菌剂强化处理炼油废水及苯酚冲击下功能菌响应机制研究

近年来，我国炼油行业发展迅速，炼油能力全世界第二，炼油行业已成为污染大户。本研究针对炼油废水生物处理中存在的稳定达标难、抗冲击负荷能力差、建设投资与运行成本高等问题，就菌剂强化处理炼油废水中试与工程应用展开了研究，以期为菌剂的工程应用与推广提供理论参考与技术支持；并以炼油废水中的主要特征污染物苯酚为研究对象，考察了不同浓度苯酚冲击下功能菌的响应机制，并以此为指导研制功能菌激活促进剂，考察其对功能菌生物学指标的调控效果，以期为废水生物处理有毒污染物冲击调控提供理论依据与技术支持。 中试研究表明，菌剂强化处理炼油废水，出水COD、NH4+-N 平均值为86.7、7.6 mg/L，其平均去除率较常规生物处理系统分别提高了35.47%、59.28%，其耐受COD、NH4+-N 容积负荷分别高达2.42、0.139kg/(m3·d)，具有良好的耐冲击能力。工程应用研究表明，菌剂强化处理炼油废水，出水COD、NH4+-N 平均值分别为85.05、8.4mg/L，其去除率较常规生物处理系统提高了25.1%、28.7%，出水水质各项指标均达到了国家《污水综合排放标准GB 8978-1996》一级排放标准。技术经济分析表明，菌剂强化处理炼油废水在建设成本、运行成本上分别降低38%、49%，具有良好的技术经济优势。 苯酚冲击下功能菌响应机制研究表明：不同浓度苯酚冲击下，生物学指标生物量、脱氢酶酶活、1,2-双加氧酶酶活对冲击都有不同程度的响应，其响应敏感程度为脱氢酶酶活＞生物量＞1,2-双加氧酶酶活。1,2-双加氧酶酶活与COD 降解率相关性良好，可表征苯酚降解过程，确认为调控重点。以此为指导研制出苯酚降解功能菌抗冲击激活促进剂，可有效调控功能菌对有毒污染物苯酚的降解效果，1000mg/L 苯酚冲击下，经调控，其COD 去除率较对照提高20%，降解时间缩短16%以上。其对生物学指标的调控效果为1,2-双加氧酶酶活＞生物量＞脱氢酶酶活，验证了功能菌在苯酚冲击下的响应机制。研究表明菌剂强化处理炼油废水切实可行，具有良好的技术经济优势。有毒污染物冲击下废水生物处理系统响应机制研究为抗冲击调控提供了新的研究思路。 Currently, China’s oil refining industry is developing rapidly and has become the second largest all over the world. The oil refining industry is one of the major pollution industries in our country. The pilot scale study and engineering application research were conducted aiming at the problems in refining wastewater such as poor treatment stability and water quality, poor anti-shock capacity and expensive running cost, etc., so as to provide theoretical references and technological supports for the engineering application and popularization of microbial preparation in wastewater treatment. Also, the response mechanism of functional microbe under shock of different phenol concentrations, which is the main pollutants in refinery wastewater, was studied. Based on this result, functional microbe activation accelerator was developed, and the regulation effect of functional microbe biological index under phenol shocking were studied, in order to provide theoretical basis and technological support for regulation of toxic shocking of wastewater biological treatment. The result of pilot scale research indicated: for treatment of refinery wastewater in bioaugmention treatment system of microbial preparation, the COD and NH4+-N average value of effluent was 86.7 and 7.6 mg/L, Comparing with normal biological treatment system, the average removal rates of COD, NH4+-N increased 35.47%,59.28% separately by bioaugmention treatment system, which showed better anti-shocking capacity, the volumetric load r of COD and NH4+-N reached 2.42 kg/(m3·d) and 0.139 kg/(m3·d), respectively. The research on engineering application of refinery wastewater bioaugmentation treatment by microbial preparation indicated:the average concentrations of effluent COD and NH4+-N in the bioaugmentation treatment system were 85.05 and 8.4mg/L, which increased by 25.1% and 28.7% comparing with normal biological treatment system of refinery wastewater, And the effluent quality meets the first grade of discharging standard of National Integrated Wastewater Discharge Standard GB 8978-1996. The economic analysis of technology indicated: the demonstration project of bioaugmentation treatment of refinery wastewater by microbial preparation decreased by 38% in construction cost and 49% in running cost. This technology has economic benefits. The response mechanism of functional microbe under phenol shock indicated: biological index such as the biomass concentration, dehydrogenase and 1,2-dioxygenase had different responses under phenol shocking of different concentrations. The response sensitivity of different biological index under phenol shocking of different concentrations is: dehydogenase activity ＞ biomass ＞1,2-dioxygenase activity, and high correlation of 1,2-dioxygenase and COD degradation percentage is achieved, thus 1,2-dioxygenase could be used to reflect the degradation situation of pollutants. So, 1,2-dioxygenase is the keypoint of regulation. The anti-shock activation accelerator of phenol degradation functional microbe was primarily developed. The results indicated: the activation accelerator could regulate the degradation effect of toxic substance-phenol by functional microbe effectively. For the functional microbe treatment system under phenol shocking of 1000mg/L, the COD degradation rate increased by 20% and the degradation time reduced by more than 16% under regulation of activation accelerator. The regulation effects of biological index are: 1,2-dioxygenase ＞ biomass ＞ dehydrogenase. In this way, the response mechanism of functional microbe under toxic shocking is verified. The result indicated: the augmented microbial preparation treatment of refinery wastewater is applicable. It has many technical and economical advantages. The research results of responses mechanism of wastewater treatment system on toxic pollutants would offer a new idea for regulation of anti-shock.

