电解-CPAM联用对印染污泥脱水性能的影响

采用铜-石墨为电极,考察了电解电压、反应时间、极板间距和阳离子型聚丙烯酰胺(CPAM)等因素对印染污泥脱水效果的影响。结果表明,在极板间距为3 cm,电压为15 V,反应时间为40 min时,印染污泥的絮体破解效果最佳。该条件下,添加6.67 mg/g(以污泥干基计,DS)CPAM后,印染污泥的比阻(SRF)、毛细吸水时间(CST)与粘度分别下降了59.30%、41.62%和68.14%,滤饼含水率由89.30%下降至82.08%。扫描电镜结果显示,经过最佳条件处理后,污泥絮体被破坏,减弱了对内部结合水的保持力,使污泥脱水性能得到改善。     

微波/超声波对污泥粒度与水分的影响

脱水是污泥处理的重要工艺,预处理技术可以改变污泥脱水特性,促使污泥含水率的降低。在总结国内外污泥脱水特性表征的基础上,对超声、微波和超声微波组合方法处理后的污泥进行实验,分析在不同的条件下,污泥的毛细吸水时间(capillary suction time,CST)、粒度分布、水分的变化情况,并根据差示扫描量热仪(differential scanning calorimetry,DSC)测试结果计算出结合水的含量。研究结果表明:在微波作用时间为180 s时效果最好,污泥的CST为5.8 s,d50为5.423μm;超声作用30 s时效果最好,污泥的CST为12.1 s,d50为4.509μm;在超声与微波组合作用下微波时间为60 s、超声时间为30 s时,污泥的CST为12.8 s,d50为3.731μm。在此3种作用条件下,DSC图谱中峰值出现较早,峰值处热流分别为3.428、4.343和4.268 W·g-1。分析结果表明,经预处理后的污泥脱水特性向着有益于脱水的方向改变,粒度分析与DSC能够表征污泥含水率的变化情况。     

超声耦合高铁酸钾对印染污泥脱水性能的影响

分别采用高铁酸钾、超声、超声耦合高铁酸钾对印染污泥的脱水性能进行研究,考察了印染污泥中沉降速率(SV30)、毛细吸水时间(CST)、污泥破解率DDCOD和泥饼含水率等脱水指标的变化情况。结果表明,低声能密度(0.225~0.45 W·m L~(-1))和短超声时间(1~6 min)都能够促进污泥的脱水性能。在声能密度为0.45 W·m L~(-1),超声时间为4 min的最佳超声条件下,SV_(30)和CST分别下降了6.3%和16.35%。同时,高铁酸钾的添加使污泥脱水效果更显著,在最佳添加量(60 mg·g~(-1))下,SV_(30)、CST和泥饼含水率较原污泥减少了18.36%、31%和13.07%。为了促进污泥脱水,最佳污泥破解率DDCOD为2%~5%。扫描电镜结果显示,在最佳条件下处理的污泥较原污泥变化明显,原有颗粒结构被破坏,利于污泥脱水。     

微波辐射对污泥性质及脱水性能的影响

将微波辐射用于污泥预处理,考察了500、750和900 W的微波作用下,污泥性质(温度,污泥粒径,胞外聚合物和水解程度)和脱水性能(毛细吸水时间和污泥比阻)的变化情况,并探讨了相关的机理。结果表明,适宜的微波条件能够增加污泥粒径,提高污泥的脱水性能。900 W微波辐射60 s后,污泥粒径增加了71.40%,污泥毛细吸水时间和污泥比阻分别减少了42.70%和73.11%。若进一步增加微波接触时间,不仅使能耗增加,同时也会恶化污泥的脱水性能。     

不同泥质类型河流底泥脱水药剂优化实验研究

为了考察几种典型脱水絮凝剂对各泥质类型底泥脱水性能的影响,对3条不同泥质类型的典型河流(沙质、泥沙混合质、泥质)底泥的脱水效果进行了研究。结果表明,在一定投加量范围内,所有脱水药剂均能不同程度改善各泥质类型底泥的脱水性能。无机絮凝剂建议选择PAFC(聚合氯化铝铁)或PAC(聚合氯化铝),其中PAFC的最佳投加范围为0.4%~1.6%,PAC的最佳投加范围为0.4%~2.0%;有机高分子絮凝剂建议选择CPAM(阳离子聚丙烯酰胺),最佳投加范围为0.01%~0.03%;在各絮凝剂最优投加条件下,泥质底泥的脱水性能提高最为明显,其比阻最大可下降86%,泥沙混合质底泥污泥比阻最大可下降81%,沙质底泥污泥比阻则最大可下降58%。而当复合混凝剂为PAC和CPAM或PAFC和CPAM时,沙质底泥在优化混凝条件下其污泥比阻最大可分别下降82%和76%。     

