Production of Curdlan Grown on Cassava Starch Waste Hydrolysates

Cassava starch waste hydrolysates (CSWHs) with different degrees of polymerisation, i.e., CSWHs-1, CSWHs-2 and CSWHs-3, were prepared through the hydrolysis of cassava starch waste with thermostable a-amylase from Thermococcus sp. HJ21. The prepared CSWHs were then used as a carbon source for curdlan production with Alcaligenes faecalis ATCC 31749. The amount of curdlan produced and the glucosyltransferase activity during curdlan synthesis increased more obviously when CSWHs-2 was used as the carbon source than when glucose was used. Using both carbon sources, the maximum curdlan production was observed at day 5, and the maximum glucosyltransferase activity was observed at day 4. Glucosyltransferase activity decreased thereafter, and biomass continued to increase until the end of the experiment (day 6). Results indicated that the enhanced curdlan production with CSWHs as the carbon source was highly correlated with glucosyltransferase activity.     

煤制乙二醇废水预处理装置的工业化调试

针对煤制乙二醇废水含高浓度硝酸盐氮的特点,设计了缺氧膨胀床(AEB)反应器预处理装置,并进行了工业化启动和调试运行,考察了其在反硝化连续流运行条件下的处理效果及工艺参数变化。结果表明,AEB反应器启动后,填料层生物膜挂膜快速且生长稳定。反应器在工业化调试阶段运行稳定,COD和TN的去除率和去除负荷较为稳定。在受到来水冲击后,AEB反应器处理效果稳定,出水可在短期内恢复正常。该技术的系统操控参数范围较广,易于工业化操控运行,在煤制乙二醇废水和其他含高浓度硝酸盐氮废水的处理中具有较大的推广价值。     

基于压力响应关系法的湖泊营养物基准制定

湖泊富营养化与氮、磷及有机物含量过高密切相关,建立数字型营养物基准能够防止富营养化对水体指定用途造成影响.太湖流域是我国华东地区经济腹地,近年来流域内湖泊水质每况愈下,对其基准研究可为湖泊治理提供依据.详细介绍了压力响应关系法制定湖泊营养物基准的步骤,并将此方法运用到太湖流域营养物基准制定研究中.为满足大多数水体指定用途,研究中将该流域湖泊基本功能确定为娱乐、永生生物栖息地及饮用水,以此构建流域概念模型.选择压力变量为总氮(TN)、总磷(TP)和有机物,响应变量为叶绿素a(chl-a).用非参数分析法和线性回归法分别建立压力-响应模型,通过2种方法相互验证得到TN、TP和CODMn基准分别为0.593、0.067和4.092 mg/L.     

16S rDNA克隆文库解析AO-MBR系统中细菌种群多样性

采用分子生物学手段16S rDNA克隆文库方法对缺氧/好氧膜生物反应器(AO-MBR)的好氧池与缺氧池中细菌进行了多样性研究.实验结果表明,好氧池污泥样品的克隆文库包括9个类群,其中变形菌(Proteobacteria)和拟杆菌(Bacteroidetes)在文库中所占比例最大,分别为37.04％和14.81％;其次是酸杆菌(Acidobacteria)、未培养菌(uncultured bacterium)、绿菌(Chlorobi)和未培养的绿弯菌(uncultured Chloroflexi bacterium)、浮霉状菌(Planctomycetes),分别为11.11％、11.11％、7.41％、7.41％和5.56％;硝化螺旋菌(Nitrospirae)和裸藻门(Euglenozoa)所占比例相对较小,均为1.85％.缺氧池样品克隆文库包括10个类群,其中变形菌(Proteobacteria)、拟杆菌(Bacteroidetes)和未培养菌(uncultured bacterium)在文库中所占比例最大,分别为27.91％、13.95％和12.79％;其次是浮霉状菌(Planctomycetes)、酸杆菌(Acidobacteria)和绿弯菌(Chloroflexi),在文库中所占比例分别为9.3％、9.3％和9.3％;硝化螺旋菌(Nitrospirae)、裸藻门(Euglenozoa)、芽单胞菌(Gemmatimonadetes)和放线菌(Actinobacteria)所占比例相对较少,分别为6.98％、8.14％、1.16％和1.16％.两池细菌的主要类群相似,但菌属及比例有所差异,变形菌是系统中的主要脱氮菌属.     

