核桃壳骨架构建剂对污泥脱水性能的影响

污泥最终处置的困难在于提高泥饼的含固量和降低其含水率。研究用核桃壳做骨架构建剂对污泥进行调理对污泥脱水性能改善的影响。通过测定污泥比阻(SRF),毛细吸水时间(CST)以及抽滤后污泥含水率,探究核桃壳骨架构建剂对污泥脱水性能的影响。结果表明,采用核桃壳做骨架构建剂调理污泥的最佳添加量为4∶6(核桃壳与污泥干重比),最佳粒径为0.25 mm。用真空抽滤脱水,核桃壳调理后污泥的含水率明显降低。含水率为97.5%的原泥经过29 min真空抽滤后泥饼含水率降至70.52%;按核桃壳与污泥干重比4∶6,添加粒径0.25 mm的核桃壳后,泥饼含水率降为63.57%,SRF由初始的3.73×1013m/kg,降为调理后的1.06×1013m/kg。     

生物淋滤改善城市污泥的脱水性能

污水处理过程中产生大量剩余污泥,使得污泥脱水逐渐成为污泥处理的关键环节。本研究采用生物淋滤方法处理城市污泥,改善污泥脱水性能。通过污泥比阻、滤饼含水率和离心脱水率的变化评价生物淋滤改善剩余污泥脱水性能的效能。综合考虑污泥脱水性能改善效果和运行成本,生物淋滤优化条件为:硫粉投加量3 g/L;Fe2+投加量4 g/L;接种物投加量(接种物与供试污泥的体积比,mL/mL)0.4。在优化条件下,污泥体系被酸化至pH为2.0左右需要36～48 h,淋滤污泥的比阻由1.26×1014 m/kg降至8.14×1012 m/kg,降低了93.54%,滤饼含水率从98.39%降至73.68%,同时污泥离心脱水率从72%提高到83%。回调淋滤污泥pH至6.0,污泥比阻继续降至8.27×1011 m/kg,污泥比阻降低99.34%,污泥从难脱水状态转化为易脱水状态。通过污泥体系中铁离子和污泥絮体特征的变化,分析生物淋滤改善污泥脱水性能的机理。作为底物投加的Fe2+在微生物氧化作用下快速转化为Fe3+。生物氧化产生的Fe3+的絮凝作用可能是生物淋滤改善污泥脱水性能的主要机理。     

过硫酸盐氧化法对污泥脱水性能的影响

以污水处理厂浓缩池污泥为研究对象,用污泥比阻、污泥含水率和污泥粘度评价污泥脱水性能,研究亚铁离子活化过硫酸盐氧化法对污泥脱水性能的影响。结果表明,单独投加过硫酸钾时,污泥比阻和含水率随过硫酸钾投加量的增加稍有下降。投加硫酸亚铁和过硫酸钾时,温度对污泥脱水性能影响不大。污泥脱水性能最佳的条件:在常温下,污泥p H为7,硫酸亚铁投加量为1.5 mmol/g VSS、过硫酸钾投加量为1.2 mmol/g VSS,亚铁离子和过硫酸根的摩尔比为1.25∶1,污泥的比阻从5.36×1012m/kg降低到1.9×1011m/kg,含水率从97.0%降低到81.6%,粘度从178 m Pa·s降低到102 m Pa·s。     

响应面法优化污泥电渗透脱水工艺参数

以泥饼含固率作为衡量污泥脱水效果的指标,采用响应面法进行污泥电渗透脱水工艺参数的优化研究。结果表明,最佳反应条件为初始污泥含固率为8.58%,初始电压梯度为20.88 V/cm,初始污泥厚度为2.25 cm,此条件下得到的污泥含固率为48.82%(预测值为48.45%)。方差分析结果表明,回归模型达到显著水平,在研究区域(初始污泥含固率:5%~10%、初始电压梯度12~30 V/cm、初始污泥厚度:1~2.5 cm)内拟合较好,与实验结果吻合度较高。     

制药污泥处理技术研究现状与实验对比

随着制药行业的发展,制药污泥的处理处置问题逐渐成为研究的热点。对污泥处理技术研究现状进行介绍,并以制药污泥为研究对象,分别使用臭氧氧化技术、好氧消化技术、PAM絮凝技术以及污泥制作活性炭技术开展小试研究,以污泥减量、资源化利用为评价指标,通过对各项技术工艺参数的优化及费用估算,筛选适合制药污泥处理的最优技术。研究发现,在各项技术最优条件下,PAM絮凝技术可将污泥含固率由6.32%提高至46.89%;臭氧氧化技术和好氧消化技术分别减少污泥挥发性固体质量(VS)50.55%和26.59%;制备的污泥活性炭饱和吸附量可达28.57 g COD/kg。结合经济预算结果,PAM絮凝技术在高效提高污泥含固率的同时,处理费用最低,是制药污泥处理工程应用经济可行的一种技术。     

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.     

