Bioassays for the Evaluation of Landfill Leachate Toxicity

Abstract

This article reviews the application of bioassays for assessing the toxicity hazard posed by landfill leachate discharged to an aquatic environment. Landfill leachate is a complex mixture of chemicals; thus it is difficult to assess the risk posed to aquatic wildlife using standard chemical identification techniques, such as gas chromatography-mass spectroscopy (GC-MS). From this review it is clear that toxicity testing, using species that represent the different trophic levels, is a superior way to predict the risk posed by discharge than chemical analysis. Previous studies assessed leachate toxicity using bacteria, algae, plants, invertebrates, fish, and genotoxicity. Studies showed that leachate exhibits a wide range of toxicities to the species tested. Ammonia, alkalinity, heavy metals, and recalcitrant organics were identified to be the cause of adverse responses from the test organisms. Concentrations of these chemicals were found to depend upon the types of waste landfilled. As part of this review, Slooff analysis was applied to published results to calculate the sensitivity of test species. It was concluded that Lemna minor and Thamnocephalus platyurus were the most sensitive tests and, Vibrio fischeri (Microtox) was the least sensitive test available. Little is known about the sensitivity of each species to the different types of waste that might have been landfilled. A battery of tests needed for a more accurate assessment of landfill leachate is proposed. Some of the more common tests have been replaced by more sensitive tests that produce more relevant results for the industry and regulators.

Comparison of chronic low-dose effects of alpha- and beta-emitting radionuclides on marine bacteria

“…Later, it was modified by different researchers and adapted for their specific purposes [2][3][4][5][6]. Now, the bacterial bioluminescent assay is a traditional and important biotechnological application of the bioluminescence phenomenon [7][8][9][10][11]. The tested physiological parameter here is luminescence intensity that can be easily measured instrumentally.…”

Options for the Treatment and Management of Municipal Landfill Leachate: Common and Specific Issues

“…Given the complexity of landfill leachates, the exact contribution of each potential toxic substance is difficult to be determined precisely applying standard chemical identification techniques, such as gas chromatography-mass spectroscopy (GC-MS) [57,58]. The hazard poses by landfill leachate is evaluated today using species that represent various trophic levels (bacteria, algae, plants, intervertebrates, fish, and genotoxicity), in order to predict the risk induced by the complex mixture of chemicals from leachate [58].…”

Sorption of Pyrene by Clay Minerals Coated with Dissolved Organic Matter (DOM) from Landfill Leachate

“…The contamination of soil and groundwater attributed to the migration of municipal solid waste (MSW) leachate from dilute-and-disperse landfills has aroused much concern [1][2][3]. High content of dissolved organic matter (DOM) is present in the landfill leachate, which significantly affects the sorption and transport of various pollutants in soils [4][5][6][7], and adsorption of DOM onto clay minerals in soils is an important process in the natural environment.…”