硼聚硅酸铝絮凝剂调理城市污泥

试验以硅酸钠、三氯化铝、四硼酸钠等为原料制备硼聚硅酸铝絮凝剂,以污泥含固率和污泥比阻为污泥脱水性能指标对城市污泥进行了研究。结果表明,当硅酸钠浓度为0.4mol/L,活化pH为4.0,铝硅摩尔比为2.0,硼硅摩尔比为0.4,絮凝剂投加量为干污泥质量的3%,混凝时间为20min,污泥pH为6-7时,污泥含固率和污泥比阻分别为14.3%、4.2×10~(12)。     

浓浆铁氧体法对含镍重金属污泥的处理

该试验以氢氧化镍重金属污泥为研究对象,在一定条件下与硫酸亚铁反应,使含镍重金属污泥中的大部分镍渣,形成稳定的铁镍复合铁氧体,从而达到对含镍重金属污泥无害化固定的目的。研究了硫酸亚铁投加量、pH、温度和搅拌时间等因素对铁镍复合铁氧体生成的影响。结果表明在n(Fe2+):n(N(iOH)2)=4:1、pH为8.5-9.0、温度为50℃、搅拌时间为1 h的最佳反应条件下,含镍重金属污泥中镍的去除率为90.10%,并且生成的铁镍复合铁氧体性质稳定有一定回收价值。     

超声波-高锰酸钾耦合工艺对污泥破解效果的研究

采用超声波、超声波-高锰酸钾耦合工艺预处理剩余污泥。通过对比破解前后污泥上清液中混合液挥发性悬浮固体浓度/混合液悬浮固体浓度(MLVSS/MLSS)、污泥体积指数(SVI)、污泥破解率(DD)、溶解性蛋白质质量浓度、溶解性多糖质量浓度、含固率等变化,考察超声波、超声波-高锰酸钾(KMnO_4)耦合工艺对污泥破解以及污泥特性的影响。结果表明,超声波单独处理最佳处理条件为:声能密度为2. 0 k W/L、反应时间为20 min。此时,污泥的DD、蛋白质质量浓度、多糖质量浓度分别可达18. 41%、180. 21 mg/L、185. 88 mg/L,同时污泥破解后含固率可达6. 2%,污泥的离心脱水性能得到改善。KMnO_4-超声耦合工艺可进一步促进剩余污泥破解。破解效果影响因素的主次顺序为声能密度反应时间KMnO4投加量。因此,确定的最佳声能密度为2. 4 kW/L、最佳反应时间为25 min、最佳KMnO_4投加量为2 200 mg/L。此时污泥上清液中蛋白质、多糖的质量浓度分别可达295. 56、361. 27 mg/L;粒径和电镜结果与此匹配。     

污泥活性炭对含酚废水的吸附性能研究

文章利用泉州市污水处理厂生化池污泥为主要原料制备污泥活性炭,研究其对含酚废水的吸附效果,考察了污泥活性炭添加量、振荡时间、反应温度、p H、初始浓度对含酚废水去除率的影响。结果表明,污泥活性炭的碘值为530 mg/g,吸附含酚废水的最佳条件为:污泥活性炭添加量为15 g/L、吸附时间为70 min、p H为6、温度为25℃、初始浓度为10 mg/L对苯酚溶液去除率最佳可达97.9%,符合Frenndlich吸附模型。     

负载纳米TiO_2污泥光催化剂的制备及应用

以纳米TiO_2和焦化废水污泥为原料,ZnCl_2为活化剂,一步法制备AC-TiO_2。以罗丹明B为目标污染物进行光催化去除实验,考察了活化剂浓度、固液比、热解温度、热解时间等对AC-TiO_2催化性能的影响。实验结果表明,污泥基催化剂制备条件为ZnCl_2的浓度4.5mol/L、热解温度为400℃、热解时间为90min、固液比为1:2、TiO_2与污泥比值为1:10时,对罗丹明B的光催化去除率最高,达到了98.16%。由spss估计平均值可得污泥基催化剂的最佳制备条件为ZnCl_2的浓度4.5mol/L、热解温度为550℃、热解时间为60min、固液比为1:2、TiO_2与污泥比值为1:5。通过spss第三类平方和分析,各因素对催化剂性能影响程度为:TiO_2与污泥比值ZnCl_2浓度固液比热解温度热解时间。     

