PAC与铁盐对污泥深度脱水性能的对比研究

在工业废水和生活污水的处理过程中,会产生大量的污泥。污泥中水分含量达到95%~99%,只要将其中的水分去除.就会大大缩小污泥的体积,以便于进一步处理。文章还通过试验从污泥比阻和泥饼含水率两个方面比较四种加药方案(PAC、PFC、FC和PFS)的脱水效果,四种加药方案各有优点。FC、PFC的脱水效果最佳,在投药量为干污泥的21%以上时,泥饼含水率可降至60%以下;PFS和PAC的效果次之。     

Fenton试剂预氧化对污泥脱水效果影响的研究

采用Fenton试剂对100mL含水率为95%的剩余污泥进行预氧化,探究其对污泥脱水效果的影响。结果表明:Fenton试剂预氧化污泥的最佳条件为:pH=3、反应时间60min、H_2O_2投加量为6g、H_2O_2与Fe~(2+)的质量比为12/1。分别将原污泥和预氧化的污泥在0.04MPa真空度下进行抽滤脱水,原污泥含水率降到74.3%,预氧化的污泥含水率降到了64.5%,说明Fenton试剂预氧化能够有效改善污泥的脱水效果。     

阳离子表面活性剂CTMAB对污泥脱水的影响研究

考察了阳离子表面活性剂十六烷基三甲基溴化铵(CTMAB)浓度、添加量、调理时间和温度对活性污泥脱水和沉降性能的影响。结果表明,使用1 m L浓度1%的CTMAB调理污泥效果最佳,重力沉降的滤液体积最大。在最佳用量下,搅拌2 h,搅拌温度60℃时污泥的脱水性能最好,毛细吸水时间为8. 7 s,泥饼含水率下降了25%。通过SEM观察了原污泥和CTMAB调理后的污泥微观形态。     

电化学联合酸法对污泥脱水性能的影响

剩余污泥处理处置是当今社会的一大难点。要解决污泥产量大的问题,一个关键要素就是要提高脱水效率,改进脱水技术。探讨了电化学联合酸法对污泥脱水性能的影响,通过分析污泥含水率和毛细吸水时间来探究电解电压、极板间距、电解时间和极板插入深度对脱水的影响。实验结果显示:电化学联合酸法的最佳污泥脱水条件为极板间距6cm、极板插入深度6cm、电解时间30min、电解电压15V和pH为4。此时,污泥含水率降低9.04%,毛细吸水时间下降了42.6%。     

增强垃圾渗滤液处理厂污泥脱水性能的研究

以污泥比阻(SRF)、毛细吸水时间(CST)、Zeta电位作为污泥脱水性能的评价指标,对显著影响污泥脱水性能的絮凝剂的添加条件进行优化,并结合傅里叶转换红外光谱(FTIR)对污泥脱水机理进行阐述。结果表明,最佳投加条件下,相比PAM和FeCl_3联用,PAM和Al2(SO4)3联用对污泥脱水性能更好。投加比为:6 mL的污泥投加1 mL的0.77%PAM联用6 mg Al_2(SO_4)_3,此条件下,SRF由3.49×10⁽¹¹⁾m/kg降至0.2×10(11)m/kg降至0.2×10⁽¹¹⁾m/kg,CST由30.2 s降至11.5 s,Zeta由-21.2 mV升至-6.4 mV。FTIR光谱研究也从机理上表明,PAM、Al(11)m/kg,CST由30.2 s降至11.5 s,Zeta由-21.2 mV升至-6.4 mV。FTIR光谱研究也从机理上表明,PAM、Al⁽³⁺⁾、Fe(3+)、Fe⁽³⁺⁾能够与污泥的O—H等官能团相互作用,并且在最佳投加条件下,PAM与Al_2(SO_4)_3联用在3 284.23 cm-1处的红外吸收峰峰值明显高于PAM与FeCl_3联用的红外吸收峰峰值。研究证明,此方法可提高西安市江村沟垃圾填埋场污泥脱水性能。     

