Abstract
Extracellular polymeric substances (EPS) are an extracellular matrix found in sludge which plays a crucial role in flocculation by interacting with the organic solids. Therefore, to enhance pretreatment of sludge, EPS have to be removed. In this study, EPS were removed with a chemical extractant, NaOH, to enhance the bacterial pretreatment. A lysozyme secreting bacterial consortium was isolated from the waste activated sludge (WAS). The result of density gradient gel electrophoresis (DGGE) analysis revealed that the isolated consortium consists of two strains. The two novel strains isolated were named as Jerish03 (NCBI accession number KC597266) and Jerish 04 (NCBI accession number KC597267) and they belong to the genus Bacillus. Pretreatment with these novel strains enhances the efficiency of the aerobic digestion of sludge. Sludge treated with the lysozyme secreting bacterial consortium produced 29 % and 28.5 % increase in suspended solids (SS) reduction and chemical oxygen demand (COD) removal compared to the raw activated sludge (without pretreatment) during aerobic digestion. It is specified that these two novel strains had a high potential to enhance WAS degradation efficiency in aerobic digestion.
| Original language | English |
|---|---|
| Pages (from-to) | 2733-2743 |
| Number of pages | 11 |
| Journal | Environmental Science and Pollution Research |
| Volume | 21 |
| Issue number | 4 |
| DOIs | |
| State | Published - Feb 2014 |
Keywords
- Aerobic digestion
- Central composite design
- Chemical oxygen demand
- Extracellular polymeric substance
- Lysozyme secreting bacterial consortium
- Response surface methodology
- suspended solids reduction