基于复杂系统建模的水管理政策研究进展

基于Agent的建模方法（ABSS）通过自下而上的方式，考察系统中主体的不同状态和行为特征、主体与环境的作用、主体之间的作用，来表征系统的宏观特征，是进行复杂社会环境系统分析和政策研究的重要手段，在水资源、水环境管理系统中得到了有效的应用。本文在大量文献调研的基础上，讨论了ABSS建模方法的基本原理、主要特征、系统构成、分类方法和开发工具等特征，总结了其供水系统发展、水资源分配和流域水资源管理、农业土地和水资源利用、居民用水行为、农业污染控制及人类活动的水环境影响等方面的应用，分析了其在研究内容、研究方法、研究结果等方面的发展趋势，讨论了利用该方法研究我国水资源管理和水污染控制政策的必要性和重要性。     

A fragment constant QSAR model for evaluating the EC50 values of organic chemicals to Daphnia magna.

The quantitative relationship between the median effective concentration (EC50) of organic chemicals to Daphnia magna and the number of molecular fragments was investigated based on experimental EC50 values for 217 chemicals derived from the literature. A fragment constant model was developed based on a multivariate linear regression between the number of fragments and the logarithmically transformed reciprocal values of EC50. Functional correction factors were introduced into the model. The model was verified using an independent set of randomly selected data. The mean residual of the final model was 0.4 log-units. The robustness of the model was discussed based on the results of three jackknife tests.     

水-粮食贸易:虚拟水研究进展

虚拟水思想强调的是水资源贡献，量化计算是其深入研究的基本，而是否选择虚拟水作为战略政策，应该考虑由不同国家的资源贡献和生产技术决定的比较利益。社会调适能力要求社会针对资源的第一性缺乏做相应调适并谋求解决手段，以提高资源管理能力。为此，需要结合我国的水和粮食安全问题，提出用虚拟水贸易解决我国水资源和粮食问题，提高我国对水资源缺乏的调适能力。     

Enhanced sludge solubilization by microbubble ozonation

A microbubble ozonation process for enhancing sludge solubilization was proposed and its performance was evaluated in comparison to a conventional ozone bubble contactor. Microbubbles are defined as bubbles with diameters less than several tens of micrometers. Previous studies have demonstrated that microbubbles could accelerate the formation of hydroxyl radicals and hence improve the ozonation of dyestuff wastewater. The results of this study showed that microbubble ozonation was effective in increasing ozone utilization and improving sludge solubilization. For a contact time of 80 min, an ozone utilization efficiency of more than 99% was obtained using the microbubble system, while it gradually decreased from 94% to 72% for the bubble contactor. The rate of microbial inactivation was obviously faster in the microbubble system. At an ozone dose of 0.02 g O₃ g⁻¹ TSS, about 80% of microorganisms were inactivated in the microbubble system, compared with about 50% inactivation for the bubble contactor. Compared to the bubble contactor, more than two times of COD and total nitrogen, and eight times of total phosphorus content were released from the sludge into the supernatant by using the microbubble system at the same ozone dosage. The application of microbubble technology in ozonation processes may provide an effective and low cost approach for sludge reduction.     

城市能源利用与环境保护的综合管理初探

能源短缺和环境污染已成为中国推行全面协调可持续发展的重要制约因素,作为能源消耗的主体和环境污染的控制重点,在城市层面推动能源发展战略的转变和强化环境保护是发展的基本要求.鉴于能源与环境之间的高度关联性,在管理方面要求对能源发展和环境保护进行统筹考虑和综合管理,充分强调能源经济效率和环境制约因素在能源发展中的作用.通过制定合理的产业能效标准和排放绩效标准,为城市经济、能源和环境的可持续性发展提供科学性、系统性决策支持.     

灰色协调度模型在产业用水系统分析中的应用

揭示产业用水系统的时空动态发展规律，探讨其内部的协调关系，是开展节水型社会建设规划，实现水资源可持续利用的关键。然而，目前对产业用水系统的协调性分析还缺乏较为有效的理论和方法。以往在利用协调度模型进行用水系统有序度研究时，通常采用两段叙述的线性分段函数表示，较不适用于描述产业用水系统内部要素的非线性结构。因此，针对产业用水系统的特性，利用灰关联原理建立有序度函数，以建立更适于用水系统分析的灰色协调度模型。利用该模型对上海市1997~2005年产业用水系统进行实证研究，结果显示：上海市产业用水系统基本有序，发展比较协调，其用水综合效益较大，但距离最优状态尚有潜力可挖；其中，农业用水子系统的发展较为欠缺，在未来用水规划中应予以重视。