Evaluation of Pathogen Removal in a Solar Sludge Drying Facility Using Microbial Indicators

Abstract

South East Queensland is one of the fastest growing regions in Australia with a correspondingly rapid increase in sewage production. In response, local councils are investing in more effective and sustainable options for the treatment and reuse of domestic and industrial effluents. A novel, evaporative solar dryer system has been installed on the Sunshine Coast to convert sewage sludge into a drier, usable form of biosolids through solar radiation exposure resulting in decreased moisture concentration and pathogen reduction. Solar-dried biosolids were analyzed for selected pathogenic microbial, metal and organic contaminants at the end of different drying cycles in a collaborative study conducted with the Regional Council. Although fecal coliforms were found to be present, enteroviruses, parasites, E. coli, and Salmonella sp. were not detected in the final product. However, elevated levels of zinc and copper were still present which restricted public use of the biosolids. Dilution of the dried biosolids with green waste as well as composting of the biosolids is likely to lead to the production of an environmentally safe, Class A end-product.

Fecal contamination of wastewater treatment plants in Portugal

“…It is essential to guarantee the elimination of potential pathogenic bacteria, which may be responsible for diseases such as dysentery, typhoid, and gastroenteritis (Hendricks and Pool 2012;Romano et al 2012). Biological, physical, and chemical methods can be applied with the purpose of eliminating potential pathogenic bacteria from wastewater (Prasse et al 2015) and respective sludges (Shanahan et al 2010), to produce effluents and other by-products that can be reused. The methods chosen depend on the future application of the treated effluents and also on each country's legislation (Shanahan et al 2010).…”

“…Biological, physical, and chemical methods can be applied with the purpose of eliminating potential pathogenic bacteria from wastewater (Prasse et al 2015) and respective sludges (Shanahan et al 2010), to produce effluents and other by-products that can be reused. The methods chosen depend on the future application of the treated effluents and also on each country's legislation (Shanahan et al 2010). Wastewaters from municipal plants are mostly contaminated by human feces, whose amount and composition have influence in the bacterial load of these effluents (Dubreuil 2012;Hendricks and Pool 2012).…”

Behavior of Metals, Pathogen Parasites, and Indicator Bacteria in Sewage Effluents During Biological Treatment by Activated Sludge

“…Generally, the release of raw sewage into rivers causes environmental degradation by the spread of disease and the impairment of water quality, which may then become unfit for certain uses [2,3]. The composition of the sewage sludge depends mainly on the origin of the residues treated: domestic or industrial activities [3,4].…”

Avaliação da sobrevivência de indicadores bacterianos e vírus durante higienização de lodo de esgoto por secagem térmica em estufa agrícola

“…A estratégia de tratamento adotada no estudo por meio da manutenção de lodo previamente desaguado em estufa agrícola, disposto diretamente no solo na forma de leira, revolvido manualmente a cada sete dias, proporcionou a obtenção de um produto granulado, extremamente seco e de volume reduzido, corroborando o que foi reportado em estudos no Brasil (COMPARINI & ALÉM SOBRINHO, 2002; LIMA, 2010; DIAS, 2012) e em diferentes países (BUX et al, 2002;SALIHOGLU;PINARLI;SALIHOGLU, 2007;SHANAHAN et al, 2010;MATHIOUDAKIS et al, 2009), em que a exposição à radiação solar incidente sobre o filme plástico da estufa eleva a temperatura interna e proporciona a perda progressiva da umidade, na mesma medida em que concentra os sólidos presentes e reduz o volume da leira de lodo.…”

“…*Unidade formadora de placa/grama de sólidos total. (BUX et al, 2002;SALIHOGLU;PINARLI;SALIHOGLU, 2007;SHANAHAN et al, 2010;MATHIOUDAKIS et al, 2009).…”