石油污染土壤多酚氧化酶的动力学及热力学特征

土壤多酚氧化酶是一种氧化还原酶,能够将土壤中芳香族化合物氧化成醌,促进土壤中石油类物质的分解转化.以距大庆油田工作区不同距离（1、5、15 km）的石油污染地为对象,研究不同温度下石油污染裸地及羊草（Leymus chinensis）修复地的土壤多酚氧化酶活性及其动力学和热力学特征的变化.结果表明:土壤多酚氧化酶活性随温度和底物浓度的增加而逐渐增大,在温度为30℃或40℃、底物浓度为80 mmol/L或160 mmol/L时达到最大值;各样地土壤酶的动力学参数K_m（Mihaelis常数）随温度的变化规律不同,V_max（酶促反应最大速度）和V_max/K_m（催化效率）随温度升高而逐渐增大,均在30℃或40℃时达到最大值;热力学参数Q₁₀（温度系数）、ΔH（活化焓）、ΔS（活化熵）随温度变化差异不显著,ΔG（活化自由能）随温度升高呈逐渐增加趋势.在同一温度下,石油污染裸地土壤多酚氧化酶活性高于羊草修复地;K_m和V_max/K_m在各样地均表现为无规律性变化,V_max最大值出现在距油田工作区5 km处的裸地（BMP）,最小值出现在距油田工作区5 km处的羊草修复地（LMP）;Q₁₀、E_a（活化能）、ΔH、ΔS的最大值均出现在距油田工作区1 km处的裸地（BVP）,最小值均出现在距油田工作区1 km处的羊草修复地（LVP）.研究显示,升温和植物修复对土壤多酚氧化酶活性的反应特征有较大影响.      

Photocatalytic degradation of phenol

In this study photocatalytic degradation of phenol in thepresence of UV irradiated TiO₂ catalyst andH₂O₂was investigated. Effects of TiO₂ andH₂O₂concentrations and pH on photocatalytic degradation were examined. The rate constants for photocatalytic degradation wereevaluated as a function of TiO₂ and H₂O₂ concentrations and pH of the solution. It was found thatphotodegradation is an effective method for the removal of phenoland disappearance of phenol obeyed first order kinetics. The amount of CO₂h produced during photocatalytic degradation wascorresponding to the complete mineralization. Photodegradationcan be an alternative method for the treatment of phenol containing wastewaters.     

Time dependent influx and efflux of phenol by immobilized microbial consortium

Phenol, like many other organic solvents, is toxic to micro-organisms even at low concentrations. However, some micro-organisms can withstand this toxicity to a certain concentration. To observe the uptake mechanism of phenol, bacteria were isolatedfrom a petroleum refinery effluent and identified. Study was carried out to understand the effect of varying sub-lethal concentrations of phenol, on all the isolated individual bacterial cultures. Out of the bacteria isolated, Serratia liquefaciens was found to tolerate phenol concentration up to 1500 mg l^-1. A microbial consortium of the isolated bacteriawas formulated and immobilized. Individual cultures were also immobilized and uptake of phenol by the immobilized micro-organisms was observed in a nutrient-rich and nutrient-stressed medium containing phenol as a sole source of carbon. A time-dependent uptake of phenol was exhibited by the micro-organismsin nutrient-stressed medium, after which a sudden increase in phenol concentration occurred in the extracellular medium, till it reached back to the initial concentration. This was attributedto an active efflux mechanism adopted by the micro-organisms to withstand the toxic shock.     