Solid-state MAS NMR studies on the hydrothermal stability of the zeolite catalysts for residual oil selective catalytic cracking

By using the solid-state MAS NMR technique, the hydrothermal stabilities (under 100% steam at 1073 K) of HZSM-5 zeolites modified by lanthanum and phosphorus have been studied. They are excellent zeolite catalysts for residual oil selective catalytic cracking (RSCC) processes. It was indicated that the introduction of phosphorus to the zeolite via impregnation with orthophosphoric acid led to dealumination as well as formation of different Al species, which were well distinguished by Al-27 3Q MAS NMR. Meanwhile, the hydrothermal stabilities of the zeolites (P/HZSM-5, La-P/HZSM-5) were enhanced even after the samples were treated under severe conditions for a prolonged time. It was found that the Si-O-Al bonds were broken under hydrothermal conditions, while at the same time the phosphorous compounds would occupy the silicon sites to form (SiO)(x)Al(OP)(4 - x) species. With increasing time, more silicon sites around the tetrahedral coordinated Al in the lattice can be replaced till the aluminum is completely expelled from the framework. The existence of lanthanum can partially restrict the breaking of the Si-O-Al bonds and the replacement of the silicon sites by phosphorus, thus preventing dealumination under hydrothermal conditions. This was also proved by P-31 MAS NMR spectra. (C) 2004 Elsevier Inc. All rights reserved.

Demulsification of emulsions exploited by enhanced oil recovery system

Experimental data are presented to show the influence of the enhanced oil recovery system's components, alkali, surfactant, and polymer, on the demulsification and light transmittance of the water separated from the emulsions. Among which, the effects of surfactants, polyoxyethylene (10) alkylphenol ether (OP-10) and sodium petroleum sulfonate (CY-1) on emulsion stability, are the strongest of any component, the effects of polymer, hydrolytic polyacrylamide (HPAM) 3530S, on emulsion stability are the weakest. This research also suggests a possible emulsion minimization approach, which could be implemented in refineries utilizing microwave radiation. Compared with conventional heating, microwave radiation can effectively enhance the demulsification rate by an order of magnitude and increase the light transmittance of the water separated from the emulsions. The demulsification efficiency may reach 100% in a very short. time under microwave radiation.

