The reason for such enormous efforts in palm oil mill effluent research would be what has been singled out as one of the major sources of pollution in Malaysia, and perhaps the most costly and complex waste to manage. Palm oil mill final discharge, which is the treated effluent, will usually be discharged to nearby land or river since it has been the least costly way to dispose of. Irrefutably, the quality level of the treated effluent does not always satisfy the surface water quality in conformity to physicochemical characteristics. To work on improving the treated effluent quality, a vertical surface-flow constructed wetland system was designed with Pennisetum purpureum (Napier grass) planted on the wetland floor. The system effectively reduced the level of chemical oxygen demand by 62.2 ± 14.3%, total suspended solid by 88.1 ± 13.3%, ammonia by 62.3 ± 24.8%, colour by 66.6 ± 13.19%, and tannin and lignin by 57.5 ± 22.3%. Heat map depicted bacterial diversity and relative abundance in life stages from the wetland soil, whereby bacterial community associated with the pollutant removal was found to be from the families Anaerolineaceae and Nitrosomonadaceae, and phyla Cyanobacteria and Acidobacteria.
Wastewater containing ammonia is normally sent to the wastewater treatment system in a chemical plant for the removal of ammonia compound. Alternatively, it is proposed to remove the ammonia compound by incinerating the wastewater using the existing incinerator system. However, it is essential to ensure that the gaseous and aqueous emission produced by the incinerator system do not exceed the Clean Air Regulations (CAR) 2014 and Industrial Effluent Regulations (IER) 2009 limits, especially the nitrogen oxides (NOx) content and unburnt ammonia compound. A process simulation model of the incinerator system was developed using a Gibbs energy minimization reactor approach coupled with Gasification property package to predict the products of the incineration process. Two case study runs were conducted to evaluate the impact of incinerator operating temperature and ammonia concentration in the wastewater feed. Theoretically, there are two causes of NOx production; from thermal NOx (oxidation of nitrogen at high temperature) and fuel NOx (oxidation of liberated nitrogen from ammonia). The study showed that the thermal NOx effect is significantly higher than fuel NOx effect through this study. This is because the total liberated nitrogen molecules from the intended concentration of ammonia in the aqueous water is comparatively small when compared with the amount of nitrogen molecules in the combustion air. Based on the case study results, there is very minimal impact of ammonia injection on total NOx production as the incinerator temperature is commonly controlled on a fixed set point. There is also opportunity to reduce fuel gas requirement because the heating value of the waste streams increases through the combustion of hydrogen molecules in ammonia.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.