城市垃圾填埋场粘土基防渗浆材的实验研究

文章研制了一种低渗透系数并对污染物有一定吸附阻滞作用的浆材,即膨润土-粉煤灰-水泥(BFS)浆材,用于垃圾填埋场以防治渗沥液渗漏污染周围地下水和土壤。通过正交试验优选出了以膨润土为主的配方:膨润土22%~25%、粉煤灰20%~23%、水泥15%~18%、纯碱1.2%~1.4%、稀释剂TMH加量0.3%~0.45%。该浆材结实率大于99.6%,固结体28d渗透系数小于0.8×10-7cm/s,无侧限抗压强度小于2.0MPa,渗透系数比一般水泥粘土浆材降低约2个数量级。通过采自长春某垃圾填埋场的渗沥液进行固结体的渗透试验,该浆材的固结体对CODCr、氨氮和磷的吸附阻滞率均达到了82%以上。文章的创新点在于浆材配方的选材不但考虑了降低固结体渗透系数,使其符合规范要求,而且考虑了材料成分对渗沥液中污染物的吸附阻滞作用,同时降低了固结体的抗压强度和脆性,使其有一定的塑性和韧性,以适应填埋场的地基变形。     

城市垃圾填埋场水泥基防渗浆材的研究

针对垃圾填埋场防治沥出液渗漏的要求，研制了一种水泥基膨润土-粉煤灰-水泥（BFS）防渗浆材，该浆材具有渗透系数低、吸附阻滞性能好的特点。介绍了该浆材的材料及试验研究成果。     

河南信阳上天梯膨润土制备高效活性白土试验研究

上天梯膨润土属于钙基膨润土,主要矿物成分是钙质蒙脱石。矿石的胶体分散性较差,阳离子交换总量较低,主要的可交换阳离子是钙、镁离子。蒙脱石的晶体化学结构研究表明,蒙脱石有较高的有序度和较大的层电荷,因此,上天梯膨润土适合于制备高效活性白土。试验讨论了酸性活化、固液比及活化时间对产品质量的影响,确定了最佳工艺条件。对原矿进行捣浆提纯后,用16％～20％的硫酸溶液对膨润土进行活化,活化时间 6～8小时,固液比1∶2。制得的活性白土的脱色力达156～218,活性度大于222m.mol/100g ,其质量达到和超过了国家行业标准和同行业该产品的指标,脱色效果良好。     

超细钠基膨润土的制备

以莱西的钙基膨润土为原料,研究了分散方法、分散时间、分散剂种类及分散剂用量对膨润土钠化的影响,确定了最好的分散设备,提出了以3％的碳酸钠为钠化剂,0．4％的焦磷酸钠为分散剂,制备超细钠基膨润土的新工艺,并制备出了平均粒径为0．496μm的超细钠基膨润土。     

四川三台膨润土的基本物化性能及其对铅、钴的吸附性研究

对四川三台钙基膨润土的基本物化性能和对Pb^2 ，Co^2 离子的吸附性能作了初步的研究。基本物化性能主要包括化学成分、阳离子交换容量、密度、比表面积、孔径、渗透系数及热稳定性。通过实验得出：1)经过钠化改型并酸化处理后的膨润土的阳离子交换容量(CEC)明显高于未经处理的原土；2)膨润土的最佳酸活化条件为在96℃左右以15％的硫酸活化4小时的性能最佳；3)膨润土土的密度为2．11g／cm^3，颗粒密度钠化土为1．996g／cm^3，原土为2．079g／cm^3；渗透系数为0．013cm／s(20C)；体积平均粒径为30．950μm；比表面积为329．7482m^2／g，平均孔径为33．238nm；4)膨润土对对重金属离子的吸附实验，得出膨润土对重金属离子Pb^2 的吸附性能优于Co^2 ，Pb^2 和Co^2 的吸附比(Rd)分别为167．8ml／g及53．3ml／g；Pb^2 和Co^2 去除率(r)分别为45．87%和21．20％。     

吉木萨尔县帐篷沟膨润土矿矿石性能及工业应用试验

该矿为钠基膨润土,由硬质矿块与软质胶结物组成。主要矿物为蒙脱石,平均含量72.85％,其次为石英、方英石及少量石盐、赤铁矿。阳离子交换容量75.95mmol/100g胶质价93ml/15g,湿态抗压强度4.41×10~4～5.79×10~4Pa,20％HCl活化土脱色力110.4～332.5,原矿造浆率5.78m~3/t～12.2m~3/t。浇注铸件质量优良,表面光滑。     

