固化污泥对渗滤液中氟阻滞作用的数值分析

固化污泥是一种新型填埋场底部防渗阻滞材料,为论证其防渗阻滞作用的有效性,需进行典型污染物的穿透试验,但由于固化污泥渗透性很低,采用常规土柱试验很难得到污染物透过其迁移时的相关参数。为解决该问题,用柔性壁渗透试验代替传统土柱试验。渗滤液中污染成分较多,取含量较高且较易穿透的污染物即氟离子作为典型污染物,首先进行穿透试验获得迁移参数,然后结合二维有限元法研究分析其在防渗阻滞层及周边岩土环境中60 a内的运动迁移范围、浓度分布情况,并对比分析未设防渗阻滞层的情况。研究表明,在填埋场底部设置固化污泥防渗层对于以氟为代表的阴性污染物有较好的延迟阻滞作用。由于阳性污染物的穿透能力较阴性污染物弱,因而固化污泥防渗层对重金属等阳性污染物也应具有较强的阻滞作用,从而能进一步延迟填埋场渗滤液对周边环境的污染。     

垃圾渗滤液的絮凝和固化处理

采用天然高分子絮凝剂和固化剂,对垃圾渗滤液进行絮凝沉淀和固化后焚烧处理,特别适合城市生活垃圾焚烧发电的环保治理和资源化利用.     

含砷污泥的固化处理

废水处理后的污泥含有大量的有害物质，其中的砷及其化合物对环境危害极大，因此，对含砷污泥的安全处理与处置研究，有重要的现实意义。对固体废物的处理有物理、化学和生物的多种方法，综合比较了各种方法后，本文提出应用包括化学和物理反应的水泥固化方法对含砷污泥进行处理。对比研究了不同水泥的性能后，选择了普通硅酸盐水泥和矿渣硅酸盐进行实验，通过对比浸出液的含As浓度发现矿渣硅酸盐水泥的固化效果较好。     

污水处理厂污泥固化及影响因素的试验研究

通过对2种含水率的污水处理厂污泥采用石灰与粘土或水泥与粘土进行固化,测试不同龄期和掺量下固化污泥的无侧限抗压强度。研究发现：固化强度随龄期和掺量增大均增大,且相同条件下,水泥的固化效果要好于石灰,前者固化强度约是后者的2~5倍;龄期较短时,粘土对固化强度影响明显,龄期较长时,石灰或水泥的影响明显。短龄期内提高固化材料的掺量,对于强度提高不明显;污泥含水率由92.1%减小到53.1%时,强度增大2~10倍。最后,建立固化强度预测模型,预测含水率相近污泥的固化强度。     

生活垃圾渗滤液蒸发母液固化

为了解决处置生活垃圾渗滤液蒸发母液时缺少适合的固化用胶凝材料的问题,以水泥、水泥+石灰和自配固化剂分别对某项目蒸发母液进行固化试验.结果表明,蒸发母液固化后化学需氧量、氨氮质量浓度、油脂质量浓度和电导率等指标下降显著,重金属离子质量浓度限值也满足生活垃圾填埋场填埋要求.水泥和水泥+石灰固化蒸发母液凝结时间长,强度低,无法满足浆体及时转场填埋的要求,而在采用自配固化剂后,浆体工艺和强度指标提升明显,符合快速转场的要求.综合分析可知,固化剂在钙基膨润土和添加剂的协同作用下有效消除了蒸发母液对Ca²⁺的吸附,确保固化体系中生成了足量的钙矾石和水化硅酸钙并且都能稳定存在,保证了固化蒸发母液的快速凝结和强度稳定.     

