Adsorption characteristics of Cu(II) from aqueous solution onto biochar derived from swine manure

The purpose of this study was to investigate adsorption characteristic of swine manure biochars pyrolyzed at 400 °C and 700 °C for the removal of Cu(II) ions from aqueous solutions. The biochars were characterized using BET surface area, Fourier transform infrared spectroscopy (FTIR), zeta potential, scanning electron microscopy/energy dispersive spectrometer (SEM–EDS), and X-ray diffraction (XRD). The adsorption of Cu(II) ions by batch method was carried out and the optimum conditions were investigated. The adsorption processes of these biochars are well described by a pseudo-second-order kinetic model, and the adsorption isotherm closely fitted the Sips model. Thermodynamic analysis suggested that the adsorption was endothermic. The maximum Cu(II) adsorption capacities of biochars derived from fresh and composted swine manure at 400 °C were 17.71 and 21.94 mg g^?1, respectively, which were higher than those at 700 °C. XRD patterns indicated that the silicate and phosphate particles within the biochars served as adsorption sites for Cu(II). The removal of Cu(II) ions from industrial effluent indicated that the fresh swine manure biochar pyrolyzed at 400 °C can be considered as an effective adsorbent.     

生物过滤技术在恶臭污染治理中的应用研究

利用生物技术治理恶臭污染是一项有效经济的环境友好技术,生物技术目前正成为一种处理各种废气的有效的选择.研究了生物过滤技术在不同恶臭环境中的应用效果,分析了应用过程中出现的一些问题,介绍了生物过滤技术治理恶臭气体的原理和过程.研究结果表明,生物过滤设备在生活污水厂和垃圾压缩站具有理想的恶臭净化效果,但不能满足挥发性有机废气的净化需求,仍然需要工艺的改进和完善.     

Spatial Dynamics of Soil Moisture in a Complex Terrain in the Semi‐Arid Loess Plateau Region,China1

Abstract: Soil moisture is an important hydrological variable in reforestation practices in a water‐limited region of the Loess Plateau of northwestern China. The objective of this study was to quantify the spatial dynamics of soil moisture on a complex terrain. During 2004‐2006, a total of 313 sample points in two kinds of grid (2 × 2 m and 20 × 20 m) were arranged for soil moisture measurements (two soil layers: 0‐30 and 30‐60 cm) with Time Domain Reflectometry. The geostatistical properties of soil moisture patterns, the variance and correlation structure of the soil moisture, and the effects of terrain factors on soil moisture were analyzed. The results suggested that our sampling grid captured the spatial variability of soil moisture distributions for this complex terrain. Principal Component Analysis and Cluster Analysis statistics showed that soil moisture decreased as slope gradient increased; that sunny aspects (112.5°‐292.5°) had relatively lower soil moisture than did shady aspects (292.5°‐112.5°); that soil moisture was lowest in the SWW direction and highest in the NWN direction; and that hillslope aspect was the main factor affecting soil moisture in the 0‐ to 30‐cm soil layer, whereas the main factor for the 30‐ to 60‐cm layer was slope gradient. It was found that the relative values of soil moisture for steep slopes (>36%) with shady aspect (292.5°‐112.5°), gentle slopes (<36%) with sunny aspect (112.5°‐292.5°), and steep slopes with sunny aspect were 99, 82, and 80, respectively – assuming a soil moisture value of 100 for gentle slopes with shady aspect. The results of this study are expected to be relevant to and useful for reforestation planning and design, parameterization of distributed hydrology models, and land productivity assessment in the study region.     

Hyperaccumulation of Pb, Zn and Cd in herbaceous grown on lead-zinc mining area in Yunnan, China

A field survey of herbaceous growing on lead-zinc mining area in Yunnan, China were conducted to identify species accumulating exceptionally large concentrations of Pb, Zn and Cd in shoots. In total, 220 plant samples of 129 species of 50 families and 220 soil samples in which the plants were growing were collected. According to accumulation concentration in plant shoots and the concentration time levels compared to plants from non-polluted environments, 21 plant samples of 16 species were chosen as best-performing specimens, 11 plant samples of 10 species for Pb, 5 plant samples of 4 species for Zn and 5 plant samples of 5 species for Cd. Sonchus asper (L.) Hill in Qilinkeng had hyperaccumulation capacity to Pb and Zn. Corydalis pterygopetala Franch in Paomaping had hyperaccumulation capacity to Zn and Cd. All 5 Cd hyperaccumulators came from Lanping lead-zinc mining area. Out of 11 Pb hyperaccumulators, 7 came from Minbingying of Huice lead-zinc mining area. The average of the concentration time levels compared to plants from non-polluted environments were higher than 10 times in all plant samples, the concentration time levels changed from 203 times to 620 times for Pb, from 50 times to 70 times for Zn and from 145 times to 330 times for Cd. Out of 21 plant samples, translocation factor changed from 0.35 to 1.90, only translocation factor of 7 plant samples were higher than 1. Enrichment coefficients of all samples were lower than 1. These plant species were primarily heavy metal hyperaccumulator, and will be used in phytoremediation of the metallic pollutants in soils after further research in accumulation mechanism.     

