Table 2.
Development of palm oil waste management.
| Substrate (waste type) | Management (development technology) | Results | References | 
|---|---|---|---|
| Liquid waste | Organic liquid fertilizer (fermentation using the EM4 activator) | Decreased COD from 2.362 mg/l to 1.580 mg/l and some of the organic matter was converted into new bacterial cells. The resulting product contains nutrients similar to organic fertilizers | [47] | 
| EFB | Compost | The compost produced had the characteristics of pH 9, moisture content 57.24%, water holding capacity 76%, C/N ratio 12.5%, P 0.58%, and K 0.95% with a composting period of 40 days | [48] | 
| EFB | Compost (mixture using palm oil mill effluent) | Compost nutrition is similar to other studies. In-vessel systems such as rotating drum composters are the systems with the fastest degradation of EFB -liquid waste of palm oil substrates | [49] | 
| EFB | Compost (the addition of mud to the decanter and chicken manure) | Compost produced by standard nutrition | [50] | 
| EFB | Compost (mixture of palm oil mill effluent and earthworm Eisenia fetida) | Good compost content on vermicompost is EFB with the addition of liquid waste of palm oil (50% EFB + 50% liquid waste of palm oil) | [51] | 
| EFB | Compost (the addition of palm oil mill effluent anaerobic sludge) | Anaerobic liquid waste of palm oil. Anaerobic accelerates the composting period in 40 days with a C/N ratio of 12.4 | [52] | 
| 
 | |||
| Bunch fiber cell | (i) Nucleus plantation fertilizer (mulching) | 100% EFB is used for land applications, and 100% fiber is used as fuel in the boiler. Refusing and reducing the system can save costs and increase company revenue | [53] | 
| (ii) Plasma plantation fertilizer (mulching) | |||
| (iii) Partnership plantation fertilizer (mulching) | |||
| (iv) Community plantation fertilizer (mulching) | |||
| (v) Boiler energy | |||
| (vi) Boiler surplus | |||
| (vii) Dryer fuel | |||
| 
 | |||
| Liquid waste | Land application | Applying the thermophilic system to the anaerobic reactor unit might increase the decomposition of bacteria, thereby making the processing more efficient | [54] | 
| Liquid waste | Biogas production (pilot-scale closed pond system with semi and continuous feeding) | The liquid waste of palm oil processing was stable at an organic loading rate of 0.9–3.11 kg/m3/day with a COD reduction percentage of more than 90% and a maximum biogas production of 2.59 m3/day | [55] | 
| Liquid waste | Reduce odor (flotation system) | Flotation of palm oil's liquid waste effectively reduces fat/oil content, COD, MLSS, and MLVSS. The longer the period of residence of the liquid in the flotation, the higher the decrease | [39] |