaminant has been recognized. This revision also showed that natural adsorbent, very low cost adsorbent such as activated carbon of Ricinus Communis is an alternative option for COD removal from water and wastewater.2.0 MATERIALS AND METHODSThe material used for the experiment was activated carbon prepared from stems and roots of Ricinus Communis. Groundwater samples were collected directly from bore wells located nearby tannery region of Vellore district using clean stoppered polythene bottles and it was preserved in a refrigerator. Analyze were carried out according to BIS and WHO standard methods5. The pH and TDS were measured by electrometric method by using digital pH meter-E1model (111E) and TDS meter labtronics”LT15 model. To prepare all the reagents and calibration standards, double deionized water was used.2.1. Activated CarbonThe stems, roots and leaves of Ricinus Communis and waste coconut shell pieces (Fig 1 & 2) were collected from local area of Vaiyambadi ,Velloredistrict and washed with double distilled water. It was dried in sunlight; these materialswere heated until to generate a char, this char was then activated in a furnace around 250 to 350°C with steam in the absence of air. The carbonized Ricinus Communis and coconut shell pieceswere cooled off, the removal ofash content done by using deionized water and dehydrated in an oven at 105 – 120°C for 20 hrs. The final product was kept in an air close-fittingpolyethylene cover; the physical properties were analyzed by means of Scanning Electron Microscope (SEM) techniques. Fig 1: Collected cocunet shells Fig 2: Ricinus Communis plant2.3. Contaminants AdsorptionsThe adsorption experiments were carried out by using the prepared granuleactivated carbon of 5, 10, 15 and 20 g quantity. Each quantity was placed in a 250 ml titration flask contains 100 ml of collected groundwater samples. The flasks contains 20g of activated carbon was agitatedcontinuously while the flask contains 5, 10 and 15 g of activated carbon were shaken intermittently for 2- 3hrs. Activated carbon was infiltrated with the groundwater contaminants until equilibrium was attained and this occurred within 2-3 hoursagitating. Samples were taken at 15 minutes interval and the resulting mixture from everyconical flask was filtered and the COD of the filtrate was determined. The quantity of organic removal attained at the changingdoses of carbon gave an indication of activated carbon usage rate required to treat wastewater to a specified effluent quality, as well as the type of solid-fluid phase equilibrium that exists for the particular case under concern. The balance data obtained was processed to understand the adsorption of the contaminant on the activated carbon prepared using in water and waste water treatment.3. RESULTS AND DISCUSSION3.1 Activated Carbon CharacterizationThe surface characteristics of activated carbon prepared from mixture of coconut shell with stems and roots of Ricinus Communis (bulk density, porosity, pore volume, ash content pH, Average particle size, iodine number etc.,) are given in table 6.1, SEM data of the prepared samples are shown in (Fig.3,4,&5).Table 1: Characteristics of Ricinus Communis and commercial activated carbonParameter Activated carbon ofstems of Ricinus Communis Activated carbon ofroots of RicinusCommunis Activated carbon ofleaves of Ricinus Communis Commercial activatedCarbon Bulk Density 0.54 0.54 0.54 0.42Porosity 0.16 0.18 0.18 0.210Iodine No. 1120 1084 1012 1122Pore volume 0.92јm 1.02јm 0.94јm 1.109 јmAsh content 13 9 17 8Ave. particle size 29.64 27.50 27.62 5-50 Fig 3: SEM of activated carbon of Stem of Ricinus Communis with coconut shell Fig 4: SEM of activated carbon of roots of RicinusCommunis with coconut shell Fig 5: SEM of activated carbon of leaves of Ricinus Communis with coconut shellThe amount of pollutants present in groundwater samples are given in table. 2. The sample GWS-1, GWS-2 and GWS-3 were collected at different polluted industrial sites from Chennai city. These three groundwater samples collected from near tannery region of Vaniyambadi, Vellore district. The physical and chemical analyses for these samples were carried out using Indian standard method. These samples have higher concentration of various Physico-chemical parameters.Table 2:Physico-chemical parameters of groundwater samples collected from study areasParameters Groundwater sample ” 1(GWS-1) Groundwater sample – 2(GWS-2) Groundwater sample – 3(GWS-3)pH 6.85 7.96 8.02TDS (ppm) 1536 1502 1022COD (ppm) 262 268 194Nitrate (ppm) 42 18 18Chromium (ppm) 3.5 4.0 2.83.2 Effect of pH on adsorptionAdsorption studies were carried out over the pH range 2.0 – 9.0 (Fig. 6). Experiments were carried out at 214 mg /Linitial COD concentration with 5g adsorbent mass at room temperature (30 ± 50C) for 3 hour equilibrium time. The maximum Adsorption was observed at pH 4.0 for LAC, SAC and RAC. At Only acidic pH (pH = 4) the adsorbent surface get favors uptake of COD. Fig 6: Effect of pH on adsorption for COD by SAC, LAC and RAC (dosage = 5 g/100 mL, temp = 300 K)3.3 Effect of Contact Time on adsorption of COD by activated carbonThe rate of adsorption is important for designing batch adsorption experiments. The