Study on effects of temperature, moisture and pH in degradation and degradation kinetics of aldrin, endosulfan, lindane pesticides during full-scale continuous rotary drum composting

• High removal rate was obtained for used pesticides within 7–8 d in FSCRDC.
• Pesticides degraded 20–30%, 30–60% and 20% in inlet, middle and outlet zones respectively.
• Temperature, moisture, pH and heterotrophic bacteria played key role in degradation.
• Degradation kinetics is observed as first order.
• T1/2 of used pesticides was significantly reduced from the natural decay.

Study focused on effects of temperature, moisture and pH on degradation and degradation kinetics of aldrin, endosulfan (α), endosulfan (β) and lindane during vegetable waste composting using full-scale continuous rotary drum composter (FSCRDC). Extraction, concentration and quantification of pesticides were made from waste material at different stages by ultra-sonification, silica gel column and GC–MS analysis. Removal efficiency of aldrin, endosulfan α, endosulfan β and lindane was found 85.67%, 84.95%, 83.20% and 81.36% respectively due to optimum temperature, moisture, pH and enhanced microbial activity. Maximum temperature in inlet zone was found 60–65 °C which is most suitable for complex microbial population. After feeding and turning in inlet zone, temperature reduced to 38 °C from 60 to 65 °C and regained it within 7–8 h, and pH reduced to 5.3 ± 0.2 from 7.5 ± 0.3 in 4 h and regained it in 10 h. Heterotrophic bacteria Bacillus sp., Pseudomonas sp. and Lactobacillus sp. also decreased from 4.4 × 103 to 7.80 × 102 CFU g−1 in 2 h due to gradual variation in temperature and pH. No significant temperature change was found in middle and outlet zones during feeding and turning. Degradation of pesticides was observed as first order kinetics and half-life of aldrin, endosulfan α, endosulfan β and lindane was reduced to 25.54, 18.43, 18.43 and 27.43 d from 1095, 60, 270 and 160 d respectively. Thus, the observations in contrast of removal and degradation kinetics of organochlorine pesticides residues in vegetable waste though full-scale rotary drum composting proved it the best suited technique.