Potential of Waste Water Sludge as Environmental-Friendly Manure after UV-Treatment

Laila Zafar ； Asif Javed ； Syed Shahid Ali ； Zubair Anwar ； Jabar Zaman Khan Khattak

《Research Journal of Environmental and Earth Sciences》 4卷10期 (2012/10) Pp. 917-922

並列摘要

Due to exponential population increase in developing world, the wastewater and solid waste generation has tremendously increased and their management has become a serious health and environmental issue. A large amount of sewage sludge generated by sewage treatment plants however, can be re-used after proper segregation and treatment as fertilizer and for energy production. Hence, this study was carried out to find out the potential use of sludge produced at Islamabad Capital Territory (ICT) Sewage Treatment Plant (STP) as organic fertilizer. For this purpose, chemical analysis of the waste water was carried out to determine the quality of raw waste water (influent) and treated waste water (effluent) intermittently. Furthermore, post-wastewater treatment, sewage sludge was analyzed for its chemical characteristics, i.e., for Total Nitrogen (TN), Total Phosphorous (TP) and Organic Matter (OM) contents; and microbial analyses for the presence of Total Coliforms, Fecal Coliforms and E. Coli was also carried out sewage sludge was exposed to sunlight for 0, 3 and 6 months. The results were with commercial compost (control) similar characteristics. According to the results, pH, EC, TSS, COD and BOD5 were found very high in the influent however, after the waste water treatment; the effluent quality was found within the limits of National Environmental Quality standards (NEQs). On the other hand, TN, TP and OM content remained high in sewage sludge as compared to the controls. In order to enumerate harmful microbes in sewage sludge, microbial analyses for Total Coliforms, Fecal Coliforms and E. coli was carried out in pre-treated, UV-post-treated and control sludge samples. According to the results, the Total and Fecal Coliforms were found very high (＞16000 MPN/g) whereas, E. Coli population remained between (7000-12000 MPN/g). The most important aspect noted in this study was: as the sludge aged, this figure (7,000, 12,000, and 1,600 MPN/g after 0, 3 and 6 months of exposure to sunlight (UVlight). However, the number of microbes was above NEQs Standard. From the results, it can be concluded that sewage sludge has the potential to be used in greenbelts, forests and can also be applied for some restricted agricultural purpose after ample sunlight exposure.

並列關鍵字

Natural manure ； reuse potential ； sludge ； UV-light treatment ； waste water