Aerobic biodegradation of chlordane in natural and enhanced water environment

• Main Authors: Rosqueta, Ryan Lloyd O., Tan, Aimee Kathleen T., Wong, Joana P.
• Format: text
• Language: English
• Published: Animo Repository 2005
• Subjects: Chlordan > Toxicology; Chlordan > Environmental aspects; Chemical Engineering
• Online Access: https://animorepository.dlsu.edu.ph/etd_bachelors/5868
• Institution: De La Salle University

Chlordane water contamination is a major issue that should be addressed in our country due to its adverse effects in human health and on the environment. Biodegradation of chlordane in natural and enhanced water environment must be studied since there is no specific work on this that has been published. Chemical oxygen demand (COD), pH, optical density and gas chromatography with electron capture detection were used to determine the degradation of chlordane. In the enhanced biodegradation, microorganisms from PCB-acclimatized biofilm were used to develop biofilms on cement balls in a three-phase fluidized-bed Imhoff cones with Basal salt medium. Natural biodegradation used mixed microbial culture isolated by enrichment with chlordane from a chlordane-contaminated soil. The biofilm and isolated microorganisms were acclimatized to chlordane weekly by batch for a period of 4 weeks. Biodegradation experiments were conducted in a 24-hour batch runs after the acclimatization. Based on the water culture analysis, Acinetobacter baumannii, Acinetobacter iwoffii and Bacillus species were the mixed bacterial species present in the natural environment while Acinetobacter iwoffii was found in the enhanced environment. Growth of microorganisms was observed in the presence of chlordane as sole carbon source in natural environment. The COD gradually reduce with time for all the weekly batch acclimatization and the 24-batch run experiments. In natural environment, the degradation of trans- and cis-chlordane was faster in 24 hour batch run than in weekly batch acclimatization. High range of 8 increasing peaks was observed in the GC chromatogram during fifth and seventh day of the weekly batch acclimatization for the natural and enhanced environment that indicates possible metabolites of chlordane.