Department of Civil & Environmental Engineering, Duke University, Durham, NC, USA; Triangle Environmental Health Initiative, Durham, NC, USA.
Department of Civil & Environmental Engineering, Duke University, Durham, NC, USA.
Chemosphere. 2020 Oct;257:127219. doi: 10.1016/j.chemosphere.2020.127219. Epub 2020 May 28.
There is a great need for simple methods for digestate management for potential household sanitation systems based on anaerobic digestion of minimally diluted fecal waste in countries that lack safe sanitation. Herein, a full-scale three-stage filter for nitrogen and phosphorus removal from anaerobic digester effluent was implemented in Madagascar. It included a trickling filter with crushed charcoal (for aerobic nitrification), a submerged anaerobic filter with bamboo chips (for denitrification), and a submerged filter with scrap iron (for phosphorus removal). All filter materials were sourced locally. Three parallel replicate systems were operated in two sequential 8-week phases for a total of 16 continuous weeks. Though the influent feed was not as expected, with much of nitrogen in the feed coming in as organic N and not as NH-N, the filters still removed 38-49% of total incoming nitrogen. The filters achieved high rates of nitrogen transformation along with removing solids (73-82% turbidity removal), chemical oxygen demand (67-75% removal), and phosphorus (31-50% removal). Overall, the reaction rates from this full-scale study were in line with previous lab-scale investigations with scaled-down systems, supporting their application in real-world scenarios. Based on this study, simple effluent filters can support nutrient removal for small-scale and onsite fecal sludge treatment systems.
对于那些缺乏安全卫生设施的国家，基于最小稀释粪便的厌氧消化来开发家用卫生系统，因此需要简单的粪便处理方法。本文在马达加斯加实施了一种从厌氧消化废水中去除氮磷的全规模三级过滤系统。该系统包括一个带有碎木炭的滴滤器（用于好氧硝化）、一个带有竹片的淹没式厌氧滤池（用于反硝化）和一个带有废铁的淹没式滤池（用于除磷）。所有的过滤材料均来自当地。三个平行的重复系统在两个连续的 8 周阶段运行，共持续 16 周的连续运行。尽管进水并不如预期，进水中的大部分氮以有机氮的形式存在，而不是 NH-N，但过滤器仍去除了 38-49%的总进水氮。过滤器实现了高氮转化速率，同时去除了固体（73-82%的浊度去除率）、化学需氧量（67-75%的去除率）和磷（31-50%的去除率）。总的来说，这项全规模研究的反应速率与以前使用缩小规模系统的实验室规模研究一致，支持它们在实际场景中的应用。基于这项研究，简单的出水过滤器可以支持小型和现场粪便污泥处理系统的养分去除。
