Bioaugmentation process of secondary effluents for reduction of pathogens, heavy metals and antibiotics

• Published in: Journal of water and health Vol. 14; no. 5; pp. 780 - 795
• Main Authors: Al-Gheethi, A A, Mohamed, R M S R, Efaq, A N, Norli, I, Abd Halid, Abdullah, Amir, H K, Ab Kadir, M O
• Format: Journal Article
• Language: English
• Published: England IWA Publishing 01.10.2016
• Subjects: Adsorption; Amides; Anti-Bacterial Agents - metabolism; Antibiotics; Bacillus subtilis; Bacillus subtilis - physiology; Bacteria; Bacterial Physiological Phenomena; beta-Lactams - metabolism; Bioaccumulation; Biodegradation; Cephalexin; Detection limits; Efficiency; Effluents; Enterobacteriaceae - physiology; Environmental protection; Fecal coliforms; Feces - microbiology; Heat treatment; Heavy metals; Hot Temperature; Indicators; Metals, Heavy - metabolism; Oxidation; Pathogens; Reduction (metal working); Salmonella; Sewage disposal; Sludge; Staphylococcus aureus; Staphylococcus infections; Urine; Waste Water - analysis; Waste Water - microbiology; Water Pollutants, Chemical - metabolism; β-Lactam antibiotics
• ISSN: 1477-8920; 1996-7829
• DOI: 10.2166/wh.2016.046

The study probed into reducing faecal indicators and pathogenic bacteria, heavy metals and β-lactam antibiotics, from four types of secondary effluents by bioaugmentation process, which was conducted with Bacillus subtilis strain at 45 °C. As a result, faecal indicators and pathogenic bacteria were reduced due to the effect of thermal treatment process (45 °C), while the removal of heavy metals and β-lactam antibiotics was performed through the functions of bioaccumulation and biodegradation processes of B. subtilis. Faecal coliform met the guidelines outlined by WHO and US EPA standards after 4 and 16 days, respectively. Salmonella spp. and Staphylococcus aureus were reduced to below the detection limits without renewed growth in the final effluents determined by using a culture-based method. Furthermore, 13.5% and 56.1% of cephalexin had been removed, respectively, from secondary effluents containing 1 g of cephalexin L (secondary effluent 3), as well as 1 g of cephalexin L and 10 mg of Ni L (secondary effluent 4) after 16 days. The treatment process, eventually, successfully removed 96.6% and 66.3% of Ni ions from the secondary effluents containing 10 mg of Ni L (secondary effluent 2) and E4, respectively. The bioaugmentation process improved the quality of secondary effluents.