壳聚糖—硅胶复合载体固定化乙醇脱氢酶技术研究

为提高乙醇脱氢酶使用率,以涂敷壳聚糖的硅胶为载体、戊二醛作为交联剂,采用吸附法与交联法相结合方法对乙醇脱氢酶进行固定化,并以酶活力、相对酶活、活力回收率为指标;结果表明:以制备复合硅胶为载体,选择1%戊二醛为交联剂,载体与酶以1∶1(w/v)比例振荡交联2 h,酶活力回收率可达75%,重复使用10次后,酶活力仍可保留28%以上。     

Isocitrate analysis using a potentiometric biosensor with immobilized enzyme in a FIA system

A potentiometric biosensor for the analysis of isocitrate was developed by using a CO₃²⁻-selective electrode and enzyme immobilization in flow injection analysis (FIA). The biosensor consisted of a peristaltic pump, injector, enzyme reactor, reference electrode, working electrode, pH/mV meter and record. The experimental parameters that influenced the sensitivity and selectivity of the biosensors were optimized in the FIA system. A linear correlation between the potential difference and logarithmic isocitrate concentration was obtained in the range of 10⁻³–10⁻¹ M isocitrate under optimal conditions. The interference effect of major sugars and organic acids on the sensor system was less than 5%. Isocitrate concentrations of some fruit juices analyzed by the isocitrate sensor system were compared with those analyzed by gas chromatography (GC). There was no significant difference between the two analytical methods in any of the fruit juices. This suggests that the isocitrate sensor system is reliable in determining the isocitrate concentrations of foods.     

Characterization of PCB-degrading bacteria immobilized in polyurethane foam

This study is carried out to investigate (1) conditions for the synthesis of polyurethane foam to be used for immobilizing microorganisms, (2) the viability of microorganisms immobilized simultaneously into the pores of a polyurethane foam when the foam is synthesized, and (3) the difference in the ability to degrade PCBs between the immobilized and suspended microorganisms. The results of this study show that polyurethane foam is suitable for synthesizing 10% NCO-prepolymer, water and surfactant in the ratio of 100:2.6:1.2 (w/w), respectively, and the viability of microorganisms (input microbes) immobilized in the foam is high. The input microbes, designated as strain SY5, are isolated from a municipal sewage treatment plant. In addition, immobilized strain SY5 degrades 5-40% more PCB of a PCB mixture (Aroclor 1242) than the suspended strain SY5.     

Ethyl esterification of docosahexaenoic acid in an organic solvent-free system with immobilized Candida antarctica lipase

Ethyl docosahexaenoate (EtDHA) is regarded as a potentially useful pharmaceutical substance on account of its beneficial physiological activities. We attempted the ethyl esterification of docosahexaenoic acid (DHA) in an organic solvent-free system using Candida antarctica lipase, which acts strongly on DHA and ethanol. Esterification of 88% was attained by shaking a mixture of DHA/ethanol (1:1, mol/mol) and 2 wt% immobilized C. antarctica lipase at 30 degrees C for 24 h. However, even in the presence of an excess amount of ethanol, the extent of esterification could not be raised above 90%. To attain a higher level of esterification, a two-step reaction was found to be effective. The first step was performed in a mixture of DHA/ethanol (1:1, mol/mol), and the reaction mixture was then dehydrated. In the second step, the resulting mixture was shaken at 30 degrees C for 24 h with 5 molar equivalents of ethanol against the remaining DHA using 2 wt% immobilized lipase. By means of this two-step procedure, 96% esterification was attained. Repetition of the first and second reactions showed that the immobilized lipase was reusable for at least 50 cycles. In addition, DHA remaining in the second-step reaction mixture was removed by a conventional alkali refining process, giving purified EtDHA with a high yield.     

生物铁-SMBR法处理印染废水

为提高膜生物反应器（SMBR）的处理效果,在一体式膜生物反应器中加入氢氧化铁絮体,将生物铁法与一体式膜生物反应器相结合,提出了生物铁SMBR法.利用生物铁-SMBR法处理模拟印染废水,并与PAC-SMBR及普通SMBR进行平行对比试验,结果表明,生物铁-SMBR法在提高处理效果方面具有明显优势.在其容积负荷比普通SMBR平均高25%的情况下,生物铁-SMBR法对COD、染料、NH3-N（氨-氮）的去除率分别高1.0%、9.5%、5.2%.与普通SMBR相比,PAC-SMBR也能够提高对印染废水的处理效果.在其容积负荷比后者平均高6%的情况下,对COD、染料、NH3-N的去除率分别比后者高0.6%、4.0%、5.3%.     

