Effects of detention time and ozone dosage on organic content removal and biodegradability index in high salinity leachate

Abstract

Old leachate from the waste management process can negatively impact the environment if it is not appropriately treated. Commonly, old leachate processing is complicated in view of its low biodegradability, making it impossible to be treated by biological processes. One technology that can increase biodegradability is ozonation. This study aims to determine the effects of dosed ozone on organic removal and the improvement of biodegradability in aged high salinity leachate. This study used leachate samples from the Jungut Batu Landfill in Nusa Lembongan, Klungkung Regency, Indonesia. Something that needs to be considered from the leachate characteristics in the study site included the high salinity value that might lead to low biodegradability. Variations in this study were detention time and ozone dose administration (1, 10, 30, and 100 mg·O3 /min). The initial characteristics of leachate in the study site showed very low biodegradability, reaching 0.084. During the 60-min detention, the maximum chemical oxygen demand (COD) removal could only reach a value of 21.1% (100 mg·O3 /min). At the same time, the ozonation process could achieve an increase in biochemical oxygen demand (BOD)/COD biodegradability of 0.156. Multivariant test results on ozone dosing variations significantly affected organic degradation (BOD and COD) and increased biodegradability.