Enquiry into sewage pump station problems with specific focus on removing solids

[摘要] ENGLISH ABSTRACT: There is a general lack of published research on sewage pump station problems and the removalof solids in South African sanitary sewers. Research was undertaken to investigate the problemsat sewage pump stations by means of site visits, interviews, literature reviews and laboratoryexperiments. An in-depth literature study is presented on sewage pump stations, pump stationproblems and solids in sewers. The problems at sewage pump stations were categorised intoidentifiable groups with possible generalised solutions. The site visits and literature reviewindicated a specific lack of knowledge regarding screening baskets used to remove solids atsewage pumping stations. This led to the experimental testing of a screening basket on full scalein a controlled environment to develop an efficiency index for screening baskets. The efficiencyindex was determined using fuzzy logic methodology with predetermined solids load, basketheight above the sump level and solids retention time. The fuzzy logic proved that the basket isbest operated halfway submerged, after one hour retention time and with degradable solids in thesystem. The literature compiled and problems identified in this study were used as the backbonefor the development of a conceptual Decision Support Tool (DST) for sewage pump stations. TheDST is aimed at requiring limited inputs and providing maximum knowledge output and ispresented as a software tool in MS Excel format. The functionality was added by applying visualbasic applications in MS Excel user forms. The idea of developing a DST is to assist designers,sewage service providers and operators with understanding the various components and forproblem identification pertaining to sewage pump stations in the future. The DST is relativelyself-explanatory with a user friendly visual interface that is easy to operate. This study sets thescene for further research into efficiency indices pertaining to different components of sewagepump stations and their application in comprehensive sewage pump decision support tools.

[发布机构] Stellenbosch University