*Article* **Treatment of Landfill Leachate Using Palm Oil Mill E**ffl**uent**

### **Tawfiq J. H. Banch 1, Marlia M. Hanafiah 1,2,\*, Salem S. Abu Amr 3, Abbas F. M. Alkarkhi 3 and Mohammed Hasan 1**


Received: 18 April 2020; Accepted: 14 May 2020; Published: 18 May 2020

**Abstract:** Sanitary landfilling is the most common method of removing urban solid waste in developing countries. Landfills contain high levels of organic materials, ammonia, and heavy metals, thereby producing leachate which causes a possible future pollution of ground and surface water. Recently, agricultural waste was considered a co-substratum to promote the biodegradation of organics in industrial wastewater. The use of low-cost and natural materials for wastewater treatment is now being considered by many researchers. In this study, palm oil mill effluent (POME) was used for treating stabilized leachate from old landfill. A set of preliminary experiments using different POME/leachate ratios and aeration times was performed to identify the setting of experimental design and optimize the effect of employing POME on four responses: chemical oxygen demand (COD), total suspended solids (TSS), color, and ammoniacal nitrogen (NH3-N). The treatment efficiency was evaluated based on the removal of four selected (responses) parameters. The optimum removal efficiency for COD, TSS, color, and NH3-N was 87.15%, 65.54%, 52.78%, and 91.75%, respectively, using a POME/leachate mixing ratio of 188.32 mL/811.68 mL and 21 days of aeration time. The results demonstrate that POME-based agricultural waste can be effectively employed for organic removal from leachate.

**Keywords:** landfill; leachate treatment; POME; removal efficiency; mixing ratio
