[Effects of operating parameters on organic toxicity of sludge treating synthetic bisphenol A wastewater].

In order to investigate the influence of hydraulic retention time (HRT) and sludge retention time (SRT) on sludge organic toxicity in sequencing batch reactors (SBR(S)), the sludge toxicity was compared when HRT and SRT were controlled at various levels. The influents COD were controlled at around 300 mg x L(-1), HRT and SRT were changed from 12 h to 8 h and from 20 d to 10 d, respectively. The effluents COD, BPA contents both in liquid and sludge were measured, and sludge toxicity was also analyzed and compared between the blank group (no BPA content) and BPA control groups (40 mg x L(-1)).

Sonochemical degradation of organophosphorus pesticide in dilute aqueous solutions.

Ultrasonic irradiation was found to accelerate the rate of hydrolysis of omethoate in aqueous solution over the pH range of 2-12. Process parameters studied include pH, steady-state temperature, concentration, and the type of gases. Greater than 96% hydrolysis was observed in 30 minutes through this process and the rate of destruction increased with the help of more soluble and low thermal inert gas.