Treatments and Recycle of Food Processor Wastewater Effluent
Effective best management practice (BMP) was developed for treating fruit processing membrane bioreactor (MBR) effluent for reuse. The micro-molecular soluble microbial products (SMP) and extracellular polymeric substances (EPS), which crossed through the 0.04 µ ultrafiltration (UF) MBR and constituted in the effluent as dissolved organic matters (DOM), was found to foul and block the permeation of the down-stream RO membrane hindering the recycle and reuse processes. Efficient treatment composed of enhanced coagulation coupled with granular activated carbon (GAC) sorption, reduced the DOM content to about 98%, and consequently the fouling potential. This maintained steady performance without any flux decline, while the intermittent flush-cleaning removed loosely bound deposits, if any, from the membrane surface. Membrane preservation experiments showed steady permeation even after 3-4 months of preservation in deionized water, providing additional safety to the membrane during a shutdown period of the processing unit. The developed BMP will provide a sustainable reuse operation for the industrial partner, reducing freshwater needs.