Decomposition of transformer oil under ultrasonic irradiation during degassing process

In the degassing process of transformer oil with ultrasonic waves, decomposition of the oil was observed. Light hydrocarbons, including methane, ethane, ethylene, acetylene, propane etc, were found to be released continuously from the oil into headspace within a closed vial placed in an ultrasonic field. The gases came from decomposition of hydrocarbon Molecules under cavitation effect.

用固定化Oil-56黄杆菌修复地表水菌体形态变化

利用聚乙烯醇-海藻酸钠(PVA-Na.A lg)联合包埋固定化一株黄杆菌O il-56,进行污染地表水修复实验研究,结果表明固定化细菌的修复效果明显好于游离细菌。同时利用扫描电子显微镜观察了固定化颗粒内部细菌形态的变化,解释了由于Na.A lg溶解导致水体CODC r升高的原因,并分析了固定化颗粒传质扩散性能的缺陷,指出PVA-Na.A lg固定化工艺尚需改进。

Directing single-walled carbon nanotubes to self-assemble at water/oil interfaces and facilitate electron transfer

Both the behavior and the general key factors for assembling flexible SWNT films at the water/oil interface were investigated; the electron transfer, one of the most fundamental chemical processes, at the SWNT-sandwiched water/oil interface was also firstly illustrated using scanning electrochemical microscopy.

Effects of soil pH and organic matter on distribution of thorium fractions in soil contaminated by rare-earth industries

The labilities of thorium fractions including mobility and bioavailability vary significantly with soil properties. The effects of soil pH and soil organic matter on the distribution and transfer of thorium fractions defined by a sequential extraction procedure were investigated. Decrease of soil pH could enhance the phytoavailability and the potential availability of thorium in soil. Increase of organic matter reduced the phytoavailability of thorium, but enhanced the potential availability of it.

Adsorption Behavior of Exogenous Thorium on Soil Contaminated by Rare Earth Industries

The adsorption behavior of exogenous thorium on soil was studied to evaluate the contaminated risk on soil. The adsorption capacity, equilibrium time, distribution coefficient and desorption ability were investigated by the experiments of static adsorption. The strong adsorption ability of exogenous thorium on soil samples was observed by high adsorption ratio (> 92%) and low desorption ratio (< 5%) in equilibrium, and the biggest distribution coefficient was over 10(4). The adsorption capacity and equilibrium time were related to soil properties. According to the results of adsorption, Freundlich equation (r >= 0.916 7) and Elovich equation (R-2 >= 0. 898 0) were primely fit for describing the thermodynamics and kinetics of the adsorption of exogenous thorium on soil samples, respectively, which indicated that the adsorption was belonged to the nonlinear adsorption, and was affected by the diffusion of thorium on soil surface and in mineral interbed. Sequential extraction procedure was employed to evaluate the bound fractions of exogenous thorium adsorbed on soil samples.

Low-temperature synthesis of oil-soluble CdSe, CdS, and CdSe/CdS core - Shell nanocrystals by using various water-soluble anion precursors

Colloidal CdSe and CdS quantum dots were synthesized at low temperatures (60-90 degrees C) by a two-phase approach at a toluene-water interface. Oil-soluble cadmium myristate (Cd-MA) was used as cadmium source, and water-soluble Na2S, thiourea, NaHSe, Na2SeSO3, and selenourea were used as sulfur and selenium sources, respectively. When a cadmium precursor in toluene and a selenium precursor in water were mixed, CdSe nanocrystals were achieved at a toluene-water interface in the range of 1.2-3.2 nm in diameter. Moreover, we also synthesized highly luminescent CdSe/CdS core-shell quantum dots by a two-phase approach using poorly reactive thiourea as sulfur source in an autoclave at 140 degrees C or under normal pressure at 90 degrees C. Colloidal solutions of CdSe/CdS core-shell nanocrystals exhibit a photoluminescence quantum yield (PL QY) up to 42% relative to coumarin 6 at room temperature.