南苏鲁超高压变质带东海地区富钛榴辉岩及金红石矿的成因

苏鲁超高压变质带南部的东海地区有富Fe—Ti的钛铁矿榴辉岩和富Ti的金红石榴辉岩。富Fe—Ti榴辉岩的次要矿物主要由钛铁矿和钛磁铁矿组成，可舍少量金红石，具有很低的Si02（38．0％-42．3％）、Na20＋K20（0．48％～2．13％）和Zr、Nb、Ta、Ba、1Kb、REE含量，很高的FeO（18．24％-25．33％）、V和Co含量，并具有不同程度的LREE亏损、明显的正Eu异常；富Ti金红石榴辉岩舍有丰富的金红石和磷灰石，SiO2含量范围（38．0％-54．8％）较宽，FeO含量较低，P2O5含量较高（可达4．1％），而X-TiO2与P205含量具正相关性。相对于原始地慢岩．富Ti金红石榴辉岩具有Rb、Th、K、Nb、Pr、Nd、Eu、Ti、Lu的负异常和Ba、Sr、Zr的正异常．并具相对较高的IKEE含量，LREE富集和HREE亏损的1KEE分配型式。岩石学和地球化学特征揭示，Fe—Ti榴辉岩的原岩是变质的Fe—Ti辉长岩，是基性岩浆强烈分离结晶作用形成的超基性-基性-中酸性层状侵入体的特征组成部分。     

造浆用粘土分析鉴定与造浆试验方法的探讨(下)

二、造浆试验方法的探讨用作钻井泥浆之粘土的造浆率高低是很重要的。试验发现有些膨润土造浆率不高，即使用纯碱改为钠型膨润土后，造浆还是不高，仍小于6米~3/吨土。相反，有些非膨润土的造浆率还比它高。笔者初步分析认为，造浆率高低与粘土分散度和水化程度等有关。小于1微米以下的细颗粒越多且水化程度又好的粘土，其造浆率较高。     

一个新的铋亚碲酸盐矿物—平谷矿

平谷矿是在北京市平谷县一小型金矿氧化带中发现的一种新矿物。共生和伴生矿物有褐铁矿、孔雀石、磷氯铝矿、泡铋矿、自然金、银金矿、石英、方解石和白钨矿。通常呈粒状集合体出现，单体板柱状，极为细小（0．3～0．6μm），黄绿色，玻璃至金刚光泽。实测密度＝8．44g／cm3，计算密度8．64g／cm3。维氏硬度449～572kg／mm2，相当摩氏硬度5～6。反射率＝13．25％，折射率＞2．0，计算折射率为2．145，电子探针分析结果Bi2O379．56％、TeO220．17％，总和99．73wt％，化学式Bi5。8043Te2。1475O13理想式Bi6Te2O13。X射线粉晶分析主要强线3．146（100）（12）、2．841（80）（200）、2．694（20）（040）、1．695（20）（321）、1．956（10）（240）、1．631（10）（16），斜方品系，a＝0．5689（1），b＝1．0791、c＝0．5308（1）um，晶胞体积V＝0．3258um3，Z＝1。     

辰山岩体岩石学地球化学特征及其大地构造环境意义

辰山岩体位于湘中安化县,形成于晚三叠世,主要由黑云母花岗闪长岩和二云母二长花岗岩组成。岩石高硅、高钾、富碱,SiO2含量为69．63％～69．76％;K20含量为3．28％～3．71％;Na20＋K：0为5．87％～7、28％;A／CNK比值为0．9～61．31,KN／A比值为0．53～0．64,属高钾钙碱性系列过铝质花岗岩类。∑REE含量为157．73～176．84μg／g;6Eu值0．86～1．16;具Ba、Nb、sr和Ti负异常。结合区域岩石圈结构,上述特征表明花岗岩源岩应为中地壳结晶片岩、片麻岩。根据多种氧化物与微量元素构造环境判别图解,结合地质特征、构造演化背景等,认为辰山岩体形成于同造山阶段的相对松弛的后碰撞构造环境。     

天然与改性膨润土组合处理难生物降解垃圾渗滤液的实验研究

以北京市阿苏卫垃圾填埋场中晚期渗滤液为研究对象,通过正交实验的方法分析了改性土、原土、明矾、改性土加明矾等的用量及搅拌速度、搅拌时间、静置时间等因素对垃圾渗滤液CODcr去除率的影响。通过对改性土、原土、明矾处理垃圾渗滤液的机理进行分析后,将改性土、原土分别用来处理垃圾渗滤液中可溶性物质中的疏水性物质和亲水性物质,并结合明矾的絮凝作用组合处理垃圾渗滤液。处理后垃圾渗滤液CODcr值从4700mg/L明显下降到839mg/L,CODcr去除率为82.15%,BOD5从700mg/L下降到263mg/L,BOD5去除率为62.43%。有机改性膨润土、明矾、原土组合处理是一种有效的处理垃圾渗滤液方法。     

