ABSTRACT

Chemical Engineering Programme, Faculty of Engineering, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia

*Corresponding author. E-mail: zahrim@ums.edu.my

ABSTRACT

Lignin is the major colorant in the agro-based industry wastewater such as pulp and paper mill, palm oil mill, olive oil, etc. These industries are characterized by their water-intensive nature. This review is dedicated to explore the lignin and its removal from wastewater via coagulation/flocculation. Iron-and aluminum-based coagulants are widely used for this purpose. However, the application of aluminum-and iron-based coagulant may hinder the performance of biological posttreatment. 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 aluminum-and iron-based coagulants. On the whole, it looks for the possibility of calcium-based salt as a potential coagulant. Finally, we also discussed a nontoxic coagulant, that is, calcium lactate for the treatment of anaerobically digested palm oil mill effluent. It can be concluded that calcium lactate has potential for the treatment of lignin-containing wastewater.