Pollutants’ Release, Redistribution and Remediation of Black Smelly River Sediment Based on Re-Suspension and Deep Aeration of Sediment

Abstract

Heavily polluted sediment is becoming an important part of water pollution, and this situation is particularly acute in developing countries. Sediment has gradually changed from being the pollution adsorbent to the release source and has influenced the water environment and public health. In this study, we evaluated the pollutant distribution in sediment in a heavily polluted river and agitated the sediment in a heavily polluted river to re-suspend it and re-release pollutants. We found that the levels of chemical oxygen demand (COD), NH4+-N, total nitrogen (TN), and total phosphorus (TP) in overlying water were significantly increased 60 min after agitation. The distribution of the pollutants in the sediment present high concentrations of pollutants congregated on top of the sediment after re-settling, and their distribution decreased with depth. Before agitation, the pollutants were randomly distributed throughout the sediment. Secondly, deep sediment aeration equipment (a micro-porous air diffuser) was installed during the process of sedimentation to study the remediation of the sediment by continuous aeration. The results revealed that deep sediment aeration after re-suspension significantly promoted the degradation of the pollutants both in overlying water and sediment, which also reduced the thickness of the sediment from 0.9 m to 0.6 m. Therefore, sediment aeration after suspension was efficient, and is a promising method for sediment remediation applications.

Changes of Bacterial Communities in Response to Prolonged Hydrodynamic Disturbances in the Eutrophic Water-Sediment Systems

“…This was due to the sediment resuspension, which released large amounts of nutrients from the eutrophic sediment into the overlying water [12,36]. Similar results were observed in previous research [37,38]. The pH showed no significant statistical differences, and the mean value was 8.43 ± 0.09.…”

Sewage Flow Conditions in a Hydroponic Lagoon in Terms of Quality of Treated Wastewater

“…The most important organic matter indicators in sewage are biochemical oxygen demand (BOD5), chemical oxygen demand (COD), total organic carbon (TOC) (Szabo & Lepistö, 2020). The total suspended solids (TSS) concentration largely influence organic matter content in the water courses sediments which became a significant factor in water pollution (Zhu et al, 2017). Ensuring appropriate sewage flow rates through the wastewater treatment plant (WWTP) significantly influences the organic matter content in the sewage stream.…”

Little Akaki River sediment enrichment with heavy metals, pollution load and potential ecological risks in downstream, Central Ethiopia

“…However, the metal retention capacity of sediment is subjected to many environmental factors such as natural and anthropogenic disturbances of the river water and sediment, change in water pH and redox potential (Akan et al 2010;Edokpayi et al 2016). When a change in environmental factors occur, sediment-bound metals are released into overlaying water through the process of dissolution of metals, decomposition of organic matters and desorption (Zhu et al 2017), and causing the secondary source pollution to river water (Luo et al 2010;Ren et al 2015).…”