He Ni, Xiao-Min Fan, Haojia Guo, Jianrong Liang, Qing-Rong Li, Liu Yang, Hui Li, Haihang Li
{"title":"Comprehensive utilization of activated sludge for the preparation of hydrolytic enzymes, polyhydroxyalkanoates, and water-retaining organic fertilizer","authors":"He Ni, Xiao-Min Fan, Haojia Guo, Jianrong Liang, Qing-Rong Li, Liu Yang, Hui Li, Haihang Li","doi":"10.1080/10826068.2017.1286599","DOIUrl":null,"url":null,"abstract":"ABSTRACT The urban wastewater treatment industry produces a large amount of excess activated sludge which is mainly composed of microbial biomass and costly to be disposed. In this research, a comprehensive utilization of activated sludge was developed by sequentially extracting hydrolytic enzymes and polyhydroxyalkanoates (PHAs), and the residue was used to prepare water-retaining organic fertilizer. The sludge was extracted with fourfold H2O-containing 1% Triton X-100 with the yield of 66.7% protease activity. The enzyme solution was precipitated in 80% acetone and vacuum dried at 40°C at the dried enzyme yield of 2.4 g/kg wet sludge. The enzyme product contains collagenase, lipase, amylase, and cellulase activities, which are good compound enzymes to feed. The PHAs were extracted with 30% sodium hypoclorite:chloroform (1:3). The PHA solution was decolored and dried, and pure white PHAs were obtained at the yield of 70.1 g/kg wet sludge. The residue was used to prepare water-retaining organic fertilizer at the optimal condition. The fertilizer absorbs 131.3-fold distilled water and had good performance in water retention and can effectively slow down the loss of soil moisture when added into soil. This work provides a simple and practical approach for comprehensive utilizing activated sludge with significant economic benefits.","PeriodicalId":20393,"journal":{"name":"Preparative Biochemistry and Biotechnology","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2017-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"14","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Preparative Biochemistry and Biotechnology","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1080/10826068.2017.1286599","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 14
Abstract
ABSTRACT The urban wastewater treatment industry produces a large amount of excess activated sludge which is mainly composed of microbial biomass and costly to be disposed. In this research, a comprehensive utilization of activated sludge was developed by sequentially extracting hydrolytic enzymes and polyhydroxyalkanoates (PHAs), and the residue was used to prepare water-retaining organic fertilizer. The sludge was extracted with fourfold H2O-containing 1% Triton X-100 with the yield of 66.7% protease activity. The enzyme solution was precipitated in 80% acetone and vacuum dried at 40°C at the dried enzyme yield of 2.4 g/kg wet sludge. The enzyme product contains collagenase, lipase, amylase, and cellulase activities, which are good compound enzymes to feed. The PHAs were extracted with 30% sodium hypoclorite:chloroform (1:3). The PHA solution was decolored and dried, and pure white PHAs were obtained at the yield of 70.1 g/kg wet sludge. The residue was used to prepare water-retaining organic fertilizer at the optimal condition. The fertilizer absorbs 131.3-fold distilled water and had good performance in water retention and can effectively slow down the loss of soil moisture when added into soil. This work provides a simple and practical approach for comprehensive utilizing activated sludge with significant economic benefits.