Towards a rational design to sanitation systems in developing countries

全球卫生基础设施仍然非常差。这导致了十分之四的人生活在人类排泄物周围的情况。现场卫生方面的许多技术挑战被认为是由于缺乏以健全的科学和工程为基础的适当的设计准则。城市周边社区最紧迫的问题之一是坑式厕所迅速填满的问题。贫困居民很多时候没有资源安全地清空他们的粪坑，导致露天排便。有证据表明，粪坑的填充率可能受到氨(存在于人类排泄物中)的抑制作用以及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中的污泥积累和降解过程，从而为穷人设计卫生系统的基本原理。在这一主题下，拟议项目的具体目标是：(1)确定氨气对坑厕产甲烷的抑制作用；(2)评估尿液改道和提高坑厕温度对加速坑厕内厌氧消化的益处；(3)探索可受益于对坑厕过程的进一步了解以保护人类健康和环境的有前景的坑厕废物处理技术/方法。一旦坑式厕所从只收集和储存人类排泄物的拙劣“地下洞穴”转移到可以处理粪便污泥的工程“反应堆”，它们的健康益处就可以通过延长使用寿命得到支持。

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.