Heavy metals removal from landfill leachate using vertiveria zizanioides and artificial roots

Abstract

High concentrations of heavy metals and ammonia in landfill leachate can bring hazard to water bodies if it is not treated properly before discharge. Pure water has become the most precious and valuable resource for today generations as its supply become limited and is easily being polluted by industrial wastewater. Nowadays, methods of treatment have become expensive and certainly uneconomical for smaller communities and small medium industries. Biological treatment plays an important role in processing and treating solid waste disposed in a sanitary landfill. Leachate generation is one of the main issues of concerned in a sanitary landfill, due to the existence of high concentrations of heavy metals and ammonia. A combined wetland system utilizing a free floating plant attached with artificial roots was constructed to treat landfill leachate. The aim of the study was to investigate the effectiveness of leachate treatment using floating island wetland system. A free floating plant (Vertiveria zizanioides) and artificial roots were used. The wetland systems were arranged in series and operated until the result obtained was in stable state for 50%, 75% and 100% leachate concentrations, respectively. The performances in these series were evaluated with comparison to Set D (control system). The result demonstrated that the removal efficiency of pollutants in leachate using a wetland combination of Set B (Vertiveria zizanioides and artificial roots) was achieved for 50% leachate concentration compared to 75% and 100% leachate concentrations. At 100% leachate concentration removal for ammoniacal nitrogen for Set B was 100% compared to set A and Set C which were 89% and 79%, respectively. Besides that, Set B also achieved high metal removal for Cr, Cu, Mn, Fe, Zn at 50% leachate concentration which are 95%, 88%, 93%, 98% and 96% respectively. Set A (Vertiveria zizanioides) had higher capacity of metals uptake (Fe, Zn and Mn) in leachate constituents compared to Set C (artificial roots). From the study, it shows that Fe, Zn and Mn uptake were more significant in roots compared to leaves. This study concluded that combination of free floating plants and artificial roots can increase the performances of nutrients and metal uptake and also enhance treatment of leachate.