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.     

饮食业复合油烟吸收剂的研制开发

分析了饮食油烟的成分 ,结合饮食油烟气的治理方法 ,采用正交设计法进行新型复合油烟吸收剂的实验 ,快速、有效、准确地优化确定了油烟吸收剂的配方和工艺 ,并设计了该吸收剂的油污相溶性、环境毒性、生物降解性实验 ,科学地论证了该产品的性能。结果表明 ,本实验研制的油烟吸收剂能够全面包络、粘合、皂化、附着和分离油烟废气中的油类物质 ,对饮食油烟具有快速、高效、彻底的治理效果 ,而且无毒、易降解。     

离子液体辅助水热法合成锡酸锌及其光催化性能

采用离子液体辅助水热法制备锡酸锌,考察了离子液体添加量对锡酸锌晶相、形貌及光催化性能的影响。通过XRD、TEM分别对锡酸锌的晶相和形貌进行研究。通过在紫外光照射下光催化降解亚甲基蓝溶液对锡酸锌的光催化性能进行表征。当[Emim]BF4添加量为0.5 mmol时,制得的八面体锡酸锌结晶度高且对染料亚甲基蓝有较高光催化降解能力。自由基捕获实验证明羟基自由基是光催化反应的主要活性物种。     

一株假单胞菌(Pseudomonas) SYBS01降解石油的特性

从石油污染土壤中筛选得到一株石油降解菌SYBS01,鉴定为假单胞菌（Pseudomonas sp.）。通过单因素实验和正交实验进行石油降解条件优化,结果为35℃、170 r·min-1,酵母浸粉15 g·L-1,KH2PO4 0.5 g·L-1,自然pH值。其中氮源为酵母浸粉时对菌SYBS01降解石油的影响最大。添加酵母浸粉后,4 d石油降解率达到85.6%,分别为（NH4）2SO4、NH4NO3和尿素的6.7、7.8、2.6倍。进一步分析发现酵母浸粉作为氮源的同时也起到外加营养的作用。在最佳条件下,0.5~5 g·L-1的石油的降解均符合一级动力学模型,且石油浓度为3 g·L-1和4 g·L-1的石油降解半衰期仅为26 h。     

纳米零价铁和零价铁对餐厨垃圾暗发酵制氢过程铁离子和酶活性的影响

通过投加不同浓度的纳米零价铁(NZVI)和零价铁(ZVI),考察了暗发酵制氢过程中铁离子组成和浓度变化、氢化酶和脱氢酶活性,研究了2种添加剂强化餐厨垃圾高温((55±1) ℃)暗发酵制氢的作用机制。结果表明：投加NZVI和ZVI均可提高餐厨垃圾暗发酵制氢性能;当投加100 mg·L⁻¹ ZVI时,产氢效果最佳,最大产氢潜力和最大产氢速率分别为425.72 mL和66.32 mL·h⁻¹,是投加NZVI实验组的1.64倍和1.34倍,代谢途径是以乙醇型发酵为主的混合型发酵;在投加NZVI和ZVI后,暗发酵制氢末端产物的Fe²⁺和Fe³⁺浓度升高,投加300 mg·L⁻¹ NZVI和100 mg·L⁻¹ ZVI实验组Fe²⁺浓度最大,是未投加实验组的2倍和1.87倍;与反应前相比,Fe²⁺显著升高,Fe³⁺由于微生物利用与转化浓度降低,同时可有效提高氢化酶活性。投加100 mg·L⁻¹ ZVI不仅可提高氢化酶活性,还可提高脱氢酶活性。以上结果可为提高餐厨垃圾等复杂有机废物的高效能源化提供参考。