低温对青萍生长及保护酶活性影响的研究

研究了在相对低温(10～12℃)的条件下,青萍生长和保护酶活性的变化.测定了叶状体数目相对增长率、鲜重相对增长率、根长、叶绿素含量、可溶性蛋白含量以及抗氧化酶系统的几种酶活性和含量的变化(包括过氧化物酶(POD)活性、过氧化氢酶(CAT)活性、超氧化物歧化酶(SOD)活性以及丙二醛(MDA)含量).研究结果显示在10～12℃的情况下,青萍生物量的增加基本为零,叶绿素和可溶性蛋白的含量均降低,细胞内保护酶的调节功能发生了紊乱.在10～12℃的低温下,青萍已经不具有修复富营养化水体的能力.     

Kinetics of low level chemiluminescence from plant leaf smoked by air pollutants

ＫｉｎｅｔｉｃｓｏｆｌｏｗｌｅｖｅｌｃｈｅｍｉｌｕｍｉｎｅｓｃｅｎｃｅｆｒｏｍｐｌａｎｔｌｅａｆｓｍｏｋｅｄｂｙａｉｒｐｏｌｕｔａｎｔｓＷａｎｇＹｉｎｇｙａｎ，ＷａｎｇＪｉｎｇｕａｎｇＢｅｉｊｉｎｇＭｕｎｉｃｉｐａｌＲｅｓｅａｒｃｈＩｎｓｔｉｔｕ...     

活性污泥法低温硝化及其运行控制条件研究

以我国大庆乘风庄污水厂5年运行实践为基础，研究了低水温条件下实现高效硝化的运行控制条件，指出通过保持较高的污泥浓度，控制较低负荷（＜0．5kg(BOD5）／（kg(MLSS).d）下运行，即使水温为8－10℃，仍然可达到80％以上的硝化效果和较好的有机物去除。     

Fossil carbon emissions associated with carbon flowsof wood products

Specific fossil carbon (C) emissions and primary energy useassociated with the manufacture of different wood product groups inFinland are estimated and expressed as emissions or energy use per amountof wood-based C in raw material and per amount in end product. Thecalculation includes both emissions from supplied fuels within the forestindustries, and from electricity and district heat purchased from externalsources. The results are compared to fossil C emissions from the wholelifecycle of harvested wood products. The results of the study show, forinstance, that the emission of fossil C per wood-based C in end products(MgC/MgC) is of the order of 0.07 for sawn wood and 0.3–0.6 for paperin the manufacturing stage. The primary energy use per wood-based C inend product is of the order of 2 MWh/MgC for sawn wood, whereas forvirgin paper grades the figure is between 17 and 19 MWh/MgC. Theprimary energy content is highest in papers based on chemical pulping, butaround 60% of the energy used is produced in this case from by-productwood wastes (black liquor, bark etc.). The specific fossil C emission andprimary energy divided by the estimated service life of the wood productare measures for the relative burden of maintaining the corresponding woodproduct pool. These figures should be kept in mind when considering woodproducts as a potential C sink option.     

清洁生产的无费和低费方案评述

无／低费方案着重于企业内部生产管理和小的工艺改进，具有投资少、见效快和易操作的特性。从目前的情况来说，清洁生产方案中大约有60％以上为无／低费方案，而其实施比例均在80％以上，由此可见，无／低费方案的重要性。通过3则实例证明了无／低费方案良好的环境效益和经济效益。     

官厅水库入库水生物预处理研究

进行了生物滤池系统在低温下对官厅水库入库水生物预处理可行性研究。在水温 1 0℃时水力负荷的提高对氨氮的去除效果影响很小 ,但水温为 5℃ (或低于 5℃ )时水力负荷的提高会导致氨氮的去除效果的明显下降。总体说来 ,生物滤池系统在低温条件下对有机物 (高锰酸盐指数 )仍有良好的去除率     

Low intensity ultrasound stimulates biological activity of aerobic activated sludge

