响应面法优化胡敏素对Cu2+的吸附及机理研究

采用Box-Behnken响应面优化实验设计对胡敏素吸附去除水中Cu~(2+)的过程进行了优化,设定吸附时间、吸附剂用量、pH、温度和Cu~(2+)初始浓度为5个影响因素,Cu~(2+)吸附率为响应值,建立了吸附率与上述因素之间的二次多项式模型,确定最佳吸附条件,对吸附过程的等温模型及吸附机理进行了研究.响应面分析表明,吸附剂用量、pH和Cu~(2+)初始浓度是显著因素.胡敏素对Cu~(2+)吸附的最佳条件为:吸附时间110 min、吸附剂用量2.4 g·L~(-1)、pH=5.4、温度25.0℃、Cu~(2+)初始浓度208 mg·L~(-1).在该条件下,测得胡敏素对Cu~(2+)的吸附率可达到80.78%,吸附符合Langmuir等温线方程.胡敏素表面疏松多孔,有利于其通过物理吸附方式吸附Cu~(2+),同时,胡敏素表面的羟基、羧基和羰基等活性基团可以与Cu~(2+)发生配位络合作用,Na+、Ca~(2+)、Mg~(2+)等与Cu~(2+)发生离子交换作用,从而发生化学吸附.研究结果表明,胡敏素作为一种绿色、高效、廉价的吸附剂,可应用于Cu~(2+)污染废水的治理.     

污染土壤淋洗修复技术研究进展

本文介绍了淋洗修复技术和淋洗装置在污染土壤修复技术中的应用,对有机物、重金属及放射性核素污染土壤淋洗修复技术的应用现状进行了总结和评价,还探讨了淋洗修复技术的发展方向及其应用前景。     

盐城经济技术开发区污水处理厂提标改造工程设计研究

介绍了盐城经济技术开发区污水厂提标改造工程技术路线及方案.针对污水厂进水中工业废水含量较多的特点,增设水解酸化工艺段,将现状CAST池改造为AAO生物反应池,新建二沉池及混凝沉淀设施,使出水水质稳定达到《城镇污水处理厂污染物排放标准》(GB 18918-2002)中的一级A排放标准.同时增设污泥深度脱水设施,采用化学调理+板框压滤工艺.实际运行表明,经改造后的污水处理厂对各项污染物均取得了较好的去除效果,脱水后污泥的含水率可稳定控制在60%以下.     

罐采样与气相色谱/质谱结合在VOCs监测中的应用

气态挥发性有机物(VOCs)引起的污染严重威胁人们的健康,因而对其监测技术的研究也越来越多。其中罐采样与气相色谱/质谱联用的检测技术在VOCs气态污染物测定中的应用逐步受到关注。对罐采样技术进行了综述,重点介绍了罐采样与气相色谱/质谱联用技术在环境空气、室内空气、废气中VOCs检测的应用。     

近40年湖南冰雹时空分布和变化特征及机理分析

利用湖南省1967～2006年近四十年冰雹日数资料,分析了湖南冰雹时空分布特征,着重讨论了湖南冰雹日数年代、年、季、月、旬、日际变化、地域分布特征及湖南前后二十年冰雹的变化趋势。研究表明：湖南冰雹是典型的春雹区,春季冰雹日数占全年冰雹日数的74．9％;存在2年和4．8年的周期;日变化十分明显,多出现在午后到傍晚;地理分布呈西多东少,高山多于平原,洞庭湖北侧多于南侧的特点;近二十年冰雹呈减少趋势,多雹区更集中,主要出现在湘西北和湘东南。     

浅析化工园区大气特征因子自动监测综合分析

从总体状况评价、浓度变化特征、疑似源探寻等角度初步分析了某化工园区大气特征因子自动监测数据。分析表明,合理选用不同水平的数据集可以突出大气特征因子的规律性,尤其是疑似源探寻;采用现场检查等手段与自动监测的相互校核十分必要,特别是便携式气相色谱质谱仪对特征因子自动监测系统“假阳性”识别。     

芳香酸稀溶液的络合萃取研究

络合萃取法分离极性有机物稀溶液具有高效性和高选择性。本文利用三辛胺或磷酸三丁酯为络合剂,四氯化碳、三氯甲烷、正辛醇或煤油为稀释剂,实验测定了苯甲酸、邻硝基苯甲酸稀溶液的萃取相平衡分配系数,讨论了影响因素。     

湿法烟气脱硫废水处理技术探讨

分析了火电厂湿法烟气脱硫装置排水的主要成分、水质特点，叙述了烟气湿法脱硫废水国内外的处理方法和工艺流程。结合笔者实践，提出了一种改进的处理方法，为湿法脱硫废水处理提供了一种有效的途径。     

Fraction characteristics of rare earth elements in the surface sediment of Bohai Bay, North China

Surface sediment samples were collected at 27 stations of Bohai Bay, North China. Sequential extractions were carried out in this study. REE were leached out from four labile fractions: Exchangeable (L1), bound to carbonates (L2), bound to Fe–Mn oxides (L3), bound to organic matter (L4), and the remainder was residual (R5). The total contents of REE fluctuate slightly in Bohai Bay, and are mainly concentrated in the middle region, showing relatively higher levels in the north than that in the south of Bohai Bay. Percentages of L1, L2, L3, L4, and R5 for REE suggest that the residual fraction accounts for the major component of REE, whereas Fe–Mn oxides also play important roles in combining labile REE. As the REE complex is not stabilized, the competition of complex could induce dissociation of the complex and redistribution of the REE in various environments. According to REE patterns and Y/Ho ratios of samples, REE are not anthropogenic or oceanic sources but riverine input, whereas suitable environment varieties can slightly affect the patterns and fractionations of REE. As powerful tracers for the variable of environment, higher anomaly of Eu and Ce in southern regions indicates a greater reduction in the condition of surface sediment in the south than that in the north of Bohai Bay.     

Seasonal variations of monocarbonyl and dicarbonyl in urban and sub-urban sites of Xi’an,China

Seventeen airborne carbonyls including monocarbonyls and dicarbonyls were determined in urban and sub-urban sites of Xi’an, China in three seasons in 2010. In winter, acetone was the most abundant carbonyl in the urban site due to usage of organic solvents in constructions and laboratories and its slower atmospheric removal mechanisms by photolysis and reaction with hydroxyl radical than those of formaldehyde and acetaldehyde. In the sub-urban site, acetaldehyde was the most abundant carbonyl, followed by formaldehyde and acetone. During summer, however, formaldehyde was the most dominant carbonyl in both sites. The photooxidations of a wide range of volatile organic compounds (VOCs) yielded much more formaldehyde than other carbonyls under high solar radiation and temperature. In the urban site, the average concentrations of dicarbonyls (i.e., glyoxal and methyglyoxal) in spring and summer were higher than that in winter. Transformation of aromatic VOCs emitted from fuel evaporation leads to the formation of 1,2-dicarbonyls. A reverse trend was observed in sub-urban sites, as explained by the relatively low abundances and accumulations of VOC precursors in the rural atmosphere during warm seasons. Moreover, cumulative cancer risk based on measured outdoor carbonyls (formaldehyde and acetaldehyde) in Xi’an Jiaotong University and Heihe was estimated (8.82?×?10^?5 and 4.96?×?10^?5, respectively). This study provides a clear map on the abundances of carbonyls and their source interpretation in the largest and the most economic city in Northwestern China.