异噻唑啉酮耦合氧化钙对污泥压滤脱水及燃烧热值的影响

通过正交实验考察了异噻唑啉酮耦合氧化钙对压滤污泥含水率、燃烧热值、Zeta电位和泥饼含硫量的影响,结果表明,各因素对污泥含水率影响的大小顺序依次为:氧化钙投加量、压强、压滤时间、异噻唑啉酮投加量;各因素对污泥燃烧热值影响的大小顺序依次为:氧化钙投加量、压滤时间、异噻唑啉酮投加量和压强。异噻唑啉酮投加量为5.6 mg/g TSS,氧化钙投加量为120 mg/g TSS,压强为0.40 MPa,压滤时间为1 h条件下,污泥含水率为55.5%,105℃烘干泥饼的热值为10 702 J/g,Zeta电位值为-30.082 mV,泥饼含硫量为0.408%。此时污泥含水率较低,热值较高,含硫量较低,有利于污泥的焚烧处理。     

高铁酸钾与碱耦合处理剩余污泥的实验研究

采用高铁酸钾与碱耦合工艺处理剩余污泥,分析其对污泥的减量及溶胞效果的影响。结果表明,高铁酸钾与碱耦合处理时,污泥减量效果较单独高铁酸钾处理明显提高,最佳耦合方式为高铁酸钾与碱同时投加处理,适宜的碱性物质为NaOH;高铁酸钾与碱耦合处理能有效破坏污泥絮体及细胞结构,导致污泥减量,胞外聚合物(EPS)和胞内物质大量溶出。当高铁酸钾投加量为0.24g/g(以污泥中单位质量SS的投加量计,下同),NaOH投加量为6mmol/g时,耦合处理24h后挥发性悬浮固体(VSS)去除率达25.92%,处理后的污泥离心泥饼含固率增加,污泥体积指数(SVI)降低,污泥脱水性能及沉降性能明显提高,显微镜检表明耦合处理后污泥絮体明显解离,说明高铁酸钾与碱耦合工艺具有较好的污泥减量及溶胞作用。     

减量脱水菌剂处理柠檬酸废水污泥的中试

利用规模为5m3的中试装置考察菌剂对柠檬酸废水污泥减量脱水效果的影响。结果表明:(1)满负荷运行阶段,菌剂处理后污泥的混合液悬浮固体质量浓度(MLSS)和混合液挥发性悬浮固体质量浓度(MLVSS)平均值分别为9.76、6.06g/L,比原污泥分别减量6.69%、12.93%;真空抽滤泥饼含水率平均值为78.12%,比原污泥下降11.87百分点;溶解性COD(SCOD)为214.40~323.71mg/L,平均值为279.69mg/L,相对于原污泥SCOD平均值,SCOD去除率可达到44.89%。说明菌剂可有效减少污泥量,改善污泥脱水效果,可进一步改善水质,对该柠檬酸废水污泥有着很好的针对性。(2)菌剂处理后污泥的脱水效果明显。较高压力、加入聚丙烯酰胺(PAM)及选用孔隙较小的滤纸均能进一步提高污泥的脱水效果。     

粉煤灰与生石灰复合调理剂对市政污泥深度脱水性能的影响

污泥在污水厂厌氧消化和离心脱水后,一般含水率在80%~85%,为了后期有效的处理处置,需要进行深度脱水。实验采用化学干化法,投加不同比例的粉煤灰与生石灰复合调理剂,测定调理后污泥的含水率、脱水过滤速度和pH。实验结果表明,粉煤灰与生石灰复合调理剂可以有效改善污泥脱水性能,使泥饼含水率降低到60%以下,同时将污泥抽滤的脱水时长从20 min降至6 min内。此外,适当比例的复合调理剂可以大大降低污泥的pH,减小污泥后期处置带来的环境污染。     

