城市地表径流-灰尘-污染物输移研究进展

城市地表"径流-灰尘-污染物"作为一个三相介质系统,相互作用机理十分复杂。分别从城市地表灰尘颗粒对不同种类污染物的吸附效应及时空分布规律、地表(坡面)降雨径流特性及过程模拟、地表径流-灰尘-污染物协同输移与削减等方面,总结与分析了现有的研究进展。从本质上来看,城市地表灰尘可视为由不同粒径泥沙颗粒组成的综合体,有必要基于泥沙运动力学理论加强对地表径流中灰尘颗粒运动规律的研究,并以灰尘颗粒对不同污染物的吸附、沉淀作用为纽带,探讨"径流-灰尘-污染物"的协同输移与削减机制。其中,如何有效扩展城市调查样本容量,比较研究不同下垫面径流动力特性,并从径流能量或功率角度出发,研究不同粒径灰尘颗粒的分组起动与输移规律,并建立在径流输送过程中的挟沙力方程,将是今后需要深入研究的问题。

重金属-有机污染物复合污染土壤修复工程实例

采用异位化学氧化和稳定化技术联合修复重金属-有机污染物复合污染土壤,污染土壤中重金属类和有机物共计16项污染物指标超出《上海市场地土壤环境健康风险评估筛选值(试行)》中非敏感用地标准,土方量共计1.64×105m3。项目于2018年10月通过环保验收,修复后的场地土壤质量满足《上海市场地土壤环境健康风险评估筛选值(试行)》和《地下水质量标准》Ⅳ类标准。对该工程的场地布置、开挖清运、土方筛分、固废分类合规处置、化学氧化及稳定化技术等关键环节进行了介绍。

植物修复重金属-有机物复合污染河道疏浚底泥的研究

针对目前国内普遍存在的排污河道污染问题,通过盆栽试验研究了玉米、印度芥菜、超积累油菜、紫花苜 蓿在施用不同配比的排污河道疏浚底泥上对重金属-有机物复合污染的修复情况及超积累的机理．结果表明,随着 底泥配比的增加,植物发芽率的抑止程度也增加;适应底泥中高浓度复合污染的植物,底泥施用能促进其生长,提 高植物体内的叶绿素含量．植物体内积累的重金属Zn、Pb、Cd以生长在底泥与土壤比为2:1的印度芥菜为最大,分 别为1 521 mg／kg、453 mg／kg和11．7 mg/kg;Cu、Ni积累量以生长于底泥中的玉米为最大,分别为128 mg／kg和 89．1 mg／kg．在本实验条件下,底泥中有机物以种植玉米的底泥为最大,为76．89％．通过环境扫描电子显微镜及配 套的能谱分析发现,重金属在植物体内的聚集存在;经X荧光光谱仪和X射线衍射仪分析,确证了配合体之间及重 金属和配合体相互形成架桥而聚集成团,形成重金属结合物积累在植物体内,且在植物根部发现积累了Cu的有机 氯化物．种植前后底泥的X射线衍射对比表明,种植后重金属的晶格结构和存在形态发生了变化．

污染物在多孔介质饱和水中运移规律的研究

以淮北市萧濉新河为研究对象,进行了河水与地下水原型水质监测,结合现场地质勘探、土工试验和室内土槽试验,获得了大量有价值资料。藉此,论述了萧濉新河污染对浅层地下水的影响程度和范围,揭示了污染物在土壤饱和水中的扩散运移规律。

Adsorption of Cr(VI) by modified chitosan from heavy-metal polluted water of Xiangjiang River, China

