pH和土壤性质影响下三苯基锡的吸附行为

用振荡平衡吸附法研究了典型有毒有机金属化合物三苯基氯化锡在内蒙古黑土(NM)、浙江杭州石灰土(ZJ)、云南赤红壤(YN)、新疆棕钙土(XJ)和江西红壤(JX)中的吸附行为及pH对吸附影响。结果表明,TPT在5种土壤上的吸附等温线都能较好地被直线方程拟合,回归系数R2在0.88~0.99之间;相同pH条件下,土壤样品上的吸附能力大小次序为:NM(1 708.6~4 194.7 L/kg)>ZJ(276.2~574.5 L/kg)>YN(217.1~497.5 L/kg)>XJ(88.3~155.7 L/kg)>JX(27.4~75.4 L/kg);吸附量随着有机碳含量和CEC含量的增大而增加,其中OC起着主要作用;TPT在水溶液中的存在形态随着pH的变化而改变,造成TPT在土壤上的吸附量随着pH增大先增大后变小,TPT的最大吸附发生在pH 5.27(TPT的pKa附近)。因此,土壤对TPT的吸附可能是分配作用,离子交换作用和物理吸附等多种机制共同作用的结果。     

等离子体联合纳米技术降解甲苯废气的研究

以自制的纳米材料作为催化剂,利用低温等离子体联合纳米技术研究了不同电场强度、不同填料情况下的甲苯的降解,初步探讨了等离子体催化降解甲苯的机理,分析了降解产物.结果表明,甲苯降解率随电场强度的提高而上升;随反应器内填料变化[无填料(1),普通填料(2),镀有普通钛酸钡的介电填料(3)和镀有纳米催化剂的填料(4)],降解率( η)呈现为η (4)> η (3)> η (2)> η (1),最高可达95%.能量分配率(R)为R(1)>R(2)>R(3)>R(4).纳米钛酸钡基介电材料作为等离子体反应器内的填充材料,处理同量甲苯废气其消耗功率要低于填充其他填料的等离子体反应器.通过GC-MS 分析,中间产物包括醛、醇、酰胺及带有苯环的衍生物等有机物,但电场强度足够高时,甲苯分子最终可被氧化成CO₂、CO 和H₂O.     

三峡水库动态水位下有机锡的多介质归趋模拟

为探究三峡水库（TGR）动态水位下水环境中有机锡（OTs）的多介质迁移与归趋行为,构建了动态水位下OTs的IV级多介质逸度模型,对大气相、水相、沉积物相及鱼相中三丁基锡（TBT）和三苯基锡（TPT）浓度的动态分布进行了模拟,并依据实测值进行了验证,计算了TBT和TPT在各相间的迁移通量（N）和残留质量,探讨了其主要的迁移途径和归趋行为,并进行了参数敏感性和模型不确定性分析.结果表明,实测浓度与模拟浓度的吻合度较高,TGR水环境中OTs浓度受水位变化影响较大.TBT和TPT的N值随水位变化明显,呈现与水位涨落相反的变化趋势,与坝前水位、入库流量和降雨量的变化相关.平流输入输出、沉积物沉降、掩埋、再悬浮、水相降解和平流输入输出、鱼-水两相迁移是TBT和TPT的主要迁移过程,平流输出与降解是两者主要的损失途径.较大的沉积物输入净迁移通量（NN）表明沉积物相是TBT和TPT重要的储藏库,易在鱼相富集也是TPT的重要归宿.模拟期内TBT和TPT在沉积物相的残留质量最高,分别占总残留量的89%和84%,其在沉积物相、水相、鱼相及大气相的分配比例分别为89.17%、10.81%、0.04‰、0.19‰和83.81%、14.51%、1.68%、1.15×10^-5‰.平流输入浓度（COW）和速率（GOW）对4个环境相TBT和TPT的敏感性系数（SC）>0.6,产生显著正影响,TBT和TPT模拟浓度的变异系数（CV）≤0.15,模型模拟的效果较好.     

