微生物聚酯的合成和应用研究进展

微生物聚酯是由发酵技术生产、具有生物降解性的热塑性高分子材料。本文介绍了３－羟基丁酯均聚物（ＰＨＢ）和共聚物的基本结构、生物降解性能、生物合成及其应用研究的进展。     

Degradation of cellulosic and hemicellulosic substrates using a chelator‐mediated Fenton reaction

The involvement of catechol and hydroxamate chelators, along with hydrogen peroxide and Fe³⁺, in the degradation of cellulosic and hemicellulosic substrates was examined with the purpose of improving our current knowledge of the non‐enzymatic mechanisms involved in wood biodegradation by fungi. It could be demonstrated that a catechol chelator‐mediated Fenton reaction not only clearly degraded hemicellulosic substrates but also significantly accelerated and increased the effectiveness of degradation reactions. On the other hand, when a hydroxamate chelator‐mediated Fenton reaction was used, an inhibitory effect was observed. When cellulosic substrates underwent a chelator‐mediated Fenton reaction, no significant difference in degradation was observed between catechol and hydroxamate chelator‐mediated reactions. However, a catechol‐mediated reaction did accelerate the degradation of cellulosic substrates at the beginning of reactions. In addition, it was observed that with a chelator‐mediated Fenton reaction, oxidation of cellulose proceeds depolymerization. Copyright © 2005 Society of Chemical Industry     

溶液共混法制备高强度淀粉基完全生物降解塑料薄膜

利用一步溶液共混法，将预糊化的淀粉糊与PvA溶液共混，用乙二醛进行交联，制备淀粉／聚乙烯醇（PVA）完全生物降解塑料薄膜。研究不同乙二醛和甘油的用量对薄膜性能的影响。薄膜的力学性能、热性能和微观形态表征表明，淀粉／PvA体系具有较好的相容性和较高的力学性能，薄膜的拉伸强度和断裂伸长率分别可达到28．52MPa和307．5％。     

厌氧型888－1石油专用胶的研究与应用

厌氧型８８８－１石油专用胶是胜利油田和烟台环宇高新技术研究所联合研制的，是我国首次试用成功的厌氧型国产石油专用胶。本文阐明了该胶的固化机理、研制过程、试验数据及油田实地使用情况。８８８－１石油专用胶经专家鉴定后，很快在胜利油田各采油厂试用成功，又在中原油田、大庆油田及中国石油天然气总公司下属很多单位推广应用，均取得了明显的经济效益，充分显示了该胶的应用前景和巨大生命力。     

Modeling of batch phenol biodegradation in internal loop airlift bioreactor with gas recirculation by Candida tropicalis

A mathematical model for simulating the dynamic behaviors of batch phenol biodegradation processes in internal loop airlift bioreactor (ILAB) with gas recirculation using free cells of the yeast Candida tropicalis was established by coupling the fluid dynamic model and the mass balance model. Based on the coupling arithmetic, the program for evaluating batch phenol biodegradation processes was achieved. The predicted results of linear liquid velocities, gas holdups, linear gas velocities, cell and phenol concentration profiles in the riser and the downcomer of the ILAB with gas recirculation agreed very well with the corresponding experimental data, and the applicability and reliability of this proposed model were validated.     

固定化微生物细胞降解邻苯二甲酸二丁酯

The biodegradation of di-n-butyl phthalate （DBP） using immobilized microbial cells was carded out in an internal airlift loop reactor with ceramic honeycomb supports. A strain that is capable of degrading DBP was isolated from the activated sludge and identified as Bacillus sp. using 16S rDNA sequential analysis. Bacillus sp. could be rapidly attached onto the ceramic honeycomb supports. The immobilized cells could effectively degrade DBP in batch and continuous experiments. When the influent concentration of DBP was 50mg·L^-1, the effluent DBP reached less than lmg.L i with 6h hydraulic retention time （HRT） in continuous experiment. The immobilized microbial cells could grow and accumulate through the biodegradation of DBP, and the rate of degradation is accordingly increased. The possible pathway of DBP biodegradation using immobilized cells was tentatively proposed.     