超声波强化给水污泥沉降和脱水性能的研究

就超声波强化给水污泥沉降和脱水性能进行了研究.通过对SV、比阻和滤饼含水率等指标的分析发现,短时间的超声预处理可以明显改善污泥的沉降和脱水性能,且低频(25 kHz)比高频(147.9 kHz)时效果更好.当超声波声密度0.25 W/mL,超声时间3 s时,污泥滤饼含水率比原污泥下降4.7%.最佳超声波声密度0.45 W/mL.短时间超声条件下,超声波与絮凝剂的联用可以进一步降低污泥滤饼含水率,且达到相同滤饼含水率时可减少絮凝剂用量约80%,投资费用大大减小.超声波可以取代絮凝剂促进污泥的沉降性能.     

软水树脂再生废液提高印染污泥脱水性能的研究

研究了软水树脂再生废液和热处理对印染污泥脱水性能的影响。以污泥比阻(SRF)和毛细吸水时间(CST)作为评价污泥脱水性能的指标,通过测定污泥Zeta电位和FT-IR光谱来阐述污泥脱水机理。实验确定的最佳污泥脱水条件为:加热温度70℃,100 m L污泥添加30 m L软水树脂再生废液(软水树脂再生废液中Ca2+的量约为干污泥质量的11.9%),污泥比阻由2.52×1011m·kg~(-1)降至0.85×1011m·kg~(-1),污泥CST由15.2 s降至8.9 s。随着Ca2+浓度的增加,可使污泥表面电荷明显减少,较高的温度可能会加强这种影响。FT-IR光谱表明,Ca2+能与絮体的O—H官能团、蛋白质等相互作用。实验还对软水树脂再生废液与常用阳离子絮凝剂Fe Cl3和Al2(SO4)3的絮凝效果进行了比较。研究证明软水树脂再生废液可作为絮凝剂使用,是一种经济有效的改善污泥脱水性能的方法,且实现了废物利用。     

阳离子聚丙烯酸酯对污泥脱水性能的影响

以比阻(SRF)、过滤时间(TTF)和泥饼含水率作为评价污泥脱水性能的指标,考察2种阳离子聚丙烯酸酯CPAL-1和CPAL-2对污泥脱水性能的影响,并与阳离子絮凝剂三氯化铁(FeCl3)、聚合氯化铝(PAC)、阳离子聚丙烯酰胺(CPAM)和阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)的作用效果进行比较.还测定了Zeta电位(ZP)和滤液中胞外聚合物(EPS)含量的变化来探讨CPAL的作用机理.实验结果表明,经CPAL-1调理的污泥脱水效果优于CPAM、PAC和FeCl3,明显优于CPAL-2和CTAB.当CPAL-1的投加剂量为0.200 g/g干基时,SRF、TTF和泥饼含水率降至最低,依次为5.37 ×1011m/kg、70 s和75.73％.CPAL主要通过电中和、吸附架桥作用和溶出EPS等来改善污泥的沉降脱水性能.     

不同预处理方法对污泥脱水性能的影响

污泥脱水是污泥处理的关键步骤,本文以污泥比阻(SRF)为考察指标,对比分析了污泥经单独酸碱调节、酸碱联合调节、水浴加热、自然冻融以及氧化剂Fenton等预处理方法调节后污泥的脱水效果。结果表明,污泥经氧化剂Fenton试剂处理后,SRF明显减小,污泥脱水性能得到改善;先酸后碱调节的方式比单独酸、碱调节更利于污泥脱水;温度调节对污泥的比阻有影响,低温条件下污泥的比阻较小。     

微波-高锰酸钾耦合调理城市剩余活性污泥

采用微波、微波-高锰酸钾耦合工艺对城市剩余活性污泥进行调理。结果表明:(1)微波辐射改善污泥脱水性能的适宜时间为100s,此时污泥比阻(SRF)降至4.49×10~(12) m/kg,较初始值减小63.79%,污泥破解度为2.97%,上清液中胞外聚合物(EPS)为236.11mg/L。(2)微波-高锰酸钾耦合工艺能有效破解污泥,但不利于污泥脱水;污泥破解的适宜高锰酸钾投量为100mg/g(以单位质量总固体计),此时污泥破解度为40.47%,上清液中EPS为542.83mg/L。(3)污泥经微波-高锰酸钾耦合调理后,30d累计产气量为284mL,较未处理污泥和微波辐射调理污泥分别高20.85%和14.06%。     

Co-conditioning of the anaerobic digested sludge of a municipal wastewater treatment plant with alum sludge: benefit of phosphorus reduction in reject water.