pH值对SBR单级好氧生物除磷的影响

在2个序批式反应器(R1、R2)中,以合成废水为对象,研究了不同pH值(R1:pH 8±0.2; R2:pH 7±0.2)对单级好氧生物除磷的影响;并通过比较周期中主要储能物质的变化,探讨了产生不同除磷效果的原因.结果表明,R1与R2均具有较高除磷性能, R1与R2中的平均去除率分别为94.9%,83.5%,pH值对SBR单级好氧生物除磷有一定的影响.导致R1具有较高除磷性能的原因是其对聚磷的依赖程度更大.好氧段R1糖原积累量低于R2(R1为1.42mmol/g, R2为1.55mmol/g),但降解量却高于R2(分别为1.41,1.19mmol/g);静置期,R1中糖原无明显变化,R2中则观察到明显的糖原降解.R1与R2均有明显的释磷现象, R1释磷量高于R2(释磷量分别为9.65,7.33mg/L).整个周期中,R1中PHA 无明显变化,而R2中则在好氧段有少量减少,静置期有少量上升.     

高效复合菌对多菌灵的生物降解

将多菌灵降解菌Alcaligenes sp.和Rhodococcua sp.(编号为A和R)按不同比例进行复配,并采用三波长校正法和HPLC法测定不同复配降解体系中多菌灵的残留量,比较了纯培养和复合菌群对多菌灵的降解效果,最后对高效复合菌的降解条件进行了优化.试验结果表明,得到的高效降解复合菌群AR5(A∶R复配比例1...     

内环境调节层对厌氧生物反应器填埋场中氮转化的影响

为探究内环境调节层对厌氧生物反应器填埋场内环境和氮组分的长效影响,特设矿化垃圾+重质碳酸钙、矿化垃圾+天然沸石这2种内环境调节层分别置入模拟反应器R2和R3中,同时设R1(不含内环境调节层)作为对照,监测分析390 d内固相垃圾和渗滤液中氮组分的变化.结果表明,R1、R2和R3中pH、碱度、氧化还原电位(Eh)、含水率(MS)的大小关系分别为pH(R2)pH(R3)pH(R1)、碱度(R2)碱度(R3)碱度(R1)、Eh(R2)Eh(R3)Eh(R1)、MS(R3)MS(R2)MS(R1).R1、R2和R3中垃圾全氮降解转化率为79.2%、82.3%和88.5%,氨氮为48.3%、60.1%和67.7%,硝态氮为38.5%、44.2%和53.4%;渗滤液中总氮、氨氮和硝态氮的浓度对比分别为TN(R3)TN(R2)TN(R1)、NH_4~+-N(R3)NH_4~+-N(R1)NH_4~+-N(R2)和NO_3~--N(R3)NO_3~--N(R2)NO_3~--N(R1).总体看来,矿化垃圾+重质碳酸钙、矿化垃圾+天然沸石组成的内环境调节层均能长期优化内环境,为氮的降解转化提供有利条件,而矿化垃圾+天然沸石不仅能促进垃圾和渗滤液中氮组分的降解转化,还能一定程度上控制渗滤液循环造成的氨氮累积.     

活性炭负载铁催化过硫酸盐降解酸性大红3R

采用浸渍-高温煅烧法制备负载型的Fe/活性炭催化剂,利用电镜扫描(SEM)、X射线衍射(XRD)对催化剂进行表征.并以酸性大红3R为目标污染物,用此催化剂研究了过硫酸盐在非均相催化体系的氧化性能.考察了Fe负载量、过硫酸钠用量、催化剂用量、初始污染物浓度等因素对酸性大红3R降解的影响,并对催化剂重复使用性能进行测试.结果表明,Fe负载量为6%时,催化降解效果最好;当Na2S2O8浓度为3.0 g·L-1,催化剂用量1.5 g·L-1,降解3 h时,酸性大红3R去除率达80%以上;催化剂可重复使用5次以上.同时还采用紫外可见、气相色谱-质谱分析其降解的历程.     