生物淋滤-Fenton对印染污泥脱水性能的影响

采用嗜酸性硫杆菌生物淋滤联合Fenton氧化法对印染污泥脱水性能进行了研究。结果表明,生物淋滤过程中pH下降速率随着硫粉添加量增加而变快,经生物淋滤处理后污泥的脱水性能在一定程度上得到了改善。对生物淋滤后的污泥进行了Fenton氧化处理,获得的最佳反应条件为反应时间2 h,H2O2和Fe2+添加量分别为6 g/L和0.5 g/L。在该条件下,污泥上清液中总有机碳(TOC)由20.8 mg/L增加到356.6 mg/L;污泥比阻(SRF)和滤饼含水率分别由5.98×1011s2/g和88.75%减少至1.26×1011s2/g和82.85%。生物淋滤-Fenton氧化法在污泥破解程度和脱水性能改善方面均优于单独Fenton氧化法。     

Assessment of sewage sludge bioremediation at different hydraulic retention times using mixed fungal inoculation by liquid-state bioconversion

Sustainable, environmental friendly, and safe disposal of sewage treatment plant (STP) sludge is a global expectation. Bioremediation performance was examined at different hydraulic retention times (HRT) in 3–10 days and organic loading rates (OLR) at 0.66–7.81 g chemical oxygen demand (COD) per liter per day, with mixed filamentous fungal (Aspergillus niger and Penicillium corylophilum) inoculation by liquid-state bioconversion (LSB) technique as a continuous process in large-scale bioreactor. Encouraging results were monitored in treated sludge by LSB continuous process. The highest removal of total suspended solid (TSS), turbidity, and COD were achieved at 98, 99, and 93 %, respectively, at 10 days HRT compared to control. The minimum volatile suspended solid/suspended solid implies the quality of water, which was recorded 0.59 at 10 days and 0.72 at 3 days of HRT. In treated supernatant with 88 % protein removal at 10 days of HRT indicates a higher magnitude of purification of treated sludge. The specific resistance to filtration (SRF) quantifies the performance of dewaterability; it was recorded minimum 0.049 × 10¹² m kg^?1 at 10 days of HRT, which was equivalent to 97 % decrease of SRF. The lower OLR and higher HRT directly influenced the bioremediation and dewaterability of STP sludge in LSB process. The obtained findings imply encouraging message in continuing treatment of STP sludge, i.e., bioremediation of wastewater for environmental friendly disposal in near future.     

Application of Fenton’s reagent combined with sawdust on the dewaterability of oily sludge

Fenton’s reagent and sawdust were used on the dewaterability of the raw oily sludge in this study. The result shows that the combination of the two treatment processes is favorable, although the application of Fenton’s reagent only is not so good. The capillary suction time (CST) and specific resistance to filtration (SRF) were used to evaluate the effect of dewaterability of the raw oily sludge, and the CST and SRF values are reduced from 1,760 s and 13.8?×?10¹² m/kg to 185 s and 1.5?×?10¹² m/kg, respectively. The dry matter contents of sludge cakes and properties of the supernatant all gained when using only the Fenton’s reagent and when using the combined treatment with Fenton’s reagent and sawdust respectively were investigated. The results indicate that the oily sludge is more suitable for further treatment after combined process with Fenton’s reagent and sawdust.     

聚丙烯酰胺对活性污泥特性的影响研究

高分子混凝剂PAM投加是强化污泥造粒的有效方法,但PAM的投加对活性污泥中微生物群落以及对其生化降解性能的影响尚缺乏系统性研究。为此,通过实验室小型实验,在SBR中连续投加PAM,运用FISH等微生物检测技术,研究了PAM对活性污泥的影响。在PAM投量为3 mg/L的条件下,反应器中活性污泥的生长过程与对照反应器没有根本性差别,且PAM投加后MLSS浓度和单位重量污泥的生物量均有一定增大,污泥的沉降性能也得到改善。FISH检测的结果表明,与对照反应器相比,总细菌、亚硝化菌、硝化菌的个数分别由9.1×105、1.8×105和1.1×105CFU/mL增长到1.0×106、2.0×105和1.2×105CFU/mL,说明PAM没有对各种菌落的生长产生不利影响。连续运行80 d的结果也表明,投加PAM的反应器中COD和氨氮的去除均有所改善。     