In this study, alum sludge was introduced to co-conditioning and dewatering with an anaerobic digested sludge from a municipal wastewater treatment plant, to examine the role of the alum sludge in improving the dewaterbility of the mixed sludge and also in immobilizing phosphorus in the reject water. Experiments have demonstrated that the optimal mix ratio for the two sludges is 2:1 (anaerobic digested sludge:alum sludge: volume basis), and this can bring approximately 99% phosphorus reduction in the reject water through the adsorption of phosphorus by alum in the sludge. The phosphorus loading in wastewater treatment plants is itself derived from the recycling of reject water during the wastewater treatment process. Consequently, this co-conditioning and dewatering strategy can achieve a significant reduction in phosphorus loading in wastewater treatment plants. In addition, the use of the alum sludge has been shown to beneficially enhance the dewaterability of the resultant mixed sludge, by decreasing both the specific resistance to filtration and the capillary suction time. This is attributed to the alum sludge acting in charge neutralization and/or as adsorbent for phosphate in the aqueous phase of the sludge. Experiments have also demonstrated that the optimal polymer (Superfloc C2260, Cytec, Botlek, Netherlands) dose for the anaerobic digested sludge was 120 mg/L, while the optimal dose for the mixed sludge (mix ratio 2:1) was 15 mg/L, highlighting a huge savings in polymer addition. Therefore, from the technical perspective, the co-conditioning and dewatering strategy can be viewed as a "win-win" situation. However, for its full-scale application, integrated cost-effective analysis of process capabilities, sludge transport, increased cake disposal, additional administration, polymer saving, and so on, should be factored in.     

Performance evaluation of a bipolar electrolysis/electrocoagulation (EL/EC) reactor to enhance the sludge dewaterability

The present study aimed to evaluate the performance of a bipolar electrolysis/electrocoagulation reactor designed to enhance the sludge dewaterability. The reactor was 15 L in volume, with two series of plates used in it; Ti/RuO₂ plates for the electrolysis of the sludge, and also aluminum and iron plates for electrocoagulation process. The dewaterability of the sludge was determined in terms of its capillary suction time (CST) and specific resistance to filtration (SRF), while the degree of sludge disintegration was determined based on the value of degree of sludge disintegration (DD_SCOD). The maximum reduction in CST and SRF was observed at a detention time of 20 min and a voltage of 30 V. However, increasing of both detention time and voltage significantly increased the values of CST and SRF even to an extent that they both exceeded those of the untreated sludge. The optimal degree of sludge disintegration achieved by the present study was 2.5%, which was also achieved at a detention time of 20 min and a voltage of 30 V. As reported previously, increased DD_SCOD values led to increasing CST and SRF values, due primarily to the disruption of the sludge flocs. According to the results from the present study, it can be concluded that simultaneous application of electrocoagulation and electrolysis is effective in enhancing the sludge dewaterability, because electrocoagulation helps to achieve a higher degree of sludge disintegration while maintaining the desired sludge dewaterability.     

超声波强化给水污泥沉降和脱水性能的研究

就超声波强化给水污泥沉降和脱水性能进行了研究.通过对SV、比阻和滤饼含水率等指标的分析发现,短时间的超声预处理可以明显改善污泥的沉降和脱水性能,且低频（25 kHz）比高频（147.9 kHz）时效果更好.当超声波声密度0.25 W/mL,超声时间3 s时,污泥滤饼含水率比原污泥下降4.7%.最佳超声波声密度0.45 W/mL.短时间超声条件下,超声波与絮凝剂的联用可以进一步降低污泥滤饼含水率,且达到相同滤饼含水率时可减少絮凝剂用量约80%,投资费用大大减小.超声波可以取代絮凝剂促进污泥的沉降性能.     