Fenton氧化法处理偶氮染料丽春红2R废水的研究

采用Fenton氧化法处理偶氮染料丽春红2R模拟废水,研究不同因素对丽春红2R模拟废水的降解效果。结果显示,p H=3.0、H2O2浓度为2 mmol/L、c(Fe2+)/c(H2O2)=1∶5条件下,Fenton氧化法对丽春红2R模拟废水反应体系的降解效果最佳。此外,在室温(30℃)和p H=3.0条件下,模拟出Fenton氧化降解丽春红2R的初始动力学方程为R=dm/dt=0.00198[c(Ponceau2R)]0.7234[c(Fe2+)]0.5297[c(H2O2)]0.3574。通过LC-MS图对Fenton氧化降解丽春红2R过程中间产物的分析,从而推断出该染料氧化降解的路径。     

高效石油降解菌群构建及降解性能

试验从受石油污染海水中分离出6株石油降解菌D3、T4、R4、T1、D4和R3,对单一菌株的降解能力进行了鉴定,采用等比混合的方式构建了混合菌群分析其降解性能。试验结果表明,T4受柴油浓度影响较小,T1和D3在柴油浓度为0.2%(v/v)时降解率最高,分别为78%和88%;R3和R4的降解率随柴油浓度的升高而上升,D4的降解率随柴油浓度的升高而下降。6种菌株构成的混合菌群的降解能力优于单一菌株,对C13~C19的组分几乎全部降解。二元混合菌T4/R4和R4/D3的实际降解率高于理论降解率,表现出较明显的协同作用。     

枯草芽孢杆菌对土臭素和2-甲基异冰片的降解动力学特性

土臭素(geosmin,GSM)和2-甲基异冰片(2-methylisoborneol,2-MIB)是2种普遍存在于养殖水体中的土腥异味化合物,微生物降解是去除这两种物质的有效途径.本文研究了枯草芽孢杆菌(Bacillus subtilis)降解GSM和2-MIB的动力学特性.结果表明,枯草芽孢杆菌对GSM(1 000~2 000 ng·L-1)和2-MIB(1 000~2 000 ng·L-1)具有较好的降解性能,降解率均达90%以上;枯草芽孢杆菌对这些异味化合物的降解符合伪一级反应动力学,其生物降解速率常数(K)范围为0.14~0.41,降解速率不随GSM和MIB初始浓度的变化而变化;枯草芽孢杆菌对GSM降解的最大比生长速率umax为0.311,Monod常数KS为1.73,而在降解MIB过程中枯草芽孢杆菌的生长不符合Monod方程(R2=0.781).     

Accelerated biodegradation of nitrophenols in the rhizosphere of Spirodela polyrrhiza

We investigated the biodegradation of 2-nitrophenol (2-NP), 4-nitrophenol (4-NP), and 2,4-dinitrophenol (2,4-DNP) in the rhizosphere of Spirodela polyrrhiza plants by conducting degradation experiments with three river water samples supplemented with each nitrophenol (NP). We then isolated NP-degrading bacteria both from the S. polyrrhiza roots and from the river water. In the river water samples, removal of the three NP was accelerated in the presence of S. polyrrhiza plants. The three NPs persisted in an autoclaved solution with sterile plants suggests that NP removal was accelerated largely by bacterial NP biodegradation rather than by adsorption and uptake by the plants. We isolated 8 strains of NP-degrading bacteria: 6 strains from the S. polyrrhiza roots and 2 strains from river water without the plants. The 2-NP- and 2,4-DNP-degrading bacteria were isolated only from the S. polyrrhiza roots. The 4-NPdegrading bacteria different from those isolated from the river water samples were also found on S. polyrrhiza roots. The 2-NP- and 4-NP-degrading strains isolated from the roots utilized the corresponding NP (0.5 mmol/L) as the sole carbon and energy source. The 2,4-DNP-degrading strains isolated from the roots showed substantial 2,4-DNP-degrading activity, but the presence of other carbon and energy sources was required for their growth. The isolated NP-degrading bacteria from the roots must have contributed to the accelerated degradation of the three NPs in the rhizosphere of S. polyrrhiza. Our results suggested that rhizoremediation with S. polyrrhiza may be effective for NP-contaminated surface water.     

黄河水体石油类污染物生物降解模拟实验研究

采用模拟实验的方法研究了自然条件下石油类污染物的生物降解规律.结果表明,向泥沙含量为0g/L或0.5g/L的黄河水样中加入大约10mg/L的石油类污染物,经过一星期左右的驯化期后,石油降解菌菌落水平逐步升高;当石油类污染物的初始浓度为11.64mg/L,温度为20℃时,泥沙含量为0.5g/L的黄河水样中大约85%的石油类污染物在63d内能得到微生物降解;水体中泥沙的含量和石油类污染物的初始浓度均显著影响石油类污染物的生物降解速率,且在不同时段的影响不一;水体中泥沙的存在亦影响到石油类污染物的生物降解动力学.     