Methacrylic acid was used together with a molecular imprinting technique to modify chitosan. In addition, the adsorption kinetics and adsorption isotherms were recorded and the results were analyzed to investigate reparative adsorption for Cr（VI） from the polluted Xiangjiang River water. A comparative X-ray analysis shows that the degree of crystallization in the imprinted polymer was significantly weakened, the area of the non-crystalline region was larger. There were more adsorption sites in the imprinted polymer, and the adsorption capacity towards Cr（VI） was increased. The adsorption capacity of the imprinted polymer towards Cr（VI） increased with time and reaches saturation after 8 h. The optimal adsorption time was 4-8 h after the adsorption starting and the optimal pH value for the solution was in the range of 4.5-7.5. When the chitosan reaches saturation, the adsorption capacity achieves a state of equilibrium, and the maximum Cr（VI） extraction rate reaches 33.7%. Moreover, the adsorption capacity of the imprinted polymer towards Cr（VI） increases with increasing chitosan concentration. In this situation, the Cr（VI） extraction rate shows little variation, and the maximum removal rate can reach 98.3%. Furthermore, the Cr（VI） extraction rate increases with an increase in the degree of deacetylation in the chatoyant and chitosan, with the best adsorption effect corresponding to 90% deacetylation. Fitting the adsorption data to the quasi first- and second-order kinetic models yields correlation coefficients of 0.9013 and 0.9875, respectively. The corresponding rate constants for the two models are 0.0091 min-1 and 7.129 g/（mg.min）, respectively. Hence, the adsorption using Cr（VI）-imprinted chitosan is more consistent with the second-order kinetics. Comparing the data to Freundlich and Langrnuir adsorption isotherms shows that the latter has a better linear fit and a maximum adsorption capacity of 15.784 mg/g.

Absorption capacity of major urban afforestation species in north-eastern China to heavy metal pollutants in the atmosphere

Totally 24 arbor tree species and 6 shrub species were measured on their absorption capacities to heavy metal Pb, Cd, Cr, and Hg by collecting and analyzing the leaves of trees along different streets in Harbin city in Sept. to Oct. of 2003. The results showed that all the measured species had certain absorbency to the pollutants (Pb, Cd, Cr and Hg), but there existed significant difference in absorption capacity for different species to different pollutants. The measured tree species were classified into three categories by their absorption quantum of heavy metal pollutants. Among the species measured,Betula platyphylla, Ulmus pumila var.pendula, andPrunus persicaf.rubro-plena had high capacity in absorbing Pb;Populus xiahei, P. nigra var.Italica, P. alba x P. berolinensis andSalix matsudana had had high capacity in absorbing Cd;Phellodendron amurense, Syringa oblata, Salix matsudana, Pinus tabulaeformis var.mukdensis, Picea koraiensis, Prunus persica f.rubro-plena, P. triloba andAcer negundo, etc. had high capacity in absorption of Cr;Prunus triloba, Quercus mongolica, Salix matsudana, Sambucus williamsii, Pyrus ussuuriensis andSpiraea fritschiana were good at absorption of Hg. This study might offer scientific foundation for selection of urban afforestation species in different polluted conditions caused by heavy metals. Keywords Greening tree species - Heavy metal - Pollutants - Plumbum - Cadmium - Chromium - Mercury - Absorptivity CLC number S731.2 - X501 Document code A Foundation item: This study is financially supported by the Special Programme for Agriculture under Ministry of Chinese Science and Technology (No. 2002BA516A15-01).Biography: MU Li-qiang (1966-), female, Associate professor in Northeast Forestry University, Harbin 150040, P. R. China.Responsible editor: Zhu Hong

黑麦草对复合污染河道疏浚底泥修复的研究

采用室温盆栽试验,研究了黑麦草(LoliummultiflorumLam)对排污河道疏浚底泥中的重金属(Zn、Pb、Cu、Cd、Ni)-有机物复合污染的修复情况。结果表明,第2次收获(剪切)的黑麦草地上部分积累的重金属Zn、Pb、Cu、Cd的数量均小于第1次收获(剪切),且第2次连根收获发现黑麦草的根部积累了大量的重金属;两次收获地上部分积累的重金属数量和重金属的离子交换态数量有很好的相关性,而与底泥中重金属总量的相关性较差;种植黑麦草后的底泥中重金属的存在形态和晶格结构发生了变化。黑麦草对底泥中的有机污染物有很好的修复作用;在两次收获后的底泥中的有机污染物的降解率达到72.6%,大部分有机物被炭化为CO2和H2O,其中部分难降解的大分子量有机污染物也被植物降解为小分子量的易于被植物吸收的形态,种植黑麦草后底泥的多酚氧化酶和脲酶活性均得到提高。证明黑麦草是修复重金属-有机物复合污染的良好植株。

