1. Kamyab, H., Chelliapan, S., Din, M.F.M., Rezania, S., Khademi, T., Kumar, A.: Palm oil mill effluent as and environmental pollutant. Palm Oil. IntechOpen. 13, 13–28 (2018)
2. Loh, S.K., et al.: Zero discharge treatment technology of palm oil mill effluent. J. Oil Palm Res. 25(3), 273–281 (2013)
3. Iskandar, M.J., Baharum, A., Anuar, F.H., Othaman, R.: Palm oil industry in South East Asia and the effluent treatment technology–a review. Environ. Technol. Innov. 9, 169–185 (2018)
4. Department of Environment, Ministry of Natural Resources and Environment Malaysia: Environmental Requirements: A Guide for Investors. 11th Edn (2010)
5. Akhbari, A., Kutty, P.K., Chuen, O.C., Ibrahim, S.: A study of palm oil mill processing and environmental assessment of palm oil mill effluent treatment. Environ. Eng. Res. 25(2), 212–221 (2019)