降解苯酚优势菌的筛选分离和培养条件研究

从膨润土中筛选出可在含2 g/L苯酚的PDA培养基上生长的菌种,经过逐级驯化,得到1株可以在1 g/L苯酚的无机盐固体培养基上生长并降解苯酚的优势菌种HJ01,其对苯酚600 g/L降解率可达94%.该菌生长的适宜碳源和氮源分别为蔗糖和NH4Cl,温度为25 ℃,pH值范围为6-7.     

3种不同工艺中莠灭净的去除特性及自由基鉴定

以三嗪类除草剂莠灭净（AMT）为目标污染物,对比研究了紫外（UV）、紫外激活过硫酸盐（UV/PS）与紫外激活过一氧硫酸氢盐（UV/PMS）3种不同工艺对AMT的去除效果以及反应动力学模型。考察了底物初始浓度、氧化剂浓度、溶液初始pH和水中腐殖酸浓度对AMT降解的影响,并对反应中生成的主要自由基进行鉴定。结果表明,3种系统下AMT降解均符合拟一级反应动力学模型（R2 ≥ 0.93）。AMT在3种不同系统下降解效率基本遵循UV/PS > UV/PMS > UV规律。随着底物初始浓度的增加,AMT降解率减小,拟一级速率常数kobs减小;增加氧化剂的投加量可以促进AMT降解;溶液pH的改变对UV系统下AMT的降解影响较小,而在UV/PS系统下,随着pH的增大降解率逐渐减小,在UV/PMS系统中降解率则呈现先减小后增大的趋势;投加腐殖酸会抑制AMT的降解;pH为7时,UV/PS和UV/PMS系统中反应生成的自由基主要是·SO4-。     

产漆酶血红密孔菌对城市污泥堆肥过程中有机氯农药的降解效应

为降低城市污泥堆肥中有机氯农药对环境的影响,实验室通过外加热源提供堆肥环境温度条件,并在不同堆料中接种不同剂量的产漆酶血红密孔菌,研究不同处理下产漆酶血红密孔菌对污泥中HCH、DDT和HCB的降解性能的影响。结果表明,供试血红密孔菌对3种有机氯农药的降解有明显的促进作用。未接种菌剂情况下,高温堆肥本身对HCH、DDT和HCB的降解率分别为51.1%、43.6%和63.4%;接种1%菌剂时,HCH、DDT和HCB比未接种堆料降解率分别提高了16.2%、34.6%和21.7%;接种3%菌剂时,HCH、DDT和HCB比未接种堆料降解率分别提高了41.1%、34.6%和20.1%。供试菌剂对DDT的降解效果最好,且DDT和HCH的降解能力与接种量大小呈正相关。此外,供试菌剂剂量大小对HCH不同异构体和DDT不同衍生物降解效果也不尽相同。     

Synergetic effects of anodic-cathodic electrocatalysis for phenol degradation in the presence of iron(II)

A novel electrocatalysis method for phenol degradation was described using a β-PbO₂ anode modified with fluorine resin and a Ni–Cr–Ti alloy cathode. In case of air sparging at the cathodic zone, the techniques of anodic–cathodic electrocatalysis (ACEC) and ferrous ion catalyzed anodic–cathodic electrocatalysis (FACEC) in the presence of iron(II) were developed. Both of ACEC and FACEC were more effective than anodic electrocatalysis (AEC). The percentage of phenol eliminated by FACEC could increase by nearly 30% compared with that of AEC, and the current efficiency could reach to 70%. Important operating factors such as ferrous ion concentration, air-sparging rate and applied current were investigated and it was found that such beneficial effects could be achieved at a suitable current and ratio of the concentration of ferrous ion to the air sparged. The mechanism of phenol degradation is proposed to be the generation of hydroxyl radicals concerned with the two electrodes. Results also indicated that the process provided an efficient way to regenerate ferrous ion compared with the conventional Fenton's system.     