EDTA在植物修复复合污染河道疏浚底泥中的调控作用

通过温室盆栽试验,在黑麦草修复重金属(Zn,Pb,Cu,Cd,Ni)-有机物复合污染的城市排污河道疏浚底泥的过程中投加3mmol.kg-1EDTA(分1次、2次、3次投加),研究了对黑麦草生长及重金属积累、底泥特性和TOC的影响.结果表明,投加EDTA:①增加了黑麦草体内积累的重金属数量,其中分3次投加的效果最为显著,Pb,Zn,Cu,Ni,Cd在地上部分的积累量分别较对照增加了2.74、1.99、1.59、1.55和7.78倍;分3次投加明显降低了黑麦草的叶绿素含量,1次投加叶绿素含量没有明显变化.②对底泥的pH没有明显的影响,但显著增加了底泥中NH4OAc提取态和DTPA提取态的重金属量.③底泥大颗粒体积百分比变大;其中分3次投加底泥颗粒体均粒径增大、比表面积减小、晶格强度减小,有助于底泥颗粒释放吸附的重金属.④提高了底泥中微生物的数量,其中分2次、3次投加,微生物数量是对照试验的1.33和1.47倍;明显降低了底泥的脲酶活性,但对过氧化氢酶活性的影响不明显.⑤增加了底泥的TOC含量.

Preparation of three-dimensional interconnected mesoporous anatase TiO_2-SiO_2 nanocomposites with high photocatalytic activities

In this article, we report the preparation of a three-dimensional（3D） interconnected mesoporous anatase TiO2-SiO2 nanocomposite. The nanocomposite was obtained by using an ordered two-dimensional（2D） hexagonal mesoporous anatase 70 TiO2-30 SiO2-950 nanocomposite（crystallized at 950 °C for 2 h） as a precursor, NaO H as an etchant of SiO2 via a ＂creating mesopores in the pore walls＂ approach. Our strategy adopts mild conditions of creating pores such as diluted NaO H solution, appropriate temperature and solid/liquid ratio, etc. aiming at ensuring the integrities of mesopores architecture and anatase nanocrystals. XRD, TEM and N2 sorption techniques have been used to systematically investigate the physico-chemical properties of the nanocomposites. The results show that the intrawall mesopores are highly dense and uniform（average pore size 3.6 nm）, and highly link the initial mesochannels in a 3D manner while retaining mesostructural integrity. There is no significant change to either crystallinity or size of the anatase nanocrystals before and after creating the intrawall mesopores. The photocatalytic degradation rates of rhodamine B（RhB, 0.303 min^–1） and methylene blue（MB, 0.757 min^–1） dyes on the resultant nanocomposite are very high, which are 5.1 and 5.3 times that of the precursor; even up to 16.5 and 24.1 times that of Degussa P25 photocatalyst, respectively. These results clearly demonstrate that the 3D interconnected mesopores structure plays an overwhelming role to the increments of activities. The 3D mesoporous anatase TiO2-SiO2 nanocomposite exhibits unexpected-high degradation activities to RhB and MB in the mesoporous metal oxide-based materials reported so far. Additionally, the nanocomposite is considerably stable and reusable. We believe that this method would pave the way for the preparation of other 3D highly interconnected mesoporous metal oxide-based materials with ultra-high performance.

玉米对受污染河道复合沉积物的修复

为减轻城市河道沉积物的受污染程度,利用温室盆栽玉米对其中的污染物进行了修复研究试验.结果表明,玉米体内累积最多的重金属是Zn,占沉积物中Zn总量的56.69%,其中地上部分为1 985.56 mg.kg-1,占沉积物中Zn总量的30.16%,其余重金属(Pb、Cu、Ni、Cd)均为地上部分小于地下部分;Cd在玉米地上部分的累积量为2.33 mg.kg-1,为沉积物中Cd总量的40.10%;地上部累积的Zn、Pb、Cu和Ni等重金属数量与其离子交换态量显著相关,与重金属总量相关性不明显.种植玉米后沉积物中大分子有机物逐渐向小分子过渡,有效降低了有机物的污染.玉米的根际作用增加了沉积物中的微生物和酶活性.种植玉米较好地修复了受污染河道复合沉积物.

