Effect of Earthworm(Pheretima sp.) Density on Revegetation of Lead/zinc Metal Mine Tailings Amended with Soil

Abstract

The objective of this study was to investigate the effects of earthworm density on the availability of nutrients and heavy metals in metal contaminated soils. Pb/Zn mine tailings were mixed throughly with a red yellow podzolic soil at the ratio (w/w) of 75:25. Earthworms (Pheretima sp.) were introduced to the mixture at four different densities, zero, three, six and nine individuals per pot planted with ryegrass (Loliun multiflorum). The results indicated that earthworm activity significantly enhanced ryegrass shoot biomass. However, as denser earthworm population was introduced, shoot biomass tended to decrease. Earthworm activity significantly increased soil pH and availability of N, P and K in the tailings and soil mixture. There was a general tendency that uptake of Zn by ryegrass increased after earthworm inoculation, although the increase in extractable Zn in tailings and soil mixture was not significant. On the contrary, there seemed to be a lower uptake of Pb by ryegrass under earthworm inoclation, despite the fact that higher extractable Pb concentrations were observed. The present project indicated that the improved growth of ryegrass was due to improved nutrient availability and other soil conditions, by inoculation of earthworms at an appropriate rate. Further studies are needed to illustrate the relationship between metal availability and earthworm activity in the field.     

随机故障、蓄意攻击与城乡路网空间稳定性——以武汉城市圈为例

基于1995~2010武汉城市圈城乡路网空间数据,综合运用复杂网络理论、动力系统理论及现代控制理论等多学科的方法和理论,采取随机故障和蓄意侵略两种攻击策略及多种评价指标,通过建立动力学演化模型并进行模拟仿真,揭示武汉城市圈城乡道路网的空间稳定性：（1）因分布相对均匀,节点连接随机多样,在面临随机攻击时,武汉城市圈城乡路网体现出“类随机性”,抗攻击能力强;（2）高度节点、高介数节点失效时,引致的城乡路网效率和结构变化程度不一,高介数节点失效往往更容易导致路网破碎和效率降低（形成众多子图）;（3）桥梁和高速成为整个圈域城乡路网的关键边,不同桥梁或高速路段相对网络稳定性的重要程度不一样：圈域中心城区的大桥和二桥、南北向的京港澳、大广高速成为整个城乡路网的关键路径     

响应面分析法优化稀土废水MAP沉淀法脱氮

经过预处理后的稀土生产废水,其氨氮浓度大幅降低,但并未达到中华人民共和国《稀土工业污染物排放标准》（GB26451-2011）中氨氮浓度限值。实验通过响应面分析法中的Box-Behnken实验设计（BBD）,取pH、n（Mg）：n（N）、n（P）：n（N）3因素,采用Design-Expert 8.0.6,建立合适的剩余氨氮浓度及剩余总磷浓度模型,得到回归方程,并分析模型各项指标,各因素及其相互作用对剩余氨氮浓度及剩余总磷浓度的影响。利用预测模型预测最佳实验条件,在最佳实验条件下验证预测结果,并对沉淀物进行X射线衍射（XRD）分析。结果显示,二次响应模型适用于剩余氨氮浓度及剩余总磷浓度,2个模型均拥有较好的拟合程度、可信度及精密度,最优反应条件为：pH=9.88、n（Mg）：n（N）=1.50：1、n（P）：n（N）=1.38：1时,剩余氨氮浓度为46.58 mg/L,剩余总磷浓度为7.85 mg/L。在最优条件下所得到的沉淀物并非纯净的MgNH₄PO₄·6H₂O,还有Mg₃（PO₄）₂·22H₂O生成。     

东湖通道工程沙滩浴场围堰施工对水中胞外碱性磷酸酶动力学行为的影响

城镇化过程常伴随市政建设面积与强度的大幅度增加,但其与湖泊富营养化的关系尚未得到充分的研究。2014年3-5月在武汉东湖通道工程沙滩浴场围堰施工区与相关湖区（郭郑湖、汤菱湖、团湖）的19个位点分5次采集水样,分析了水中胞外碱性磷酸酶的动力学参数及其与溶解有机磷和溶解反应性磷比值的关系。结果表明,施工致使酶的最大反应速度与底物亲和力均显著降低,有机磷酶促再生为生物可利用性无机磷的周转时间明显延长。这一结果指示施工区磷营养的相对充足,施工干扰可能有效促进了沉积物磷向水柱的补给。     

回流比对剩余污泥厌氧发酵产酸的影响

挥发性脂肪酸（VFAs）是强化生物除磷过程中易于利用的碳源。在影响剩余污泥厌氧发酵的因素中,回流搅拌是影响因素之一。因此,确定最适SRT为10 d后,通过采用控制回流比的方法,研究了剩余污泥在不同回流比条件下厌氧发酵的情况。结果表明：回流比的增大能够促进污泥水解过程中SCOD和STOC的溶出;回流比为300%时VFAs浓度最高,可以达到284.64 mg·L-1,约为不回流情况下（146.82 mg·L-1）的2倍;回流比为300%时产酸率也要大于不回流搅拌和回流比为500%的情况,最高可达到0.58 g·g-1（以VS计）,在VFAs中以乙酸和丙酸的含量占主导。     