基于骨架构建体污泥脱水及其固化土工性能研究

以含水率为98．5％的污泥为研究对象,添加粉煤灰、生石灰等无机复合调理剂进行改性处理,研究其对泥饼固化体的比阻、含水率、最大干密度、渗透系数和无侧限抗压强度等性能的影响。结果表明,添加的粉煤灰和石灰起到骨架构建体作用,处理污泥的比阻从原污泥的109S2／g降至107s2／g,显著改善了污泥脱水性能。在不外掺水泥等其他固化剂的条件下,脱水后的泥饼固化体7d无侧限抗压强度大于100kPa,具有优良的固化土工性能。     

油田含油污泥固化与耐水性能研究

研究含油污泥无害化处理问题。采用固化处理技术,通过实验确定固化剂和促凝剂与含油污泥的最佳配比,并测定浸出液的含油量以确定方案的可行性。同时,研究固化物在不同温度下的耐水性能。     

处理垃圾渗滤液的厌氧颗粒污泥快速形成的研究

通过对驯化后的某城市污水处理厂消化污泥的静态实验，运用正交分析法分别确定了阳离子聚丙烯酰胺、聚氯化铝和聚氧化乙烯与粉煤灰在处理垃圾渗滤液形成厌氧颗粒污泥时的最佳浓度，并用区域沉淀速度、污泥容积指数及上清液中的悬浮固体浓度评价了投加絮凝剂与粉煤灰后所形成的生物絮体的沉降性能．研究结果表明，通过对消化污泥驯化可将COD去除率提高45％；阳离子聚丙烯酰胺与粉煤灰的最佳浓度组合为50mg／L和200mg／L，聚氯化铝与粉煤灰的最佳浓度组合为40mg／L和200mg／L，聚氧化乙烯与粉煤灰的最佳浓度组合为10mg／L和100mg／L．     

重金属污泥制砖固化及其浸出试验

将含重金属污泥与粘土按不同的比例混合制砖固化,并通过毒性浸出试验研究了不同砖块的浸出液中As、Zn、Pb、Cd含量随浸出时间的变化。结果表明,重金属的浸出浓度在浸出初期逐渐升高,然后As的浸出浓度趋于稳定,而Zn和Cd的浸出浓度则呈下降趋势;As、Zn、Cd的浸出浓度与污泥的添加量有关,随着污泥添加量的增大,As的浸出浓度增大,Zn和Cd的浸出浓度是先增大,然后趋于稳定,但污泥添加量对Pb的浸出浓度影响不大;在制砖粘土中添加1%的Fe2O3和12%的含重金属污泥时,As、Zn、Cd和Pb的浸出浓度低于规范要求,固化效果良好、安全可靠。     

基于骨架构建污泥固化体收缩与开裂特性的研究

针对传统污泥固化方法中固化污泥体易收缩开裂等问题,基于骨架构造原理,用煤矸石作为骨料,加入水泥、生石灰、粉煤灰等固化材料,按照不同配比对污泥进行一系列的固化实验。考察了在28 d养护龄期污泥固化结实体的开裂与收缩特性。研究表明加入煤矸石作为骨料能有效地抑制固化污泥的收缩与开裂,生石灰能抑制开裂,粉煤灰对污泥固化体的收缩开裂特性影响较小。     

Multi-objective model of fast-solidification sludge

Many sludge curing technologies often have problems like long curing time, high cost, and low efficiency in the condition of low temperature. The compressive strength, moisture content and temperature are defined as the constraint conditions, and solidified cost, pH, COD, NH₄ ⁺-N concentration are defined as the objective functions. The response surface analysis is used to obtain a variety of response expressions of factors, and the multi-objective optimization model of fast-solidification sludge is established. Then, the curing agent formulas are optimized. After three-day conserving, the curing sludge could meet the landfill conditions.     

Accelerated carbonation and leaching behavior of the slag from iron and steel making industry

Ground granulated blast furnace slag （GGBFS） and steelmaking slag have been used as a raw material for cement production or as an aggregate to make concrete, which contribute aluminum, calcium, iron, and silicon oxides. The suitability of the slag for a particular application depends on its reactivity, cost, availability, and its influence on the properties of the resulting concrete. For the interest of durability studying of concrete in the presence of slag, the accelerated carbonation products and leaching behavior of the slag and Portland cement （PC） were studied. The experimental results confirmed that the slag was more resistant to carbonation compared to PC. The carbonation degree of GGBFS reduced by 17.74%; and the carbonation degrees of steelmaking slags reduced by 9.51%- 11.94%. Carbonation neutralized the alkaline nature of the hydrated pastes and gave rise to the redox potential of the leachate slightly （30-77 mV）. The carbonation also increased the release of most of the elements presented, except for calcium, to the aqueous environment. It is concluded that blend cements （PC plus slag） have economical advantages and better durability compared to PC,     