This work aims to explore a procedure to improve biological wastewater treatment efficiency using low intensity ultrasound. The aerobic activated sludge from a municipal wastewater treatment plant was used as the experimental material. Oxygen uptake rate (OUR) of the activated sludge (AS) was determined to indicate the changes of AS activity stimulated by ultrasound at 35 kHz for 0–40 min with ultrasonic intensities of 0–1.2 W/cm². The highest OUR was observed at the ultrasonic intensity of 0.3 W/cm² and an irradiation period of 10 min; more than 15% increase was achieved immediately after sonication. More significantly, the AS activity stimulated by ultrasound could last 24 h after sonication, and the AS activity achieved its peak value within 8 h after sonication, or nearly 100% higher than the initial level after sonication. Therefore, to improve the wastewater treatment efficiency of bioreactors, ultrasound with an intensity of 0.3 W/cm² could be employed to irradiate a part of the AS in the bioreactor for 10 min every 8 h. Translated from Environmental Science, 2005, 26(4): 124–128 [译自: 环境科学]     

中低产水稻土障碍类型图编制雏议——以广东博罗县龙溪镇为例

中低产水稻土障碍类型图是通过各种不同形状的图斑与符号,反映区域内中低产水稻土的障碍因素、土壤环境、土壤物理和土壤化学性质的空间分布状况。本文是编制1:5万中低产水稻土障碍类型图的初步偿试。通过对37个具有代表性的中低产水稻土障碍性剖面的实地勘查、119个样品的理化分析结果,以及参考有关的图件资料,运用野外考察及室内分析的方法进行制图。该障碍类型图,可为区域中低产水稻土的改良利用提供科学依据。     

耐冷氨氧化功能菌群强化人工湿地低温脱氮

针对冬季低温条件下人工湿地脱氮效率低的问题,将富集得到的耐冷氨氧化功能菌群固定化后投加到人工湿地中,探究生物强化对低温下人工湿地脱氮的强化效果及其微生物作用机制.结果表明,5℃条件下,梯度降温（R1）和梯度降温耦合选择性抑制（R2）条件下富集培养的耐冷氨氧化功能菌群强化处理的人工湿地的氨氮平均去除率分别为84%和88%,比对照组湿地分别提高24%和28%.高通量测序分析表明,富集得到的耐冷氨氧化功能菌群中优势菌种（相对丰度高达19.2%）为具有氨氧化功能的硝化螺旋菌（Nitrospira sp.）,属于全程氨氧化菌,在氨氧化过程中起主要作用.微生物相对表达水平分析表明,两组生物强化人工湿地中氨氧化功能基因amoA的表达丰度分别为2.82×10⁸,8.22×10⁸拷贝数/克基质,显著高于对照组湿地的2.50×10⁷拷贝数/克基质.投加耐冷氨氧化功能菌群可以有效提高人工湿地脱氮效率.     

低浓度甲醛和PM2.5联合暴露对哮喘小鼠的影响

为探究低浓度甲醛（FA）单独及与PM_2.5联合暴露对哮喘小鼠的影响,选取70只雄性Balb/c小鼠,随机分为5组,分别为：对照组、卵清蛋白（OVA）组、FA+OVA组、PM_2.5+OVA组、FA+PM_2.5+OVA组,每组14只,其中6只进行气道高反应性（AHR）检测,其余8只用于检测血清T-IgE、肺泡灌洗液（BALF）中IFN-γ、IL-4以及肺组织中活性氧（ROS）、丙二醛（MDA）的含量,并对BALF中炎症细胞进行计数.同时对小鼠肺组织进行H&E染色以及p-p38MAPK和p-p65NF-κB免疫组化分析.结果显示,与OVA组相比,0.5mg/m³FA单独暴露组哮喘小鼠肺部MDA水平显著升高（P<0.001）,肺部炎症细胞呈现上升趋势（P>0.05）,0.5mg/m³FA和0.5mg/kg PM_2.5联合暴露组哮喘小鼠肺部炎症显著加重（P<0.05或P<0.01）,肺功能减弱（P<0.01）,肺部氧化应激水平以及p38MAPK和NF-κB的磷酸化水平均显著升高（P<0.05或P<0.001）,Th2型细胞因子释放显著增加（P<0.01）.因此,低浓度FA单独暴露会加重哮喘小鼠肺部损伤而非抑制,并且可进一步促进PM_2.5对哮喘小鼠肺部的损伤,即低浓度FA和PM_2.5联合暴露会对哮喘小鼠肺部造成严重损害,这可能与ROS介导的p38MAPK途径加剧Th1/Th2型免疫反应失衡有关.