Effects of Landfill Leachate on Aquatic Organism: A Case Study of Leptobarbus hoevenii

Abstract

Aquaculture is one of the main contributors of protein sources to the world population. Yet, the aquaculture sector may be threatened with the ever-increasing pollution coming from various sources. Among others, landfill releases leachate into water bodies which eventually may come into contact with water supplied to the aqua farms. Unfortunately, the toxicity effects from leachate differ from one species to another. As a result, some organisms that come into contact with contaminants can accumulate the pollutants in their system, and the contaminants biomagnify as it travel higher in the food chain. Thus, it is critical to understand the level of exposure of leachate to the aquatic organism, namely freshwater fishes. This research is aimed to determine the mortality of leachate exposure on Leptobarbus hoevenii, a genus of cyprinid fish which are native to freshwater habitats in Southeast Asia. The fish was exposed to different concentration of leachate collected from two non-sanitary landfills in Klang Valley, Malaysia. Finney's probit method was used to calculate the lethal concentration (LC50). Both leachate samples have an average BOD5 and COD of 195 and 734 mg/L, respectively, which exceed the limit allowed by the Malaysian Environmental Quality Act 1974. Observation during the exposure recorded some abnormal changes to the fish in terms of its swimming pattern and breathing. From the results, the lethal concentration of leachate from the two landfills ranged from 6.3 to 7.1% v/v. Leachate collected from an active landfill recorded higher mortality than the leachate from the non-operating landfill. This is so as leachate concentration used for the definitive test was 2--10% v/v for the active landfill while it was 6.4--8% v/v from the non-active landfill. Hence, leachate from active landfill is more toxic to the fish than the non-active landfill.