Enhanced carbonate precipitation of ureolytic and nitrifying microbe treated rubber wastewater

In an earlier project rubber wastewater discharge has been remediated with biofilm developed by microalgal and bacteria consortia isolated from waste. Lead findings are microalgae/bacteria either in planktonic or biofilm environment the wastewater pH rose from 4 to 12 in a week with substantial reduction of N, PO4, COD and TDS. The alkaline water requires neutralization before recycling/disposal to environment with H ions create sludge. The raised pH in medium with microalga growth is due to sequestration of dissolved CO2 into biomass. The major carbon species prevalent with pH dynamics are HCO3- when pH7-8, CO32- in >pH10. Therefore if cations are added as Ca or Na after algal/bacterial optimum growth the carbonate salt compound will precipitate as CaCO3 or NaHCO3. The CaCO3 can be applied to rubber plantation as soil binder to reduce soil erosion in high rainfall sloppy land. The NaHCO3 can be utilized locally as cleaning agent for low cost hygienic sanitation.