PAHs代谢物对PAHs生物降解的影响作用

分别研究了芽胞杆菌CN2降解蒽产生的代谢物对蒽生物降解的影响和菲产生的代谢物对菲生物降解的影响.试验结果表明:(1)外加蒽(或菲)代谢物,对蒽(或菲)的降解均表现出促进作用.蒽156 h累计去除率可提高3.07%～6.10%,菲60 h累计去除率可提高13.14%～30.35%.(2)在芽胞杆菌CN2作用下,蒽(或菲)生物降解过程能够用一级动力学方程式较准确地描述,外加代谢物可以增大降解反应表观速率常数k值;从不同时段内蒽(或菲)的降解速率看,反应初期0～2 h内,外加代谢物对蒽(或菲)的降解速率提高最为明显,对蒽可提高0.281～1.20 mg/L·h,对菲可提高0.570～1.13 mg/L·h.(3)外加代谢物对蒽(或菲)降解液的pH值有缓冲作用,使降解液的pH值随降解时间下降趋势减缓.     

一种假单胞菌SY5降解石油的动力学研究

为了确定石油降解菌对石油污染物的生物降解特性,选用分离得到的一株石油降解菌假单胞菌SY5,对其降解石油污染物的动力学特性进行了研究．研究结果表明,在30℃,pH=7．2的反应条件下,所筛选的SY5菌对石油具有良好的降解能力,降解石油的反应基本符合一级反应动力学,且随石油初始浓度的增大,SY5降解石油的速率减小,降解受到抑制．在生物降解的过程中,SY5的生长曲线具有明显增长和衰减曲线．在生长阶段,产率系数Y值为0．3873．在内源呼吸阶段,衰减系数bd值为0．1805d^-1,SY5菌自身氧化速度比较快．SY5生物降解石油Monod方程的最大比增长速率胁,和半饱和常数Ks分别为1．6d^-1和150mg／L．     

GAC-BAF联合工艺处理高浓度含酚废水

采用活性炭（GAC）吸附-曝气生物滤池（BAF）降解联合工艺处理高浓度含酚废水,对GAC吸附、再生,BAF降解,GAC—BAF联合工艺运行工况进行了研究。结果表明：该联合工艺能有效降解含酚废水;GAC吸附容量与进水流量无关,吸附效果在原水进水pH=3．0、温度20±2℃下达到最佳;反冲进水碱性条件下对GAC解吸再生有利,反冲流量对再生有一定影响;BAF对含酚废水的容忍浓度为1100mg／L,GAC再生废水进入BAF之前需稀释至微生物适宜的pH值和苯酚浓度;GAC—BAF联合工艺中GAC柱进水流量的选择应确保BAF床有足够时间对已吸附饱和的另一平行GAC柱完成再生。该联合工艺将GAC吸附和BAF生物降解结合成连续运行的方式,使得苯酚废水处理过程不受GAC再生的影响,解决了传统GAC吸附和生物降解不适宜处理高浓度含酚废水的缺点。     

Biodegradation of low‐density polyethylene/thermoplastic starch foams before and after electron beam irradiation

Foamy low‐density polyethylene/plasticized starch (LDPE/PLST) blends at different compositions were produced in the presence of azodicarbonamide (ACA) compound as foaming agent. The LDPE/PLST blends before and after electron beam irradiation were investigated in terms of mechanical properties, bulk density, and structure morphology. Moreover, the biodegradability of these materials was evaluated by the soil burial test for 2 months, in which the buried sheets were also examined by scanning electron microscopy (SEM). The results showed that the increase of PLST content from 24 to 30% was accompanied by a decrease in the yield and break stresses of 10 and 20% for the unirradiated blends without the foaming agent, respectively. Further decrease in these mechanical parameters was observed after the foaming process. The bulk density, void fraction, cell size measurements as well as the examination by SEM illustrate clearly the cell growth of the foam structure. The soil burial test and SEM micrographs indicate the growth of microorganisms overall the blend sheets and that the blend was completely damaged after two months of burying. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007