Analysis of the major components of root exudates released from several economic forest tree using GC-MS

In 2000 and 2001, 1-year-old seedlings of 7 economic tree species including chestnut, apricot, persimmon, peach, walnut, pear and apple were cultured in garden pots that had a diameter of 40 cm and were filled with clean sand. The major components of exudates released from their roots were isolated and analysed by GC-MS. Totally 200 kinds of organic chemicals were isolated, of which 3 kinds i.e. naphthalene, dimethylbenzene and dibutyl phthalate were principally controlled pollutants according to 'Blacklist of Principal Environment Pollutants in China' and the standard of U.S. Environmental Protection Agency (EPA). The research result provided theoretical evidence for selecting low-pollution economic forest crops in the water source protection area in Miyun Reservoir.

螯合剂对植物修复污染河道疏浚底泥的调控

通过温室盆栽试验,在黑麦草修复重金属(Zn,Pb,Cu,Cd,Ni)——有机物复合污染的城市排污河道疏浚底泥的过程中投加EDTA(1mmol/kg和3mmol/kg),柠檬酸(5mmol/kg和15mmol/kg),DTPA(1mmol/kg和3mmol/kg),研究了对黑麦草生长及重金属积累、底泥特性的影响。结果表明,5mmol/kg的柠檬酸提高了重金属在植物地上部分的积累量,但没有达到显著水平,增大柠檬酸的投加量阻碍了植物的生长、抑制了对重金属的吸收。3mmol/kg的EDTA和DTPA均能提高植物对重金属的积累量,但也降低了植物的叶绿素含量。5mmol/kg的柠檬酸降低了底泥的pH,但其它2种螯合剂对底泥的pH没有明显的影响。3种螯合剂均增加了底泥溶液中重金属的浓度;增大了底泥大颗粒体积百分比,降低了其比表面积和晶格强度,有助于底泥颗粒释放吸附的重金属;提高了底泥中微生物的数量;增加了底泥的TOC含量。5mmol/kg的柠檬酸提高了底泥脲酶的活性,但效果不显著,而其它2种螯合剂均明显降低了脲酶活性,3种螯合剂对过氧化氢酶活性的影响均不明显。

Adsorptive and catalytic properties in the removal of volatile organic compounds over zeolite-based materials

Volatile organic compounds（VOCs） are a major component in air pollutants and pose great risks to both human health and environmental protection. Currently, VOC abatement in industrial applications is through the use of activated carbons as adsorbents and oxide-supported metals as catalysts. Notably, activated carbons easily adsorb water, which strongly hinders the adsorption of VOCs; conventional oxides typically possess relatively low surface areas and random pores, which effectively influence the catalytic conversion of VOCs. Zeolites, in contrast with activated carbons and oxides, can be designed to have very uniform and controllable micropores, in addition to tailored wettability properties, which can favor the selective adsorption of VOCs. In particular, zeolites with selective adsorptive properties when combined with catalytically active metals result in zeolite-supported metals exhibiting significantly improved performance in the catalytic combustion of VOCs compared with conventional oxide-supported catalysts. In this review, recent developments on VOC abatement by adsorptive and catalytic techniques over zeolite-based materials have been briefly summarized.

Ultra-Supercritical——A Preferential Choice for China to Develop Clean Coal Technology

The ultra-supercritical pressure coal-fired power-generation technology (USCT) isa mature, advanced and efficient power generation technology in the world. Comparisonsamong several principal clean coal power-generation technologies show that USCT withpollutant-emission control equipment is superior to others in efficiency, capacity, reliability,investment and environment protection etc. Analyzing the main problems existing in thermalpower industry, it is concluded that the USCT is the preferential choice for China to developclean coal power-generation technology at present. Considering the foundation of thepower industry, the manufacturing industry for power generating equipment and otherrelated industries, it is concluded that China has satisfied the qualifications to develop USCT.