城市污水处理厂剩余污泥厌氧消化试验研究

探讨了影响污泥厌氧消化的各种因素,包括温度、pH值、污泥投配率、有机负荷等,以期寻找出最佳的污泥厌氧消化条件,获得最高的污泥降解率和最高的产气量;为比较不同停留时间和有机负荷对污泥厌氧消化效率的影响,实验中维持进料含固率不变,探讨相关的污泥厌氧消化效率。     

硫酸酸浸法除磷石膏中杂质氟的研究

以H2SO4为浸取剂对磷石膏进行热浸取,考察磷石膏中杂质氟的去除情况,为磷石膏综合利用提供基础数据。研究在均匀设计实验的基础上,进一步考察了温度、时间、硫酸质量分数、含固量(质量浓度)、粒度5个因素对杂质氟去除率的影响规律。结果表明:温度、时间、硫酸是影响氟去除率的主要因素,而含固量、粒度对结果影响较小。较理想的除氟条件为浸取温度88℃,浸取时间45 min,H2SO4质量分数30%,含固量0.43 g/mL,在优化实验条件下杂质氟的去除率可以达到84.50%,处理后的磷石膏含氟仅为0.036%。采用硫酸酸浸处理磷石膏,杂质氟去除效果好,且提高了净化磷石膏的白度。     

城市污水污泥深度脱水性能的表征指标

通过分析毛细吸水时间和比阻用于预判污泥深度脱水效果的可行性,研究了高含固率污泥深度脱水性能指标的表征方法。研究结果表明:对于含固率较高的污泥,通过稀释后测定毛细吸水时间(CST)来判断污泥脱水性能是可行的,且对于不同含固率的污泥,也可稀释至相同含固率以便于比较脱水性能;与比阻相比,CST与深度脱水泥饼含水率之间的相关性更好,且具有测定简单、操作方便、可重复性好等特点,更适合用于表征污泥深度脱水性能。     

卧螺离心机在低浓度市政污泥脱水中的应用

介绍了卧螺离心机的主要特点以及在低浓度市政污泥脱水中的应用,探讨了差转速、污泥浓度对泥饼含固率,絮凝剂用量对固相回收率的影响。结果表明,低浓度市政污泥经离心脱水后平均泥饼含固率为23.28%,平均固相回收率为99.41%,处理量达到27m3/h。在卧螺离心机操作参数一定时,泥饼含固率随着差转速的减小而增大,随着污泥浓度的降低而降低。     

响应面法优化微波热解剩余污泥产酸

目前微波预处理污泥主要局限在污泥水解率及其对厌氧消化的影响, 常用溶解性COD来进行表征预处理效果, 在污泥产酸方向少有报道。为了确定微波热解剩余污泥产酸的最佳工艺条件, 通过单因素实验选取实验因素与水平, 根据中心组合设计原理, 在单因素试验的基础上采用四因素三水平的响应面分析法, 考察了微波加热温度、微波加热时间、过氧化氢投加量和乙酸投加量对污泥产酸的影响。微波热解剩余污泥产酸的最佳工艺条件为:加热温度180℃, 加热时间21min, 过氧化氢投加量0.18g/(gSS), 乙酸投加量49mg/(gSS), 最大预测乙酸增量值581mg/L, 试验值与预测值之间的相对偏差在0.033～0.074之间。研究结果表明:本工艺可有效提高污泥有机酸产率, 试验值与预测值吻合较好, 可为污泥原位碳源开发提供理论和实际指导。     

污泥深度脱水调理剂对污泥干化过程中含硫气体释放的影响

采用5种复合调理剂改善污泥脱水性能,制得深度脱水泥饼。通过检测N₂气氛下,不同干化温度（100℃、200℃）,停留时间（30 min、60 min）时,不同调理脱水污泥含水率的变化情况,以及含硫气体的种类和释放量,探讨不同调理剂对干化过程中含硫气体释放特性的影响。结果表明,提高温度、延长时间都可以有效降低污泥的含水率;原污泥干化过程释放的主要含硫气体为H₂S和SO₂,其总量占含硫气体的82.4%;FeCl₃+CaO和H₂SO₄+FeSO₄+H₂O₂+CaO复合调理剂调理脱水泥饼在干化过程中SO₂释放量占原污泥释放量的40.3%和40.6%,H₂S则基本没有释放;H₂SO₄+FeSO₄+H₂O₂+CaO调理脱水污泥在100℃和200℃干化过程中的总硫释放量分别占原污泥总释放量的75.0%和45.6%,该复合调理剂在有效提高污泥脱水性能的基础上,能最大限度地抑制含硫气体的释放。     

Enhancing dewaterability of sewage sludge by the application of tween-20 during bioleaching: Performance evaluation and mechanistic study

