Fate and Availability of Emerging Contaminants in Sewage Sludge-Amended Soil

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Marri Srinivasa Reddy, Dr. S. Gnanakumar, Dr. K. ChandraMouli


Concerns regarding the effects of organic pollutants like PPCPs on agricultural areas, which raises the amount of dissolved bioavailable pollutants that plants may absorb, are developing. This study's objectives were to address this issue and offer some potential fixes. DGT is a passive sampling instrument with the capacity to assess time-weighted averages of bioavailable compounds in soil, water, and sediments. When a study was first conducted to address this issue, it was concluded that since there was no restock of MEP, PRP, PHBA, and ETP, their sorption to DGT decreased from days 14 to 21 owing to biodegradation. This prompted a follow-up study that looked at the sewage slurry for 21 days with and without NaN3, while the same samplers were deployed 24 hours prior to the retrieval day to look at the available chemicals at the end of each week. The results showed that a longer period, possibly longer than 21, may be required to further reduce bioavailable PCPs in the sewage cakes amended soils by giving more time for degradation and desorption. It was discovered that NaN3 prevents PCP degradation, but a 24-hour deployment reveals that MEP, ETP, and PRP require a longer period for desorption and degradation before being used by farmers. A significant concentration of BPA, PHBA, MEP, NP, and BHT were found in the sludge slurry made in a ratio of 15g of sludge cakes to MQ water in a ratio of 3:37 for the later investigation. Of these, 2589 ngL-1 was adsorbed to DGT in 7 days, whereas 681 ngL-1 was adsorbed on the day 21. Yet, at that time, MEP grew from 19 ngL-1 to 1497 ngL-1 and PHBA increased from 859 ngL-1 to 2114 ngL-1. According to this study, there should be at least 28 days between the application of sludge cakes to farmland and cropping, which is thought to be safer with lower levels of toxins.



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Marri Srinivasa Reddy, Dr. S. Gnanakumar, Dr. K. ChandraMouli