冻干壳聚糖微球固定化纤维素酶的研究

分别以冻干壳聚糖微球和湿壳聚糖微球为载体，戊二醛为交联剂进行纤维素酶的固定化研究，并对2种固定化酶的热稳定性、米氏常数、重复利用次数、pH值加以对比分析。确定酶固定化的适宜条件为：0．03g冻干壳聚糖微球与10mL4g/L戊二醛交联4h后，加入10mg酶固定2h，酶活力回收率为96．3％；0．1g湿壳聚糖微球与10mL 2g／L戊二醛交联2h后，加入6mg酶固定4h，酶活力回收率为62．4％。与游离酶相比，2种固定化酶的米氏常数均降低；具有很好的热稳定性；最适酶解温度分别为60℃，50℃；酶解反应适宜pH范围3．0—4．0，最适pH值均向酸性方向移动。冻干载体更易与酶分子结合，酶活力回收率高于湿载体固定化酶。     

固定化真菌漆酶对分散兰-2BLN的脱色和降解

采用改良壳聚糖固定化的真菌漆酶对染料分散兰-2BLN进行脱色和降解条件的研究，探索了固定化漆酶活力、处理时间、染料浓度、温度和pH对其降解效果的影响。结果表明，固定化漆酶脱色降解分散兰-2BLN的适宜条件为：固定化漆酶活力18.2U／mL，染料浓度100mg／L，温度40℃，pH4.6，在上述条件下降解1.5h，分散兰-2BLN脱色率能达到87.68％。重复分批使用固定化漆酶处理2BLN兰，在使用6批次后，脱色率仍能保持在55％以上，其催化效率得到了较大提高。     

固定化酵母菌对活性艳蓝KN-R的脱色研究

采用海藻酸钙加活性碳的方法对酵母菌进行固定化。正交试验结果表明，三者合适配比为海藻酸钠3％，活性碳10％，氯化钙4％。此方法制得的凝胶颗粒机械强度好、经久耐用。固定化酵母菌凝胶小球最适条件为：培养时间为48h，培养温度为37℃，培养基pH为3．0，凝胶量为10g。固定化细胞经多次脱色后能重复使用，4次脱色后其脱色率还达79．2％。     

干旱胁迫下壳聚糖对花生幼苗生理特性的影响

为了研究壳聚糖对花生幼苗抗旱言的影响，以花生品种“花育23号”为材料，在干旱胁迫下，用不同浓度的壳聚糖溶雍处理花生幼苗，连续处理5d后测定叶绿素、可溶性蛋白、MDA和脯氨酸的含量变化。结果表明，花生幼苗在干旱条件下喷施壳聚糖与蒸馏水相比，在干旱第10天叶绿素含量提高了42．2％，MDA含量降低了36．2％；在干旱第6天，可溶性蛋白含量提高了129．0％；在干旱第8天，脯氨酸含量提高了257．0％。喷施壳聚糖溶液的最适宜浓度为0．10g／L，喷施该浓度壳聚糖可促进植物生长，增强抗旱性。     

酸改性壳聚糖载体对漆酶的固定化

利用有机酸改性壳聚糖和交联法制备酸化壳聚糖载体,然后用改性壳聚糖载体固定漆酶。结果表明,甲酸、酒石酸改性壳聚糖的最适条件是壳聚糖与酸的量比分别为100/1(g/mol)、100/0.5(g/mol),戊二醛的浓度分别为1%、2%,缓冲溶液的pH分别为4.4、3.6,反应时间分别为3h、4.5h。两种酸改性的壳聚糖用于漆酶的固定,其酶活都有所提高,尤其用酒石酸改性的壳聚糖载体的效果最好,其酶活提高了57%。     

高原地区溶解氧浓度对A2／O工艺运行效果研究

针对我国低温地区的城市污水，开展了A2／O工工艺中试研究，考察溶解氧浓度对A2／O工工艺运行效果的影响。结果表明：采用A2／O工工艺并延长好氧池HRT，在系统水温为10℃-14℃的情况下可获得良好的污水处理效果。A2／O工工艺中好氧池末端的溶解氧浓度宜控制在2．8mg／L左右，此时的系统平均出水COD、氨氮、总氮和总磷浓度分别为40mg／L、3．8mg／L、13．0mg／L和0．7mg／L，平均COD、氨氮、总氮和总磷去除率分别为92．4％、83．8％、72．7％和87．1％。     

ICP-AES法测定土壤中铜、钒、镍和铬

在HNO3-H2O2-HF体系中微波消解土壤样品，用电感耦合等离子发射光谱法测定土壤中的铜、钒、镍、铬，设定了最佳的样品处理条件和仪器条件，该方法测定铜、钒、镍、铬检出限分别为0．01mg／kg、0．05mg／kg、0．5mg／kg、0．10mg／kg，回收率为98．4％～102．0％，方法简便、准确。     

