外加营养源对氯氰菊酯降解菌GF31降解特性的影响

利用本实验室保存的一株铜绿假单胞菌(Pseudomonas aeruginosa)GF31,考察了外加不同的碳、氮源对菌株降解氯氰菊酯特性的影响.实验结果表明:适量浓度的碳、氮源对降解有明显的刺激作用,外加碳源中葡萄糖的刺激作用最为明显,外加0.8 g/L的葡萄糖,氯氰菊酯降解率提高了13.7%;外加氮源中以蛋白胨对微生物的促进作用最突出,当外加5.0 g/L蛋白胨时,氯氰菊酯降解率从27.5%提高到70.0%;降解5 d后,氯氰菊酯的降解已基本趋于平衡.     

混合菌修复石油污染土壤

选取4种从石油污染土壤中分离出的石油降解菌(包括根瘤菌(A)、节细菌(B)、嗜盐菌(C)和芽孢杆菌(D)),对模拟石油污染土壤进行了微生物修复实验。考察了4种菌单独使用时的石油降解率,确定了混合菌的最佳配比和菌群的最优培养条件,并对比了微生物修复前后土壤的各项性质。实验结果表明:4种菌均可提高微生物修复石油污染土壤的修复效果,使用D菌时石油降解率最高;当混合菌的w(A)∶w(B)∶w(C)∶w(D)=12∶2∶21∶65时,在培养条件为混合菌接种量122.0 mL/kg、土壤含水率14%(w)、鸡粪加入量90 g/kg、麦糠加入量150 g/kg和表面活性剂加入量22 mL/kg的情况下,土壤的修复效果最好,40 d后石油降解率达66.95%;经混合菌修复的石油污染土壤,其肥力明显升高,脱氢酶、过氧化酶和脲酶的活性均升高,微生物数量也有明显增加。     

镰刀菌HJ01对对氯苯酚的降解特性

采用实验室分离的一株镰刀菌HJ01,以对氯苯酚(4-CP)为降解底物,以蔗糖为外加碳源,考察了蔗糖质量浓度、降解温度、初始pH对4-CP降解效果的影响,初步探讨了镰刀菌HJ01对4-CP的降解动力学和降解机理.实验结果表明:该菌株能以4-CP为惟一碳源和能源生长;在外加蔗糖为碳源,蔗糖质量浓度为3 g/L、降解温度为30℃、初始pH为8的条件下,50 mg/L4-CP能在6 d内被完全降解.以4-CP为惟一碳源和外加蔗糖下的降解动力学分别符合Haldane模型和一级动力学方程.     

Fenton氧化—微生物法降解土壤中石油烃

以长期被苯系物污染的活性污泥为菌源,采用液相"诱导物-中间产物-目标污染物"驯化模式驯化出专性混合石油降解菌群,并将其用于Fenton氧化—微生物法处理模拟石油污染土壤。高通量测序结果表明,产黄杆菌属(Rhodanobacter)、分支杆菌属(Mycobacterium)和根瘤菌属(Rhizobiales)为主导菌属。实验结果表明:接种混合菌群后降解50 d,土样的总石油烃(TPH)去除率较土著菌提高了13.4~20.5百分点;对于TPH含量(w)分别为4%,8%,11%的土样,Fenton氧化的最佳H_2O_2加入量分别为3,4,4 mol/L(Fe~(2+)加入量0.04 mol/L),TPH总去除率分别可达88.8%,65.0%,47.7%,较单独Fenton氧化或单独微生物法均有很大程度的提高,且缩短了降解时间,增加了土壤有机质。     

纳米Al_2O_3固定化红平红球菌菌球的制备及其对苯酚的降解

以海藻酸铝为主要包埋材料、纳米Al_2O_3为添加剂,包埋固定红平红球菌,制得纳米Al_2O_3固定化红平红球菌菌球,并将其用于苯酚的降解。表征结果显示:菌球内部包含丰富的菌丝体;内部孔径以中孔居多。实验结果表明:菌球的最优制备方案为0.05 g纳米Al_2O_3加入3 m L海藻酸钠溶液中、海藻酸钠质量分数6%、微生物包埋量0.5 m L/m L(以海藻酸钠溶液计)、Al_2(SO_4)_3质量分数3%;在初始苯酚质量浓度为400 mg/L、反应时间为24h、菌球加入量为8 g/L、反应p H为8.0、反应温度为30℃的条件下,菌球首次使用时可使苯酚完全降解,使用5次后的苯酚降解率仍达93%以上,具有良好的循环使用性。     

活性艳蓝X-BR降解菌的筛选

从某印染厂废水排放出口的污泥中分离到一株活性艳蓝X-BR染料高效降解菌LPY68-14,经生理生化鉴定,该菌为埃希氏菌(Escherichia sp.).研究了影响菌株LPY68-14降解效果的因素,实验结果表明:在缺氧、质量分数为0.2%葡萄糖为外加碳源、温度37℃、接种量4 mL、pH 7的最佳条件下,质量浓度为30 mg/L的活性艳蓝X-BR经菌株LPY68-14处理24 h后的降解率可达80%;当活性艳蓝X-BR质量浓度为100～400 mg/L时,该菌处理48 h后的降解率可稳定在70%左右.     

