重金属污染物在下包气带饱水条件下迁移转化的研究

不同的重金属污染物进入饱水的下包气带土层之后,由于其形态和价态变化差异较大,在土壤中的迁移、转化特征有明显差别,其迁移顺序为Cr_2O_7~(2-)>AsO_2~->>Hg~(2+)>Cd~(2+)>Pb~(2+).不同土质对重金属污染物迁移的影响为:在砂土中迁移最快,亚砂土中次之,亚粘土中最慢.     

滇池底泥堆场次生植被富集污染物调查

对滇池周边3个底泥堆场次生演替恢复过程中主要植物的生态学特征和污染物富集情况进行了调查。结果表明：随着底泥堆场由表流湿地向潜流湿地过渡,植被的整体含水量逐渐减少,种群密度逐渐增加;3个底泥堆场优势种的生物量随着植被恢复时间的增长而逐步减少;植物优势种富集某种重金属的能力与生物量的相关性系数（Zn〈Cu〈Pb〈As〈Cr〈Cd〈Hg）随富集能力的提高而降低,其中Hg的富集与生物量有较高的相关性;水生植物富集污染物的能力高于陆生植物;水生植物富集污染物能力最强的是凤眼蓝,其次是长柱柳叶菜和水烛;陆生植物富集污染物能力最强的是稗、云南莎草和水蓼。     

应用四膜虫刺泡发射试验方法评价金属离子的毒性

应用致突变阴性、阳性对照（Cu²⁺,Cr₂O^2-₄,Cd2+,丝裂霉素MMC,环磷酰胺CP,秋水仙素Colchicine）评价四膜虫刺泡发射实验方法的可行性,并应用该方法检测稀土金属离子La³⁺,Ce³⁺,Sm³⁺,Y³⁺,Gd³⁺对四膜虫刺泡发射的影响效应。结果表明,由于细胞毒性引起阳性对照最高浓度组刺泡发射率比低浓度组低外,其它处理浓度与刺泡发射率呈现良好的相关性。四膜虫刺泡发射试验不需加活性酶,是一种值得推荐的快速、简便、可靠的水生生物短期测试方法。稀土金属离子La³⁺,Ce³⁺,Sm³⁺,Y³⁺,Gd³⁺处理四膜虫的刺泡发射率同样具有随浓度升高而增加的趋势,但在低浓度处理组各检测时间内四膜虫刺泡发射率低于对照组,该结果与稀土低浓度时的刺激效应和抗突变性不无相关。     

有机物对重金属在粘土中吸附行为的影响

实验选用填埋场垃圾降解过程中“产酸阶段”和“产甲烷阶段”产生的己酸和腐殖酸及重金属 Cd、Pb、Ni、Zn和 Mn为研究对象 ,研究有机物存在对粘土吸附重金属的影响 .结果表明 :粘土对纯重金属的吸附随着溶液 p H值升高而增强 ;对己酸的吸附随着溶液 p H值升高而增强 ,对腐殖酸的吸附随着溶液 p H值升高而减弱 .当溶液中己酸和重金属共存时 ,由于竞争吸附使得粘土对重金属的吸附能力普遍有较小幅度的下降 ;当溶液中存在腐殖酸和重金属共存时 ,粘土对重金属的吸附能力增强 ,主要是由于酸性条件下富里酸发生解离后与重金属络合 ,其络合物与粘土颗粒有一定的结合能力 ,增强了粘土对重金属的吸附能力 .     

环境因子对湖泊沉积物中吸附态磷化氢生成和释放的影响

以富营养化湖泊的沉积物湿样为研究对象,采用室内模拟的方法,考察了pH、温度和氧气对沉积物中吸附态磷化氢生成和释放的影响．结果表明,实验过程维持pH值动态恒定,当起始pH值为1或12时,沉积物磷化氢消失很快;起始pH值为10时,吸附态磷化氢的净积累量较大;起始pH值4～12的条件下,向沉积物一水体系中加碱可使吸附态磷化氢的积累量增加．温度对吸附态磷化氢的生成和释放均有影响,20℃时沉积物中吸附态磷化氢的净积累量最大．氧气对吸附态磷化氢的影响不显．沉积物中吸附态磷化氢的净含量是其生成和释放相互平衡后的结果．     

Recovery of Cu(Ⅱ) from aqueous solution by induced crystallization in a long-term operation