污泥生物沥滤工艺优化和重金属分配研究

为了得到嗜酸硫细菌沥滤污泥中重金属的最佳工艺参数,对沥滤过程进行3因素4水平的正交实验研究。3种影响因素的水平设置分别为:污泥浓度35、25、15和5 g/L,单质硫投加量15、10、5和1 g/L,接种量15、10、5和3 g/L。对沥滤过程污泥中7种重金属(As、Cd、Cr、Cu、Ni、Pb和Zn)的去除率进行极差分析,提出了因素影响程度依次为单质硫投加量污泥浓度接种量,且最佳工艺条件为:污泥浓度25 g/L,单质硫投加量10 g/L,接种量为5%。采用超声波-离心方法,分步提取污泥胞外聚合物(EPS)的2种形态:松散结合态(LB)和紧密结合态(TB)。分析其中的重金属浓度,提出沥滤后重金属在污泥EPS的赋存以LB为主。     

新型改性聚丙烯酰胺的合成及对污泥调理效果的研究

采用原位聚合法,在聚丙烯酰胺的聚合过程中引入金属离子进行改性,合成了一种新型改性聚丙烯酰胺.通过正交实验确定了改性聚丙烯酰胺的最佳合成条件.红外图谱显示,该聚丙烯酰胺是一种具有特殊结构的有机高分子化合物.以污泥脱水率和污泥比阻为考察指标,研究了改性聚丙烯酰胺对污水处理厂剩余活性污泥脱水性能的影响,结果表明,在每1000...     

Novel insights into enhanced dewatering of waste activated sludge based on the durable and efficacious radical generating

This study aims to develop a high-efficiency radical oxidation process for enhancing the dewaterability of waste activated sludge (WAS). Radical scavenging studies combined with electron paramagnetic resonance (EPR) were carried out for the direct radical identification and effectiveness evaluation of radical oxidation. The results indicated that Fe(II)-activated CaO₂ can pose a superior effect on dewatering WAS due to its distinctive capacity of stable ?OH production and the high reaction efficiency of regulated-released ?OH with water-holding organics. The mechanism for the enhanced dewatering performance was also explored. The rupture of sludge colloidal flocs and the reduction of hydrophilic functional groups in loosely bound extracellular polymeric substances (LB-EPS) were found to be mainly responsible for the release of interstitial water and improved dewaterability, respectively. In addition, an inference about the relationship between interfacial water and zeta potential of different EPS fractions was established by the simultaneous measurement of the binding affinities of Ca²⁺ and Fe²⁺/Fe³⁺ for EPS and bound water content. All these results provide the direct evidence that Fe(II)-activated CaO₂ is a promising pretreatment reagent for sludge disposal.

Implications: Fe(II)-activated CaO₂ was first proposed to be highly effective in enhancing the dewaterability of waste activated sludge. Electron paramagnetic resonance (EPR) spectroscopy provided the direct evidence for the specific advantages of CaO₂, especially the capacity of durable and efficacious ?OH production leading to the excellent conditioning performance.     

污泥脱水性能的关键影响因素研究

针对目前污泥脱水性能影响因素不明的问题,研究通过对SBR在7种运行工况条件下活性污泥胞外聚合物(extracellular polymeric substances,EPS)的提取和测试,并采用SPSS软件分析,探讨MLVSS/MLSS、胞外蛋白质/胞外多糖、胞外蛋白质含量、胞外多糖含量、EPS总含量对污泥脱水性能的影响。研究结果表明,MLVSS/MLSS、胞外蛋白质/胞外多糖是影响污泥脱水性能的关键因素,并建立了脱水污泥含水率和污泥结合水含量的影响因素模型:脱水污泥含水率=0.229×(MLVSS/MLSS)+0.023×(胞外蛋白质/胞外多糖)+0.539、污泥结合水含量=2.876×(MLVSS/MLSS)+0.335×(胞外蛋白质/胞外多糖)-0.012,通过对7个城市污水厂污泥脱水性能测试比较表明,模型对脱水污泥含水率和污泥结合水含量预测值相对误差分别在±1%和±5%以内,对污泥脱水性能预测效果良好。     

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     

污泥淤砂分离器再分离底流污泥

研究了污泥淤砂分离器对分离原污泥所得的底流污泥进行再分离时,分离分流污泥的性质。实验结果表明,原污泥MLVSS/MLSS为0.372,1次分离后得到的底流污泥MLVSS/MLSS为0.222,2次分离后得到的底流污泥MLVSS/MLSS为0.126,表明通过底流污泥再分离,能够进一步降低底流污泥中生物有机质的含量,提高底流污泥中无机淤砂的含量。同时,原污泥CST为2.85(s·L)/g SS,1次分离后得到的底流污泥CST为0.98(s·L)/g SS,2次分离后得到的底流污泥CST为0.12(s·L)/g SS,表明底流污泥再分离进一步提高了底流污泥的脱水性能,最终得到的底流污泥脱水性能良好。