A combined application of different engineering and biological techniques to remediate a heavily polluted river

Abstract

a b s t r a c tRiver pollution is becoming a serious problem worldwide. A field-scale experiment was undertaken to remediate a heavily polluted river using a combined engineering approach of aeration, microorganisms, biological aerated filtration, artificial biofilms and ecological floating beds. Prior to remediation, the river water was black, anoxic and highly sulfidic. With remediation, the chemical oxygen demand decreased from ∼250 to ∼50 mg L −1 , NH 4 + -N decreased from ∼27 to ∼4 mg L −1 , sulfide decreased from ∼3 to ∼0.3 mg L −1 , and total suspended solids decreased from ∼270 to ∼40 mg L −1 . At the same time, dissolved oxygen increased from ∼0.1 to ∼3.5 mg L −1 , and water clarity increased from ∼6 to ∼40 cm. Furthermore, the unpleasant odor emanating from the polluted river was also stopped, and local farmers have begun using the water for irrigation. This field-scale experiment thus indicates the potential usefulness of this combined engineering approach to remediate heavily polluted rivers.

Advanced nutrient removal from surface water by a consortium of attached microalgae and bacteria: A review

“…Ecological floating bed Long retention time, high effluent N/P concentration, low efficiency in cold seasons, low efficiency in deep water Hu et al (2010), Cao and Zhang (2014) Constructed wetland Long retention time, high effluent N/P concentration, large area, low efficiency in cold seasons, long setting up phase Li et al (2008), Dunne et al (2013) Macro hydrophyte pond Long retention time, high effluent N/P concentration, low efficiency in cold seasons, long setting up phase Das et al (2009) Functional microbes Long retention time, potential secondary pollution, high dependence on organic carbon availability, unstable community and easy to crash Sheng et al (2013); Michaud et al (2014), Chen et al (2015) treatment by CW (Dunne et al, 2013). These relatively high remaining nutrient concentrations make it difficult to meet the strict standards for surface water quality (e.g., less than 1.5 and 0.1 mg L À1 for TN and TP, respectively), and innovative approaches for advanced nutrient removal are urgently needed.…”

Construction of Microbial Consortium and Its Directly Treatment for the Black-odor Water

“…Especially in summer, most of urban rivers appear seasonal or perennial black-odor phenomenon [1]. This not only destroys the urban water ecological environment, but also seriously affects people's normal life.…”

Study on the application of integrated eco-engineering in purifying eutrophic river waters

“…These approaches have superiorities in maintaining the stability and longevity of the remediation effectiveness, and they usually require less time, space and cost. However, there have been only a few reports concerning the application of integrated eco-engineering in remediation of polluted rivers and most of these studies were performed with laboratory, microcosm or mesocosm experiments (Mi et al, 2014;Sheng et al, 2013;Wang et al, 2009Wang et al, , 2010. Particularly, the knowledge about ecological river engineering is still scarce in China and neighboring Korea (Woo, 2010).…”