Effects of Heavy Metal and Pollutants on the Non-special Immunity of the Shrimp and Crab

This paper attempted to review and evaluate existing information about the effects of heavy metal, ammonia-N, nitrite and the organic pollutants on the non-special immune response of the shrimp and crab, which providing theory for improving the self-immunity of shrimp and crab by meliorating cultural environment. In addition, it could provide information for further study on this field.

Time-dependent magnetometric resistivity anomalies of groundwater contamination: Synthetic results from computational hydro-geophysical modeling

We present a forward-modeling investigation of time-dependent ground magnetometric resistivity （MMR） anomalies associated with transient leachate transport in groundwater systems. Numerical geo-electrical models are constructed based on the hydrological simulation results of leachate plumes from a highly conceptualized landfill system and the resultant MMR responses are computed using a modified finite difference software MMR2DFD. Three transmitter configurations （i.e., single source, MMR-TE, and MMR-TM modes） and two hydrological models （i.e., uniform and faulted porous media） are considered. Our forward modeling results for the uniform porous medium indicates that the magnetic field components perpendicular to the dominant current flow contain the most information of the underground targets and the MMR-TE mode is an appropriate configuration for detecting contaminant plumes. The modeling experiments for the faulted porous medium also confirm that the MMR method is capable of mapping and monitoring the extent of contaminant plumes in aroundwater systems.

Remediation of in-situ Leach Mining Contaminated Soil by Amendment-plant Synergism

This study aimed to remediate in-situ leach mining contaminated soil by amendment-plant synergism. The results showed that plant species exhibited ex-tremely significant effects on the concentration of nitrate nitrogen; to be specific, the concentration of nitrate nitrogen in soil planted with wheat was reduced from 692.19 mg/kg to lower than 100 mg/kg; when the mass ratio of amendment to soil reached 3：50 and the amendment particle size was 1-2 mm, the concentration of nitrate ni-trogen in soil planted with wheat was reduced to 43 mg/kg. The amendment type exhibited extremely significant effects on the concentration of ammonium nitrogen; to be specific, when the mass ratio of amendment to soil reached 10：50, the concen-tration of ammonium nitrogen in soil added with 2-3 mm zeolite was reduced from 23 593.75 to 3 300 mg/kg on day 15. Amendments and plants mainly exhibited desorption performance for sulfate radical in soil, and the amendment type extreme-ly significantly affected the concentration of sulfate radical; to be specific, the con-centration of sulfate radical in soil added with limestone increased from 370 mg/kg to 900 mg/kg on day 7.

Study on the Remediation of Cd-contaminated Soil

[Objective] The remediation effect of the plant to Cd-contaminated soil was studied. [Method] By taking simulation test and field test, the ryegrass （Lolium perenne L.） was planted, and the remediation effect of the plant to contaminated sites was studied. [Result] The ryegrass was planted in the eluotropic soil for 0-60 d, Cd content in the soil showed a rapid decreasing trend; after 60 d, the enrich- ment ability of the plant to Cd gradually weakened over time; after 75 d of phytore- mediation, the Cd content in the soil decreased greatly, and the remediation effi- ciency was 90.66%. [Conclusion] Ryegrass remediation technology had good reme- diation effect to Cd-contaminated soil.

Impacts of Agricultural Non-point Pollution on Water-source Area in Songhua Dam

[Objective] The aim was to research impacts of agricultural non-point pol- lution on water-source region in Songhua Dam, laying foundation for control of water pollution and scientific protection of water-source region. [Method] Water in Muyang River, lengshui River and Zizania aquatica region were sampled to measure content of pollutants in water and conclude relation between water contamination and agri- cultural non-point pollution to find the major cause of pollution. [Result] Organic pollu- tant in Muyang River was higher; N and P contents in Lengshui River were higher; the measured indices in Zizania aquatica region excessively exceeded related stan- dard. [Conclusion] The chemical fertilizers and pesticides are the toxic materials lead- ing to water contamination and constitute a major cause of pollution in Songhua Dam water-source region. Agricultural non-point pollution should be controlled in a scientific way.