高浓度难降解工业废水菌种筛选及其降解特性

使用富集、稀释涂平板的方法从制药、染料、化工及精细化工、食品等多家工厂的混合高浓度难降解化工废水中筛选到8株细菌,经16S rDNA鉴定为Bacillus aquimaris、Enterobacter、Pseudomonas putida、Microbacterium、Agrobacterium、Alpha proteobacterium、Planococcus rifietoensis,其中两株细菌为Bacillus aquimaris。对各单一菌种生长条件的研究表明,各菌种生长的最适pH为7,最适接种量为15%（v/v）,最适生长温度为37℃,其中Pseudomonas putida的最适生长温度为30℃。在最适生长条件下,研究了各单一菌种及不同组合的混合菌种对废水的降解效果,结果表明在单一菌种中Pseudomonas putida对废水的降解效果最优,混合菌的降解效果优于单一菌种的降解效果,混合菌可将废水COD由1 249 mg/L降至97 mg/L,比普通活性污泥对废水的去除率提高了14.7%。     

重组大肠杆菌产CotA漆酶的发酵条件优化

CotA漆酶在环境保护、食品工业和纸浆漂白等工业中具有重要的应用价值.将重组表达载体pET-22b/CotA转入大肠杆菌BL21(DE3),得到工程菌株,采用单因素实验和正交实验相结合的方法,研究诱导表达条件和发酵培养基对重组大肠杆菌产CotA漆酶量的影响.结果表明,初始pH 7.5的培养基中,添加0.6 mmol L-1 Cu2+,1 g L-1葡萄糖作碳源、15 g L-1蛋白胨和2 g L-1硫酸铵作氮源,以10%的接种量,37℃、200 r/min,直到菌液的D600 nm值为1.0,加入终浓度为1.0 mmol L-1的IPTG,25℃诱导12 h,漆酶的产量最高.优化前发酵液的粗提液的漆酶活性仅为1 190 U mL-1,优化后达到3 526 U mL-1,正交实验优化后漆酶活性提高了2.96倍.纯化的CotA漆酶最适反应温度为45℃,最适pH值为7.2.CotA漆酶对RBBR的脱色率在90%以上,此CotA漆酶在短时间内对染料能够有效地脱色,能够成为有潜力的工业用酶.图6表3参17     

2株石油降解菌生长和降解石油条件的优化

对2株石油降解菌DH-5和DH-9生长的最适培养基成分以及降解石油的最佳环境条件进行了筛选。结果表明,DH-5的最佳培养基成分为ρ(原油)1 g.L-1、ρ(氮源)400 mg.L-1、ρ(磷源)200 mg.L-1、ρ(酵母浸出液)20 mg.L-1,最有效利用的氨基酸为精氨酸,最适环境条件为pH 7.0、盐度20、温度15～30℃;DH-9的最佳培养基成分为ρ(原油)1 g.L-1、ρ(氮源)400 mg.L-1、ρ(磷源)100 mg.L-1、ρ(酵母浸出液)20 mg.L-1,最有效利用的氨基酸为天冬氨酸,最适环境条件为pH 7.5、盐度20、温度30℃。当ρ(原油)为20 g.L-1时,DH-9的生物量和原油降解率分别是DH-5的2.58倍和2.29倍。研究表明,DH-9对高浓度原油的耐受性明显强于DH-5,而DH-5对低温的适应性优于DH-9,2个菌株对高盐度的适应性均较强。     

建设项目竣工环保验收监测中常见问题及应对措施

建设项目竣工环保验收监测中常常出现建设同环评和初步设计不相符、变更粉尘产污环节、环评文本遗漏重要敏感点评价、数据异常、工况条件不满足要求等问题,基于此提出了重新报批变更的工程内容,向环保主管部门说明变更情况,对遗漏部分进行补充评价并监测,对异常数据查明原因后科学剔除,以及按照实际工况进行监测等应对措施。     

国内外空间环境模拟试验条件分析

本文对国内外空间环境模拟试验条件进行了分析,介绍了国内外已有的空间环境模拟试验条件和试验设备。以推动空间环境工程试验研究工作的开展。     

Modeling of Fluid Flow and Heat Transfer in a Copper Based Heat Sink Application

With the trend towards increasing the speed of processors in smaller sized of computers, there has been considerable interest in heat sink technologies with higher levels of performance and further miniaturization. This work addresses the fundamental heat transfer augmentation question of how to design a copper-based heat sink, when the overall dimensions of the bottom plate or fan are specified. A three-dimensional finite-volume model has been developed and applied to investigate flow and conjugate heat transfer in the copper-based heat sink. The model was produced with the commercial program FLUENT, which allows this nonlinear, highly turbulent problem to be simulated using the k-ε turbulence model. The theoretical model developed is validated by comparing the model predictions with available experimental data. The thermal performance and temperature distribution for the heat sink were analyzed and a procedure for optimizing the geometrical design parameters based on less space occupation and more efficient heat transfer coefficient is presented. Several design examples with different types of cooling methods and manufacturing processes have been analyzed. The reliability and effectiveness in heat spreading of those has been compared. It has been shown that the copper-based heat sink with louvered fins (case No.3) has an optimum design configuration.     

Critical flow-storm approach to total maximum daily load(TMDL) development: an analytical conceptual model

One of the key challenges in the total maximum daily load (TMDL) development process is how to define the critical condition for a receiving waterbody. The main concern in using a continuous simulation approach is the absence of any guarantee that the most critical condition will be captured during the selected representative hydrologic period, given the scarcity of long-term continuous data. The objectives of this paper are to clearly address the critical condition in the TMDL development process and to compare continuous and event-based approaches in defining critical condition during TMDL development for a waterbody impacted by both point and nonpoint source pollution. A practical, event-based critical flow-storm (CFS) approach was developed to explicitly addresses the critical condition as a combination of a low stream flow and a storm event of a selected magnitude, both having certain frequencies of occurrence. This paper illustrated the CFS concept and provided its theoretical basis using a derived analytical conceptual model. The CFS approach clearly defined a critical condition, obtained reasonable results and could be considered as an alternative method in TMDL development.     

高压静电水处理技术的研究现状及其展望

高压静电场水处理技术是近几十年发展起来的、当今水处理领域中的一门高新技术。在此介绍了国内外高压静电场水处理机理和应用研究现状,并对今后高压静电场水处理技术研究提出几点展望。随着对高压静电场水处理机理研究的不断加强和完善。以及对高压静电水处理技术与其它水处理技术的联合水处理工艺研究的突破。高压静电场水处理技术有望成为一种极具应用前景的高效水处理技术。     

搅拌条件对两种染料混凝气浮去除效果的影响研究

实验以七水硫酸镁及硫酸铝钾为混凝剂,十二烷基硫酸钠为浮选剂,研究了搅拌条件对酸性大红3R、还原深蓝BO混凝气浮去除效果的影响。结果表明,当搅拌转速为100r／min、搅拌时间为10min时,混凝气浮对酸性大红3R的去除效果较好,吸光度去除率为67．33％,色度去除率为69．23％;当搅拌转速为50r／min、搅拌时间为10min时,混凝气浮对还原深蓝BO的去除效果较好,吸光度去除率为84．33％,色度去除率为99．70％。     

关于伴生放射性污染源问题的讨论

本文根据国家规定公众照射年有效剂量和假设条件,建立了确定伴生放射性污染源的模型,将重庆市伴生放射性水平实地测量数据带入该模型计算,结果表明,共有8家企业确定为伴生放射性污染源,纳入伴生放射性污染源普查范围,符合重庆市实际情况。