Application of MBR technology for laundry wastewater treatment

The application of membrane bioreactor (MBR) for industrial laundry wastewater treatment is-presented. An MBR pilot plant installation was used to test the efficiency of surfactants removal and the influence of treatment time on permeate flux. The installation consisted of (1) biological reactor (three tanks with a total capacity of 600 dm(3)), (2) membrane reactor (ZeeWeed 10 membrane module, GE Water & Process Technologies), and (3) dosing station. The hourly flow rate of the wastewater to the biological reactor amounted to Q(h) = 25 dm3 h-1. The effluent from the bioreactor was periodically recycled back to the membrane reactor at Qh = 125 dm(3) h-1. Despite periodical relaxation and back-flush with permeate, after about 11 d of operation the membrane was fouled and chemical cleaning was necessary. The membrane permeability was fully recovered after the applied cleaning procedure. The total efficiency of removal of anionic and non-ionic surfactants was in the range of 87%-95% and 94%-95%, respectively. The COD removal reached 91%-93% and the BOD was almost completely eliminated (99%) indicating high MBR treatment efficiency of the applied industrial laundry wastewater.