The Treatment of Landfill Leachate by Electrocoagulation to Reduce Heavy Metals and Ammonia-Nitrogen

Abstract

Landfill leachate contains high concentration of contaminants in the form of nitrogen, suspended solids and heavy metals, which effects the environment adversely. Hence leachate treatment is considered vital in landfill management as the effluent needs to undergo several treatments before being discharged into natural water bodies. Without treatment, the leachate will contaminate the surface and ground water as it can penetrate through soils and subsoils. Several methods have been applied for the treatment of landfill leachate. However, these methods have several constraints due to area required and cost incurred. This paper presents the application of electrocoagulation in removing pollutants from landfill leachate; particularly ammonia-nitrogen and heavy metals. Three metals namely aluminium, iron and zinc were used as electrodes. Aluminium electrode was found to be the most effective where it was capable to extract 89% of zinc and 75% of iron in 30-minute retention time. Subsequently, 93% of zinc and 83% of iron was removed in 120 minutes. In addition, 93% of ammonia-nitrogen was also removed. These results led to a conclusion that the electrocoagulation had the capacity to remove heavy metals and ammonia-nitrogen present in landfill leachate.

Combination of Electrocogulation and Aeration Processes by Addition NaCl for Leachate Treatment

“…At the cathode, the electrolysis reaction occurs in the form of the release of hydrogen gas [18]- [20]. To increase the effectiveness of decreasing metal ions and other substances contained in the waste, the researchers made variations in the addition of sodium chloride (NaCl) and the aeration process in the processing of the leachate [21], [22].…”

Operational variable effect on the COD removal efficiency using electrocoagulation in landfill leachate treatment

“…The data used in this work were collected from several scientific articles published in the last few decades. 6,40,41,48–89 The characteristics of the leachate, the parameters reported in the treatment and the response variables were considered. Only articles related to landfill leachate treatment by EC were considered, even if EC was considered a single or a combined process.…”

Production of Bricks from Sludge of Palm Oil Mill Effluent (POME)

“…A total of 40 L POME was collected to carry out this study. In the electrocoagulation process, the aluminium plate was used as an electrode to remove the contaminants in the sample [23].…”