Characteristics of aerosols collected in central Taiwan during an Asian dust event in spring 2000

Aerosol samples for PM(2.5) and PM(2.5-10) were collected at four locations in central Taiwan from 26 to 31 March 2000, a period that experienced exceedingly high PM levels from 29 to 30 March due to the passage of an Asian dust storm. The samples were analyzed for mass, metallic elements, ions, and carbon. The purpose of this paper is to investigate the influence of the dust storm on the characteristics of local ambient particulate matter. The results indicate that the concentrations of the crustal elements Ca, Mg, Al, Fe and the sea salt species Na+ and Cl- in PM(2.5-10) during the dust episode exceed the mean concentrations in the non-dust period by factors of 3.1, 2.9, 2.6, 2.2, 2.3 and 2.1 respectively. Enrichment factors of Ca, Fe, and Mg in PM(2.5-10) during the dust event are close to unity, indicating that these elements are from soil. Reconstruction of aerosol compositions revealed that soil of coarse particulates elevated approximately 50% in the dust event. It is noted that during the dust event, the ratio of Mg/Al in PM(2.5-10) ranged from 0.21 to 0.25 while that of Ca/Al ranged from 0.6 to 0.9, levels more constant than those obtained in non-dust period.     

水功能区划在流域排污权初始分配中的应用——以沙颖河流域为例

排污权交易是治理环境污染问题的有效手段,排污权初始分配则是排污权交易制度实施的基础,在流域水功能区划基础上研究排污权初始分配问题,将有助于流域排污权交易制度的有效实施.结合我国现行行政特征和流域水功能区划成果,以行政单元作为排污权初始分配主体开展排污权初始分配研究.选取沙颍河流域为例,根据淮河水利委员会制定的沙颍河流域水功能区划及COD、氨氮限排总量要求,以COD、氨氮作为排污权初始分配的客体,通过等比例削减方法对沙颍河流域内的行政单元进行了排污权初始分配,得到了流域内各行政单元的COD、氨氮初始排放权,并将分配结果与区域社会经济发展水平等进行了比较研究,研究认为将水功能区划应用于排污权初始分配研究是一种有效的尝试.在此基础上探讨了关于排污权初始分配的政策可行性、初始分配的方法及地方政府定位等几方面问题,目的在于为将来的排污权分配研究工作提供一些思考和建议.     

论流域水质与水量集成规划

“水量”与“水质”是流域大系统的两个特征,水环境研究偏重于水质,而水资源研究则更偏重水量,但是“质”与“量”是不能截然分开的,它们之间既相互关联,又互影响,相互制约,构成矛盾的统一体,基于这一出发点,本文从规划方法学的历史发展与流域水环境大系统的结构分析入手,系统阐述了提出流域水质与水量集成规划基本概念,目标及其策略与技术路线。     

Discovery of emerging organic pollutants in the atmosphere through an omics approach

● We review the framework of discovering emerging pollutants through an omics approach. ● High-resolution MS can digitalize atmospheric samples to full-component data. ● Chemical features and databases can help to translate untargeted data to compounds. ● Biological effect-directed untargeted analyses consider both existence and toxicity. Ambient air pollution, containing numerous known and hitherto unknown compounds, is a major risk factor for public health. The discovery of harmful components is the prerequisite for pollution control; however, this raises a great challenge on recognizing previously unknown species. Here we systematically review the analytical techniques on air pollution in the framework of an omics approach, with a brief introduction on sample preparation and analysis, and in more detail, compounds prioritization and identification. Through high-resolution mass spectrometry (HRMS, typically coupled with chromatography), the complicated environmental matrix can be digitalized into “full-component” data. A key step to discover emerging compounds is the prioritization of compounds from massive data. Chemical fingerprints, suspect lists and biological effects are the most vital untargeted strategies for comprehensively screening critical and hazardous substances. Afterward, compressed data of compounds can be identified at various confidence levels according to exact mass and the derived molecular formula, MS libraries, and authentic standards. Such an omics approach on full-component data provides a paradigm for discovering emerging air pollutants; nonetheless, new technological advancements of instruments and databases are warranted for further tracking the environmental behaviors, hence to evaluate the health risk of key pollutants.     

生物反应器填埋场产甲烷规律的模拟研究

生物反应器填埋场是一种新型的垃圾卫生填埋场,可以加速填埋场的稳定及甲烷的产生.通过模拟试验探讨了生物反应器填埋场在不同操作条件下的产甲烷情况及COD、pH值的变化趋势.试验证明较高的回灌频率有助于垃圾降解、产甲烷速率的升高及渗滤液中COD浓度的降低;污泥接种起缓冲作用,使垃圾的降解及产气速率更趋向平稳;甲烷的产生与COD的降低是同步进行的,因此可以通过COD的变化趋势来判断产甲烷情况.研究建立了反映垃圾含水率影响填埋场产甲烷的数学模型,该模型具有简便、直观、准确等优点.