Characterization and toxicological evaluation of leachate from Bacolod city sanitary landfill using tilapia ( Oreochromis niloticus): a preliminary study

摘要

This study was carried out to characterize and assess the toxicity of Bacolod City Landfill leachate using Tilapia as bio-indicator species. Acclimatized Oreochromis niloticus fishes (length of 14 cm ± 2.0 cm and weight of 11.8 g ± 0.9 g) were introduced into each treatment tank containing three different concentrations of leachate in duplicates (10 ppm, 50 ppm and 100 ppm) and a control group. Physical reactions were observed such as erratic swimming, loss of reflex, hyperactivities, and surfacing. Reactions and mortality rate increased with increasing concentration and duration of exposure. Mortality rate using One-way Analysis of Variance (ANOVA) and Duncan’s Multiple Range Test (DMRT) revealed a significant difference between treatment groups and exhibited 100 ppm as the most potent concentration. Heavy metal analysis of Cu and Pb as well as physicochemical analysis of color, Chimecal Oxygen Demande (COD) and Total dissolved Solids (TDS) exceeded the country’s environmental standard set by DENR. The 96 h bioassay stemmed the median lethal concentration (LC50) at 57.688 ppm. The study provides a biomarker database in taking action for the responsible enactment and enforcement of laws to upgrade, enhance and install framework for proper treatment of sanitary landfill leachate in cities and municipalities in the country.