Pulp and Paper Industry—Manufacturing Process, Wastewater Generation and Treatment

Pulp and paper mills are categorized as a core sector industry and are the fifth largest contributor to industrial water pollution. Pulp and paper production has increased globally and will contribute to increase in the near future. For every tonne of paper produced, these mills generate 220-380 m3 of highly coloured and potentially toxic wastewater. The pulp and paper mill is a major industrial sector utilizing a huge amount of lignocellulosic materials and water during the manufacturing process, and releases chlorinated lignosulphonic acids, chlorinated resin acids, chlorinated phenols and chlorinated hydrocarbons in the effluent. About 500 different chlorinated organic compounds have been identified including chloroform, chlorate, resin acids, chlorinated hydrocarbons, phenols, catechols, guaiacols, furans, dioxins, syringols, vanillins, etc. In wastewater these compounds are estimated collectively as “Adorbable Organic Halides” AOX. This paper is the state of the art review of the manufacturing process, treatability of the pulp and paper mill wastewater and performance of available treatment processes. A comparison of all treatment processes is presented emphasis being made on the treatability studies of AOX.