adsorption studies were carried out at fixed adsorbent dosage (5g), at room temperature (30 ± 50C), pH (4.0) and at different initial concentrations of COD (262,268 and 194 mg L-1) for different time intervals (15, 30, 45, 60, 90 and 120 min). The results are shown in (Table .3 and Fig. 7). The adsorption efficiency of COD increased significantly until the contact time reached 60 min. Further increase in Contact time did not enhance the adsorption.Table 3:Effect of contact time on adsorption for COD by SAC, LAC and RAC (dosage = 5 g/100 mL, pH = 4, temp = 30 ± 50C)Initial CODConcentration (mg/l) % of COD removal with different time invervals(min) SAC 15 min 30 min 45 min 60 min 90 min 120 min262 5.3 6.6 8.4 11.0 11.2 10.9268 6.3 7.3 8.9 11.2 11.0 10.8194 5.6 6.7 8.8 11.0 10.9 10.8% of COD removal with different timeinvervals (min) LAC262 2.4 4.3 4.8 6.0 5.8 5.8268 3.1 4.2 5.0 6.0 5.9 5.9194 3. 4.2 5.0 6.1 6.0 5.8% of COD removal with different time invervals (min) RAC262 7.3 8.2 8.3 12.2 12.2 11.8268 7.5 8.6 8.2 12.0 11.8 11.4194 7.3 8.4 8.5 12.1 11.9 11.6Fig 7 :Effect of contact time on adsorption for COD by SAC, LAC and RAC (dosage = 5 g/100 mL, pH = 4, temp = 300 K)3.4 Effect of Adsorbent DosageThese studies were carried out at different initial concentration of COD in 100 mL groundwater sample for varying the dosage of adsorbent (5, 10, 15 and 20 g). The increase in adsorbent dosage caused decrease in the percentage of COD removal. It is clear that the removal of COD in groundwater samples depends on the concentration of adsorbent of stems (SAC), roots (RAC) and leaves (LAC) of Ricinus CommunisThe batch adsorption experiment carried out to establish the nature of equilibrium that existed in the COD water activated activated carbon derived from Ricinus Communis indicated that 5 g of SAC could remove 8.8, 7.8 and 7.8 mg of total COD content of wastewater sample (i.e., GWS-1, GWS-2 and GWS-3), . 5 g of LAC could remove 3.8, 4.6 and 4.8 mg of total COD content of wastewater sample (i.e., GWS-1, GWS-2 and GWS-3), 5 g of RAC could remove 9.4 9.8 and 9.2 mg of total COD content of wastewater sample (i.e., GWS-1, GWS-2 and GWS-3) It can be observed from the equilibrium concentration x / m decrease with increase in activated carbon dosage and also these results indicated the concentration of organic pollutant decreases with increase in carbon dosage of SAC, RAC and also these results indicates excessive percentage of COD removed by adding adsorbent dosage of SAC and RAC. LAC having capability to remove only less % of organic pollutant than SAC & RAC.Table 4: Experimental batch adsorption data for sample GWS-1, GWS-2 and GWS-3Initial CODconcentration(mg/l) COD removal with different adsorbent dosage of stems (g/100mL) 5g 10g 15g 20g262 8.8 14.4 25 29.2268 7.8 13.2 22.6 28.4194 8.6 14.4 16.4 22.8COD removal with different adsorbent dosage of Leaves (g/100L)262 3.8 6.6 10.4 12.8268 4.6 7.1 13.0 16.6194 4.8 7.6 11.2 17.0COD removal with different adsorbent dosage of roots (g/100mL)262 9.4 13.2 19.6 23.5268 9.8 14.4 18.4 24.8194 9.2 14.5 19.8 22.6The organic concentration expressed as COD was reduced with amount of activated carbon increased.Hence significant COD removal efficiency rates of SAC 11%, LAC 6% and RAC 12% were achieved by using little quantity of adsorbent. Table 5: Physico-chemical properties of groundwater sample after adsorption treatment.Samples pH TDS (ppm) Nitrate (ppm)GWS-1 (after Stem activated carbon Treatment) 6.90 1426 17GWS-1 (after leavesactivated carbon Treatment) 6.84 1448 25GWS-1 (after roots activated carbon Treatment) 6.92 1438 23GWS-2 (after Stem activated carbon Treatment) 7.84 1396 9GWS-2 (after leaves activated carbon Treatment) 7.92 1414 11GWS-2 (after roots activated carbon Treatment) 8.05 1396 8GWS-3 (after Stem activated carbon Treatment) 7.94 928 7GWS-3 (after leaves activated carbon Treatment) 7.92 942 13GWS-3(after roots activated carbon Treatment) 7.94 924 9From the above it is cleared that when the dosage adsorbent (AC) increases the effeciencey of removal of COD also increases.Therefore the effectiveness of the activated carbon produced from Ricinus Communis for the removal of organic contaminant has been established. The study also proved that natural adsorbent such as activated carbon of Ricinus Communis is an alternative option for COD removal from water and wastewater.Comparing the result obtained from table 5 with the sample specification can be observed that pH value was slightly increases. The results showed that there was a remarkable decrease in the amount of TDS and Nitrated after the adsorption. Similarly nitrate concentration is also reduced after adsorption (Table 5).4. CONCLUSIONThe study has revealed that some concealed facts about the usefulness and effectiveness of granular activated carbon produced from stems, roots and leaves of Ricinus Communis with Coconut shells.From the results it was identified that the treatment of groundwater from near tannery region for the maximum COD reduction 29.2% was obtained for the dosage of 20g/100mL. The other dosages showssomewhat good result and stable. The suitable pH condition was identified as the range of 4. 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