PERFORMANCE OF GRANULAR CARBON FOR REMOVAL OF TRIAZINE AND ACETANILIDE HERBICIDES FROM WATER
KrishiKosh
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Title |
PERFORMANCE OF GRANULAR CARBON FOR REMOVAL OF TRIAZINE AND ACETANILIDE HERBICIDES FROM WATER
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Creator |
YENGKHOM BIJEN KUMAR
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Contributor |
Shashi Bala Singh
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Subject |
costs, manpower, additives, marketing, livestock, fruits
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Description |
T-8479
Pesticides are integral part of Indian agriculture. Residues of various pesticides are being detected in surface and ground water due to their use in agriculture. Safe and clean water is the requirement of human beings. Various water purification systems make use of granular carbon. In this study performance of granular carbon has been evaluated for the removal of two triazine herbicides i.e. atrazine and metribuzin and two acetanilide herbicides i.e. alachlor and metolachlor. Adsorption-desorption studies of atrazine, metribuzin, alachlor and metolachlor by batch method indicated the highest adsorption of triazine than acetanilide herbicides. Between atrazine and metribuzin, adsorption capacity of atrazine (Kf =17378) was found more than metribuzin (Kf =16710) when studies individually. Similarly, metolachlor (Kf =16033) has higher adsorption capacity than alachlor (Kf =4217). The trend of adsorption was atrazine> metribuzin > metolachlor> alachlor. Similar trend was found when adsorption studies were conducted with three sequential adsorption. The value of 1/n for alachlor indicated that there was a proportionate increase in adsorption of alachlor with concentration. The percent adsorption of alachlor was not affected by concentration. While for metolachlor 1/n value (0.33) value of intercept indicates that adsorption does not increase proportionately with concentration, although its adsorption intensity is more than alachlor. Desorption studies revealed that atrazine, metribuzin and metolachlor were not desorbed, but alachlor was desorbed in each cycles of desorption. When adsorption was carried out with the mixture of these four herbicide, metribuzin was the most adsorbed herbicide with a trend of metribuzin> atrazine> alachlor> metolachlor. In mixture there remains a competition between herbicides for adsorption sites and metribuzin having the more adsorption intensity (n= 2.30) than atrazine (n= 1.72) is more adsorbed followed by metolachlor and alachlor. In desorption atrazine and metribuzin were no desorbed and only metolachlor and alachlor were desorbed. Percent desorption of alachlor was more than metolachlor. Although water solubility of metolachlor (488 μg mL-1) is much higher than alachlor (242 μg mL-1), still alachlor was more desorbed which could be explained on the basis of adsorption intensity of alachlor (n=1) which was lower than metolachlor (n=3.). In column studies at higher concentration (1 and 5 μg mL-1), metolachlor was highly detected herbicide with a trend of metolachlor> alachlor> atrazine> metribuzin. But at lower concentration (0.1 μg mL-1), the most mobile and least adsorbed herbicide was alachlor. More elution of metolachlor at higher concentrations may be due to the less 73 available site of adsorption in the presence of higher concentration. The performance of horizontal column was found better than vertical column. |
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Date |
2016-11-24T09:42:49Z
2016-11-24T09:42:49Z 2011 |
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Type |
Thesis
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Identifier |
http://krishikosh.egranth.ac.in/handle/1/87342
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Format |
application/pdf
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Publisher |
IARI, Division of Agricultural Chemicals
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