增强垃圾渗滤液处理厂污泥脱水性能的研究

以污泥比阻(SRF)、毛细吸水时间(CST)、Zeta电位作为污泥脱水性能的评价指标,对显著影响污泥脱水性能的絮凝剂的添加条件进行优化,并结合傅里叶转换红外光谱(FTIR)对污泥脱水机理进行阐述。结果表明,最佳投加条件下,相比PAM和FeCl_3联用,PAM和Al2(SO4)3联用对污泥脱水性能更好。投加比为:6 mL的污泥投加1 mL的0.77%PAM联用6 mg Al_2(SO_4)_3,此条件下,SRF由3.49×10~(11)m/kg降至0.2×10~(11)m/kg,CST由30.2 s降至11.5 s,Zeta由-21.2 mV升至-6.4 mV。FTIR光谱研究也从机理上表明,PAM、Al~(3+)、Fe~(3+)能够与污泥的O—H等官能团相互作用,并且在最佳投加条件下,PAM与Al_2(SO_4)_3联用在3 284.23 cm-1处的红外吸收峰峰值明显高于PAM与FeCl_3联用的红外吸收峰峰值。研究证明,此方法可提高西安市江村沟垃圾填埋场污泥脱水性能。     

城市污水处理厂污泥脱水药剂选型研究

针对某城市污水处理厂的污泥脱水处理,进行了一系列污泥脱水药剂的烧杯倾倒实验、CST实验、污泥比阻实验。实验结果表明：在阳离子、阴离子、非离子PAM中,阳离子PAM污泥脱水效果最优;所实验药剂都有一个最佳投加量,处于4.14～5.52 kg/t绝干污泥之间;在所实验药剂中,分子量对于污泥脱水性能的影响不明显,离子度影响较大,最优离子度为50%。     

市政污泥深度脱水试验研究

随着污水量的快速增长,污泥产生量大幅增加,且大多未妥善处置。文章通过一系列试验,研究了几种通过添加有机药剂的方法,可以将污泥的毛细吸水时间大大缩短,从而使脱水性能大大提高。     

污泥化学调理中混凝剂对污泥脱水性能的影响

本文采用三氯化铁(FC)、聚氯化铁(PFC)、聚合硫酸铁(PFS)及聚合氯化铝(PAC)混凝剂对污泥进行调理,考察不同混凝剂及其投加量对生活污泥脱水性能的影响。结果表明:使用不同混凝剂对污泥脱水效果存在不同的差异,并随混凝剂投药量的增大,污泥比阻、污泥含水率、滤液pH、滤液色度及浊度得到有效降低;当混凝剂投药量为干污泥27%,污泥脱水效果最好。     

脱硫灰调理对污泥脱水性能的影响

利用脱硫灰调理生活污水剩余污泥并探讨了其作用机理,结果显示,脱硫灰可明显改善污泥脱水性能,单独用脱硫灰调理污泥,投加量为3 g·L^-1时,污泥沉降体积最大为519.5 ml,比阻有效降幅达47.56%;脱硫灰使污泥中胞外聚合物(EPS)脱离并释放出结合水,脱硫灰与聚丙烯酰胺(PAM)联用处理污泥可得到比单独投加PAM更好的脱水效果;通过对比脱硫灰处理前后污泥的粒径分布和扫描电镜照片(SEM)发现,经过脱硫灰处理后,污泥絮体粒径较原泥明显减小,污泥絮体细孔的骨架结构被改变,形成更结实致密而具有较大孔径的絮体,使污泥中的水分更容易脱除,PAM有较好的吸附桥连作用,使已脱稳的污泥絮体迅速形成更大的絮体,更易固液分离,从而提高污泥脱水性能。     

