Phytoremediation of palm oil mill effluent (POME) using water spinach (Ipomoea aquatica Forsk)

Abstract

Rapid expansion of palm oil industry poses potential threat to terrestrial environment and aquatic ecosystems as it discharges high volume and various forms of solid and liquid waste substances as by-products, known as palm oil mill effluent (POME) during oil processing. Indiscremental disposal of POME is a major source of wastewater contamination which could have catastrophic impact on the environment. Thus, remediation of POME is crucial before it released to the environment. Phytoremediation using aquatic plants including water spinach (Ipomoea aquatica) has potential to improve the quality of POME. This present study investigated the phytoremediation efficiency of POME, which contains high amount of chemical oxygen demand (COD), nitrate, phosphate using water spinach for up to 15 days and described its impact on the growth performance. Experimental design of this study consisted of five treatments with three replications namely: control: 0% POME (0 L POME + 10 L tap water), Treatment A: 25% POME (2.5 L POME + 7.5 L tap water), Treatment B: 50% POME (5 L POME+ 5 L tap water), Treatment C: 75% POME (7.5 L POME + 2.5 L tap water), and Treatment D: 100% POME (10 L POME). The results indicated that water spinach was able to reduce COD, nitrate, phosphate and color as 86.3%, 21.5%, 90.9 % and 95.3%, respectively. Water spinach had no influence on the growth performance even up to 75% of POME containing media. Furthermore, results showed that high concentrations of POME damage root structures, and ultimately impact the growth performance of water spinach. In conclusion, phytoremediation using water spinach can be a potential remediation method to improve the quality of COD, phosphate and nitrate.