水泥对铬渣无害化处理及其固化体浸出毒性的研究

对水泥作胶凝材料固化铬渣进行了研究。首先硫酸亚铁溶液与铬渣搅拌，然后再加入粉煤灰，水泥，矿渣等，部分还原的六谷铬转换为三价铬被固定在水泥基质中。研究结果表明，这样得到的固化体六价铬浸出毒性低于国家标准，抗压强度可达30MPa以上，能用于建材。本实验还考虑日晒，浸出时间和固化体粒度等因素对固化体浸出毒性的影响。     

天津滨海新区吹填土固化方案的技术比较

吹填土由水力吹填形成,颗粒很细,固结性能差,吹填以后要经过很长时间才能自然沉积固结,待表面形成硬壳后方可进行加固处理.为缩短沉积固结时间,在室内采用多种固化材料对吹填土进行固化处理试验.通过对多种添加方式的固化土样无侧限抗压强度试验的结果进行对比分析,优选出了适宜的固化方案.     

Development of Soda Residue Concrete Expansion Agent

1　IntroductionCracksformeasilyduringthecourseofhardeningofconcreteormortarbecauseofdryingandchemicalshrink age ,thusleadingtothedurabilityandstrengthdecrease .Tosolvethisproblem ,onecanuseexpansivecementoranexpansionagenttoprepareanexpansiveconcrete[1,2 ] .Concreteexpansionagentsgenerateshrinkage com pensationormicrodilatancy .Duringthecourseofhydrationandhardeningofcement,theexpansivepressureisusedtobalancethetensilestressgeneratedbyconcreteduetodryingshrinkage .Theexpansivepressureofshrink…     

Treating leachate mixture with anaerobic ammonium oxidation technology

Large amounts of ammonium and a low content of biodegradable chemical oxygen demand（COD） are contained in leachate from aged landfills, together with the effluent containing high concentration of nitric nitrogen after biochemical treatment. Treatment effect of anaerobic ammonium oxidation （anammox） process on the mixture of the leachate and its biochemical effluent was investigated. The results show that the average removal efficiencies of ammonium, nitric nitrogen and total nitrogen are 87.51%, 74.95% and 79.59%, respectively, corresponding to the average ratio of removed nitric nitrogen to ammonium, i.e. 1.14 during the steady phase of anammox activity. The mean removal efficiency of COD is only 24.01% during the experimental period. Thc,dcmand of total phosphorous for the anammox process is unobvious. Especially, the alkalinity and pH value of the effluent are close to those of the inftuent during the steady phase of anammox activity. In addition, it is demonstrated that the status of the anammox bioreactor can be indicated by the alkalinity and pH value during the course of the experiment. The anammox bioreactor has shown potential for nitrogen removal in the leachate mixture. However, COD and total phosphorous in the leachate mixture need further treatment for removal efficiencies of COD and total phosphorous are not good in the anammox bioreactor.     

水解酸化——好氧工艺处理渗滤液与城市污水混合废水的研究

采用水解酸化－好氧工艺对渗滤液与城市污水的混合废水处理的可行性、效果和运行特性进行了研究。其中水解酸化段采用ＡＢＲ反应器,好氧段采用传统活性污泥法。研究表明,原渗滤液ＣＯＤ浓度为３７００￣５５００ｍｇ／Ｌ,混合比达４：６时,处理出水ＣＯＤ和ＢＯＤ５可分别低于２００ｍｇ／Ｌ和３０ｍｇ／Ｌ。混合比达５：５时,系统运行稳定,ＣＯＤ和ＢＯＤ５去除率达８０．９％和９６．８％。当原渗滤液ＣＯＤ浓度为６５００￣