上海老港垃圾卫生填埋场隔离墙材料特性室内试验研究

为了控制垃圾渗滤液的侧向渗透,在城市垃圾卫生填埋场四周需设置垂直隔离墙。隔离墙采用现场开挖深槽,然后在槽内灌注水泥一膨润土一砂混合浆液的方法构筑。通过室内配比试验的方法,测定不同配比试件的无侧限抗压强度、渗透系数等参数,为隔离墙的施工提供合理的配比。     

Relative performance of lime stabilized amended clay liners in different pore fluids

Successful design of soil liner and covers for landfills and waste impoundments involves selection of liner material and assessment of chemical compatibility of the liner material. In this work locally available materials with different mineralogy have been evaluated from the viewpoint of liner application. Many local soils may not meet the requirements of liner material; often it is necessary to amend these soils with commercially available processed bentonite. Clay liners may be attacked by chemical waste or leachate, concentrated organic chemicals can attack compacted clay effectively destroying the characteristics of liner material. Thus the main aim of this work has been to assess the suitability of different types of locally available materials for their potential use as liners for waste containment facilities. The materials studied are kaolinitic red earth, illite and fly ash. Based on literature survey and experimental work in this laboratory, 20% by weight of bentonite has been chosen for amending selected materials. Addition of 20% bentonite to selected liner material improved the hydraulic conductivity and adsorption capacity of the amended mixture but, reduced the volume stability. To improve the volume stability of the amended material and to have better resistance towards chemicals attack, stabilizing the amended mixture with 1% by weight of lime has been considered. The relative advantages and disadvantages of four materials namely; red earth with 20% bentonite, illite with 20% bentonite, fly ash with 20% bentonite and illite alone, stabilized with 1% by weight of lime were brought out. The chemical compatibility of the materials to electrolyte solution (0.5 N NaCl), alkaline solution (0.5 N NaOH), acid (0.5 N HCl) and organic fluid (CCl₄) has been studied. The relative efficiency of the selected materials with selected pore fluids was compared.     

磁处理对注浆用黏土浆液的改性作用

对黏土浆液进行磁化处理,研究磁化处理后黏土浆液的黏度、密度、pH值、电导率、析水率、结石率及抗渗性等物理性质变化特征。磁处理后,黏土浆液密度、黏度、析水率均减小,pH值、电导率、结石率增大,黏土浆液的析水率与结石率的改善效果随磁化时间的增长而增大,磁处理改善了浆液的流变性能,磁化后黏土浆液固结体的抗渗性能较未磁化黏土浆液固结体抗渗性能有了大幅提高。黏土浆液经磁化后Zeta电位值、pH值增大,使得其分散程度提高,从而降低了析水率,提高了结石率,同等质量黏土浆液抗渗性能的提高得益于磁处理后黏土浆液结石率的大幅增加,而其黏度的降低,是因磁处理后黏土浆液颗粒间有较强的排斥力导致。      

钻孔灌注桩施工过程中垃圾渗滤液对地下水的污染分析

采用大直径钻孔灌注桩时,施工时会破坏现有垃圾填埋场的防渗体系,且渗滤液将对地下水造成一定程度的污染。通过对基桩施工过程中渗滤液污染传输过程以及特征进行分析,提出了包括全护筒支护、膨润土泥浆护壁以及减少钻孔成孔至灌注混凝土的间隔时间等控制污染的主要措施,建立了基桩施工过程中钻孔泥浆浆液的损失模型以及渗滤液传输到地水下中的污染物质浓度的计算模型。根据某一具体施工条件进行估算,预测了地下水中污染物质浓度以及污染程度。最后,提出了垃圾填埋场内钻孔灌注桩的施工工艺以及施工注意事项。     

可渗透反应墙处理垃圾渗滤液的实验研究

文章以垃圾渗滤液为研究对象,分别用铁粉、改性膨润土、活性炭及其混合物为反应介质,设计4种不同介质配比的PRB反应器进行实验研究。结果表明,PRB对垃圾渗滤液有较好的处理效果,其中,以还原铁粉、改性膨润土为介质的反应器,对氨氮的去除效率最大为97.58%,以还原铁粉、活性炭为介质的反应器对COD的去除效率为84.87%,对总磷的去除效率最大为80%。     

Swelling characteristics of compacted lateritic soil–bentonite mixtures subjected to municipal waste leachate contamination