Preparation of rare-earth metal complex oxide catalysts for catalytic wet air oxidation

Catalytic wet air oxidation (CWAO) is one of the most promising technologies for pollution abatement. Developing catalysts with high activity and stability is crucial for the application of the CWAO process. The Mn/Ce complex oxide catalysts for CWAO of high concentration phenol-containing wastewater were prepared by coprecipitation. The catalyst preparation conditions were optimized by using an orthogonal layout method and single-factor experimental analysis. The Mn/Ce serial catalysts were characterized by Brunauer-Emmett-Teller (BET) analysis and the metal cation leaching was measured by inductively coupled plasma torch-atomic emission spectrometry (ICP-AES). The results show that the catalysts have high catalytic activities even at a low temperature (80°C) and low oxygen partial pressure (0.5 MPa) in a batch reactor. The metallic ion leaching is comparatively low (Mn<6.577 mg/L and Ce<0.6910 mg/L, respectively) in the CWAO process. The phenol, COD_Cr, and TOC removal efficiencies in the solution exceed 98.5% using the optimal catalyst (named CSP). The new catalyst would have a promising application in CWAO treatment of high concentration organic wastewater. Translated from Techniques and Equipment for Environmental Pollution Control, 2005, 6(2): 40–44 [译自: 环境污染治理技术与设备]     

含酚废水治理方法的研究

根据含酚废水的性质，用ClO2氧化除酚，ZL—1和聚丙烯酰胺(PAM)混凝沉降除悬浮物的方法处理该废水。实验结果表明，经处理后废水中的主要污染物酚、焦油和悬浮物等去除率都很高，该水可以满足循环使用的要求。     

提高酚氰废水生化处理工艺的效率

主要介绍了投加葡萄糖类物质显著提高煤气厂酚、氰废水生化处理装置效率的情况 ,并对其机理进行了分析探讨     

QSAR法研究取代苯酚的生物活性

基于表征成键原子的生物活性特征值Ai构建取代苯酚的自相关拓扑指数tT,并以0T1、T为结构描述符,分别建立了取代苯酚诱发浮萍萎黄、对日本长腿蛙蝌蚪的QSAR模型:pC=-2.4591+0.51730T-6.3888×10-21T,r=0.9778;24h-LC50=2.1269+1.1013×10-20T+3.4552×10-41T2,r=0.9676.它们的估算结果均优于文献结果,用Jackknife法检验,以上模型具有总体稳健性。     

热带假丝酵母8953菌株对苯酚的降解特性研究

实验室分离的一株热带假丝酵母(编号为8953)具有较强的苯酚降解能力,并可以利用苯酚、间苯二酚、联苯胺等芳烃为唯一碳源和能源生长。该菌株在48h内可完全降解约14.88mmol/L苯酚,完全降解10.63mmol/L苯酚只需要24h,其降解苯酚浓度最高可达19.13mmol/L。在pH4～9,温度20℃～40℃范围内,苯酚浓度为10.0mmol/L条件下该菌株均保持100%的降解率。该菌株降解苯酚的最适pH范围为6.0～8.0,最适温度范围为28℃～30℃,最佳接种量为1%～3%,外源添加氮源能促进酵母生长和苯酚的降解。     

新型负载型纳米TiO_2光催化降解苯酚的试验研究

以岩棉为载体制备一种新型负载型纳米TiO2,对有机污染物苯酚的降解效果较好。岩棉对苯酚有一定的吸附作用。经过120min的处理,苯酚基本上被完全降解。流速对降解率的影响较大,本试验选择流速为5mL/min。初始浓度越小,苯酚的降解效果越好。通入O2和加入适量H2O2均有利于苯酚的降解,且少量的H2O2可使苯酚的降解率大大提高。苯酚在pH=4.5时降解效果最好。     

一株苯酚降解菌的分离和鉴定

:从工业废水中分离到一株高效降解苯酚的菌株PHEA 2 ,它能够在以苯酚为单一碳源和能源的无机培养基上生长 ,其最高苯酚降解率为 394nmol/ (mg·min) .经Biolog细菌自动鉴定仪鉴定 ,该菌株为醋酸钙不动杆菌 (Acinetobactercalcoaceti cus) .采用PCR扩增获得的该菌 16SrDNA片段 ,核苷酸序列分析结果表明 ,该菌株的 16SrDNA的核苷酸序列与醋酸钙不动杆菌同源性为 98% .在细菌系统发育分类学上 ,PHEA 2归属变形细菌γ亚类、不动杆菌属、醋酸钙不动杆菌 .