甲苯对铁屑降解三氯乙烯的影响

为了探讨甲苯仔任时铁屑降解三氯乙烯（TCE）的有效性及影响因素,考察了铁屑粒径、铁屑预处理方法及甲苯初始质量浓度对TCE降解效果的影响。实验结果表明：选用粒径0．35—0．83mm的铁屑较好;用0．05mol／L的盐酸清洗后的铁屑对TCE的降解效果好于未进行酸洗的铁屑对TCE的降解效果;当m（甲苯）：m（TCE）分别为0,1．2,10．3,18．6时,TCE降解的反应速率常数分别为0．0691,0．0595,0．0458,0．0361h^-1,半衰期分别为10．03,11．65,15．13,19．20h,即随着甲苯初始质量浓度的提高,TCE降解的反应速率常数变小,半衰期变长;铁屑对甲苯具有吸附作用,甲苯的初始质量浓度越高,甲苯吸附量越大。     

Fenton氧化—微生物法降解土壤中石油烃

以长期被苯系物污染的活性污泥为菌源,采用液相“诱导物-中间产物-目标污染物”驯化模式驯化出专性混合石油降解菌群,并将其用于Fenton氧化—微生物法处理模拟石油污染土壤。高通量测序结果表明,产黄杆菌属（Rhodanobacter）、分支杆菌属（Mycobacterium）和根瘤菌属（Rhizobiales）为主导菌属。实验结果表明：接种混合菌群后降解50 d,土样的总石油烃（TPH）去除率较土著菌提高了13.4~20.5百分点;对于TPH含量（w）分别为4%,8%,11%的土样,Fenton氧化的最佳H₂O₂加入量分别为3,4,4 mol/L（Fe²⁺加入量0.04 mol/L）,TPH总去除率分别可达88.8%,65.0%,47.7%,较单独Fenton氧化或单独微生物法均有很大程度的提高,且缩短了降解时间,增加了土壤有机质。     

混合菌修复石油污染土壤

选取4种从石油污染土壤中分离出的石油降解菌（包括根瘤菌（A）、节细菌（B）、嗜盐菌（C）和芽孢杆菌（D））,对模拟石油污染土壤进行了微生物修复实验。考察了4种菌单独使用时的石油降解率,确定了混合菌的最佳配比和菌群的最优培养条件,并对比了微生物修复前后土壤的各项性质。实验结果表明：4种菌均可提高微生物修复石油污染土壤的修复效果,使用D菌时石油降解率最高;当混合菌的w（A）∶w（B）∶w（C）∶w（D）=12∶2∶21∶65时,在培养条件为混合菌接种量122.0 mL/kg、土壤含水率14%（w）、鸡粪加入量90 g/kg、麦糠加入量150 g/kg和表面活性剂加入量22 mL/kg的情况下,土壤的修复效果最好,40 d后石油降解率达66.95%;经混合菌修复的石油污染土壤,其肥力明显升高,脱氢酶、过氧化酶和脲酶的活性均升高,微生物数量也有明显增加。     

锌粉对1,2,4-三氯苯的脱氯性能

采用锌粉对1,2,4-三氯苯（1,2,4-TCB）进行了脱氯的研究。实验结果表明,在40mL质量浓度为22.94m g/L的1,2,4-TCB水溶液中加入1.0g锌粉,反应24h时,1,2,4-TCB的还原率可达94.6%;反应16h时,试样中的Cl-浓度约为1,2,4-TCB完全脱氯所得Cl-理论浓度的30%;锌粉还原1,2,4-TCB的反应能在较宽的pH范围内进行,弱碱性条件下的脱氯效果最好,1,2,4-TCB的还原率达70%。     

Enhanced anaerobic bioremediation of a TCE source at the Tarheel Army Missile Plant using EOS