海水管道系统大型污损生物特点与防除对策

海水管道系统内的生物污损现象会造成严重的经济损失,其中大型海洋生物主要为贻贝、无柄蔓足类、管栖多毛类和水螅,优势种是紫贻贝及翡翠贻贝.目前管道污损生物防除主要有热处理、电解海水和添加水处理药剂等方法.为满足环保要求,应注重新型多功能绿色环保防污剂的研究与开发和多种技术的协同作用,加强管道内污损生物原位调查,弄清主要种类特点及其幼虫附着机理.     

我国调整环境监测站业务费预算标准的建议

提出一种基于工作任务量增长倍数、人员增长率、监测方法和工作效率增长率等参数的环境监测业务费成本核算公式,并将公式模拟结果与2012年江苏省13个省辖市环境监测中心站(二级站)全年实际业务费进行比较,为制定适应当前经济社会发展水平的环境监测站业务费年度预算标准提供技术参考。     

济南市冬季一次典型重污染过程分析

为掌握济南市重污染天气发生规律,从而更好地为重污染天气预报预警和大气污染防治提供参考,采用空气质量监测数据、气象观测资料、雷达探测资料及轨迹模式模拟相结合的方法,对济南市2016年12月31日-2017年1月7日的持续性重污染过程,从污染演变过程、环流背景分析、气象要素特征和区域污染传输等多方面分析其形成原因及主要影响因素.结果表明:此次重污染过程期间首要污染物为颗粒物,ρ（PM₁₀）平均值为318 μg/m3,ρ（PM_2.5）平均值为200 μg/m3;地面风速在0.6~1.8 m/s范围内,风力均为1~2级,相对湿度为68%~95%,平均相对湿度为81%.在重污染过程中,从地面至800 m左右高度始终维持较强逆温层,逆温频次高达91.1%,污染边界层高度较低,大部分时间都在500 m以下.采用情景模拟分析方法计算得到,区域输送对济南市PM_2.5的贡献率为20%~35%.研究显示:此次重污染过程是在区域性污染背景下由本地不利的扩散条件造成的,静稳大气形势提供有利的环流背景,平流雾、辐射雾交替产生,持续性的高湿加重了污染程度;近地面的静风、高湿,垂直方向的双逆温层甚至多逆温层的结构是影响此次重污染过程的重要气象要素;区域性污染传输对此次重污染天气的发展有显著贡献,污染初期主要来自河北省中南部的输送,随着污染加重,有来自偏南、偏东方向的局地气团输送.      

阳离子表面活性剂改性沸石对铬酸根的吸附机制

研究了由十六烷基三甲基溴化铵(CTAB)改性制成的有机沸石对水体中铬酸根的吸附性能及吸附机制.结果表明,与沸石原矿相比有机沸石对铬酸根的吸附容量更高,而铬酸根在有机沸石表面的吸附量随着体系离子强度的增加而显著减小,说明铬酸根的吸附以静电作用为主.研究还发现沸石经有机改性后表面Zeta电位由负变正,说明表面活性剂在沸石表面的吸附改变了沸石表面的电荷性质,这也是有机沸石能够对铬酸根发生静电吸附的主要原因.铬酸根的吸附量及吸附的铬酸根的解吸量均随着体系pH值的升高而增加,分别约在pH=5.0和pH=6.0时达最大,随后铬酸根的吸附量和解吸量随着pH值的进一步增加逐渐减小.铬酸根的吸附量与解吸量之间的差值随pH升高而减小,说明在低pH条件下非静电吸附所占比例较高pH值条件下有所增加.     

客土覆盖对降低放射性锶在作物中积累的效应

采用模拟污染物的同位素示踪技术研究了客土覆盖对降低大豆和白菜(尤其是作物的可食用部分)中⁸⁹Sr积累的效应.结果表明客土覆盖能有效降低大豆和后茬白菜对⁸⁹Sr的吸收和积累,当客土覆盖深度为9cm时,豆籽、豆壳、豆秸和豆根中⁸⁹Sr比活度分别下降了82.8%、56.4%、38.7%和66.5%,后茬白菜下降了68.8%;作物中吸收积累的⁸⁹Sr比活度随客土覆盖深度的增加而下降,实验数据线性回归分析表明两者间呈显著线性负相     

饮用水源中不同粒径颗粒物吸附抗生素特征研究

天然水体中存在大量的细小颗粒,它们往往与污染物相互作用并成为其载体,在饮用水传统处理工艺中亦不能被很好去除,进而随水厂出水进入人体,对人体健康造成潜在威胁.抗生素在饮用水源中的固、液相分配规律以及不同粒径颗粒对抗生素的吸附能力及影响因素亟待研究.实验利用微波萃取(MAE)和高效液相色谱与质谱联用(HPLC-MS/MS)的方法分别对颗粒物上吸附的抗生素进行了前处理和测定,进而分析了饮用水源颗粒物对4种典型抗生素的吸附特征.连续吸附平衡实验在360 min达到平衡,平衡时抗生素有32%~44%分布在颗粒上;除青霉素外,粒径0.05~1μm小颗粒的吸附量又占颗粒总吸附量的56%~70%.同时p H是影响饮用水源中颗粒吸附抗生素的重要因素,无论对于所有颗粒还是0.05~1μm的小颗粒,其吸附能力的最大值均出现在中性条件(p H=7)下.