Dewatering is recognized as an important method for treating sewage sludge before its disposal. In this paper, the nonionic surfactant Tween-20 was used for the first time to improve the dewaterability of sewage sludge during bioleaching. The specific resistance to filtration (SRF), water content (WC) and bound water content (BW) of the sludge cake were used to evaluate sludge dewaterability. The results indicated that a 1?g/L Tween-20 dosage with an inoculum ratio of 20%, a S⁰ dosage of 2?g/L and a FeSO₄?·?7H₂O dosage of 10?g/L provided oxidation efficiencies up to 100% for Fe²⁺ and 65.8% for S⁰. The SRF of the bioleached sludge decreased to as low as 0.81?×?10¹²?m/kg from the initial 12.6?×?10¹²?m/kg for raw sludge. A WC of 47.16% was achieved while 48.1% of BW was released during bioleaching. The results from this study indicate that adding of an appropriate amount of Tween-20 to sewage sludge is a promising method to enhance dewaterability by bioleaching.     

碱性发酵污泥脱水性能的变化及其原因分析

通过控制温度在25℃和35℃,利用Ca(OH)₂和NaOH调节碱性发酵过程中pH至10,研究了碱性产酸发酵过程中碱性发酵液脱水性能的变化,并且分析了影响碱性发酵液脱水性能的因素。研究发现NaOH条件下得到的发酵污泥的脱水性能比Ca(OH)₂条件下得到的发酵污泥的脱水性能差,同种碱试剂条件下,35℃条件下的发酵污泥脱水性能比25℃条件下差。通过对溶解的蛋白和多糖含量的分析,得出在一定范围内,两者的含量与标准化CST(毛细吸水时间)存在较好的线性关系,并且单位多糖比单位蛋白更能引起发酵污泥脱水性能的恶化。通过对溶解的蛋白多糖结合Zeta电位、平均粒径分析,得出温度和Ca²⁺可能是引起碱性发酵污泥脱水性能差异的根本原因,Ca²⁺能中和胶体表面较多的负电荷,在污泥絮体之间起到良好的吸附架桥作用,从而不利于污泥的水解,抑制有机物的溶出,而有利于污泥的脱水。从脱水成本和产酸量综合分析,Ca(OH)₂比NaOH更适合作为碱试剂调节pH,25℃条件下更适合作为碱性发酵的温度。     

Influence of microwave irradiation on sludge dewaterability

The study focuses on the effect of microwave irradiation on sludge dewaterability. Capillary suction time and specific resistance of filtration were used to evaluate sludge dewaterability. Soluble chemical oxygen demand, extracellular polymeric substance (EPS) content and sludge particle size were determined in an attempt to explain the observed changes in sludge dewaterability. The results indicated that microwave application slightly enhanced sludge dewaterability with short contact time, while it significantly deteriorated sludge dewaterability with long contact time. The results show that 900 W and 60 s is an ideal microwave condition, yielding maximum sludge dewaterability characteristics by generating sludge with optimal disintegration (1.5–2%), EPS concentration (1500–2000 mg/l), and particle size distribution (120–140 μm).     

微波辐射对脱水城市污泥穿透性和脱水性的影响

研究了频率2450 MHz、功率500 W的微波在脱水城市污泥中的穿透性及辐射过程中污泥脱水性的变化. 结果表明,微波的穿透深度为8.7 mm,适宜的辐射可显著提高污泥的脱水性. 微波辐射5 min,上层容器中污泥离心后含水率由80.61%降至75.09%. 当温度高于约60℃时,污泥中微生物细胞开始大量破碎,胞内水释出,离心后含水率随温度升高而降低;高于88℃时,胞外聚合物含量无明显增加而亲水性下降,污泥脱水性迅速改善.     

污泥水热处理制备清洁燃料的研究进展

目前,庞大的污泥产生量是困扰工业与市政工程的一个主要问题,对其减量化与能源化利用是污泥处置的关键。其中,水热技术是一种可直接并有效利用污泥等高含水率废弃物的处理手段。本文首先介绍了污泥的特点以及处理现状,然后总结了国内外近年来关于污泥水热处理工艺的发展历程与工业应用情况。此外,着重讨论了水热处理对污泥能源化利用的各项优势,包括：降低NO_x、酸性气体与飞灰等污染物的排放,固定污泥重金属,改善污泥燃料性能,提高污泥脱水性能以及降低其处理成本等。同时,针对不同种类污泥的不同组分在水热处理过程中的反应过程与影响因素进行了详细讨论。最后,对于污泥水热处理能源化利用的发展前景作出展望,指出深入研究污泥与其他废弃物混合水热或焚烧过程中的协同作用是制备高品质燃料的重要途径。     

