Quaternization-based Graft Modification of Straw Fibers for Conditioning the Sludge Dewatering Performance

Author:

Zhang Qingfang1,Zhao Yanbin1,Yang Qiyong2,Wang Tianfeng1,Xu Binjie2,Zhang Xinhua2,Xiong Houfeng2

Affiliation:

1. Lanzhou University of Technology

2. Jiujiang University

Abstract

Abstract

Extracellular polymeric substances (EPS) are a critical influencing factor in sludge dewatering. Disrupting such EPS contributes to the release of bound water in sludge, enhancing the sludge dewatering performance. This study quaternized straw fibers destructive for the EPS structure and components in active sludge were prepared with heterogeneous free radical graft polymerization. Straw fibers, dimethyl diallyl ammonium chloride (DMDAAC), ammonium persulfate (APS), and acrylamide (AM) were taken as the substrate, grafting monomer, catalyst, and cross-linking agent, respectively. The impacts of reaction temperature, reaction time, catalyst dosage, and monomer dosage on the grafting efficiency of straw fibers were explored. Further, the morphology, elemental composition, and structure of the modified fibers were characterized employing scanning electron microscopy (SEM), elemental analysis (EA), and Fourier transform infrared spectroscopy (FTIR), respectively. The optimal processing conditions determined for the DMDAAC-based quaternization and graft modification of straw fibers were as follows: reaction temperature of 60°C, reaction time of 5 h, 0.1 g of catalyst APS dosage per gram of straw, and 3 ml of DMDAAC dosage per gram of straw. The optimal processing conditions yielded 1.335 g of modified straw fibers per gram of straw, 33.5% grafting rate, and 31.70% substitution of the quaternary ammonium groups. The modified straw fibers disrupted the sludge EPS, boosting sludge dewatering. They improved the filtering performance of the sludge. The capillary suction time (CST) was conditioned from 243.3 ± 22.6 s in the original sludge to 134.5 ± 34.45 s. The specific resistance to filtration (SRF) was reduced from 8.82 ± 0.51 × 1012 m/kg in the original sludge to 4.59 ± 0.23 × 1012 m/kg. The modified straw fibers disruptively affected the structure of sludge EPS, significantly changing its content and composition. The proportion of tightly bound extracellular polymeric substances (T-EPS) in the sludge declined from 77–62% due to such modified fibers. Moreover, the protein and polysaccharide contents in soluble extracellular polymeric substances (S-EPS) and loosely bound extracellular polymeric substances (L-EPS) showed an increasing trend.

Publisher

Springer Science and Business Media LLC

Reference30 articles.

1. A review of flocculants as an efficient method for increasing the efficiency of municipal sludge dewatering: Mechanisms, performances, influencing factors and perspectives[J];Hyrycz M;Sci Total Environ,2022

2. The influence of key chemical constituents in activated sludge on surface and flocculating properties[J];Wilén B-M;Water Res,2003

3. A review on sludge conditioning technology based on skeleton builde[J];Qi J;Energy Res Manage,2023

4. Research progress on the application of modified skeletal materials for sludge deep dewatering[J];Ge Z;China Environ Sci,2023

5. Enhancement of alum sludge dewatering capacity by using gypsum as skeleton builder[J].Colloids and Surfaces;Zhao YQ;A- Physicochemical and Engineering Aspects,2002

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3