MANCO 21st : Greening Drainage - The Zero Discharge Option


Ir Sardar Ali 

The health of rivers can be determined by 6 well-known parameters namely BOD, COD, dissolved oxygen, ammonia, pH and total solids (dissolved and suspended). However the most common parameter adopted to define the health of a water body or river is its level of BOD. The BOD of water source for water treatment plant should normally be below 3mg/l. When the BOD of river water exceeds 5 mg./l, most fish life ceases and when it exceeds 10mg/l, foul smells arise from the river. The oil palm mill releases palm oil mill effluent (POME) that has a BOD of about 30,000 mg/l and they need treatment to comply with the mandatory level of 100 mg/l that was introduced by DOE in 1984. 
The mills complied with the legislation through the ‘lagoon system’, comprising of anaerobic ponds, facultative ponds and finally aerobic ponds and even additionally in some cases by ‘polishing’ plants. However this system occupies large footprint, has long hydraulic retention times, and does not recycle useful residues in the POME. One option to improve this further is the ‘Zero Discharge’ option. This has been successfully implemented for the past 4 years in the Tereh mill under Kulim Bhd. 
The ability to obtain Zero Discharge is through the unique co-composting of POME with EFB where POME and whose amount is 3 to 4 times to that of EFB, instead of being discharged into the river, is released into the atmosphere as steam through the process of ‘biological drying’ by specialized composting microbes. The resulting compost is recycled as organic fertilizer replacing 25% of environmentally non-friendly chemical fertilizers. 

Keywords:  Oil Palm, Effluent, Zero Discharge, Compost, Recycling, Organic Fertilizer, Aerobic Ponds, POME, EFB