RBC or porous pots for textile wastes treatment

Textile industries in Kenya have mushroomed over the last few years with the result that there has been an increase in the amount of wastewater produced. This wastewater has previously not been adequately treated prior to discharge to receiving waters with the result that these streams are highly polluted. Textile processing uses bleaches and dyes in large quantities and these create problems in the form of difficult effluents which are discharged from the works. This paper reports the results of investi­gations on the treatment of high strength textile wastewaters by rotating biological contactors (RBC's) and Porous Pots. The effects of loading rate and disk media composition on organic removal rate were examined. The results show that comparatively, RBCs can treat high strength textile wastewaters better than porous pots. The resulting effluent organic content was adequate for discharge into either marine or freshwater receiving waters without fear of polluting these sources. Mean COD, BOD5, TOC removals of 80%, 71% and 60% respec­tively for the RBC and 69%, 60% and 50% respectively for the Porous Pot using a hydraulic loading rate of 0.08 m3/m2 day. At higher loading rates up to 0.30 m3/m2.day, the organic removal efficiency was reduced.