无机调理剂与表面活性剂联合调理对污泥脱水性能的影响

研究了CaO、PAFC联合表面活性剂预处理对污泥脱水性能的影响。以污泥滤饼含水率和比阻（SRF）作为评价污泥脱水性能的指标,通过测定污泥调理过程中胞外聚合物（EPS）含量、Zeta电位的变化来阐明污泥脱水性能的变化。实验结果表明,十二烷基二甲基苄基氯化铵（1227）的加入导致上清液中EPS含量发生变化,有效降低了SRF和滤饼含水率,提高污泥脱水性能。CaO、PAFC和表面活性剂的联合调理污泥比单独使用表面活性剂的效果更好,CaO、PAFC的投加不仅改善污泥脱水性能,并有助于减少表面活性剂的用量。污泥上清液中EPS及其各组分含量与污泥滤饼含水率、SRF均有较高的相关性,对污泥的脱水性能有重要贡献。实验中确定的最佳污泥调理条件是CaO投加量为66.67 mg·（g DS）^-1、PAFC投加量为33.33 mg·（g DS）^-1和表面活性剂投加量为56.25 mg·（g DS）^-1,污泥滤饼含水率和SRF分别降至69.41%、0.294×10¹³ m·kg^-1。     

Effects of current density and electrode material on the dewaterability of the thickened activated sludge by electro‐flotation

BACKGROUND: Electro‐flotation (EF) could improve thickening and subsequent dewatering characteristics of activated sludge although the settling characteristics of the sludge were very poor. The objectives of this study were to evaluate the performance of EF in the thickening and dewatering of activated sludge and the effects of current density and electrode material on the dewaterability of the sludge. RESULTS: The specific resistance to filtration (SRF) of the sludges thickened by EF was much lower than that by gravity sedimentation. The SRF of the thickened sludge decreased exponentially with increase of gas generation rate of the EF system. Gas generation rate could be controlled by varying the current density of the electrode. Degassing of the microbubbles by moderate mixing of the thickened sludge layer deteriorated the dewaterability of the sludge. Therefore, it is obvious that the gas bubbles entrapped in the thickened sludge play a key role in the observed dewaterability improvement. The effect of electrode material on the thickening and dewatering efficiency was trivial compared with the effect of current density of the electrode. CONCLUSION: The EF system was quite promising as an alternative to gravity sedimentation for thickening of activated sludge and the dewaterability was also improved by microbubbles generated in the system. Copyright © 2009 Society of Chemical Industry     

酸化污泥膨润土的颗粒化制备

以污泥为添加剂,研究了制备多孔污泥膨润土颗粒及其酸化的最佳条件. 考察了焙烧温度与时间及配料比对颗粒孔隙的影响和酸种类、液固比、酸浓度、活化温度及活化时间对染料脱色效果的影响,并对颗粒的性能指标(比表面积、散失率、吸水率和形貌等)进行了表征. 结果表明,酸化污泥膨润土颗粒的优化制备工艺条件为：污泥/膨润土最佳质量比1:3,焙烧温度700℃,焙烧时间7 h,硫酸浓度6 mol/L,液固比25 mL/g,常温下酸活化4 h. 将其用于活性翠蓝染料的脱色,常温下反应2 h的脱色率可达47%,效果明显优于不规则炭、柱状炭和酸化前颗粒.     

Optimization Study of Municipal Sludge Conditioning,Filtering, and Expressing Dewatering by Partial Least Squares Regression

The effect of different conditioner doses and different applied pressures on the dewaterability of municipal sludge during the filtration and expression stage was assessed using a series of experiments referred to as a uniform design. The relative importance of conditioner dose and applied pressure on the dewatering characteristics of municipal sludge was evaluated with a quadratic model using partial least squares (PLS) regression analysis. It was shown that the developed quadratic model was able to accurately predict the dewatering characteristics during the whole process. It was further shown that lime as a physical conditioner had the most significant impact on filtration rate, expression rate, cake dry solids content, net sludge solids yield, and total cycle time. Aluminum polychloride as the inorganic flocculant had a quite complex effect although not as significant as lime. Filtration pressure had only a slight effect on dewaterability of the municipal sludge, though higher feeding pressure was needed in order to enhance the total feeding amount. Furthermore, expression pressure was only of benefit to cake dry solids content and expression rate and failed to improve other dewatering characteristics of the municipal sludge.