EOS, or emulsified oil substrate, was used to stimulate anaerobic biodegradation of trichloroethene (TCE) and tetrachloroethene (PCE) at a former Army‐owned manufacturing facility located in the Piedmont area of North Carolina. Previous use of chlorinated solvents at the facility resulted in soil and groundwater impacts. Ten years of active remediation utilizing soil vacuum extraction and air sparging (SVE/AS) were largely ineffective in reducing the TCE/PCE plume. In 2002, the Army authorized preparation of an amended Remedial Action Plan (RAP) to evaluate in situ bioremediation methods to remediate TCE in groundwater. The RAP evaluated eight groundwater remediation technologies and recommended EOS as the preferred bioremediation alternative for the site. Eight wells were drilled within the 100 × 100 feet area believed to be the primary source area for the TCE plume. In a first injection phase, dilute EOS emulsion was injected into half of the wells. Distribution of the carbon substrate through the treatment zone was enhanced by pumping the four wells that were not injected and recirculating the extracted water through the injection wells. The process was repeated in a second phase that reversed the injection/extraction well pairs. Overall, 18,480 pounds of EOS were injected and 163,000 gallons of water were recirculated through the source area. Anaerobic groundwater conditions were observed shortly after injection with a corresponding decrease in both PCE and TCE concentrations. Dissolved oxygen, oxidation‐reduction potential, and sulfate concentrations also decreased after injection, while TCE‐degradation products, ferrous iron, and methane concentrations increased. The reduction in TCE allowed the Army to meet the groundwater remediation goals for the site. Approximately 18 months after injection, eight wells were innoculated with a commercially prepared dechlorinating culture (KB‐1) in an attempt to address lingering cis‐1,2‐dichloroethene (cis‐DCE) and vinyl chloride (VC) that continued to be observed in some wells. Dehalococcoides populations increased slightly post‐bioaugmentation. Both cis‐DCE and VC continue to slowly decrease. © 2007 Wiley Periodicals, Inc.     

Treatment Optimization Through Refinement of a Conceptual Site Model Using Compound Specific Isotope Analysis

Two adjacent automotive component manufacturers in Japan had concentrations of trichloroethene (TCE) and perchloroethene (PCE) in soils and groundwater beneath their plants. One of the manufacturers extensively used these solvents in its processes, while the adjacent manufacturer had no documentation of solvent use. The conceptual site model (CSM) initially involved a single source that migrated from one building to under the adjacent building. Further, because low concentrations of daughter products (e.g., cis‐1,2‐dichloroethene; 3.6 to 840 micrograms per liter [μg/L]) were detected in groundwater, the CSM did not consider intrinsic degradation to be a significant fate mechanism. With this interpretation, the initial remedial design involved both source treatment and perimeter groundwater control to prevent offsite migration of the solvents in groundwater. Identifying whether intrinsic degradation was occurring and could be quantified represented a means of eliminating this costly and potentially redundant component. Further, incorporating intrinsic degradation into the remediation design would also allow for a more focused source treatment, resulting in further cost savings. Three rounds of sampling and data interpretation applying compound specific isotope analysis (CSIA) were used to refine the CSM. The first sampling round involved three‐dimensional CSIA (¹³C, ³⁷Cl, and ²H), while the second two rounds involved ¹³C only, focusing on degradation over time. For the May 2012 sampling, δ¹³C for PCE ranged from –31‰ to –29.6 ‰ and for TCE ranged from –30.4‰ to –28.3‰; showing similar values. δ²H for TCE ranged from 581‰ to 629‰, indicating a manufactured TCE rather than that resulting from dehalogenation processes from PCE. However, mixing of manufactured TCE with that resulting from degraded PCE cannot be ruled out. Because of the similar δ¹³C ratios for PCE and TCE, and ³⁷Cl data for PCE and TCE, fractionation and enrichment factors could not be relied upon. Fractionation patterns were evaluated using graphical methods to trace TCE to the source location to better focus the locations for steam injection. Graphical methods were also used to define the degradation mechanism and from this, incorporate intrinsic degradation processes into the remedial design, eliminating the need for a costly perimeter pump and treat system. ©2015 Wiley Periodicals, Inc.     

