Eawag: Swiss Federal Institute of Aquatic Science and Technology, Sandec: Department of Water and Sanitation in Developing Countries, Dübendorf, Switzerland.
Eawag: Swiss Federal Institute of Aquatic Science and Technology, Siam: Systems Analysis, Integrated Assessment and Modelling, Dübendorf, Switzerland.
J Environ Manage. 2020 May 1;261:110202. doi: 10.1016/j.jenvman.2020.110202. Epub 2020 Mar 2.
The importance of faecal sludge management is gaining recognition. However, methods are still lacking to reasonably estimate the quantities and qualities (Q&Q) that need to be managed, which makes the planning for and implementing of management solutions quite difficult. The objective of this study was to collect and analyse Q&Q of faecal sludge at a citywide scale, and to evaluate whether "SPA-DET" data (=> spatially analysable - demographic, environmental and technical) could then be used as predictors of Q&Q of faecal sludge. 60 field samples and questionnaires from Hanoi and 180 from Kampala were analysed. Software tools were used in an iterative process to predict total solids (TS) and emptying frequency in both Hanoi, Vietnam and Kampala, Uganda. City-specific data could be predicted with types of "SPA-DET" data as input variables, and model performance was improved by analysing septic tanks and pit latrines separately. Individual models were built for TS concentrations and emptying frequency. In addition, a model was built across both cities for emptying frequency of septic tanks based on number of users and containment volume, indicating predictive models can be relevant for multiple cities. Number of users, containment volume, truck volume and income level were identified as the most common variables for the correction function. Results confirm the high intrinsic variability of faecal sludge characteristics, and illustrate the importance of moving beyond simple reporting of city-wide average values for estimations of Q&Q. The collected data and developed scripts have been made available for replication in future studies.
粪便污泥管理的重要性正在得到认可。然而，仍然缺乏合理估计需要管理的数量和质量（Q&Q）的方法，这使得管理解决方案的规划和实施变得相当困难。本研究的目的是在全市范围内收集和分析粪便污泥的 Q&Q，并评估“SPA-DET”数据（可空间分析的人口统计学、环境和技术数据）是否可以用作粪便污泥 Q&Q 的预测因子。对来自越南河内的 60 个现场样本和问卷调查以及来自乌干达坎帕拉的 180 个样本进行了分析。软件工具在迭代过程中用于预测越南河内和乌干达坎帕拉的总固体（TS）和排空频率。可以使用特定于城市的数据作为输入变量来预测“SPA-DET”数据类型，并且通过分别分析化粪池和坑式厕所可以提高模型性能。针对 TS 浓度和排空频率分别建立了个体模型。此外，还基于用户数量和容纳体积，针对化粪池的排空频率在两个城市之间建立了一个模型，表明预测模型可以适用于多个城市。用户数量、容纳体积、卡车体积和收入水平被确定为校正函数的最常见变量。结果证实了粪便污泥特性的高度内在可变性，并说明了超越简单报告全市平均值进行 Q&Q 估计的重要性。已收集的数据和开发的脚本可用于未来研究的复制。
