Application of a cellulose filter aid in municipal sewage sludge dewatering and drying: Jar, pilot, and factory scale. (25th October 2019)

• Record Type: Journal Article
• Authors: Shi, Qi; Lu, Yufei; Guo, Wenjing; Wang, Tianrun; Zhu, Qinyun; Zhang, Yaxian; Wang, Hongtao; Li, Fengting; Xu, Taiming; Li, Chunjiang
• Is Part Of: Water environment research. Volume 92:Number 4(2020)
• Page Start: 495
• Page End: 503
• Publication Date: 2019-10-25
• Subjects: cellulose filter aid -- low‐temperature vacuum dewatering and drying -- moisture content -- municipal sewage sludge -- sludge feeding amount; Water quality management -- Periodicals; Water -- Purification -- Periodicals; Water -- Pollution -- Periodicals; Water -- Pollution; Water -- Purification; Water quality management; Sewage; Water Pollution; Periodicals; Electronic journals; Periodicals; 628.16
• DOI: 10.1002/wer.1254
• Languages: English
• ISSNs: 1061-4303

Abstract

Abstract: Cellulose filter aid (CFA), a skeleton builder, has been studied for sludge conditioning at laboratory scale because of its function in reducing compressibility of sludge cake. However, there are few practical applications of CFA at the pilot and factory scales. In this study, we combined CFA with an advanced sludge dewatering technology, in practical applications. For jar test, the optimum CFA dose was 3 wt.% dry solid (DS); furthermore, the combination of CFA with polyaluminum chloride (PAC) and polyacrylamide (PAM) resulted in the lowest moisture content (73.92%) and the highest calorific value (13, 628 kJ/kg) of the sludge cake. In the pilot test, the 5 wt.% DS of the CFA resulted in the optimal sludge feeding amount. In the factory test, the optimal CFA dose was further increased to 10%, and the amount of sludge feeding in a single batch was 20.5% higher than that without CFA. The optimal dose of CFA in the jar–pilot–factory test increased, which may occur because the CFA more easily penetrated the cake and performed better in building the skeleton when the sludge cake was thin. This study could provide a reference for the application of CFA and other skeleton builders in sludge dewatering and drying. Practitioner points: An advanced sludge treatment process—low‐temperature vacuum dewatering and drying was tested. Cellulose filter aid showed good effect in jar test, pilot test, and factory test. When the scale of the experiment was from jar to factory, the optimal dosage of the cellulose filter aid was magnified. The amplification phenomenon of optimal dosage was related to the distribution pattern of cellulose filter aid in different thickness mud cakes. Abstract : After conditioned with PAC ‐ cellulose filter aid (CFA) ‐PAM, the sludge was dehydrated in jar, pilot and factory scale, and the optimal dosages of CFA were 3 wt.% DS, 5 wt.% DS, and 10 wt.% DS, respectively. This amplification phenomenon may be caused by the change of distribution mode of CFA in the sludge cake with the increase of cake thickness. .