光合产氢-膜曝气生物膜反应器耦合系统产氢与底物降解特性

为提高光合产氢反应器性能,构建了一种采用沼泽红假单胞菌CQK01接种的光生物产氢-膜曝气生物膜反应器（PBR-MABR）耦合系统。实验表明,在序批培养条件下,由于产氢过程中有机酸和氢离子不断积累,使得PBR系统的产氢速率远低于PBR-MABR系统,其产氢速率为0.49 mmol·（L·h）-1;而PBR-MABR、PBR-2MABRs和PBR-3MABRs的产氢速率则分别可达到0.61、0.76和0.85 mmol·（L·h）-1。这主要是由于有机酸被MABR中的透气膜上生长的生物膜不断降解所致。有机酸的降解不仅提高了耦合系统内pH值并在一定程度上缓解了体系中的产物抑制。     

降酚菌株的固定化细胞处理含酚废水的性能研究

用海藻酸钠作为载体将一株降酚菌株进行固定化包埋。利用正交实验确定了该菌株固定化细胞制备的最优条件。研究表明,该降酚菌株的固定化细胞对苯酚的降解能力和耐受能力均大于游离细胞。降酚菌株固定化细胞降解苯酚的最适温度范围是30~35℃,最适pH值范围为6~8。该菌株的固定化细胞对废水中的COD也具有良好的降解效果。     

气-固流化床光催化氧化甲苯的研究

在自制的流化床光催化反应装置中研究了中低浓度(28~140mg/m3)甲苯的气相光催化降解过程,考察了光照时间、初始浓度、表观气速和催化剂负载量等因素对甲苯光催化降解率的影响规律。结果表明,紫外灯照射约1·5h,甲苯的转化率达最大值,甲苯初始浓度越低,维持此最大值的时间越久;在一定低浓度范围内(28~55mg/m3),甲苯的转化率不随浓度变化,符合一级反应动力学,浓度进一步增加,则甲苯的转化率下降;表观气速和催化剂负载量的最佳值分别为3·3Umf和0·19gTiO2/gSiO2。     

可见光/H2 O2/海藻酸铁非均相催化降解吖啶橙的研究

由海藻酸钠和氯化铁反应制备了海藻酸铁凝胶小球催化剂,考察了该催化剂的吸附和可见光下催化降解吖啶橙的性能.结果表明催化剂的吸附能力随pH升高而提高,且催化剂用量为40个凝胶小球时,可见光下吖啶橙能够在较宽pH值范围内脱色,脱色速率随H2O2的用量增加而增加,该反应符合Arrhenius规律,其表观活化能为49.6 kJ/mol.自由基清除剂的加入不会降低脱色速率,表明催化反应不是羟基自由基的机理,而与高活性的类{ Fe(Ⅳ)=O}高价铁中间产物有关.     

Anaerobic degradation of diethyl phthalate, di-n-butyl phthalate, and di-(2-ethylhexyl) phthalate from river sediment in Taiwan

We investigated anaerobic degradation rates for three phthalate esters (PAEs), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), and di-(2-ethylhexyl) phthalate (DEHP), from river sediment in Taiwan. The respective anaerobic degradation rate constants for DEP, DBP, and DEHP were observed as 0.045, 0.074, and 0.027 1/day, with respective half-lives of 15.4, 9.4, and 25.7 days under optimal conditions of 30 °C and pH 7.0. Anaerobic degradation rates were enhanced by the addition of the surfactants brij 35 and triton N101 at a concentration of 1 critical micelle concentration (CMC), and by the addition of yeast extract. Degradation rates were inhibited by the addition of acetate, pyruvate, lactate, FeCl₃, MnO₂, NaCl, heavy metals, and nonylphenol. Our results indicate that methanogen, sulfate-reducing bacteria, and eubacteria are involved in the degradation of PAEs.     

一株木材腐朽菌及其粗酶液对七氯的降解

Phlebia acanthocystis TMIC34875是一株具有七氯降解能力的木材腐朽菌。为利用微生物技术去除环境中的七氯残留提供理论依据,研究了该菌株及其粗酶液对七氯的降解性能及其动力学特性。结果表明,菌株在七氯的初始浓度为50μmol/L时具有最大降解速率,为0.3031μmol/（L·h）;而菌体接种量为15%时,降解速率达到最高,为0.2045μmol/（L·h）。降解酶定位研究表明,七氯的降解主要是胞内酶在起作用。七氯胞内酶降解的酶促反应最适温度是35℃,在30-40℃之间有较高的催化活性;最适pH值为5.0,在pH 4.5-6.0之间有较高的催化活性,最适条件下反应1 h后七氯的降解率为65%。胞内粗酶液降解七氯的米氏常数K m为5.42μmol/L,最大反应速率V max为4.55μmol/min。胞内酶处理体系的GC/MS图谱显示,主要降解产物为1-羟基六氯、1-羟基-2,3-环氧六氯和环氧七氯,表明胞内酶对七氯的初始代谢机理同菌株相似,均是通过环氧化和置换反应来完成的。