Towards a rational design to sanitation systems in developing countries

全球卫生基础设施仍然极其薄弱。这导致十分之四的人生活在人类排泄物的包围中。现场卫生方面的许多技术挑战被认为是由于缺乏基于健全科学和工程的适当设计准则。近郊社区最紧迫的问题之一是坑式厕所迅速被填满。贫困居民很多时候没有安全排便的资源，导致露天排便。有证据表明，坑的填充率可能受到氨（存在于人类废物中）的抑制作用和缺乏有利于生物质转化的工程条件的影响。*总体目标是更好地了解坑式厕所的污泥积累和降解过程，从而为穷人设计基本的卫生系统。在这个主题中，拟议项目的具体目标是：(1)描述氨对坑式厕所甲烷生成的抑制作用；(2)评价尿液分流和提高坑-厕所温度加速坑内厌氧消化的效益；(3)探索有前途的坑废物处理技术/方法，这些技术/方法可以从进一步了解坑-厕所过程中受益，以保护人类健康和环境。一旦坑式厕所从只是收集和储存人类排泄物的简陋的“地洞”转变为可以处理粪便污泥的工程“反应器”，它们的健康效益就可以通过延长使用寿命而得到加强。

Global sanitation infrastructure remains extremely poor. This contributes to the situation in which four-in-ten people live surrounded by human excrement. Many of the technical challenges in on-site sanitation are thought to result from a lack of adequate design guidelines based on sound science and engineering. One of the most pressing problems in peri-urban communities is that of rapidly-filling pit-latrines. Poor residents many times do not have resources to safely empty their pits, resulting in open defecation. Evidence indicates that the filling rate of pits may be affected by inhibitive effects of ammonia (present in human waste) and a lack of engineered conditions favouring biomass conversion.*The overall objective is to better understand sludge accumulation and degradation processes in pit latrines, leading to a rationale design of sanitation systems for the poor. Within this theme, the specific objectives of the proposed project are to (1) characterise ammonia inhibition of methanogenisis in pit-latrines; (2) evaluate benefits of urine diversion and raised pit-latrine temperatures to accelerate anaerobic digestion within pits; and (3) explore promising pit waste treatment technologies/methods that could benefit from the further understanding of pit-latrine processes to protect human health and the environment. Once pit-latrines move from being poorly-conceived "holes in the ground" that only capture and store human waste to engineered "reactors" that can treat faecal sludge, their health benefits can be bolstered through an extended service life.