Technical and natural conditions and operating efficiency of a municipal stormwater treatment plant

Abstract

A decade of observations provided grounds for assessing the operation of one of the few stormwater treatment plants in Poland (system: screens—grit chambers—settler—retention pond) which collects effluents from 471 ha of the city. Among other aspects, the following were evaluated: treatment efficiency, relationship between the quality of treated stormwater and that of waters in the receiving body (the ox-bow lake of the Vistula river), operating stability of key units, significance of the facility for nature. During the assessment, the plant had a positive effect on the quality of stormwater effluents—the content of the analysed pollutants was reduced (more than 80% average efficiency for mineral forms of nitrogen and suspension matter) and oxygen ratios improved (23% increase in the average concentration of dissolved oxygen and more than 50% decrease in 5-day biochemical oxygen demand and chemical oxygen demand). Although the overall assessment of the facility’s operation was good, some omissions and operating errors were noted (method of removing retained pollutants, stormwater flow control). Eliminating them is a prerequisite for maintaining the expected reliability of the system. An effect of stormwater ponds on the increase in biodiversity in the poor urbanised landscape has also been observed. The structures, forming a uniform system along with urban green areas, constitute specific enclaves which attract living organisms.

Occurrence, environmental implications and risk assessment of Bisphenol A in association with colloidal particles in an urban tropical river in Malaysia

“…During heavy rainfall periods, which correspond to our case in Bentong, WTPs and retention basins become overloaded causing untreated wastewater to spill straight into receiving water. Moreover, as rainfall scour across impermeable tops, it collects sediments, nutrients and further contaminants and deposits them into the closest watercourse 34 . Both of these incidents can increase BPA’s level in river water during heavy rain seasons, which overall might cause higher levels of BPA in summer in comparison with other seasons.…”

Time and Spatial Variability in Concentrations of Selected Pollutants in the New Bypass Rainwater Harvesting System

“…Taking into account individual reservoirs, the highest coefficients of variation, amounting to approximately 140%, were recorded in the case of NO 2 -(R5), TP (R2 and R4) and Cl -(R2). The research carried out in other facilities of the rainwater management in Lublin region also confirms significant variability in the quality of retained water (Zubala, 2013(Zubala, , 2018. This phenomenon results from the existence of a large number of factors determining the extent of pollution of rainfall runoffs.…”

The Working Conditions and Optimization of a Large Rainwater Harvesting and Treatment System in an Area at a Risk of Erosion

“…In other cases, it ranged from 7.1 (pH) to 76.0% (temperature). Studies carried out in other rainwater management facilities also con rm a considerable variability in the quality of rainwater (Peng et al 2016;Zubala 2018). This phenomenon is connected with the presence of many factors determining the degree of pollution of rainwater and rainwater run-offs.…”

“…Scienti c literature points to a strong correlation between the method of development of the drained area and the quality of precipitation run-off. Increased migration of pollutants can be expected in the case of road infrastructure, city centres, industrial grounds, and certain types of roo ng material (Liu et al 2014;Zubala 2018).…”