The influence of industrial (pharmaceutical and chemical) wastewater composition on membrane bioreactor (MBR) performance was investigated in a pilot-scale installation. The study focussed on nitrification performance, which was evaluated based on influent and effluent parameters as well as batch nitrification rate tests. The industrial wastewater was pumped into the MBR in a mixture with municipal wastewater at constant flow rate. The loading of the MBR with industrial wastewater was increased stepwise from 0 to 75% share in the mixed influent to study the adaptation of nitrifying bacteria. Stable nitrification performance was observed until the content of industrial wastewater in the influent reached 40%, with effluent values of around 0.56 mg L(-1) NH4-N and 98.3% ammonia removal. Breakdown of nitratation was observed at a 40% industrial wastewater dose and breakdown of nitritation at a 50% dose, respectively. However, after several months of adaptation, both processes recovered. No nitrification was observed when the industrial wastewater share exceeded 50%. Adaptation of nitrifying bacteria in the MBR was also confirmed by results of kinetic tests. The inhibition effect of the concentrated industrial wastewater to the MBR sludge decreased substantially after several months of exposure, while the inhibition of referential activated sludge remained constant.
Keywords: ATU; AUR; Activated sludge; Adaptation; COD; EPS; F/M; HRT; IWW; Industrial wastewater; Inhibition; MLSS; MWCO; Membrane bioreactor; N(T); Nitrification; OUR; P(T); PES; PVDF; SMP; SRT; TMP; allylthiourea; ammonia uptake rate; chemical oxygen demand; extracellular polymeric substances; food to microorganisms ratio; hydraulic retention time; industrial wastewater; mixed liquor suspended solids; molecular weight cut-off; oxygen uptake rate; polyethersulfone; polyvinylidene fluoride; sludge retention time; soluble microbial products; total nitrogen; total phosphorus; transmembrane pressure.
Copyright © 2013. Published by Elsevier Ltd.