Field‐scale evaluation of a biobarrier for the treatment of a trichloroethene plume

In the 1960s, trichloroethene (TCE) was used at what is now designated as Installation Restoration Program Site 32 Cluster at Vandenberg Air Force Base to flush missile engines prior to launch and perhaps for other degreasing activities, resulting in releases of TCE to groundwater. The TCE plume extends approximately 1 kilometer from the previous launch facilities beyond the southwestern end of the site. To limit further migration of TCE and chlorinated degradation by‐products, an in situ, permeable, reactive bioremediation barrier (biobarrier) was designed as a cost‐effective treatment technology to address the TCE plume emanating from the source area. The biobarrier treatment would involve injecting carbon‐based substrate and microbes to achieve reductive dechlorination of volatile organic compounds, such as TCE. Under reducing conditions and in the presence of certain dechlorinating microorganisms, TCE degrades to nontoxic ethene in groundwater. To support the design of the full‐scale biobarrier, a pilot test was conducted to evaluate site conditions and collect pertinent design data. The pilot test results indicated possible substrate delivery difficulties and a smaller radius of influence than had been estimated, which would be used to determine the final biobarrier well spacing. Based on these results, the full‐scale biobarrier design was modified. In January 2010, the biobarrier was implemented at the toe of the source area by adding a fermentable substrate and a dechlorinating microbial culture to the subsurface via an injection well array that spanned the width of the TCE plume. After the injections, the groundwater pH in the injection wells continued to decrease to a level that could be detrimental to the population of Dehalococcoides in the SDC‐9^TM culture. In addition, 7 months postinjection, the injection wells could not be sampled due to fouling. Cleaning was required to restore their functions. Bioassay and polymerase chain reaction analyses were conducted, as well as titration tests, to assess the need for biobarrier amendments in response to the fouling issues and low pH. Additionally, slug tests were performed on three wells to evaluate possible localized differences in hydraulic conductivity within the biobarrier. Based on the test results, the biobarrier was amended with sodium carbonate and inoculated a second time with SDC‐9^TM. The aquifer pH was restored, and reductive dechlorination resumed in the treatment zone, evidenced by the reduction in TCE and the increase in degradation products, including ethene. © 2011 Wiley Periodicals, Inc.     

长链烷烃降解菌C6的鉴定及性能研究

从含油活性污泥中筛选出一株长链烷烃降解菌C6,进行了菌种鉴定,考察了该菌对正十六烷及柴油和石蜡的混合物的降解能力,并对由菌株C6产生的生物表面活性剂进行了鉴定。实验结果表明:该菌为鲍曼不动杆菌(Acinetobacterbaumannii);对液体培养基中质量浓度为1 000 mg/L的正十六烷降解48 h后,降解率接近100%,降解动力学曲线的拟合结果符合Monod模型;对液体培养基中质量浓度为1 000 mg/L的柴油和石蜡的混合物降解96 h后,降解率达93%;菌株C6产生的生物表面活性剂经FTIR分析鉴定为磷脂类表面活性剂,排油圈直径为60 mm,临界胶束质量浓度约为25 mg/L,可将水的表面张力降至27.09 mN/m。     

铝碳微电解法降解水中邻苯二甲酸酯

采用铝碳微电解法降解水中邻苯二甲酸酯（PAEs）。首先考察了初始废水pH、铝碳质量比和反应时间对邻苯二甲酸二甲酯（DMP）降解率的影响,然后分别考察了超声波频率、其他金属的添加和H₂O₂加入量对铝碳微电解法降解模拟混合PAEs废水中DMP、邻苯二甲酸二乙酯（DEP）和邻苯二甲酸二丁酯（DBP）的影响。实验结果表明：在初始DMP质量浓度为20 mg/L、初始废水pH为12.0、铝碳质量比为1∶1、反应时间为30 min的条件下,DMP降解率达49.94%;在上述最佳反应条件下处理DMP,DEP,DBP的质量浓度分别为20,10,8 mg/L的模拟混合PAEs废水,当超声波频率为80 kHz时,模拟混合PAEs废水中DMP,DEP,DBP的降解率分别为63.38%,32.75%,32.23%,当铝铁质量比为100∶1时,DMP,DEP,DBP的降解率分别为59.61%,37.39%,31.50%;添加铜和H₂O₂对PAEs的降解有抑制作用。     

Chlorinated Solvent Treatment Wetland

A first‐of‐its‐kind wetland restoration project was completed in October 2000 to treat trichloroethene‐(TCE‐)impacted groundwater from a former manufacturing facility prior to discharge into a highly valued recreational surface water body in the upper Midwest. This article summarizes the design, construction, operation, and effectiveness of the restored wetland. The groundwater‐surface water discharge zone at the site was restored as a wetland to improve the natural degradation of TCE and subsequent degradation by‐products. For the past 11 years, the treatment wetland performance was evaluated by monitoring the wetland vegetation, wetland hydraulics, and water chemistry. Water quality data have been used to assess the wetland geochemistry, TCE and TCE‐degradation by‐product concentrations within the wetland, and the surface water quality immediately downgradient of the wetland. The treatment wetland has been performing according to design, with TCE and TCE‐degradation by‐products not exceeding surface water criteria. The monitoring results show that TCE and TCE‐degradation by‐products are entering the treatment wetland via natural hydraulic gradients and that the geochemistry of the wetland supports both reductive dechlorination (anaerobic degradation) and cometabolic degradation (aerobic degradation) of TCE and TCE‐degradation by‐products: cis‐ and trans‐1,2‐dichloroethene and vinyl chloride. © 2013 Wiley Periodicals, Inc.     