电解法处理高浓度印染废水

采用自制试验装置，用电解法处理高浓度印染废水。通过正交试验，讨论了电压、pH值、处理时间、NaCl投加量对处理效果的影响；依据试验结果分析了电解法处理印染废水的机理。在最佳工艺条件下，即在电压25V、pH值8．0、NaCl投加量0．3g／L、循环8次、时间104min时，COD系统去除率可达90．40％，色度去除率可达100％。     

PSF混凝剂对印染废水的处理

以鼓风炉铁泥作原料，制备一种无机高分子混凝剂聚硅酸铁（PSF），并将其用于印染废水处理。结果表明，在pH值6～9内，PSF混凝剂对印染废水均有很好的处理效果。在常温、pH值7．5、混凝剂的投加量85mg／L条件下，SS（悬浮固体）、色度及CODCr，的去除率分别为92，4％、87．2％和78．6％。与传统混凝剂PFS（聚合硫酸铁）和PAC（聚合氯化铝）相比，PSF混凝剂具有混凝沉降速度快、污泥体积小、色度及CODCr，去除率高、处理费用低等特点。     

膜生物反应器处理印染废水

采用膜生物反应器处理印染废水,探讨膜产水量与抽吸压力的关系,膜的安装方式对减缓膜污染的影响,以及在中试运行过程中所存在的问题;分析该系统的可靠性、连续性和稳定性.试验结果表明,用膜生物反应器法处理印染废水是可行的,出水满足DB 61-234-2006地方一级排放标准.     

Stability evaluation of an immobilized enzyme system for inulin hydrolysis

The stability of free and Amberlite-immobilized inulinase, aiming at inulin hydrolysis was evaluated. The apparent activation energy of the biotransformation decreased when the immobilized biocatalyst was used, suggesting diffusional limitations, despite a decrease in the optimal temperature for catalytic activity for the immobilized biocatalyst. Thermal deactivation, of both forms of the biocatalyst, was evaluated by the linear inverted model. Inulinase immobilization consistently enhanced half-life of the enzyme, which increased up to 6-fold, as compared to the free form. Mean enzymatic activity was computed for both forms of the biocatalyst, and evidenced a decrease of optimal temperature with increased incubation periods. The deactivation energies estimated by an Arrhenius plot, evidenced a decrease of roughly 20% when free inulinase was used. The immobilized biocatalyst was effectively reused in successive batch runs for the hydrolysis of a 5% inulin solution.     

Stimulating accumulation of nitrifying bacteria in porous carrier by addition of inorganic carbon in a continuous-flow fluidized bed wastewater treatment reactor

Porous polyurethane carrier particles have been successfully applied for microbial immobilization to simultaneously remove carbonaceous and nitrogenous substances from wastewater by a fill-and-draw operation. This reactor system was extended to a continuous-flow operation mode, by which inorganic carbon (IC) was supplemented in order to stimulate the growth of autotrophic nitrifying bacteria. By addition of sodium bicarbonate, the ammonia oxidation reaction proceeded remarkably in the porous particle fluidized bed reactor, while a small increase in the nitrification was observed in a reactor with suspended microbes. Dissolved oxygen profile was obtained using an oxygen microelectrode to measure the microbial consumption of oxygen in the porous carrier. The size of ammonia-oxidizing bacterial populations in the carrier was proportional to the volume of the aerobic region of the carrier. The aerobic region decreased with the increase in sodium bicarbonate concentration, which improved the ammonia-oxidizing activity of retained nitrifiers in the carrier. The maximum ammonia oxidation rate was up to 55.6 gN/m3/h within the aerobic region of the carrier under the following feed conditions: 100 mg/l of total organic compound, 55 mg/l of ammonium concentration and 48 mg/l of inorganic carbon.     

针织印染废水的C-HC-PBCO-C处理工艺

采用混凝+水解酸化+推流式接触氧化+混凝(C-HC-PBCO-C)处理针织印染废水,结果表明,此工艺能有效去除废水中污染物,出水平均CODCr、BOD5、SS和色度分别为77 mg/L、13 mg/L、35 mg/L和30倍,出水水质达到广东省DB44/26—2001《水污染排放限值》第Ⅱ时段一级排放标准。     

印染废水的微生物絮凝剂处理

研究了各种因素对H14菌株所产絮凝剂絮凝特性的影响：该絮凝剂具有一定的热稳定性,最佳絮凝时间为10 min,最佳投入量为10 mg/L,最佳pH值范围为6~8,助凝剂1%Ca2+的最佳投入量为4 mL。用H14菌株所产絮凝剂分别处理印染废水水样一、水样二：COD最高去除率为79.8%和79.3%;脱色率最高为83.6%和81.4%、SS去除率为65.6%和67.7%。得出了其去除COD和脱色的经验动力学方程。     

二氧化氯催化氧化处理印染废水

采用二氧化氯催化氧化法对沉淀后的印染厂废水进行处理,讨论了影响COD和色度去除率的各种因素;确定了该方法最佳的反应条件:二氧化氯投加量100mg/L,催化剂用量1g/L,溶液pH值6.5,反应时间45min。氧化后的废水CODCr120mg/L,色度≤40倍。     

曝气吸附生物滤池处理制浆造纸废水工艺研究

采用曝气吸附生物滤池,对制浆造纸废水处理工艺进行了研究。得到最佳的工艺运行条件：水力停留时间20～30h、吸附填料：废水（V/V）=1：1、污泥：废水=1：1（V/V）、曝气量300L/h、温度为20～30℃,废水的COD和色度去除率分别可达到85%和90%。以铁炭（1：1）为吸附填料更有利于废水COD和色度的去除。     

