Journal article
Effects of microwave, thermomechanical and chemical treatments of sewage sludge ash on its early-age behavior as supplementary cementitious material
Journal of cleaner production, Vol.258, p.120647
06/10/2020
Handle:
https://hdl.handle.net/2376/120151
Abstract
To better inform the recycling of sewage sludge ash (SSA) in cement-based construction materials, this laboratory study investigated a variety of modification methods aimed at improving the value of SSA. For pre-treatment, three different methods of physical modification including low-temperature drying, grinding, high-temperature calcination were selectively performed. Microwave treatment was also explored as an alternative to the calcination procedure. Subsequently, chemical modification of the SSA was performed by blending with quicklime (QL) for likely chemical activation. The effectiveness of these treatments was assessed in terms of leachability of heavy metals out of the treated SSA and the reduction in total organic carbon (TOC). High-temperature calcination of SSA enhanced the immobilization of heavy metals (e.g., Mn, Zn, and Ba). In contrast, the QL treatment helped immobilize some heavy metals (e.g., Mn and Zn) but re-liberated other metals (e.g., Ba). Compared with calcination at 500 °C for 2h, 15-min microwave heating of pre-treated SSA exhibited better performance in immobilizing the heavy metals and nearly as good performance in reducing the TOC in the SSA Finally, based on the compressive strength data of the cement pastes, microwave treatment is an effective alternative to thermal calcination, in terms of mitigating the side effects of admixed SSA on the cement hydration.
•This laboratory study explored the use of SSA as SCM.•Vibration grinding and calcination is instrumental in improving mechanical properties of cement pastes incorporating SSA.•High temperature calcination in the range of 500 to 900 °C facilitates metallic immobilization in SSA.•15-min microwave activation treatment greatly removes organic matters in SSA.
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Details
- Title
- Effects of microwave, thermomechanical and chemical treatments of sewage sludge ash on its early-age behavior as supplementary cementitious material
- Creators
- Xinyu Cong - School of Civil Engineering, Harbin Institute of Technology, 150090, Harbin, ChinaShuang Lu - School of Civil Engineering, Harbin Institute of Technology, 150090, Harbin, ChinaYunhe Gao - School of Civil Engineering, Harbin Institute of Technology, 150090, Harbin, ChinaYan Yao - China Building Materials Academy, Beijing, 100024, ChinaMohamed Elchalakani - Department of Civil, Faculty of Engineering and Mathematical Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, AustraliaXianming Shi - National Center for Transportation Infrastructure Durability & Life-Extension, Department of Civil and Environmental Engineering, Washington State University, Pullman, 991644, USA
- Publication Details
- Journal of cleaner production, Vol.258, p.120647
- Academic Unit
- Civil and Environmental Engineering, Department of
- Publisher
- Elsevier Ltd
- Identifiers
- 99900612857001842
- Language
- English
- Resource Type
- Journal article