Cohesive strength changes of sewer sediments during and after ultrasonic treatment: The significance of bound extracellular polymeric substance and microbial community
| Autor: | Yingjie Zhu, Daizong Meng, Chen Keli, Wei Jin, Chen Zhang, Huaizheng Li |
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| Rok vydání: | 2019 |
| Předmět: |
Geologic Sediments
Environmental Engineering 010504 meteorology & atmospheric sciences Bacteria Sewage Chemistry Extracellular Polymeric Substance Matrix Microbiota Sediment 010501 environmental sciences 01 natural sciences Pollution Anaerobic digestion Extracellular polymeric substance Microbial population biology Environmental chemistry medicine Environmental Chemistry Polysaccharide transport Degradation (geology) Flushing Particle size medicine.symptom Waste Management and Disposal 0105 earth and related environmental sciences |
| Zdroj: | The Science of the total environment. 723 |
| ISSN: | 1879-1026 |
| Popis: | Sewer flushing is widely used to remove sewer sediment from drainage systems; however, its performance and cleaning efficiency are limited by the cohesive strength of sewer sediment. To address this, ultrasound, as a clean technology, is proposed to reduce the cohesive strength of sewer sediment. This study investigated the variations in the cohesive strength, extracellular polymeric substances (EPSs), and microbial community of sewer sediment with ultrasonic treatment. During ultrasonic conditioning, the degradation process of the cohesive strength followed the first-order kinetic model and was positively related to the degradation of bound-EPSs. Field emission scanning electron microscopy, particle diameter, and three-dimensional excitation emission analyses suggested that ultrasound reduced the cohesive strength by decreasing the bound-EPS concentration, which reduced the particle size of sewer sediment, and by destroying the structure of tryptophan proteins, which impaired the stability of agglomerated particles. Following ultrasonic treatment, the cohesive strength of the treated sediment was reduced to 69.3% of that of the raw sewer sediment after storage for 21 days; this result could be ascribed to the improvements in polysaccharide transport, amino acid transport, and the cell wall biogenesis functions of the microbial community, as indicated by PICRUSt. Furthermore, next-generation sequencing studies suggest that the proportions of Syntrophomonadaceae, Bacteroidetes_vadinHA17, Synergistaceae, and Syntrophaceae, which are associated with anaerobic digestion and methane production in sediment, improved conspicuously after ultrasonic conditioning. |
| Databáze: | OpenAIRE |
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