乳品生产废水处理方法

乳业生产废水可以使用生化方法很好的加以处理，通过对乳业废水成分的研究，制定了一套切实、可行的方案“混凝沉淀＋复合生物反应器”，实践表明运行稳定，耐冲击负荷，出水达到国家《污水综合排放标准》（GB8978—1996）的一级标准。     

无溶剂体系中固定化脂肪酶催化的维生素A棕榈酸酯的合成

研究了一种维生素A棕榈酸酯(vitamin A palmitate)的合成新途径。实验结果表明,棕榈酸甲酯作为酰基供体,在固定化酶催化下,在无溶剂体系中与维生素A醋酸酯通过酯交换反应生成维生素A棕榈酸酯。对无溶剂体系中催化合成维生素A棕榈酸酯的工艺进行优化,确定的最佳工艺参数为:转速250 r/min;温度60℃;固定化脂肪酶质量分数5%(占反应体系总重);棕榈酸甲酯和维生素A醋酸酯摩尔比1.3∶1。反应到达平衡的时间为3h,转化率为26.93%。此外,研究发现,在反应到达平衡后,连续抽真空,带走反应中产生的醋酸甲酯,反应平衡向产物生成的方向移动,继续反应12 h后,反应转化率可达80%,此时反应液中维生素A棕榈酸酯浓度可高达800 g/L。     

Bio-transformed sawdust by white rot fungi used as a carrier for plant growth-promoting bacteria

This study assessed the bio-transformation of sawdust wood waste by a white rot fungi consortium and explores the use of the final product as a carrier for plant growth-promoting bacteria. During 75 days, Tabebuia roseae and Eucalyptus pellita (1:1) sawdust wood were used as growing substrates for Ganoderma lucidum, Pleurotus ostreatus, Trametes versicolor and Phanerochaete chrysosporium. Then, bio-transformed sawdust was evaluated as carrier of two strains of Enterobacter sp. and one strain of Stenotrophomonas maltophilia. Biologic activity and viability were determined at two storage temperatures (23–4 °C) for 60 days. Sawdust mixture was bio-transformed by white rot fungi. After 45 days, the carbon/nitrogen ratio was reduced up to 46 %, and 4.8 mg/g of CO₂ of residue was produced. Enzymatic activities attained a peak of 36.7 and 0.8 U g^?1 for laccase and manganese peroxidase, respectively in 45 days. Population of plant growth-promoting bacteria immobilized in bio-transformed sawdust wood decreased to 10⁵ CFU g^?1. However, this concentration and its biologic activity remained stable at 23 °C.     

填料对曝气吸附生物滤池深度处理造纸废水的影响

在曝气吸附生物滤池中分别加入不同的吸附剂作填料,对造纸废水进行深度处理,以此选择出最佳的吸附填料。研究结果表明:以活性炭和3A分子筛为填料的曝气吸附生物滤池深度处理造纸废水的效果最佳,废水COD的去除率可达78%;直径3mm的不规则形状颗粒活性炭比其他粒径和形状的活性炭处理效果更好;活性炭与石英砂或铁屑混合组成的填料,更有利于造纸废水COD和SS的去除。     

Interaction of apple polyphenols in a multi-compound system upon adsorption onto a food-grade resin

Adsorption of catechin, caffeic acid, chlorogenic acid, phloridzin and rutin from multi-compound model solutions onto Amberlite^® XAD 16HP was studied in laboratory experiments. The adsorption conditions were adapted to those optimal for single compound binding, which were determined in previous studies. The following order of affinity towards the styrene–divinylbenzene copolymer was determined: caffeic acid < catechin < chlorogenic acid < phloridzin < rutin, and the data also reveal significant interactions of the phenolics upon adsorption from multi-compound solutions. The affinity order was successfully derived from differences in the consecutive phases of the adsorption kinetics of individual phenolic compounds. At the very beginning of adsorption polyphenol binding is characterized by processes, which may result in the formation of a subsurface surrounding the resin particles and which precede surface reactions, whereas the final phase is dominated by intraparticle diffusion processes. The results presented in this work contribute to a better understanding of the complexity of adsorption mechanisms and of the influence of adsorption conditions. Thus, detailed evaluation of such complex systems may contribute to optimize the selective recovery of plant secondary metabolites, e.g. by providing phloridzin-enriched extracts with promising health-promoting properties.     

三维电极法降解活性染料废水

用三维电极电化学方法对活性墨绿KE-4BD染料废水进行降解试验,考察反应器电压、电解时间、主电极极间距、电流密度、粒电极形状等因素对降解效果的影响.试验结果表明,以1Cr18Ni9Ti作阳极,石墨作阴极,圆柱形活性炭作粒电极,在电压为30 V,电流密度为6 mA/cm^2,主电极极间距为6 cm的条件下,初始浓度为800 mg/L的活性染料废水电解40min后,脱色率达99.5%以上,COD去除率达92.2%以上.