萘降解菌的筛选及其对多环芳烃的降解

从柴油污染土壤中筛选分离出一株萘降解菌N-3,进行了菌种鉴定及萘双加氧酶基因(nah)验证,并考察了该菌对不同种类多环芳烃(PAHs)的降解能力及降解过程中脱氢酶活性的变化。实验结果表明:该菌为铜绿假单胞菌(Pseudomonas aeruginosa),含有nah基因;当分别对液体培养基中质量浓度为50 mg/L的萘、菲、蒽、芘、芴降解84 h时,菌株N-3对萘、菲、蒽、芘、芴的降解率分别为28.81%,34.83%,36.65%,27.50%,23.47%。菌株N-3的脱氢酶活性与其对不同PAHs的降解率呈一定的正相关性。该菌不仅能有效降解萘,且对其他种类PAHs也有一定降解作用。     

掺硼金刚石电极降解模拟焦化废水中的喹啉

采用掺硼金刚石（BDD）电极电化学氧化法降解模拟焦化废水中的喹啉,并通过GC-MS技术分析了喹啉的降解机理及途径。实验结果表明：在常温、初始喹啉质量浓度为50.0 mg/L、电解质Na₂SO₄浓度为0.05 mol/L、模拟废水pH为7、电解时间为2.5 h、电流密度为30 mA/cm²、极板总面积与模拟废水体积的比为160 cm²/cm³的条件下,喹啉降解率接近100%;TOC由初始时的29.43 mg/L降至5.76 mg/L,TOC去除率达80%;COD由初始时的95.25 mg/L降至20.65 mg/L,COD去除率达78%;在降解过程中,首先在喹啉苯环的5位和8位发生羟基化反应,然后苯环发生断裂,形成带有吡啶环的中间产物及羧酸类产物,最后氮杂环开环,生成二氧化碳和水。     

GC-MS在电子束辐照降解甲苯中的应用

用甲苯作为挥发性有机化合物的代表物质,建立了活性炭吸附-二硫化碳解吸气相色谱-质谱分析方法,对电子束辐照甲苯的静态实验和动态实验进行了定性、定量分析。实验结果表明：电子束辐照能有效地降解甲笨,其降解率随吸收剂量的增加而增大;同时,甲苯降解过程中也会生成部分有毒有害物质。该分析方法的检出限为0．02mg／L,工作曲线的线性范围为10～1000mg／L,相关系数为0．9998,活性炭吸附、解吸甲苯的加标回收率大于90％。     

Remediation with cyclodextrin: Recovery of the remedial agent by membrane filtration

Cyclodextrin‐enhanced flushing of contaminants from the subsurface is a promising innovative remediation technology. It will become more economically viable at more sites if methods can be developed to recover and reconcentrate the cyclodextrin solution after it has been flushed through an aquifer. The goal of this study was to determine if membrane technology is capable of meeting that need. Five membranes with different material properties were tested for this purpose in the laboratory. The results of these tests indicate that there are large differences both in the efficiency of these membranes to extract hydroxpropyl‐β‐cyclodextrin (HPCD) and their stability when exposed to trichloroethylene (TCE) at concentrations near aqueous solubility. Not only does the molecular weigh cutoff (MWCO) of a membrane determine if HPCD can be retained, but crucial selection criteria are the membrane's resistance and compatibility with TCE. Of the five membrane materials tested, only two (polymer composite membrane and polysulfone) met both these requirements. The polymer composite membrane (MPF‐44) showed reliable and stable HPCD recoveries (>95 percent) even when exposed to high TCE concentrations. The polysulfone membrane showed high HPCD recoveries, 88.5 ± 0.4 percent to 97 percent ±1 percent for ultrafiltration and nanofiltration membranes, respectively. However, membrane swelling and deterioration became a problem at high TCE concentrations (>1,000 mg/L). These problems diminished when the TCE concentration was less than 1 mg/L. Field tests demonstrated that batch mode treatment by ultrafiltration doubled the cyclodextrin concentration from 5 to 10 percent within three hours at a constant operating pressure of 13 psi. Under continuous single‐pass treatment conditions, cyclodextrin concentration also increased, although the rate of increase was much smaller than in batch mode. Overall, these tests showed that cyclodextrin recovery is possible under field conditions. © 2007 Wiley Periodicals, Inc.