Evaluation of acute phytotoxicity of raw leachate and landfill leachate using Sorghum bicolor seeds

Abstract

Background: Leachate, a highly contaminated liquid, is produced by separating wastes and introducing moisture into the waste layers. Biological toxicity evaluation is a method that may be used to analyze the toxicity of leachate to organisms and plants. Sorghum bicolor was employed in this study to evaluate the acute toxicity of raw leachate and landfill leachate. Methods: Leachate was collected from different locations within the refuse that was collected and mixed in a sampling container. The physiochemical characteristics of the leachate were analyzed in both raw leachate and landfill leachate. Germination rate, root weight, and root length were measured 24, 48, and 72 hours after planting for leachate dilutions of 25%, 50%, 75%, and 100%, respectively. Results: Raw leachate had greater concentrations of metals (Fe, Zn, Cu, Mn, Cr, Cd, and Pb), chemical oxygen demand (COD), total dissolved solids (TDS), total suspended solids (TSS), nitrate, ammonia, and phosphate, as well as a more acidic pH (<6), as compared to landfill leachate. The results showed that landfill leachate had a lower potential for toxicity than raw leachate, with seed-germination rates of 0.1 and 0 in the presence of 75% landfill leachate after 48 and 72 hours, respectively, as opposed to 0.3 and 0.1 in the presence of raw leachate. Conclusion: The findings show that raw leachate can include higher concentrations of metals and organic compounds, which can be one of the causes of Sorghum seed phytotoxicity. Waste leachate management is one of the most important pillars of environmental protection, and it should be taken into consideration by the right authorities.