Krithika D, Thomas Anu Rachel, Iyer Gomathy R, Kranert Martin, Philip Ligy
Environmental and Water Resources Engineering Division, Department of Civil Engineering, IIT Madras, Chennai, 600 036, India.
Institute for Sanitary Engineering, Water Quality and Solid Waste Management, University of Stuttgart, Stuttgart, Germany.
Environ Sci Pollut Res Int. 2017 Mar;24(8):7060-7076. doi: 10.1007/s11356-016-8336-z. Epub 2017 Jan 16.
Septage is the solid sludge that accumulates in septic tanks over a period of time. Many of the developing countries in the world face the challenging task of septage management. Due to the high variability in the nature of septage, there is a need to study its physical and chemical characteristics in order to suggest a sustainable treatment methodology. The present study deals with the characterization of septage collected from different locations of Chennai city in India, in two different seasons (summer and winter). The characterization includes parameters such as solids, organics, inorganics, nutrients and heavy metals. Septage showed significant difference in concentrations of pollutants from one season to the other (p > 0.05). The average total solids concentration is found to be 1.6 times higher during winter season than compared to summer season. Average concentrations of solids were 2185 ± 1070 and 3555 ± 2935 mg/L during summer and winter, respectively. Liquid characterization of septage showed total chemical oxygen demands (COD) of 905 ± 603 mg/L (summer) and 1460 ± 1295 mg/L (winter). Similarly, average soluble biochemical oxygen demand (sBOD) was found to be 117 ± 54 mg/L during summer and 211 ± 220 mg/L during winter season. Studies also showed that septage was rich in nutrients such as total nitrogen (4-500 mg/L), ammoniacal nitrogen (2-129 mg/L), total phosphate (5-236 mg/L) and heavy metals such as copper, zinc, lead and manganese. Overall characterization indicates that the collected septage samples are highly variable in nature with respect to sources, season and locations of collection. As the septage is rich in organic matter and nutrients, it can be used as a resource like soil conditioner or as a substitute for chemical fertilizer in agriculture, after proper treatment, leading to a new evolution in sanitation.
化粪池污泥是一段时间内积聚在化粪池中的固体污泥。世界上许多发展中国家都面临着化粪池污泥管理这一具有挑战性的任务。由于化粪池污泥性质的高度变异性，有必要研究其物理和化学特性，以便提出一种可持续的处理方法。本研究涉及从印度钦奈市不同地点在两个不同季节（夏季和冬季）收集的化粪池污泥的特性分析。特性分析包括固体、有机物、无机物、营养物质和重金属等参数。化粪池污泥在不同季节的污染物浓度存在显著差异（p>0.05）。发现冬季的平均总固体浓度比夏季高1.6倍。夏季和冬季固体的平均浓度分别为2185±1070和3555±2935mg/L。化粪池污泥的液体特性表明，夏季和冬季的总化学需氧量（COD）分别为905±603mg/L和1460±1295mg/L。同样，夏季平均可溶性生化需氧量（sBOD）为117±54mg/L，冬季为211±220mg/L。研究还表明，化粪池污泥富含总氮（4 - 500mg/L）、氨氮（2 - 129mg/L）、总磷（5 - 236mg/L）等营养物质以及铜、锌、铅和锰等重金属。总体特性表明，收集到的化粪池污泥样品在来源、季节和收集地点方面性质差异很大。由于化粪池污泥富含有机物和营养物质，经过适当处理后，它可以用作土壤改良剂等资源或替代农业中的化肥，从而带来卫生领域的新变革。
