淮南潘集采煤沉陷区地表水中氮、磷特征

根据2012年11月至2013年9月的9次监测数据,分析了淮南潘集开放型和封闭型采煤沉陷区地表水中氮、磷时空分布特征及污染源;通过相关性分析揭示了同类水体内氮、磷之间的响应关系和运移特征;通过各形态氮、磷比率分析了两类水体中氮、磷组成.结果表明,NH3-N(氨氮)年内时间差异性较小,整体呈KB(开放型地表水)>FB(封闭型地表水),最大值分别为0.621 mg·L-1(6月)和0.813 mg·L-1(6月);NO-2-N(亚硝酸氮)时空差异性均较小,NO-3-N(硝酸盐氮)和TN(总氮)年内时间差异性较大,空间差异性较小,整体上均呈FB>KB.KB与FB内NO-2-N最大值分别为0.0485 mg·L-1(6月)和0.0532 mg·L-1(6月),NO-3-N(硝酸盐氮)最大值分别为0.635 mg·L-1(11月)和0.623 mg·L-1(4月),TN最大值分别为2.295 mg·L-1(11月)和2.261 mg·L-1(1月).PO3-4和DTP(溶解性总磷)含量基本呈KB>FB,两形态磷在KB内的最大值分别为0.174 mg·L-1(11月)和0.055 mg·L-1(11月),FB内最大值分别为0.0298 mg·L-1(6月)和0.0391 mg·L-1(5月);TP(总磷)基本呈KB相似文献   

Experimental investigations on the performance of a new design of foaming agent adding device used for dust control in underground coal mines

In order to overcome the drawbacks of foam technology for controlling mine dust, an original design of foaming agent adding device was introduced, and its performance was investigated experimentally under different working flows and outlet pressures, and compared to the conventional jet adding device. The results show that the new design of the foaming agent adding device has a reasonable cavity negative pressure, does not produce cavitations, and has a lower inlet pressure demand with less pressure loss. Furthermore, it can add foaming agent at 0.5%–1.0% and regulate the proportions at this low ratio range continuously and stably, which significantly reduces the cost of controlling dust with foam. In addition, it decreases electric energy consumption and simplifies the foam system with no need for extra boosters. Besides, its effect on suppressing mine dust was investigated in the field via dust sample collections, and the results show that this new device is as effective at dust suppression as the conventional one. Therefore, it is believed that this study laid an important foundation for the widespread application of foam technology for dust control in underground coal mines.     

Lead adsorption to metal oxides and organic material of freshwater surface coatings determined using a novel selective extraction method

Surface coatings were collected in three lakes and a river in China to study the role of the components of natural surface coatings in controlling Pb adsorption. Chemical reagents, 0.02 mol/l NH2OH HCl+0.01 mol/l HNO3, 0.4 mol/l Na2S2O4 and 10% oxalic acid, were employed to extract one or more components from surface coatings, and then Pb adsorption to extracted and unextracted surface coatings was carried out. The observed Pb adsorption to extracted and Unextracted surface coatings were analyzed using the nonlinear least squares fitting (NLSF) to estimate the relative contribution of components to the total Pb adsorption. The amounts of Pb absorption to components described by estimated gamma(max) ranged from 0.1126 to 0.7291 (mol Pb/mol Mn) for Mn, 0.0528 to 0.1927 (mol Pb/mol Fe) for Fe and 0.0196 to 0.1020 (mol Pb/kg COD) for organic material, respectively. In all waters studied, metal oxides contributed most to Pb adsorption with a lesser role indicated for organic material.     

Kinetics of microwave-enhanced oxidation of phenol by hydrogen peroxide

Aqueous solutions of phenol were oxidized by hydrogen peroxide assisted by microwave (MW) irradiation. A simple kinetic model for the overall degradation of phenol in the presence of excess H₂O₂ is proposed in which the degradation rate of phenol is expressed as a linear function of the concentrations of phenol and H₂O₂. A detailed parametric study showed that the degradation rate of phenol increased with increasing [H₂O₂] until saturation was observed. Phenol degradation followed apparent zero-order kinetics under MW radiation or H₂O₂ oxidation. However, after 90 min of irradiation, the observed kinetics shifted to pseudo first order. The overall reaction rates were significantly enhanced in the combined MW/H₂O₂ system, mainly because microwave could accelerate H₂O₂ to generate hydroxyl radical (·OH) and other reactive oxygen intermediates. The observed synergetic effects of the MW/H₂O₂ process resulted in an increased in the net reaction rate by a factor of 5.75. When hydrogen peroxide is present in a large stoichiometric excess, the time required to achieve complete mineralization is reduced significantly.     

