Anaerobic treatment of the domestic sewer for fertirrigation

Abstract The utilization of treated sewage for agricultural purposes means saving of fertilizer and water of good quality, therefore, it may seen as an alternative in its scarcity. Several treatment processes have been developed to produce an effluent with a suitable quality for fertirrigation, while avoiding contamination of the environment with pathogens that may cause serious public health problems and may affect workers consumers of and agricultural product. This research had as its objective to treat sewage in a UASB reactor followed by an anaerobic filter with the aim of obtaining an adequate effluent for agricultural reuse. The filter effluent contained suficiente macro and micro nutrients to grow most crops under the local conditions of the semi arid region. However the concentration of thermo tolerant Coliforms was above the recommend maximum by the WHO, while no helminth eggs were observed in the effluent. Hence the effluent could only be used for restricted irrigation.

摘要 将经处理的污水用于农业生产，可节约优质肥料与水资源，因此在优质资源匮乏的情况下，该方案可作为替代途径。目前已开发出多种污水处理工艺，可制备出符合水肥灌溉（fertirrigation）要求的出水，同时避免环境受到病原体污染——此类病原体可能引发严重公共卫生问题，还会对农产品从业者与消费者造成不利影响。本研究采用升流式厌氧污泥床（UASB）反应器搭配厌氧滤池处理污水，旨在获取可用于农业回用的达标出水。该厌氧滤池出水含有充足的宏量与微量营养元素，在半干旱地区的本地条件下，可满足多数农作物的生长需求。然而，出水中的耐热大肠菌群（thermotolerant Coliforms）浓度超出了世界卫生组织（WHO）推荐的最高限值，但出水未检出蠕虫卵。因此，该出水仅可用于受限灌溉。