板框压滤机内酒精污泥过滤脱水特性

采用螺杆泵输送和板框过滤机压滤的方法对酒精污泥进行机械脱水,研究了絮凝剂(聚丙烯酰胺PAM)添加量、污泥的进口湿含量、螺杆泵转速、过滤介质和过滤时间对污泥过滤特性的影响,并对滤饼吹气压榨进一步脱水。实验表明,在PAM添加量wPAM=3 kg/(t干污泥),污泥的进口湿含量x0=95%,螺杆泵转速n=180 r/min,过滤时间t=2.5 h并进行吹气压榨可将污泥的湿含量降至69.91%。     

CPAM调质浓缩污泥脱水的影响因素及其机理研究

污水处理厂剩余污泥的处置是当前业界的热点。研究了阳离子聚丙烯酰胺(CPAM)调质浓缩污泥脱水的一些影响因素，如药剂投加量、污泥pH值、环境温度、搅拌条件等。同时，还对污泥絮凝脱水机理进行了一定的探讨。研究表明：阳离子聚丙烯酰胺(CPAM)作为浓缩污泥脱水剂，在优化投加量下、污泥pH值在5.0～7.5、低速搅拌时，有较好的脱水效果。环境温度对污泥的脱水效果也有一定的影响，夏天处理优于冬天处理。     

聚二甲基二烯丙基氯化铵-聚合硫酸铁复合絮凝剂对污泥的脱水性能

研究了聚二甲基二烯丙基氯化铵-聚合硫酸铁复合絮凝剂(PDMDAAC-PFS)对活性污泥的脱水性能,考察了投加量、配比和PDMDAAC的特性粘数等对污泥比阻降低和滤液浊度与COD去除的影响,并与PFS、PDMDAAC、PFS与PD-MDAAC联用(分开加入)、聚丙烯酰胺(PAM)、阳离子型聚丙烯酰胺(CPF130)和KHYC型絮凝剂的脱水效果进行了比较.结果表明,PDMDAAC-PFS对污泥比阻的降低和滤液浊度与COD的去除效果最好,但产生絮团的大小和强度比CPF130差,而其中PDMDAAC和PFS的用量分别比单独使用PDMDAAC和PFS减少了一半以上;PDMDAAC与PFS复配,增加了絮凝剂分子聚集体体积,利于在污泥粒子群间吸附架桥.     

酸处理对活性污泥脱水性能的影响及其作用机理

用硫酸对活性污泥进行脱水前预处理,可使污泥中水分分布发生有利于机械脱水的变化,即结合水含量减少、可脱水程度增大,从而改善活性污泥脱水效果.试验数据表明,只加阳离子PAM调理,污泥经过板框压滤脱水后(压榨时间30 min)泥饼含水率为76.14%;经过酸化预处理后再加阳离子PAM可以使泥饼含水率降至70.24%.不管是过滤脱水还是离心脱水过程,酸处理对污泥脱水速率没有太大影响,却可以提高污泥可脱水程度.进一步研究发现,酸处理的机理是:酸处理使污泥中胞外聚合物ECP水解、微生物细胞瓦解,从而絮体内部间隙水、细胞内部间隙水被释放变成自由水,污泥水分分布发生变化,污泥可脱水程度提高,最终导致污泥脱水效果好.     

臭氧处理剩余污泥的减量化实验研究

采用质子交换聚合物膜电解法（PEM）产生臭氧,单独对剩余污泥进行氧化破解实验,结果表明,随着臭氧化反应时间的增加,污泥微生物细胞裂解,胞内物质进入到污泥溶液中,污泥固体物质减少,使得TS和VTS均显著下降,处理40 min后,其去除率分别达到57.33%和72.76%;SCOD前30 min呈线性增长,通入臭氧60 min后,由处理前的3 501.24mg/L上升到6 298.32 mg/L,增长率达79.88%;SV30及滤饼含水率均呈下降趋势,表明剩余污泥的沉淀性能及脱水性能得到明显改善。实验结果表明,直接利用臭氧对剩余污泥进行处理,可获得良好的减量化效果。     

Synthesis and characterisation of new cationic polyelectrolytes by inverse emulsion polymerisation and their application in activated sludge dewatering

Water soluble hydrophobically associated polyelectrolytes were copolymerised with dimethyl- [2-(2-methyl-acryloyloxy)-ethyl]-alkyl ammonium bromide (alkyl: propyl, hexyl, dodecyl) (DEAC_n) and acrylamide (AM) in inverse emulsion. Cationic hydrophobically modified polyacrylamides having different molecule weight and cationic degree were obtained by varying the total monomer concentration and DEAC_n/AM mole ratio. Polyelectrolytes were characterised by ¹H-NMR and ¹³C-NMR. The dewatering indexes, such as CST, settling rate and water content in sludge cake were investigated and used to evaluate the dewaterability and settleability of activated sludge conditioned by these polyelectrolytes. Afterwards, some characteristics of sludge floc, such as: floc size, sludge viscosity and floc strength were measured. The function of hydrophobic association in sludge conditioning was elucidated by comparing dewatering performances with these polyelectrolytes