纳米级Pd/Fe@SiO2复合颗粒对2,4-DCP的还原脱氯研究

为有效抑制纳米级Pd/Fe颗粒的团聚和钝化及改善其表面特性,将纳米SiO_2包覆在Pd/Fe颗粒表面,超声波辐照下液相还原法制备纳米级Pd/Fe@SiO_2复合颗粒,采用TEM、SEM、XRD、EDX及BET表征其物性,以2,4-二氯苯酚(2,4-DCP)为目标污染物,探究其对2,4-DCP的还原脱氯影响因素、降解机理和动力学,结果表明:制备的纳米级颗粒粒径均匀、分散性好,比表面积大;体系中纳米级Pd/Fe投加量、钯化率、TEOS投加量、反应温度及溶液初始pH均会对2,4-DCP的降解效果产生明显影响;并推测出纳米级Pd/Fe@SiO_2复合颗粒对2,4-DCP的降解机理即快速吸附—逐步脱氯—最终脱附释放,其降解符合拟一级动力学关系.     

西安市夏末秋初PM_(2.5)中碳组分分析

2012年9月1日至30日利用大气气溶胶OC/EC在线分析仪在线分析了西安PM2.5中的OC、EC,并结合O3和紫外辐射数据(UV)进行了分析。结果表明:PM2.5、OC、EC、及O3的日均值分别为85.22,19.50,7.18,56.69μg/m3。PM2.5及其中OC、EC的日变化规律呈现"双峰"分布,OC、EC的日波动范围较PM2.5小,且OC的波动范围较EC大,OC、EC的相关性较高(R2=0.73)。PM2.5中TCA的平均比重为47.85%,是PM2.5的主要成分之一,TCA以OM为主,OM中SOC的平均比重高达54.76%,PM2.5中SOC的平均比重为21.25%,SOC和O3的相关性较高,表明研究期间西安市有机物光化学反应较重。1 d中10:00至19:00是PM2.5中SOC比重最高的时段且呈上升趋势,而PM2.5中TCA的变化规律则呈"W"型双峰分布。     

湿地水环境中采集的生物膜吸附铅和镉的特性

利用向海自然保护区湿地水环境中直接采集的生物膜进行了铅、镉的吸附实验发现,Freundlich和Langmuir方程均可描述生物膜吸附铅、镉的热力学过程.在所研究的浓度范围内,生物膜吸附铅的能力(1.55～8.25μmol/g)大于吸附镉(0.66～3.03μmol/g)的能力,而且随着生物膜浓度的增加,生物膜吸附铅、镉的最大吸附量呈下降趋势,并具有显著的相关性(n=5,p=0.10,0.05).     

页岩气油基钻屑脱油灰渣资源化利用进展

针对页岩气开发过程中产生的油基钻屑在堆放、运输和处理过程中均有可能对环境造成危害的问题,研究油基钻屑脱油灰渣的处置和资源化利用现状。在实际应用中,各种资源化利用技术由于政策、环保标准、经济性等原因,除水泥窑协同处置技术外,很多技术还不能大量推广应用。文章通过系统调研,阐述了各项技术的原理、优缺点及资源化利用所面临的政策障碍、实际应用及二次污染等问题,指出了资源化利用技术在开发过程中需要加强过程污染控制、开展相关政策和标准制定、提高产品高附加值等方面研究。     

Design a flower-like magnetic graphite carbon microsphere for enhanced adsorption of 2,4-dichlorophenol

Environmental Science and Pollution Research - 2,4-Dichlorophenol (2,4-DCP) is a hazardous chlorinated organic chemical, so its removal is an important task to protect the whole ecosystem and human...