Estimating design parameters for sustainable operation of a membrane bioreactor treating s-triazine herbicide

An Ametryn (an s-triazine herbicide) fed laboratory-scale membrane bioreactor (MBR) was studied for 214 days under sub-tropical conditions (20-22 °C) for evaluating its treatment/operating performance and to consolidate the previous findings and establish the design parameters. Ten short-term critical flux tests were carried out at different stages of the study and the Critical Flux Values (CFV) varied from 6 to 33 L/m2h for the experiments carried out under intermittent suction mode. Two numerical models were used to estimate the “critical times”, which is useful to establish the chemical cleaning frequency of membrane modules and to assess the key kinetic parameters required to design a pilot/full scale MBR. The study also confirmed the overall fluctuation of the components of polymeric substances (proteins and carbohydrates of extra-cellular polymeric substances (EPS) and soluble microbial products (SMP)) in the MBR due to the addition of different concentrations of Ametryn (0-4 mg/L).