Survey on Filamentous Bacteria in Activated Sludge Processes in Concentrated Latex Rubber and Seafood Industries

Abstract

This study surveyed seventeen wastewater treatment plants, in concentrated latex rubber and seafood industries, in southern Thailand. The researchers concerned mainly in the bulking sludge problems caused by filamentous bacteria. Wastewaters from those factories contained high organic contents, high BOD5 and TKN concentrations. All of the existing activated sludge process were equipped with other pre- and post-treatments. Sixteen of them were concerned with only carbon and suspended removal. They were operated with high hydraulic retention time (HRT) and low food per microorganism ratio (F/M ratio), which are the main causes of bulking sludge problem. Most operators faced up with this problem, but could not realize the reasons and solutions. This study observed their settle ability and presented filamentous bacteria in each plant. It can be evidently seen that some filamentous bacteria such as type 0041 and Nostocoida limicola II appeared at seafood treatment plants only, and type 1863 found in rubber treatment plants only. This can be affirmed to the nature of influent composition of wastewater.