The feasibility of copper recovery by induced crystallization in a long period(174 days) was investigated in a seeded fluidized bed reactor(FBR). The process was divided into 3 periods according to different influent conditions, and the period III was separated into III-a and IIIb due to the adjustment of the molar ratio of CO_3~(2-)concentration to copper concentration([CT]/[Cu~(2+)]). The removal efficiency could exceed 95% and the average effluent copper concentration decreased to 3.0 mg/L. The mean particle size of seed grains with copper crystals coating on, raised to 0.36 mm from initial 0.18 mm. During period III-a, the supersaturation exceeded 2.88 × 104, the removal efficiency decreased to 60%–80% and the particle size dropped to 0.30 mm, due to the generation of fines by homogeneous crystallization and seeds breaking. And the morphology of the crystals on the seed grains changed from rod-like to spherical which lead to the particle size decreasing. In period III-b,the supersaturation was modified by adjusting the molar ratio of [CT]/[Cu2+] to 1.2 from 2.The efficiency was back to 95% and the mean particle size grew to 0.36 mm at the end of IIIb, the crystals coating on the seeds turned back to rod-like products of good stability. This study illustrated that the copper salt crystal could keep on growing on the seed grains for over 150 days, the feasibility and controllability of copper recovery by induced crystallization process in FBR were satisfactory, even under the dramatic changes in influent conditions.     

New insights on the enhanced non-hydroxyl radical contribution under copper promoted TiO2/GO for the photodegradation of tetracycline hydrochloride

TiO₂/graphene oxide (GO) as photocatalyst in the photo-degradation of multitudinous pollutants has been extensively studied. But its low photocatalytic efficiency is attributed to the high band gap energy which lead to low light utilization. Cu-TiO₂/GO was synthesized via the impregnation methods to enhance the catalytic performance. The Cu-TiO₂/GO reaction rate constant for photo-degradation of pollutants (tetracycline hydrochloride, TC) was about 1.4 times that of TiO₂/GO. In 90 min, the removal ratio of Cu-TiO₂/GO for TC was 98%, and the maximum degradation ratio occurred at pH 5. After five cycles, the removal ratio of Cu-TiO₂/GO still exceeded 98%. UV–visible adsorption spectra of Cu-TiO₂/GO showed that its band gap was narrower than TiO₂/GO. Electron paramagnetic resonance (EPR) spectra test illustrated the generation rate of ?O₂^? and ?OH was higher in Cu-TiO₂/GO system than TiO₂/GO and TiO₂ system. The contribution sequence of oxidative species was ?O₂^? > holes (h⁺) > ?OH in both TiO₂/GO and Cu-TiO₂/GO system. Interestingly, the contribution of ?OH in Cu-TiO₂/GO was less than that in TiO₂/GO during the photo-degradation process. This phenomenon was attributed to the better adsorption performance of Cu-TiO₂/GO which could reduce the accessibility of TC to ?OH in liquid. The enhanced non?hydroxyl radical contribution could be attributed to that the more other active species or sites on (nearby) the surface of Cu-TiO₂/GO generated after doping Cu. These results provide a new perspective for the tradition metal-doped conventional catalysts to enhance the removal of organic pollutants in the environment.     

主体功能区建设与财政生态补偿研究——以安徽省为例

党的十六届五中全会明确提出了“优化开发、重点开发、限制开发、禁止开发”四类主体功能区。主体功能区划是中国国土空间区划与规划理论中的一个重大突破,实行主体功能区生态补偿政策,对于实现不同类型主体功能区的健康协调发展,具有重要的意义。从传统的生态补偿理论来探讨主体功能区建设的生态补偿模式,要充分发挥市场补偿机制的功能,同步落实主体功能区财政、产业、土地、人口管理、绩效评价和政绩考核政策,从法律上明确生态补偿责任和各生态主体的义务,为生态补偿机制的规范化运作提供法律依据。     

塞氏盘法对水质透明度的测定

本文阐述了塞氏盘法测定水质透明度的历史．叙述了塞氏盘法对水质透明度的测定，详细总结了包括水体物理指标、光线条件、水生生物、水气界面和水面至观测者之间的距离和角度等各类因素对水质透明度测定的影响．并在透明度盘（塞氏盘）的制作、试验步骤、测定结果的记录、数据处理等方面做了进一步的修改和完善。     

微生物在环保中的作用

本文介绍了微生物在环境保护的各个领域中的应用.