我国排污权交易制度的相关问题探析

随着经济的快速发展,工业生产中排放的废弃物越来越多,由此造成的环境压力也越来越大,随着可持续发展概念的不断提出,排污权交易制度也被逐渐确定下来,该制度在我国的施行不但具有可行性,更加具有必要性。本文对我国当前排污权制度实施的不足之处进行了详细分析,并提出了我国排污权制度未来的完善路径。     

城镇污水厂污泥农用重金属源头控制技术措施

城镇污水厂污泥堆肥农用是一种经济合理的利用方式,但其前提是污泥中的重金属必须满足相应控制标准要求。末端降低或去除污泥中的重金属,需要一定的技术、资金和人力资源,推广起来有难度;采用"源头控制技术措施",可从根本上消减污泥中重金属,确保污泥堆肥农用的安全、可靠,且其操作简单,经济合理,方便实施。     

低温域人工湿地强化脱氮效果研究

在低温条件下(0¹5℃),研究麦冬湿地在预曝气、非曝气两种状态下的脱氮效果。结果表明,预曝气人工湿地内氧环境得到明显改善,供氧前湿地内溶氧浓度低于0.6 mg/L,供氧后氧浓度上升至0.9 mg/L以上。对TN、NH+4-N去除率,预曝气湿地>非曝气湿地。因此,预曝气是低温域人工湿地强化脱氮的一种有效措施。     

废弃钻井泥浆无害化处理与评价方法的研究

本文简述了废弃钻井泥浆对环境的影响及无害化处理原则,分析了废弃钻井泥浆处理存在的问题,详细论述了废弃钻井泥浆无害化评价标准、浸出毒性评价方法以及分析结果的应用,为废弃钻井泥浆分类贮存、处置和土壤环境修复提供合理化建议。     

Kinetic and mechanism studies of the adsorption of lead onto waste cow bone powder (WCBP) surfaces

This study examines the adsorption isotherms, kinetics and mechanisms of Pb2(+) sorption onto waste cow bone powder (WCBP) surfaces. The concentrations of Pb2(+) in the study range from 10 to 90 mg/L. Although the sorption data follow the Langmuir and Freundlich isotherm, a detailed examination reveals that surface sorption or complexation and co-precipitation are the most important mechanisms, along with possibly ion exchange and solid diffusion also contributing to the overall sorption process. The co-precipitation of Pb2(+) with the calcium hydroxyapatite (Ca-HAP) is implied by significant changes in Ca2(+) and PO?3? concentrations during the metal sorption processes. The Pb2(+) sorption onto the WCBP surface by metal complexation with surface functional groups such as ≡ POH. The major metal surface species are likely to be ≡ POPb(+). The sorption isotherm results indicated that Pb2(+) sorption onto the Langmuir and Freundlich constant q(max) and K( F ) is 9.52 and 8.18 mg g?1, respectively. Sorption kinetics results indicated that Pb2(+) sorption onto WCBP was pseudo-second-order rate constants K? was 1.12 g mg?1 h?1. The main mechanism is adsorption or surface complexation (≡POPb(+): 61.6%), co-precipitation or ion exchange [Ca?(.)?? Pb?(.)?? (PO?)? (OH): 21.4%] and other precipitation [Pb 50 mg L?1 and natural pH: 17%). Sorption isotherms showed that WCBP has a much higher Pb2(+) removal rate in an aqueous solution; the greater capability of WCBP to remove aqueous Pb2(+) indicates its potential as another promising way to remediate Pb2(+)-contaminated media.     

Potential application of sludge produced from coal mine drainage treatment for removing Zn(II) in an aqueous phase

Various analyses of physico-chemical characteristics and batch tests were conducted with the sludge obtained from a full-scale electrolysis facility for treating coal mine drainage in order to find the applicability of sludge as a material for removing Zn(II) in an aqueous phase. The physico-chemical analysis results indicated that coal mine drainage sludge (CMDS) had a high specific surface area and also satisfied the standard of toxicity characteristic leaching procedure (TCLP) because the extracted concentrations of certain toxic elements such as Pb, Cu, As, Hg, Zn, and Ni were much less than their regulatory limits. The results of X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) showed that the CMDS mainly consists of goethite (70%) and calcite (30%) as a weight basis. However, the zeta potential analysis represented that the CMDS had a lower isoelectric point of pH (pH(IEP)) than that of goethite or calcite. This might have been caused by the complexation of negatively charged anions, especially sulfate, which usually exists with a high concentration in coal mine drainage. The results of Fourier transform infrared (FT-IR) spectrometry analysis revealed that Zn(II) was dominantly removed as a form of precipitation by calcite, such as smithsonite [ZnCO?] or hydrozincite [Zn?(CO?)?(OH)?]. Recycling sludge, originally a waste material, for the removal process of Zn(II), as well as other heavy metals, could be beneficial due to its high and speedy removal capability and low economic costs.     

沼液培养的普通小球藻对CO2的去除

利用微藻固定CO2和处理污水已成为微藻应用的一个重要研究方向.利用营养丰富的沼气发酵废液培养小球藻,藻种经驯化后在不同浓度沼液中能良好生长.小球藻在高浓度的CO2中有较好的生长和较强的耐受能力,在1.5%CO2通气下生物量最高.在此基础上考察了沼液中小球藻对CO2的去除情况.结果表明,提高小球藻生长速率和CO2浓度可以增加小球藻对CO2的去除量,降低通气也可提高CO2去除率.在1.5%CO2浓度、通气量60 mL min-1条件下,CO2去除率可达30.61%;在10%CO2浓度、通气量100 mL min-1时最高去除量为279.7 mg L-1 h-1.采用六管串联通气培养小球藻去除粗沼气中的CO2,去除量为(205.80±13.20)mg L-1 h-1,去除率为60.32%±3.73%.在同样的通气量下,CO2的去除量与单管培养相近,去除率是单管培养的近6倍,因此小球藻对沼气中的CO2具有良好的去除效果.图4表2参17     

强降雨在滑坡发育中的关键控制机理及典型实例分析

通过构建水动力作用模型,对降雨的激发控制作用进行分析,得出水动力控制机理的结论:强降雨控制滑坡发育,集中表现在改变土体的静水压力、动水压力与浮托力的作用三方面.选取重庆市黔江流水湾滑坡为典型实例,对强降雨的激发控制作用进行验证,强降雨的水动力作用过程分为坡体剪切、滑动开始、剧烈滑动三个不同阶段.最后,提出久旱过后强降雨...     

纳米ZnO与TiO2对赤子爱胜蚓(Eisenia foetida)的毒性效应

以赤子爱胜蚓(Eisenia foetida)为受试生物,研究纳米TiO2与ZnO两种纳米颗粒的毒理学效应及环境释放风险.实验采用滤纸法(浓度组:0、0.15、0.75、1.5和3.0 mg·cm-2)和溶液法(浓度组:0、10、50和100 mg·L-1),染毒时间为48 h,以抗氧化系统的响应和DNA损伤作为毒理效...