Performance evaluation of different wastewater treatment technologies operating in a developing country

Abstract

This article analyses the performance of 166 wastewater treatment plants operating in Brazil, comprising six different treatment processes: septic tank þ anaerobic filter, facultative pond, anaerobic pond þ facultative pond, activated sludge, UASB reactors alone, UASB reactors followed by post-treatment. The study evaluates and compares the observed effluent quality and the removal efficiencies in terms of BOD, COD, TSS, TN, TP and FC with typical values reported in the technical literature. In view of the large performance variability observed, the existence of a relationship between design/operational parameters and treatment performance was investigated. From the results obtained, no consistent relationship between loading rates and effluent quality was found.The influence of loading rates differed from plant to plant, and the effluent quality was dictated by several combined factors related to design and operation.

Evaluation of Wastewater Treatment Plants in El-Gharbia Governorate, Egypt

“…This process is widely used worldwide for the treatment of domestic and industrial wastewater, in situations where high effluent quality is necessary [22,23]. According to Francioso et al a number of AS processes and design configuration have evolved due to new regulations for effluent quality, technological advances, better understanding of microbial processes and to reduce costs.…”

“…Chemical oxygen demand (COD) is a measure of the amount of oxygen required to chemically oxidize reduced minerals and organic matter [22,23]. Higher levels of COD were observed in influent but were reduced, with a mean percentage removal efficiency of 38.9 (± 62.22) % in effluent in average.…”

Influence of Temperature on the Performance of a Full-Scale Activated Sludge Process Operated at Varying Solids Retention Times Whilst Treating Municipal Sewage

“…This practice is both environmentally unacceptable and obviously creates a potential threat to human and aquatic life alike [3]. In order to overcome this environmental pollution, more properly operated wastewater treatment plants are needed [4]. It has been reported that in Pakistan only 8% of the effluent discharged from domestic and industrial sources receive any treatment [5].…”

Urban Wastewater Treatment in Brazil

“…Source: Oliveira and von Sperling (2011) It was observed that the influent wastewater presented a mean concentration higher than that usually reported in the literature for prevailingly domestic wastewater. The simpler treatment systems, that is, ST+AF, FP and AP+FP, showed systematically much higher influent concentrations for all constituents, except fecal (thermotolerant) coliforms.…”

“…Due to the climatic, social and economic diversity of the region investigated, the results obtained are likely to be representative for other similar regions. The text below is mainly based on a simplification of Oliveira and von Sperling (2011), which links treatment performance with loading conditions and other factors.…”