颗粒活性炭载体新型生物转盘去除生活污水中COD和NH3-N的研究

开发一种改进型生物转盘处理生活污水，将盘片改为转笼状，并向其中加入颗粒活性发作为载体，研究该系统对生活污水的处理效果。结果表明：在转盘转速为15rpm和HRT分别为10h、8h、6h、4．5h情况下，进水COD平均浓度约为223mg／L，出水COD平均浓度分别为15．6、17．9、23．4、28．2mg/L，平均去除率为93．0％、91．9％、89．5％、86．6％；进水NH3-N平均浓度约为22mg／L，出水NH3-N平均浓度分别为0．32、1．13、2．30、5．71mg／L，平均去除率为98．5％、94．8％、89．7％、74．6％。     

微波化学工艺处理烟草行业综合废水工程实践

采用微波化学工艺处理了烟草行业综合废水，工程规模为2500m3／d。处理前废水水质指标平均值为：CODCr1700mg／L，SS475mg，L，氨氮10．1mg/L，P0．72mg／L，pH值8．93；处理后废水水质指标平均值为：CODCr42．1mg／L，SS4mgL，氨氮3．7mg／L，P0．019mg／L。pH值7．91。除氨氮外，废水污染物去除率均达到95％以上，出水水质完全符合GB8978—1996《污水综合排放标准》的一级标准，经过消毒可回用。     

化学沉淀法处理高浓度氨氮废水的试验研究

实验采用磷酸氨镁沉淀法（MAP法）去除垃圾渗滤液中的高浓度氨氮。通过对MgCl2＋Na2HPO4^-、MgSO4＋Na2HPO4、MgO＋Na2HPO4、MgCl2＋NaH2PO4、MgSO4＋NaH2PO4和MgO＋NaH2PO4等六种组合药剂去除氨氮效果的分析比较，得出MgCl2＋Na2HPO4对氨氮的去除效果最好。继而对该组合药剂去除氨氮的影响因素进行了优化。结果表明：pH为9．0，反应时1．3为50min，n（Mg^2＋）：n（NH4^＋）：n（PO4^3-）为1．2：1：0．9时，氨氮可由原来的2100mg／L降低到317mg／L，去除率达84．9％．     

The Kinetics of Interesterfication on Waste Cooking Oil (Sunflower Oil) for the Production of Fatty Acid Alkyl Esters using a Whole Cell Biocatalyst (Rhizopus oryzae) and Pure Lipase Enzyme

Recent research and technology have provided promising outcomes to rely on biodiesel as the alternative and conventional source of fuel. The use of renewable sources constitutes the main stream of research. Waste Cooking Oil (WCO) was used for biodiesel production in this study. Lipase enzyme producing fungi Rhizopus oryzae 262 and commercially available pure lipase enzyme were used for comparative study in the production of FAAE. The whole cell biocatalyst and pure enzyme were immobilized using calcium alginate beads. It was prepared by optimizing with different molar ratios of calcium chloride and different percent sodium alginate. Entrapment immobilization was done for whole cell biocatalyst. PE was also immobilized by entrapment for the transesterification reaction. Four different solvents methanol, ethanol, n-propanol, n-butanol were used as the acyl acceptors. The reaction parameters like temperature, molar ratio, reaction time, and amount of enzyme to be used were also optimized for methanol alone. The same parameters were adopted for the other acyl acceptors too. Among the different acyl acceptors, methanol whose reaction parameters were optimized showed maximum conversion of triglycerides to FAAE - 94% with PE and 84% with WCB. On the whole, PE showed better catalytic converting ability with all the acyl acceptor compared to WCB, further study, it was observed that three consecutive and reversible reactions occurred in the interesterification of triglycerides. So, a kinetic model based on Michaelis-Menten equation with competitive substrate inhibition was used to find the maximum reaction rate V_i for the four solvents using pure enzyme and WCB.     

Kinetic and equilibrium characterization of uranium(VI) adsorption onto carboxylate-functionalized poly(hydroxyethylmethacrylate)-grafted lignocellulosics

This study investigated the feasibility of using a new adsorbent prepared from coconut coir pith, CP (a coir industry-based lignocellulosic residue), for the removal of uranium [U(VI)] from aqueous solutions. The adsorbent (PGCP-COOH) having a carboxylate functional group at the chain end was synthesized by grafting poly(hydroxyethylmethacrylate) onto CP using potassium peroxydisulphate-sodium thiosulphite as a redox initiator and in the presence of N,N'-methylenebisacrylamide as a crosslinking agent. IR spectroscopy results confirm the graft copolymer formation and carboxylate functionalization. XRD studies confirm the decrease of crystallinity in PGCP-COOH compared to CP, and it favors the protrusion of the functional group into the aqueous medium. The thermal stability of the samples was studied using thermogravimetry (TG). Surface charge density of the samples as a function of pH was determined using potentiometric titration. The ability of PGCP-COOH to remove U(VI) from aqueous solutions was assessed using a batch adsorption technique. The maximum adsorption capacity was observed at the pH range 4.0-6.0. Maximum removal of 99.2% was observed for an initial concentration of 25mg/L at pH 6.0 and an adsorbent dose of 2g/L. Equilibrium was achieved in approximately 3h. The experimental kinetic data were analyzed using a first-order kinetic model. The temperature dependence indicates an endothermic process. U(VI) adsorption was found to decrease with an increase in ionic strength due to the formation of outer-sphere surface complexes on PGCP-COOH. Equilibrium data were best modeled by the Langmuir isotherm. The thermodynamic parameters such as DeltaG(0), DeltaH(0) and DeltaS(0) were derived to predict the nature of adsorption. Adsorption experiments were also conducted using a commercial cation exchanger, Ceralite IRC-50, with carboxylate functionality for comparison. Utility of the adsorbent was tested by removing U(VI) from simulated nuclear industry wastewater. Adsorbed U(VI) ions were desorbed effectively (about 96.2+/-3.3%) by 0.1M HCl. The adsorbent was suitable for repeated use (more than four cycles) without any noticeable loss of capacity.     