双菌种协同代谢酚类化合物的机制研究

以恶臭假单胞菌和热带假丝酵母为对象,进行了苯酚、间甲酚和4-氯酚的生物降解实验,研究了2种菌的纯培养和混合培养方式下3种酚的降解特性和代谢机制.结果表明,当苯酚、间甲酚和4-氯酚的初始浓度分别为100、50和60 mg.L-1时,相对于纯培养,混合培养的动力学常数k的绝对值分别提高了19.0%、2.6%和46.4%.苯...     

三苯基锡吸附降解菌的分离及特性研究

通过菌种筛选和吸附降解特性实验,分离三苯基锡(TPhT)的吸附降解菌,研究TPhT的微生物吸附降解性能和机制.结果表明,肺炎克雷伯氏菌(Klebsiella pneumoniae)对TPhT具有良好的吸附降解效果.0.3~3.0 g.L-1菌体在2.0 h内对3 mg.L-1TPhT的吸附率均超过70%,最高达97.9%;5 d内对TPhT的降解率为26.4%~54.6%;其离体胞内酶2.0 h内对TPhT的降解率也高达28.1%~77.8%.K.pneumoniae对TPhT的降解发生在细胞内,降解速率的增长趋势随时间的延长而变缓,胞内酶在细胞体外对TPhT的降解在2.0 h时达最大值,完整细胞在第1 d对TPhT的降解速率最快,而第2~5 d的变化趋势较平稳.菌体对TPhT的吸附降解过程包括了TPhT的细胞表面吸附、体内外双向运输和体内降解过程.其中,表面吸附的TPhT含量随时间的增长呈现线性增加的趋势;细胞内部的TPhT含量在前3 d快速下降,从55.9%降至17.0%,之后则趋于稳定;上清液中的TPhT含量变化趋势则与细胞内部的相反.     

土壤微生物对苯的降解研究

使用大庆油田石油污染土壤中分离出优势菌种(革兰氏阴性G^-、黄杆菌属Flavobacterium),在实验室可控条件下,研究了该菌种对苯的降解规律和特点.研究发现:微生物对苯浓度耐受范围8.8～17.6 mg·L^-1,大于17.6mg·L^-1时,对该菌株产生明显的抑制作用.降解体系在pH为6.5～7.0之间达到对苯的较高降解水平,最佳降解率出现在苯初始浓度7.04～13.2mg·L^-1之间;苯在微生物细胞内外的浓度变化趋势呈现一致.-lgP(P为有机溶剂苯在细胞膜和水相中的分配系数的比值)的变化能够较好的表征苯在微生物细胞内外的降解趋势和毒性变化;当体系中苯的初始浓度大于8.8mg·L^-1时,苯的降解率与P值变化趋于一致.     

久效磷降解菌的分离及其酶促降解特性研究

从某农药厂废水处理池的污泥中分离到1株久效磷高效降解菌株M-1,经过对其形态特征、生理生化、以及16S rDNA序列分析,该菌株初步鉴定为Paracoccus sp..M-1能以久效磷作为唯一碳源生长,24 h对100 mg·L^-1久效磷的降解效率为92.47%.久效磷降解酶定域表达试验表明该酶为胞内酶,组成表达.久效磷酶促降解的最适反应pH为8.0,最适反应温度为25 ℃;其米氏常数（K_m）为0.29 μmol·mL^-1,最大降解速率(V_max)为682.12 μmol·(min·mg)^-1.久效磷降解酶热稳定性差,碱性条件下能够保持较高降解活性.     

