Domestic wastewater treatment using Tanfloc: A tannin based coagulant

Abstract

Fresh water resources in most areas of world are shrinking at an alarming rate and may not meet the ever increasing demands for domestic, agriculture and industry in future.Moreover, estimates reveal an annual production of ∼30 MT of wastewater in the World.In India, estimated sewage water generation from Class-I and Class-II cities is 38255 MLD, out of which only 11787 MLD is being treated.The untreated wastewater enters in groundwater, rivers, and other water bodies thereby making it unfit for human consumption.The projected wastewater generation in India will be 122000 MLD by 2050, which necessitates strengthening of existing treatment plants and investment in new treatment plants for safeguarding fresh water resources and human health.Pre-treatment is an integral part of any wastewater treatment scheme and results in appreciable reduction in capital as well as operating cost associated with downstream units due to reduction in organic load.A tannin based natural flocculent (Tanfloc) along with ferric chloride was used for pre-treatment of domestic wastewater using jar-test.It was able to achieve reduction in turbidity, COD, and BOD up to 95%, 69%, and 60% respectively.The optimum dosage for treatment of municipal wastewater under investigation was 10 ppm ferric chloride with 15 ppm Tanfloc.