Plant Diversity in a Constructed Wetland for Pollutant Parameter Processing on Leachate: A Review

The leachate from landfill constitutes wastewater with high pollutant content. The high pollutant content impacts the public and ecosystem health surrounding the landfill site. Therefore, it is essential to process the leachate first before its disposal to water body. Landfill leachate processing can be carried out using three processes, i.e., physical-chemical, biological, and a combination of those. A constructed wetland is currently considered as an environmentally friendly technology to tackle water pollution and leachate. Another advantage of a constructed wetland is the low operational cost and natural maintenance, so it can be a solution related to the cost, technical, and operating system problems of conventional processing. This article aimed to discover the characteristic differences of landfill leachate, constructed wetland installation position, and types of plants used in the constructed wetland. This article was written using the literature reviews from experimental studies on water processing with the same parameter for leachate and leachate processing. The literature review result shows that landfill leachate processing depends on different leachate characteristics. The toxic quality of landfill leachate was found through a toxicity test. Leachate treated by the physical-chemical process contains toxic and non-biodegradable organic substances. Hence, the physical-chemical methods should be applied at the beginning of the process and coupled with the biological method at the end of the process to improve the treatment quality. A constructed wetland with diverse plants was found to be more effective in biomass distribution, less prone to seasonal variations, and had a more diverse microbe population than the constructed wetland with a single plant.