FENTON AND FENTON-LIKE AOPs FOR ALUM SLUDGE CONDITIONING: EFFECTIVENESS COMPARISON WITH DIFFERENT Fe2+ AND Fe3+ SALTS

Currently, organic polymers are adopted in alum sludge (aluminum-coagulated drinking water treatment sludge) conditioning. However, there are important concerns regarding the use of these polymers because of the unknown and long-term effects of the potential release of excess polymer to the surrounding environment when the sludge is landfilled. Therefore, as an initial action, this study aimed at investigating alternative chemical conditioning methods and focused mainly on exploiting Fenton (Fe²⁺/H₂O₂) and Fenton-like (Fe³⁺/H₂O₂) reagents as the conditioner. Experiments have been conducted to test the effectiveness of Fenton's reagent (containing the ferrous salts of chloride, sulfate, or oxalate), Fenton-like reagent (containing ferric salts of chloride and sulfate), and the coagulation method using FeCl₃ for alum sludge conditioning at constant hydrogen peroxide and iron salt concentrations of 125 and 20 mg/g DS (dry solids), respectively. The effectiveness on dewaterability of the alum sludge demonstrated that the maximum reduction (%) of SRF (specific resistance to filtration) and CST (capillary suction time) of 74% and 47%, respectively, can be obtained when Fenton's reagent was adopted for sludge conditioning. Such reduction of 64% for SRF and 38% for CST can be achieved when Fenton-like reagents were applied.     

Influence of Mechanical Mixing Rates on Sludge Characteristics and Membrane Fouling in MBRs

Abstract

The influence of shear intensity (G) induced by mechanical mixing on activated sludge characteristics as well as membrane fouling propensity in membrane bioreactors (MBRs) was investigated. Four MBRs were operated at different mechanical mixing conditions. The control reactor (MBR₀) was operated with aeration only supplemented by mechanical stirring at 150, 300, and 450 rpm in MBR₁₅₀, MBR₃₀₀, and MBR₄₅₀, respectively. It was found that the MBR₃₀₀ demonstrated minimum rate of membrane fouling. The fouling potential of the MBR₃₀₀ mixed liquor was lowest characterized by the specific cake resistance and the normalized capillary suction time (CST_N). Moreover, it was found that the mean particle size reduced with an increase in the shear intensity. These results reveal that membrane fouling can be significantly mitigated by appropriate shear stress on membrane fibers induced by mechanical mixing condition.     

Water Resistance of Poly(imide-siloxane) Adhesives: An IGC Surface Energetics Study

Inverse Gas Chromatography was utilized to examine the interaction of water vapor with the surfaces of a polyimide homopolymer and poly(imide-siloxane) random-block copolymers of increasing siloxane content. The studies employed 45-60 meter, thin-polymer-film mega-bore capillary columns to maximize surface area. The free energies of specific surface interaction with water and the dispersive components of the solid surface free energies were determined. An increase in the polymer siloxane content from 0-wt% to 10-wt% resulted in a decrease of approximately 4 kJ/mol in the free energy of water-specific surface interaction. A further increase in siloxane content to 30-wt% was not found to increase surface water resistance significantly. Dispersive components of the solid surface free energies of the copolymers were comparable to values reported for poly(dimethylsiloxane) homopolymer.     

Water Resistance of Poly(imide-siloxane) Adhesives: An IGC Surface Energetics Study

Inverse Gas Chromatography was utilized to examine the interaction of water vapor with the surfaces of a polyimide homopolymer and poly(imide-siloxane) random-block copolymers of increasing siloxane content. The studies employed 45-60 meter, thin-polymer-film mega-bore capillary columns to maximize surface area. The free energies of specific surface interaction with water and the dispersive components of the solid surface free energies were determined. An increase in the polymer siloxane content from 0-wt% to 10-wt% resulted in a decrease of approximately 4 kJ/mol in the free energy of water-specific surface interaction. A further increase in siloxane content to 30-wt% was not found to increase surface water resistance significantly. Dispersive components of the solid surface free energies of the copolymers were comparable to values reported for poly(dimethylsiloxane) homopolymer.