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Zhao X, Jiang J, Zhou Z, Yang J, Chen G, Wu W, Sun D, Yao J, Qiu Z, He K, Wu Z, Lou Z. Applying organic polymer flocculants in conditioning and advanced dewatering of landfill sludge as a substitution of ferric trichloride and lime: Mechanism, optimization and pilot-scale study. CHEMOSPHERE 2020; 260:127617. [PMID: 32683031 DOI: 10.1016/j.chemosphere.2020.127617] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 07/05/2020] [Accepted: 07/07/2020] [Indexed: 06/11/2023]
Abstract
In this study, poly dimethyl diallyl ammonium chloride (PDADMAC) and polyacrylamide (PAM) were applied to substitute ferric trichloride (FeCl3) and lime conditioning for advanced dewatering of landfill sludge (LS). Four response surface methodology (RSM) models were constructed for FeCl3-lime, FeCl3-PAM, PDADMAC-lime and PDADMAC-PAM, and identical dosages, namely 29.86, 57.91, 5.73 and 2.99 mg/g dry solids (DS) for FeCl3, lime, PDADMAC and PAM, were obtained by solving the system of four RSM equations at water content of 60% to investigate conditioning mechanisms. Compared to FeCl3-lime, PDADMAC-PAM conditioning had strong charge neutralization and bridging performance, and obtained conditioned LS with large flocs size, strong network structure and rapid dewatering rate. By integrating RSM with nonlinear programming for optimization, the total cost of PDADMAC-PAM route was saved by 7.9% and close to FeCl3-lime, and the optimized condition with dosages of 1.93 and 3.47 kg/t DS was further confirmed by pilot-scale experiments. The results indicated that PDADMAC-PAM was a feasible substitute for FeCl3-lime in sludge conditioning, and showed more advantage if dewatered sludge was further treated by incineration.
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Affiliation(s)
- Xiaodan Zhao
- Shanghai Engineering Research Center of Energy - Saving in Heat Exchange Systems, College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai, 200090, China
| | - Jie Jiang
- Shanghai Engineering Research Center of Energy - Saving in Heat Exchange Systems, College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai, 200090, China
| | - Zhen Zhou
- Shanghai Engineering Research Center of Energy - Saving in Heat Exchange Systems, College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai, 200090, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China.
| | - Jiazhe Yang
- Shanghai Engineering Research Center of Energy - Saving in Heat Exchange Systems, College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai, 200090, China
| | - Guang Chen
- Shanghai Chengtou Wastewater Treatment Co., Ltd, Shanghai, 201203, China
| | - Wei Wu
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China
| | - Dongqi Sun
- Shanghai Engineering Research Center of Energy - Saving in Heat Exchange Systems, College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai, 200090, China
| | - Jie Yao
- Shanghai Chengtou Wastewater Treatment Co., Ltd, Shanghai, 201203, China
| | - Zhan Qiu
- Shanghai Chengtou Wastewater Treatment Co., Ltd, Shanghai, 201203, China
| | - Kankan He
- SNF (China) Flocculant Co., Ltd, Shanghai, 200040, China
| | - Zhichao Wu
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China; State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China
| | - Ziyang Lou
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
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Rashid N, Nayak M, Suh WI, Lee B, Chang YK. Efficient microalgae removal from aqueous medium through auto-flocculation: investigating growth-dependent role of organic matter. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:27396-27406. [PMID: 31327138 DOI: 10.1007/s11356-019-05904-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 07/03/2019] [Indexed: 06/10/2023]
Abstract
This study investigated the growth-dependent role of algal organic matters (AOMs) to achieve high removal efficiency (R.E) of microalgae. The results showed that the microalgae cells produced 96 ± 2% of total AOMs as loose bound AOMSS (LB-AOMs) and 4 ± 1% as cell-bound (CB-AOMs) in exponential phase. In stationary phase, LB-AOMs and CB-AOMs were 46 ± 0.7percentage and 54 ± 0.2 percentage, respectively. The R.Es in exponential and stationary phase were 83 ± 2.6% and 66 ± 1.2%, respectively. It is found that the difference of biomass concentration (between exponential and stationary phase) had no significant impact on the R.E (P > 0.01). Further investigations revealed that LB-AOMs inhibit flocculation in exponential and CB-AOMs in stationary phase; however, CB-AOMs showed stronger inhibition than the LB-AOMs (P < 0.01). The provision of calcium (17 ± 0.9 mg/L) to the culture reduced the AOMs inhibition and improved the R.E from 66 ± 1.2% (in control) to 90 ± 4.2%. An increase in R.E was attributed to the interaction of calcium with AOMs and subsequently acting as a flocculant. The findings of this study can be valuable to improve the performance of auto-flocculation technology, which is mainly limited by the presence of AOMs. Graphical Abstract.
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Affiliation(s)
- Naim Rashid
- Advanced Biomass R&D Center, Korea Advanced Institute of Science and Technology (KAIST), 291- Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
- Department of Chemical Engineering, COMSATS University Islamabad, Lahore Campus, Lahore, Pakistan
| | - Manoranjan Nayak
- Advanced Biomass R&D Center, Korea Advanced Institute of Science and Technology (KAIST), 291- Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - William I Suh
- Advanced Biomass R&D Center, Korea Advanced Institute of Science and Technology (KAIST), 291- Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Bongsoo Lee
- Advanced Biomass R&D Center, Korea Advanced Institute of Science and Technology (KAIST), 291- Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea.
- Department of Microbial and Nano Materials, College of Science and Technology, Mokwon University, 88 Doanbuk-ro, Seo-gu, Daejeon, 35349, Republic of Korea.
| | - Yong-Keun Chang
- Advanced Biomass R&D Center, Korea Advanced Institute of Science and Technology (KAIST), 291- Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea.
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