Treatment of agro based industrial wastewater in sequencing batch reactor: performance evaluation and growth kinetics of aerobic biomass

Modelling and parameter optimisation for performance evaluation of sequencing batch reactor for treating hospital wastewater

Hospital wastewater treatment is gaining attention in recent studies due to its complex nature. The performance of the sequencing batch reactor coupled with tube-settler was investigated for hospital wastewater treatment. The performance was evaluated regarding removing organic matter and nutrients (nitrate and phosphate). The phosphate was removed in the sequencing batch reactor and its associated tube-settler with a 60% removal efficiency margin. Nitrification was observed in sequencing batch reactor and tube-settler, but denitrification could not be achieved. The nitrification-denitrification process was not completed during the process. The current work's main aim was to understand and optimise the operational parameters involved in the performance of the sequencing batch reactor. The operational parameters were optimised using Design expert software, and Response Surface Methodology involved a four-factor and five-level central composite design. The percentage removal of chemical oxygen demand, nitrate, and phosphate was selected to be observed during this study.

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Supplementary Information

The online version contains supplementary material available at 10.1007/s13399-022-03406-z.

Novel investigation of the performance of continuous packed bed bioreactor (CPBBR) by isolated Bacillus sp. M4 and proteomic study

The present study reveals the benzene degrading potential of bacterial species isolated from petroleum contaminated soil. Genomic analysis suggests that Bacillus sp. M4 was found to be dominating species. The process parameters were optimized and found to be pH 7.0 ± 0.2, temperature 32 ± 5 °C, immobilization time (20 days) and benzene concentration 400 mg/L. The maximum removal efficiency of benzene was calculated and found to be 93.13% at elimination capacity156 (mg/L/day) and inlet loading rate 192 (mg/L/day) achieved in 54th days of operation. In the study, the residual metabolites were analyzed by GC/MS analysis and identified as benzene-1,2-diol. In order to identify the responsible protein involved in the process of benzene biodegradation The proteomic study was performed and proteins were identified by MALDI-TOF analysis. The molecular docking was confirmed by the benzene biodegradation.

Assessment of pesticides removal using two-stage Integrated Aerobic Treatment Plant (IATP) by Bacillus sp. isolated from agricultural field

The biodegradation of synthetic wastewater containing Atrazine, Malathion and Parathion was studied in two stage Integrated Aerobic Treatment Plant using Bacillus sp. (consortia) isolated from agricultural field. The influent stream containing these pesticides with initial COD of 1232mg/L were fed to first reactor and treated effluent of first reactor was fed to second reactor. The maximum removal of pesticides in IATP was found to be greater than 90%. The various process parameters such as pH, DO, Redox potential and BOD₅/COD were monitored during the treatment. The degradation of pesticides and its metabolites in the treated effluent were confirmed by GC-MS. Kinetic parameters such as first order rate constant (K_obs), cell yield (Y_X/C) and decay coefficients (K_dp) were evaluated and found to be 0.00425 per hr, 0.696mg of COD/mg MLSS and 0.0010 per hr respectively. This integrated process was found more effective than physico-chemical treatment of pesticides.