药剂预处理对污泥干化特性及粘滞特性影响规律
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摘要
在搅拌干化实验中发现,污泥添加CaO或Ca(OH)2预处理均可提升污泥的干化速率,且两种试剂均能使污泥的粘滞区的低含水率临界值向高含水率方向偏移,使粘滞区范围缩小。CaO提升污泥干化速率的主要原因是CaO与水反应生成了Ca(OH)2,Ca(OH)2呈强碱性,破坏污泥细胞结构,释放了大量的结合水,加快了污泥的干化速率,与此同时,CaO与水的反应会产生大量的热量从而进一步促进了污泥的干化进程。
It is found that CaO and Ca(OH)2 can promote sludge drying. The sticky region of sludge drying transferred to higher moisture content under the effect of both reagents, which narrows the range of the sticky region. The main reason for the increase of sludge drying rate by CaO addition is that CaO transformed into Ca(OH)2 by reacting with water. Ca(OH)2 is a strong alkaline, which can destroy sludge cell and release a large amount of bound water. In addition,CaO-water is a exothermal reaction, thus the released heat can further promote sludge drying.
It is found that CaO and Ca(OH)2 can promote sludge drying. The sticky region of sludge drying transferred to higher moisture content under the effect of both reagents, which narrows the range of the sticky region. The main reason for the increase of sludge drying rate by CaO addition is that CaO transformed into Ca(OH)2 by reacting with water. Ca(OH)2 is a strong alkaline, which can destroy sludge cell and release a large amount of bound water. In addition,CaO-water is a exothermal reaction, thus the released heat can further promote sludge drying.
引文
[1]住房和城乡建设部. 2015年城乡建设统计公报[J].城乡建设,2016,(8):58-63.
[2] Tuncal T, Uslu O. A review of dehydration of various industrial sludges[J]. Drying Technology, 2014, 32(14):1642-1654.
[3] Deng W Y, Su Y X. Experimental study on agitated drying characteristics of sewage sludge under the effects of different additive agents[J]. Journal of Environmental Sciences, 2014, 26(07):1523-1529.
[4] Deng W Y, Yuan M H, Mei J, et al. Effect of calcium oxide(CaO)and sawdust on adhesion and cohesion characteristics of sewage sludge under agitated and non-agitated drying conditions[J]. Water Research, 2017, 110:150-160.
[5] Deng W Y, Yan J H, Li X D, et al. Measurement and simulation of the contact drying of sewage sludge in a Nara-type paddle dryer[J]. Chemical Engineering Science, 2009, 64(24):5117-5124.
[6] Liu H, Liu P, Hu H Y, et al. Combined effects of fenton peroxidation and Ca O conditioning on sewage sludge thermal drying[J].Chemosphere, 2014, 117:559-566.
[2] Tuncal T, Uslu O. A review of dehydration of various industrial sludges[J]. Drying Technology, 2014, 32(14):1642-1654.
[3] Deng W Y, Su Y X. Experimental study on agitated drying characteristics of sewage sludge under the effects of different additive agents[J]. Journal of Environmental Sciences, 2014, 26(07):1523-1529.
[4] Deng W Y, Yuan M H, Mei J, et al. Effect of calcium oxide(CaO)and sawdust on adhesion and cohesion characteristics of sewage sludge under agitated and non-agitated drying conditions[J]. Water Research, 2017, 110:150-160.
[5] Deng W Y, Yan J H, Li X D, et al. Measurement and simulation of the contact drying of sewage sludge in a Nara-type paddle dryer[J]. Chemical Engineering Science, 2009, 64(24):5117-5124.
[6] Liu H, Liu P, Hu H Y, et al. Combined effects of fenton peroxidation and Ca O conditioning on sewage sludge thermal drying[J].Chemosphere, 2014, 117:559-566.