2019

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Browsing 2019 by Author "Muhammad Ali Khurram"

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    Persistence and degradation of pesticides in composting
    (UMT, Lhr, 2019) Muhammad Ali Khurram
    Pesticides use is the most effective tool for pest and weeds control which allows maintenance of crop yields and thus contribute to economic viability On the other hand, pesticides have toxic impact on the environment. Therefore, repeated pesticides use has promoted research into the environmental fate of these agents. In such context, composting being a biological decomposition of organic constituents of wastes and manures is considered to dissipate hazardous impact of pesticides due to increasing temperature, microbial diversity, & activity, and organic matter. During composting process, pesticides persistence/ degradation is affected because of mineralization, volatilization, adsorption, leaching, and may also disappear during microbial decomposition. Microorganisms have ability to attract both physically and chemically with huge range of chemical compounds leading to a structural change and completely degradation. Keeping in view the degradative potential of composting on pesticides, the study was planned and conducted to check the persistence and degradation of Chloropyrifos (insecticide), Paraquat (weedicide), Acetamiprid (insecticide). Each pesticide was spiked and mixed in the composting material and filled in pits, keeping one control treatment. Urea solution was added in each pit as a composting activator. Samples were taken after 3 days of trial commencement, then after 1.0 months and last sampling was done after 3 months. It was observed that Humic acid contents( 6.84 %, 6.77, 7.23 %),Organic carbon (30.66% ,36.49 %,41.06 % ) and Nitrogen( 0.97%, 96%, 3.06 % ) were improved from initial level to 1.0 months and 3 months composting period respectively. C: N ratio was 32: 1 at star of study, 19:1 after 1.0 months and 13:1 after 3 months interval. Pesticides analyses in the compost at 3 days, 1.0 month and 3 months interval shown Chloropyrifos active 0.37%, 0.135 % & 0.095 % respectively (3 days, 1 moth, 3 month intervals) Similarly Acetamiprid active was 0.17 % , 0.06 % & 0.013 % ; while Paraquat Dichloride active was found 0.63 % , 0.22 % and 0.032 % respective intervals. Thereby, Chloropyrifos degradation was 74.3 % after 3 months, that of Acetamiprid 92 % and for Paraquat dichloride it was 95 %. Obviously Chloropyrifos persistence was comparatively higher.