海南马尾藻海藻酸钠的提取工艺及表征

采用正交试验方案首次研究了海南马尾藻海藻酸钠的提取工艺,得出最佳的提取工艺条件:Na2CO3浓度为2%、消化温度为55℃、消化时间为3h,海藻酸钠提取率最高达40.4%.用FTIR表征发现,提取的马尾藻海藻酸钠与市场售的海带海藻酸钠在结构上差别不大,同时测得提取海藻酸钠的分子量为36万、粘度为185mPa.S,高于GB1976-80要求的150mPa.S.     

Layer—By—Layer技术构建化学传感器酶电极检测水体中有机磷的研究

基于层层累积自组装法将胆碱氧化酶和胆碱酯酶逐层固定在电极表面，制备了电流型水质有机磷检测化学传感器。讨论了自组装膜层数、pH值、温度对传感器电流响应的影响。制备的化学传感器对有机磷在浓度10^-9～10^-5mol／L呈良好的线性响应，检出限为1×10^-10mol／L。传感器的稳定性好，30天时的响应值仍保持90％。     

Physicochemical and mineralogical characterization of soil-saprolite cores from a field research site, Tennessee

Site characterization is an essential initial step in determining the feasibility of remedial alternatives at hazardous waste sites. Physicochemical and mineralogical characterization of U-contaminated soils in deeply weathered saprolite at Area 2 of the DOE Field Research Center (FRC) site, Oak Ridge, TN, was accomplished to examine the feasibility of bioremediation. Concentrations of U in soil-saprolite (up to 291 mg kg(-1) in oxalate-extractable U(o)) were closely related to low pH (ca. 4-5), high effective cation exchange capacity without Ca (64.7-83.2 cmol(c) kg(-1)), amorphous Mn content (up to 9910 mg kg(-1)), and the decreased presence of relative clay mineral contents in the bulk samples (i.e., illite 2.5-12 wt. %, average 32 wt. %). The pH of the fill material ranged from 7.0 to 10.5, whereas the pH of the saprolite ranged from 4.5 to 8. Uranium concentration was highest (about 300 mg kg(-1)) at around 6 m below land surface near the saprolite-fill interface. The pH of ground water at Area 2 tended to be between 6 and 7 with U concentrations of about 0.9 to 1.7 mg L(-1). These site specific characteristics of Area 2, which has lower U and nitrate contamination levels and more neutral ground water pH compared with FRC Areas 1 and 3 (ca. 5.5 and <4, respectively), indicate that with appropriate addition of electron donors and nutrients bioremediation of U by metal reducing microorganisms may be possible.     

Specific Conductance and pH as Indicators of Watershed Disturbance in Streams of the New Jersey Pinelands, USA

/ We used linear regression to independently and jointly relate specific conductance and pH measured at New Jersey Pinelands stream sites to the percentage of altered land in a watershed. Percentage altered land included developed and agricultural land uses and represented watershed disturbance for a given site. Median values calculated for a 2-year period (September 1992 through August 1994) characterized pH and specific conductance at the study sites. We found the relationships between the median values for both water-quality measures and percentage altered land for a site to be consistent across subregion and dominant altered-land use. Our results also demonstrated that the water-quality/altered-land relationships developed using median values were similar to relationships developed using data from any single-sample period within the entire study period. Individually, pH and specific conductance explained 48% and 56%, respectively, of the variability in watershed disturbance among study sites. The joint use of pH and specific conductance explained 79% of the watershed disturbance variability among sites. The joint use of these easily obtained water-quality measures can provide a quick assessment of instream water-quality impacts from upstream watershed disturbance at any Pinelands stream site. Additionally, a range in pH and specific conductance, and hence a range in ambient water quality, can be predicted for a given altered-land percentage or a change in existing altered-land conditions.     

小叶榕落叶改性条件优化及其处理含Cu~(2+)废水动力学研究

以废弃的小叶榕落叶作为吸附剂,通过正交试验选择制备改性小叶榕落叶的最佳条件,结果表明:当硝酸浓度为10moL/L,干燥温度为120℃和氢氧化钠浓度为1moL/L时,改性后的小叶榕落叶的活性最强,对废水中Cu2+的吸附率最高。利用改性后的小叶榕落叶进行了吸附去除水中Cu2+的研究,得出当pH为5.7,铜的最大吸附容量Qmax=0.59mg(Cu)/g(改性落叶)。并通过非线性回归,构建了影响因素同吸附率之间的数学模型和落叶吸附的动力学模型。