Abstract

Current Review on the Coagulation/Flocculation of Lignin Containing Wastewater

Abu Zahrim Yaser, Cassey TL, Hairul MA and Shazwan AS

Agro based industries including pulp and paper mill, palm oil mill, textile, dairy parlour etc. are characterised by its water intensive nature. The pollution problems related to the agro-based industries wastewater are colour, odour and toxicity. Lignin is the major colorant in the agro based industry wastewater. This review is dedicated to explore the lignin and its removal from wastewater via coagulation/flocculation. Over the years, several studies have been conducted for lignin removal using coagulation/flocculation. Aluminium based and iron based coagulants are widely used for this purpose. However, their usage could deteriorate the performance of biological post treatment. Among others coagulant, calcium based coagulant is seems to be an alternative. Hence, there is interest in developing the use of calcium based coagulants alone or hybrid calcium-other metals coagulant that might fully dismiss or minimize the adverse impact of the aluminium and iron based coagulants. On the whole it looks for the possibility of calcium based salt as a potential coagulant.