Hafford Lauren M, Ward Barbara J, Weimer Alan W, Linden Karl
Department of Civil, Environmental, and Architectural Engineering, University of Colorado Boulder, Boulder, CO, USA E-mail:
Sandec - Department of Sanitation, Water and Solid Waste for Development, Eawag - Swiss Federal Institute of Aquatic Science and Technology, Zurich, Switzerland.
Water Sci Technol. 2018 Dec;78(12):2437-2448. doi: 10.2166/wst.2019.005.
In many low-income cities, a high proportion of fecal sludge, the excreta and blackwater collected from onsite sanitation systems such as pit latrines, is not safely managed. This constitutes a major danger to environmental and human health. The water, sanitation, and hygiene sector has recognized that valorization of treated fecal sludge could offset the upfront cost of treatment by using it as a fuel source. The few quantitative studies on fecal sludge fuel published to date have focused on heating value, moisture, ash fraction, and heavy metals. However, other factors impacting fuel utility, specifically ash speciation, have not been adequately quantified for fecal sludge. This study contributes to closing that gap and shows the value of more detailed quantification. It first characterizes fecal sludge samples from Colorado and Uganda, confirms that the fuel is better if cofired with other biomass, and outlines a framework for determining safe cofire ratios. Second, the study evaluates two methods for improving fecal sludge as a fuel: carbonization and ash leaching. Carbonization of fecal sludge did not improve fuel quality, but leaching showed promise in ash reduction.
在许多低收入城市，很大一部分粪便污泥，即从诸如坑式厕所等现场卫生系统收集的排泄物和黑水，没有得到安全处理。这对环境和人类健康构成了重大威胁。水、环境卫生和个人卫生部门已经认识到，经过处理的粪便污泥的资源化利用可以通过将其用作燃料来源来抵消前期处理成本。迄今为止，为数不多的关于粪便污泥燃料的定量研究主要集中在热值、水分、灰分和重金属方面。然而，对于粪便污泥而言，影响燃料效用的其他因素，特别是灰分形态，尚未得到充分量化。本研究有助于填补这一空白，并展示了更详细量化的价值。它首先对来自科罗拉多州和乌干达的粪便污泥样本进行了表征，证实了与其他生物质混烧时燃料性能更佳，并概述了确定安全混烧比例的框架。其次，该研究评估了两种改善粪便污泥作为燃料的方法：碳化和灰分浸出。粪便污泥的碳化并未提高燃料质量，但浸出在减少灰分方面显示出了前景。
