The use of the purple non sulfur bacterium isolate P1 and fermented pineapple extract to treat latex rubber sheet

Abstract

A central composite design using two variables (concentrations of isolate P1 and Fermented Pineapple Extract (FPE) 
each at three levels was used to study their effects on the treatment efficiency of latex rubber sheet wastewater under 
microaerobic-light conditions. The optimum combination over a 72 h period consisted of 3% P1 and 0.13% FPE and 
resulted in the removal of 80% Chemical Oxygen Demand (COD), 82% Suspended Solids (SS) and 85% Un-ionized 
Hydrogen Sulfide: H2S in wastewater (UHS). The selected experimental condition was then verified by varying the 
retention times. A 96 h retention time gave the highest treatment efficiency with a 92% reduction of COD, 87% SS and 
83% UHS and the effluent met both standards for industrial effluent discharge and crop irrigation. This effluent in its 
undiluted and diluted between 1: 25-1: 200 showed no phytotoxicity and also stimulated rice seed germination based 
on a germination index when compared with distilled water. Addition of 3% P1 into the raw wastewater either alone or 
in combination with 0.13% FPE yielded an effluent that passed the standard guidelines within 72 h, while with FPE 
alone a 96 h retention time was required. Based on morphological, physiological and biochemical properties, the 
isolate P1 was identified as Rhodopseudomonas palustris.