Changes of main secondary metabolites in leaves of Ginkgo biloba in response to ozone fumigation

To investigate the effect of elevated O3 on the accumulation of main secondary metabolites in leaves of Ginkgo biloba L., four-year-old trees were exposed in open-top chambers with ambient air and the air with twice ambient O3 concentration in Shenyang in 2006.Elevated O3 increased the concentrations of terpenes, but decreased the concentrations of phenolics in G.biloba leaves.The results showed that secondary compounds from G.biloba leaves responded to the elevated O3 exposure in a different way when compared to previous studies which showed elevated O3 increased the concentrations of phenolics but had no effect on the terpenes in leaves of other deciduous trees.Furthermore, reduced synthesis of phenolics may decrease the resistance of G.biloba to O3 and other environmental factors.On the other hand, the induced synthesis of terpenes may enhance the antioxidant abilities in G.biloba leaves at the end of O3 fumigation.     

三峡大学文思湖水污染评价

根据三峡大学文思湖近几年水质监测资料,以及对其水质状况、污染源进行调查研究的基础上,采用单因子指数评价、W值水质评价、富营养化评价、有机污染评价4种方法对文思湖进行了水体质量综合评价,以期为文思湖水环境的综合整治提供科学依据。     

膜序批式生物反应器脱氮性能研究

采用厌-好氧交替膜序批式反应器,实验室人工合成配水,连续运行300 d,对反应器脱氮性能进行了研究.结果表明,污泥浓度达到18 g·L-1时,污泥粒径大小在100μm以上的占96%,污泥出现颗粒化.FISH-CLSM分析AOB及NOB的群落空间分布表明它们在污泥中大量存在.NH4 -N进水50 mg·L-1左右时出水在1 mg·L-1以下,硝化反应在180～210 min就可以完成.曝气强度与硝化反应速率密切相关,曝气强度为100 m3·(m2·h)-1时,NH4 -N降解速率最佳达24.25 mg·(L·h)-1,系统硝化性能稳定.影响系统脱氮的主要因素是反硝化速率,曝气强度为69 m3(m2·h)-1时,对NO3--N的利用率为10.98 mg·(L·h)-1,出水NO3--N浓度为4.4 mg·L-1,滞留在厌氧段的浓度3.5 mg·L-1为最低,反硝化效果最好.曝气过量或不足时反硝化速率都低.在保证系统处理能力的同时,大的交换比0.35有利于系统脱氮运行.C/N比为2时,反硝化速率最高,>2时出现NO2--N的积累.     

HAZOP技术在溴化丁基橡胶装置的应用

介绍了危险与可操作性分析(HA-ZOP)的程序以及在溴化丁基橡胶装置的应用,根据分析结果提出相应的安全措施。     

活性炭纤维的改性及对Cu~(2+)吸附性能影响的研究

采用硝酸、磷酸、磷酸二氢铵和硝酸铜水溶液对聚丙烯腈基活性炭纤维(PAN-ACF)进行浸渍改性,制备了4种改性活性炭纤维(ACF1-ACF4)。测定了改性活性炭纤维表面含氧酸性官能团、零电荷点、比表面积和孔容,评价了改性纤维对铜离子的吸附性能。结果表明改性后活性炭纤维表面含氧酸性官能团明显增加,其零电荷点相应降低,比表面积和微孔孔容增大。改性活性炭纤维对Cu2+的吸附容量显著提高,其中ACF2吸附性能最佳,其吸附容量从改性前的4.80 mg/g增加到17.32 mg/g,提高了3.6倍。     

吹扫捕集-气质联机法测定水中三氯乙醛

用吹扫捕集-气相色谱/质谱法对水中三氯乙醛进行了测定,研究了吹扫时间、NaOH溶液加入量对三氯乙醛响应值的影响,确定的实验条件为:吹扫4 min,每40 ml水样中加入0.20 ml NaOH溶液,标准曲线范围在1.0～200μg/L时,线性相关系数可达0.999,取样量5 ml时,检出限0.21μg/L。精密度和准确度实验结果为:空白水分别加标2.0μg/L和20μg/L时,6次平行测定的平均回收率分别为108%和94.4%,RSD分别为3.1%和2.4%。     

苏南典型城区河网地区沉积物重金属调查研究

本研究对太湖上游集水区重要城市常州城区河网的12条主要河流开展了城市主要河道沉积物中的重金属分布状况及特征调查,采用Hakanson生态风险指数法对沉积物中的主要重金属对所在水域的污染程度及对水域和周围环境造成的潜在风险影响进行了评价。结果显示,常州河道沉积物已受到严重污染,不同类型河道的沉积物污染程度趋势为:城区>郊区>城市外围河道,其中以Hg的污染最重。     

米糠炭吸附水中镉的研究

文章研究了米糠炭的用量、溶液温度、Cd^2＋浓度、溶液pH值和吸附时间对米糠炭吸附Cd^2＋性能的影响。实验结果表明,米糠炭对Cd^2＋具有很好的吸附效果,吸附率达94．6％。其最佳吸附条件为：米糠炭用量20g／L,温度30℃,pH=3,Cd^2＋质量浓度低于50mg／L,吸附平衡时间30min。     

我国环境保护规划实施中的问题分析

环境规划是国民经济和社会发展的有机组成部分,本文剖析了当前我国环境保护规划在实施中存在的主要问题,认为现阶段我国环境保护规划存在缺乏法律效力、实施过程中缺乏统一协调、资金难以落实、缺乏有效地实施监管机制和公众参与机制缺乏实质性等问题;总结了国外在环境保护规划实施过程中可以借鉴的经验;结合我国环境保护工作的形势和环境保护规划的发展,提出了完善环境保护规划的法律机制、加强环境规划衔接、建立完善的实施监督机制、加大规划实施的资金投入、加强环境保护规划的公众参与等建议,以保证环境保护规划的可达性和可操作性。     

NOx photocatalytic degradation on active concrete road surface — from experiment to real-scale application

The use of titanium dioxide (TiO₂) as a photocatalyst in concrete pavements has received considerable attention in recent years due to its ability to decontaminate via photocatalytic processes. The objective of this study is to assess the effectiveness of activated concrete road in the degradation of nitrogen oxides (NO_x). We have used a TiO₂ and activated carbon (AC) permeable spray solution to coat concrete to assess its NO_x purifying ability. A number of experiments were undertaken to ascertain the conditions that affect NO_x purification. Indoor simulation experiments with active concrete road at optimum conditions show that it has good purification ability, self-regeneration and repetition ability, with a minimum decontamination rate for NO and NO₂ of 37.4% and 25.84%, respectively. Outdoor experiments show that the photodegradation of NO_x is related to light intensity and temperature. As the light intensity increases the reaction rate increases, and conversely as temperature increases the reaction rate decreases.