摘要
为了解决藻液脱水面临的含水率高、药剂投加量大、不利于后续资源化利用的问题,采用钛凝胶/聚丙烯酰胺/聚合氯化铝(TXC/PAM/PAC)絮凝和中温加热联合调理强化藻液脱水性能,以藻液分离效果、毛细吸水时间(CST)表征TXC/PAM/PAC复合絮凝调理效果,结合调理前后含水率、水分分布、粒径、Zeta电位、胞外聚合物量和藻细胞形貌等方面探讨脱水效果和脱水机理.结果表明:TXC/PAM/PAC调理的最佳投量为100 mg·L^(-1)TXC(以Ti计)、0.7 mg·L^(-1)PAM和70 mg·L^(-1)PAC,藻液分离效果高达99.6%,CST为11.7 s,藻饼含水率降低至81.1%±1.1%.加热再调理结果显示,在35℃调理5 s时效果最好,CST分别为12.5 s,滤饼含水率为63.8%±0.9%.相较于对照组,TXC/PAM/PAC絮凝和35℃加热再调理联合强化过后,间隙水含量大幅度降低至5.5%±0.1%,表面水含量轻微增加至44.5%±0.5%.TXC/PAM/PAC调理可以将胞外聚合物(EPS)降低90.0%以上,35℃加热再调理后,多糖松散结合型胞外聚合物(LB-EPS)的含量减少1.00 mg·g^(-1),溶解型胞外聚合物(SL-EPS)含量增加了0.89 mg·g^(-1),表明LB-EPS转移成为SL-EPS.Pearson分析结果显示,LB-EPS中的蛋白(PN,r=0.787)和多糖(PS,r=0.790)与表面水呈正相关,SL-EPS中的PN(r=-0.592)和PS(r=-0.673)与间隙水呈负相关.粒径与Zeta电位显示联合处理方法有利于进一步改善粒径与静电排斥力.藻细胞扫描电子显微镜(SEM)图表明TXC/PAM/PAC和中温加热均有利于EPS剥离,细胞间疏水通道增大.研究表明,TXC/PAM/PAC和35℃加热联合处理藻水是一种在较低化学药剂投加量下达到藻饼含水率小于80%的技术,有利于后续藻的资源化利用.该方法有助于藻类脱水的进一步研究,为大规模工程处理实际复杂藻水环境提供思路.
To address the challenges of high moisture content,excessive chemical dosage,and suboptimal subsequent resource utilization in algal liquid dewatering,a combined approach of titanium xerogel/polyacrylamide/polymeric aluminum chloride(TXC/PAM/PAC)flocculation and midtemperature heating reconditioning was employed to enhance dewatering efficiency.The efficacy of TXC/PAM/PAC flocculation and conditioning was evaluated through algae separation efficiency and capillary suction time(CST),with assessments conducted both pre-and post-conditioning.Moisture content,water distribution,particle size,zeta potential,extracellular polymer quantity,and algal cell morphology were analyzed before and after conditioning to elucidate the dewatering effect and mechanism.The results indicated that the optimal dosages of TXC/PAM/PAC were 100 mg·L^(-1) TXC(as Ti),0.7 mg·L^(-1) PAM,and 70 mg·L^(-1) PAC,achieving 99.6%separation efficiency,a CST of 11.7 s,and a reduction in the moisture content of the algal cake to 81.1%±1.1%.Heating and reconditioning experiments revealed that the optimal conditions were at 35℃for 5 seconds,resulting in a CST of 12.5 s and a cake moisture content of 63.8%±0.9%.Compared to the control group,the combined treatment of TXC/PAM/PAC flocculation and heat conditioning at 35℃significantly reduced the interstitial moisture content to 5.5%±0.1%,while slightly increasing the surface moisture content to 44.5%±0.5%.TXC/PAM/PAC conditioning reduced extracellular polymer(EPS)content by over 90.0%.After heating and reconditioning at 35℃,the polysaccharide content in loosely bound extracellular polymer(LB-EPS)decreased by 1.00 mg·g-1 VSS,while solubilized extracellular polymer(SLEPS)content increased by 0.89 mg·g-1 VSS,indicating a transfer from LB-EPS to SL-EPS.Pearson analysis revealed that protein(PN,r=0.787)and polysaccharide(PS,r=0.790)in LB-EPS were positively correlated with surface water,while PN(r=-0.592)and PS(r=-0.673)in SL-EPS were negatively correlated with interstitial water.Analysis of particle size and zeta potential demonstrated that the combined treatment method effectively enhanced particle size and electrostatic repulsion.Scanning electron microscopy(SEM)images of algal cells revealed that both TXC/PAM/PAC and mid-temperature heating facilitated EPS stripping and increased intercellular hydrophobic channels.The combined treatment of algal water with TXC/PAM/PAC and heating at 35℃proved to be an effective technique for achieving a moisture content of less than 80%in the algal cake at a lower chemical dosage,facilitating subsequent resource utilization of the algae.This method is valuable for advancing research into algal dewatering and offers insights for large-scale technical treatment of real-world complex algal water environments.
作者
黄天寅
孙琪
钟爱成
朱丽燕
蒋朵颐
范晓燕
吴兵党
杨晶晶
HUANG Tianyin;SUN Qi;ZHONG Aicheng;ZHU Liyan;JIANG Duoyi;FAN Xiaoyan;WU Bingdang;YANG Jingjing(School of Environmental Science and Engineering,Suzhou University of Science and Technology,Suzhou 215009;Suzhou Key Laboratory of Sponge City Technology,Suzhou 215009;Suzhou River Management Department,Suzhou 215011)
出处
《环境科学学报》
北大核心
2025年第1期60-71,共12页
Acta Scientiae Circumstantiae
基金
国家自然科学基金(No.52070137)
苏州市科技计划项目(No.SS202107)。
关键词
铜绿微囊藻
含水率
水分分布
EPS
相关性分析
Microcystis aeruginosa
moisture content
moisture distribution
EPS
correlation analysis
作者简介
黄天寅(1975-),男,E-mail:huangtianyin111@163.com;杨晶晶,E-mail:yjjnancy@163.com。
