Arora Sudipti, Rajpal Ankur, Kumar Tarun, Bhargava Renu, Kazmi A A
Environmental Engineering group, Department of Civil Engineering, Indian Institute of Technology Roorkee (IIT), Roorkee-247667, India E-mail:
Water Sci Technol. 2014;70(6):996-1003. doi: 10.2166/wst.2014.318.
The present study focuses on the effect of filter media (riverbed gravel, mud balls, coal and glass balls) for the removal of pathogens during vermifiltration of domestic wastewater. This novel study was conducted for the first time on different vermifilters (VFs) with different media, and pathogen removal was extensively investigated for a period of 3 months. Results indicated that vermifilter with riverbed material (VFR) showed maximum biochemical oxygen demand and chemical oxygen demand removal of 76 and 67%, respectively and vermifilter with mud balls (VFM) showed maximum log removal of total coliforms (2.8), fecal coliforms (2.7), fecal streptococci (2.2), Salmonella (2.1) and Escherichia coli (2.1). The area-based bacterial removal rate constant (k) was found in the range of 2.96-6.68 m/d, which is very high in comparison to the reported values. The population of total heterotrophic bacteria and total fungi was found to be 2-log (99%) higher in VFR and VFM, as compared to other media. The growth rate of Eisenia fetida was higher (42% increase in biomass) in glass balls vermifilter (VFG), and also the abrasions on the body wall of earthworms in VFG showed fewer injuries. Overall, the results of the study described the importance and role of each filter medium.
本研究聚焦于过滤介质（河床砾石、泥球、煤和玻璃球）在生活污水蚯蚓过滤过程中对病原体的去除效果。这项新颖的研究首次在使用不同介质的不同蚯蚓滤池（VF）上进行，并对病原体去除情况进行了为期3个月的广泛研究。结果表明，装有河床材料的蚯蚓滤池（VFR）的生化需氧量和化学需氧量去除率最高，分别为76%和67%，装有泥球的蚯蚓滤池（VFM）对总大肠菌群（对数去除率2.8）、粪大肠菌群（对数去除率2.7）、粪链球菌（对数去除率2.2）、沙门氏菌（对数去除率2.1）和大肠杆菌（对数去除率2.1）的对数去除率最高。基于面积的细菌去除速率常数（k）在2.96 - 6.68 m/d范围内，与报道值相比非常高。与其他介质相比，VFR和VFM中总异养细菌和总真菌的数量高出2个对数（99%）。在玻璃球蚯蚓滤池（VFG）中，赤子爱胜蚓的生长速率更高（生物量增加42%），而且VFG中蚯蚓体壁的擦伤显示损伤较少。总体而言，该研究结果描述了每种过滤介质的重要性和作用。
