State-of-the-art approaches in sago wastewater treatment and resource recovery: Towards a circular and sustainable industry

Abstract

The sago industry plays a crucial role in global food security, but its production generates wastewater rich in nutrients and organic matter, which pose serious environmental challenges. This study critically reviews recent advances in sago wastewater treatment technology and proposes a scalable, nature-based, integrated treatment framework that is in line with Malaysia’s Sustainable Development Goals (SDG6, SDG12, SDG14 and SDG15) and the principles of the circular economy. The proposed system combines anaerobic digestion, coagulation–flocculation, bioadsorption and phytoremediation. Scientific reports show that anaerobic digestion can reduce chemical oxygen demand (COD) by 70 %–95 %, but residual total suspended solids (TSS ≥200 mg/L) and nutrients (nitrogen ≥100 mg/L, phosphorus ≥30 mg/L) still require further treatment. The coagulation–flocculation method using natural biocoagulants successfully removes up to 81.5 % of TSS, and bioadsorption using activated carbon achieves impressive removal efficiencies of 81.16 % for total dissolved solids, 87.58 % for TSS, 91.32 % for COD and 48.66 % for biochemical oxygen demand (BOD) in sago industry wastewater. Phytoremediation using Scirpus grossus and Chlorella pyrenoidosa improves effluent quality by reducing TSS by up to 98 %, COD by up to 90.2 % and BOD by up to 93 %. These findings confirm the feasibility of a cost-effective, phased, sustainable, nature-based effluent treatment model. Analysis of strengths, weaknesses, opportunities and threats is also conducted to assess the potential implementation and feasibility of this system in the context of a circular economy. This study provides a strategic plan for policymakers, industry players and researchers to accelerate the transition towards sustainable sago industry development.