Effects of surfactants on the improvement of sludge dewaterability using cationic flocculants

Yongjun Sun; Huaili Zheng; Jun Zhai; Houkai Teng; Chun Zhao; Chuanliang Zhao; Yong Liao

doi:10.1371/journal.pone.0111036

Effects of surfactants on the improvement of sludge dewaterability using cationic flocculants

PLoS One. 2014 Oct 27;9(10):e111036. doi: 10.1371/journal.pone.0111036. eCollection 2014.

Authors

Yongjun Sun¹, Huaili Zheng¹, Jun Zhai¹, Houkai Teng², Chun Zhao¹, Chuanliang Zhao¹, Yong Liao¹

Affiliations

¹ Key laboratory of the Three Gorges Reservoir Region's Eco-Environment, State Ministry of Education, Chongqing University, Chongqing, China; National Centre for International Research of Low-carbon and Green Buildings, Chongqing University, Chongqing, China.
² CNOOC Tianjin Chemical Research and Design Institute, Tianjin, China.

Abstract

The effects of the cationic surfactant (cationic cetyl trimethyl ammonium bromide, CTAB) on the improvement of the sludge dewaterability using the cationic flocculant (cationic polyacrylamide, CPAM) were analyzed. Residual turbidity of supernatant, dry solid (DS) content, extracellular polymeric substances (EPS), specific resistance to filtration (SRF), zeta potential, floc size, and settling rate were investigated, respectively. The result showed that the CTAB positively affected the sludge conditioning and dewatering. Compared to not using surfactant, the DS and the settling rate increased by 8%-21.2% and 9.2%-15.1%, respectively, at 40 mg·L-1 CPAM, 10×10-3 mg·L-1 CTAB, and pH 3. The residual turbidities of the supernatant and SRF were reduced by 14.6%-31.1% and 6.9%-7.8% compared with turbidities and SRF without surfactant. Furthermore, the release of sludge EPS, the increases in size of the sludge flocs, and the sludge settling rate were found to be the main reasons for the CTAB improvement of sludge dewatering performance.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Cations / chemistry*
Flocculation
Hydrogen-Ion Concentration
Sewage / chemistry*
Surface-Active Agents / chemistry*
Waste Disposal, Fluid*

Substances

Cations
Sewage
Surface-Active Agents

Grants and funding

This research was supported by the National Natural Science Foundation of China (Project No. 21177164), Major projects on control and rectification of water body pollution (Project No. 2013ZX07312-001-03-03), and the 111 Project (Project No. B13041). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.