Biodegradation of 2-naphthol and its metabolites by coupling Aspergillus niger with Bacillus subtilis

To explore biodegradation of 2-naphthol and its metabolites accumulated in wastewater treatment, a series of bio-degradation experiments were conducted. Two main metabolites of 2-naphthol, 1,2-naphthalene-diol and 1,2-naphthoquinone, were identified by high-performance liquid chromatography with standards. Combining fungus Aspergillus niger with bacterium Bacillus subtilis in the treatment enhanced 2-naphthol degradation e ciency, lowered the accumulation of the two toxic metabolites. There were two main phases during the degradation process by the kinetic analysis: 2-naphthol was first partly degraded by the fungus, producing labile and easily accumulated metabolites, and then the metabolites were mainly degraded by the bacterium, attested by the degradation processes of 1,2-naphthalene-diol and 1,2-naphthoquinone as sole source of carbon and energy. Sodium succinate, as a co-metabolic substrate, was the most suitable compound for the continuous degradation. The optimum concentration of 2-naphthol was 50 mg/L. The overall 2-naphthol degradation rate was 92%, and the CODCr removal rate was 80% on day 10. These results indicated that high degradation rate of 2-naphthol should not be considered as the sole desirable criterion for the bioremediation of 2-naphtholcontaminated soils/wastewater.     

聚丙烯酰胺生物降解研究

研究了黄孢原毛平革菌对聚丙烯酰胺(PAM)的生物降解,从葡萄糖的加入量、pH、N浓度、Mn²⁺浓度和降解时间5个方面考察了对PAM降解的影响.结果表明,黄孢原毛平革菌对聚丙烯酰胺具有特殊的酶催化降解的能力,降解率可达50%,限氮条件(NH₄⁺=0.2g/L)和Mn2+浓度(Mn²⁺=0.017 5g/L)是菌株产聚丙烯酰胺降解酶的最佳条件.     

Kinetics of phenol and m-cresol biodegradation by an indigenous mixed microbial culture isolated from a sewage treatment plant

An acclimatized mixed microbial culture, predominantly Pseudomonas sp., was enriched from a sewage treatment plant, and its potential to simultaneously degrade mixtures of phenol and m-cresol was investigated during its growth in batch shake flasks. A 2² full factorial design with the two substrates at two different levels and different initial concentration ranges (low and high), was employed to carry out the biodegradation experiments. The substrates phenol and m-cresol were completely utilized within 21 h when present at low concentrations of 100 mg/L for each, and at high concentration of 600 mg/L for each, a maximum time of 187 h was observed for their removal. The biodegradation results also showed that the presence of phenol in low concentration range (100–300 mg/L) did not inhibit m-cresol biodegradation. Whereas the presence of m-cresol inhibited phenol biodegradation by the culture. Moreover, irrespective of the concentrations used, phenol was degraded preferentially and earlier than m-cresol. A sum kinetics model was used to describe the variation in the substrate specific degradation rates, which gave a high coefficient of determination value (R² > 0.98) at the low concentration range of the substrates. From the estimated interaction parameter values obtained from this model, the inhibitory effect of phenol on m-cresol degradation by the culture was found to be more pronounced compared to that of m-cresol on phenol. This study showed a good potential of the indigenous mixed culture in degrading mixed substrate of phenolics.     

低浓度重金属对蜡状芽孢杆菌复合菌降解BDE209性能的影响

针对电子废弃物引起的重金属及多溴联苯醚(PBDEs)复合污染问题,采用GC-MS, ICP、紫外扫描、红外光谱等分析方法,研究了蜡状芽孢杆菌(XPB、XPC)复合菌对十溴联苯醚(BDE209)的好氧脱溴降解性能及低浓度重金属对其降解特性的影响.结果表明,复合菌对BDE209有良好的脱溴性能,能将其降解为酚类有机物,反应1 d时其最高脱溴量可达1.18mg·L-1,脱溴率至少为14.16%.低浓度重金属的存在虽减缓BDE209的降解速率,但依然能保持良好的降解效果,脱溴率仍至少达13.92%.复合菌降解BDE209和吸附重金属的过程主要与羟基、酰胺基团和C--H键有关.单一降解BDE209过程中,复合菌大量释放K 和Na ,最高释放量分别为148.867和225.835μmol·g-1.复合菌在降解BDE209并吸附重金属的过程中,也存在K 和Na 的大量释放现象,且释放量高于单一的降解过程,最高释放量分别为156.482和261.217 μmol·g-1.菌体降解BDE209的同时,对Pb2 、Zn2 、Cu2 的吸附率最高值分别为89.47%、72.22%、39.83%.