Compacted soil–bentonite mixtures are finding wide application as buffer material for waste repositories for their favorable self-sealing qualities. The swelling properties of such materials which serve as a measure of their self-sealing capabilities and, thus, the efficiency of the repository in sealing off their contents from the environment are closely related to the chemistry of the leachate that emanate from the wastes. For this reason, the swelling parameters (namely swelling potential and pressure) of compacted lateritic soil–bentonite mixtures under consideration for use as barrier in municipal waste landfill were evaluated. Series of swelling potential and pressure tests were performed using variable content (0–10 %) of bentonite at predetermined optimum moisture content. Soil mixtures were compacted with British Standard Heavy compactive effort and saturated with processed tap water as well as three leachate solutions of varying ionic strength that were generated in active open dump landfills. Experimental results showed that swelling potential based on the free swell together with the maximum swell pressures of compacted soil mixtures measured at equilibrium increased approximately linearly with increase in the amount of bentonite when inundated with processed tap water and the three leachate solutions. On the other hand, these swelling parameters decreased as the ionic strength of the leachate solutions measured by their electrical conductivity increased for the various soil mixtures. These results provide an insight into the swelling behavior and the possible degradation in the efficiency of the proposed lateritic soil–bentonite mixtures in relation to their use as buffer material in waste landfills.     

Effect of Water and Leachate on Hydraulic Behavior of Compacted Bentonite,Calcareous Sand and Tuff Mixtures for Use as Landfill Liners

Compacted soil–bentonite liners, consisting of a sandy soil mixed with bentonite as backfill, are used extensively as engineered barriers for contaminant containment. This paper studies the valorization of local materials containing calcareous sand, tuff obtained from Laghouat region (in the South Algeria), to associate with bentonite in order to improve their hydraulic characteristics for use as landfill liner material. Firstly, a geotechnical characterization of mixtures chooses from a fixed percentage to 10% bentonite and different percentages of calcareous sand and tuff so that they are complementary to 90% by not 10%. Thereafter, the determination of saturated hydraulic conductivity at falling-head permeability (K_v) and oedometer (K_id, indirect Measure) tests of all compacted mixtures at Optimum Normal Proctor have been carried out using both permeates by tap water and a landfill leachate in order to simulate long-term conditions. The results showed that the saturated hydraulic conductivity of tap water is relatively lower than the one saturated by leachate in the falling-head test, unlike the oedometer test. The B₁₀CS₂₀T₇₀ mixture has satisfied the hydraulic conductivity criterion of bottom barriers (i.e. water permeated: k_v20° = 1.97 × 10^?9 and k_id from 7 × 10^?9 to 1.83 × 10^?10 < 10^?9m/s; leachate permeated: k_v20° = 2.91 × 10^?9 and k_id from 7 × 10^?9 at 1.44 × 10^?10 < 10^?9 m/s). Finally, a comparison between direct measurements of the saturated hydraulic conductivity by triaxial (K_d) test and oedometer test (K_id) in the range of effective stress applied 100–800 kPa led to propose equations of correlations between these two methods. In conclusion, adopted formulation B₁₀CS₂₀T₇₀ perfectly meets the regulatory requirements in force and constitutes an economic product based on available local materials for engineers barriers.     

首钢曹妃甸钻孔桩海水泥浆应用研究

在滨海浅滩进行钻孔灌注桩施工时,能否应用海水配制泥浆、应用什么样的造浆材料和处理剂、泥浆指标的合理应用是钻孔灌注桩成功施工的重要因素。通过对几种造浆材料的比选,泥浆配比的优化,对使用海水配制膨润土泥浆的可行性进行了分析。结合首钢曹妃甸2号高炉区钻孔桩施工实例,简要介绍了膨润土海水泥浆的成功应用,对施工过程中的控制方法做了说明,以达到指导类似工程施工的目的。     

水化后GCL中膨润土的微观结构研究

近年来土工织物膨润土垫（GCL）被越来越多地应用到各种防渗工程之中,而水化后GCL中膨润土的微观结构会对GCL的长期防渗性能和力学性能产生影响。采用压汞试验,对水化后GCL中膨润土的微观结构进行定量分析,研究了液体对微观结构的影响,并通过化学分析来揭示液体产生影响的机制。结果表明,(1) 采用垃圾渗滤液水化后的膨润土孔隙体积密度最大,大孔径孔隙所占比例最高;(2) 出现上述规律的原因可以归结为两个方面,一是由于渗滤液中阳离子浓度最高而使得蒙脱石表面双电层厚度最小,二是更加频繁的离子交换作用使得蒙脱石表面大直径离子比例最高。