Distribution,bioavailability, and potential ecological risk of Cu,Pb, and Zn in soil in a potential groundwater source area

In this study, we examined three horizontal and vertical soil profiles along a sewage drainage ditch in order to determine the spatial distribution of Cu, Pb, and Zn in soils and to assess the bioavailability and potential ecological risks associated with these metals in a potential groundwater source area. Results showed that the concentrations of Cu, Pb, and Zn were approximately at background level, suggesting that human activities (industrial and agricultural pollution) had a negligible influence on these metals in soil, and that the concentrations reflected the natural background levels in the study area. Cu, Pb, and Zn concentrations were slightly higher in topsoil (0–20 cm) than deeper in the soil profile. Using a modified BCR sequential extraction method to evaluate the mobility and bioavailability of metals showed that the potential bioavailability sequence of Cu, Pb, and Zn at three depths in the soil profile was in the order Cu?≈?Pb?<?Zn. The potential ecological risk from the metals was evaluated using risk assessment code, and the results suggest that Cu and Zn pose no or low risk, while there is a low or medium risk from Pb. Results from groundwater monitoring showed that the groundwater was not polluted by leaching from soil.     

便携式重金属测定仪在龙江河镉离子污染事件应急监测中的应用研究

PDV6000plus便携式重金属测定仪具有体积小、精度高、操作简便等特点,能够快速完成样品分析,为环境管理部门在突发环境污染事件中及时掌握污染变化趋势,作出科学决策提供技术支持。本文通过介绍便携式重金属测定仪在广西龙江河镉离子污染事件应急监测中的具体应用,以期为今后在应急监测中更好地发挥作用提供参考。     

总有机碳分析仪测定水中的游离二氧化碳

利用总有机碳分析仪、结合酸化吹气装置对水样中的游离二氧化碳的测定条件进行试验。结果表明水浴温度80℃,流量150 ml/min通氮气30 min为水样释放游离二氧化碳的最佳条件。总有机碳分析测定水中游离二氧化碳含量方法的建立为水质分析提供了新的方法参考。     

苯酚羟化酶基因工程菌转化4-乙烯基苯酚特性研究

4-乙烯基苯酚广泛用作食品的调味剂及聚4-乙烯基苯酚类聚合物等的合成。近年来,研究发现4-乙烯基苯酚是苯乙烯在小鼠和人体中的次要代谢物,具有肝毒性和呼吸毒性。因此,利用生物定向转化技术降低4-乙烯基苯酚的毒性将具有实际意义。文章考察了含苯酚羟化酶基因的工程菌PH_IND生物转化4-乙烯基苯酚的条件,确定其最优条件为:菌株PH_IND的OD600为2.5,4-乙烯基苯酚的浓度为1 mmol/L,葡萄糖浓度为20 mmol/L,缓冲溶液的pH为8。在该条件下,生物转化呈一级动力学趋势,反应180 min后,转化率为31%。分子对接结果表明,4-乙烯基苯酚可以和苯酚羟化酶大亚基的活性位点结合,液相色谱-质谱联用分析结果表明4-乙烯基苯酚被转化为4-乙烯基儿茶酚。     

草原区煤炭开发的生态问题及其税费改革对策

锡林郭勒盟是我国重要的煤炭能源基地,近年来,煤电一体化开发为地区带来经济效益的同时也给环境带来巨大压力,大面积的草原受到破坏和威胁,引发了一系列生态问题,需要在锡盟未来的地区经济发展中引起注意。应该借鉴国际上对煤炭业开征环境保护税的经验,进行我国草原区煤炭业环境保护税费改革的制度设计和政策落实。     

Effects of penconazole enantiomers exposure on hormonal disruption in zebrafish Danio rerio (Hamilton, 1822)

Environmental Science and Pollution Research - PEN is a widely used triazole fungicide, usually used to control grape white rot. In the process of agricultural use, PEN will be scattered to the...     

不同污染区巨菌草生物炭内源污染物分布及其生物毒性

由于生物质原料来源广泛,缺乏生物炭内源污染物及其用量限制标准,极有可能将含有高内源污染物的生物炭用于环境修复,产生潜在的环境风险.采用清洁区、中度和重度污染区的巨菌草为原料制备生物炭,考察其内源铜（Cu）和镉（Cd）全量及其酸溶态含量和持久性自由基（PFRs）分布,并研究生物炭浸出液对小麦根伸长抑制率和抗氧化酶活性的影响.结果表明,重度污染区九牛生物炭Cu和中度污染区水泉生物炭中Cd含量分别是清洁区红壤生物炭Cu和Cd的3.73倍和4.43倍,九牛生物炭中酸溶态Cu含量分别是水泉和红壤生物炭的3.32倍和2.84倍,水泉和九牛生物炭中酸溶态Cd含量分别是红壤生物炭的7.95倍和5.11倍.3种生物炭中均含有相邻氧原子以碳为中心的PFRs,表现为：红壤>九牛>水泉.3种生物炭浸出液对小麦根伸长均表现为抑制作用,但均不同程度地提高了小麦幼苗超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）活性,其中九牛生物炭浸出液对小麦根伸长抑制率最高,达到27.7%.本研究表明,生物炭中内源重金属及PFRs等污染物的共同作用对小麦幼苗产生了显著的生物毒性,后期的研究需关注生物炭内源污染物的潜在环境风险,避免产生二次污染等环境问题.     

航空发动机成附件橡胶件的“积木式”试验设计

在飞机结构"积木式"试验的基础上,提出了针对航空发动机成附件橡胶件元件级、模拟件级、工装级和系统级试样的四级"积木式"试验.明确了各级试验的试验对象、主要任务、试验目的和基本试验思路.提出了在系统级试验的开展中,保证橡胶件的结构状态、安装状态与实际工作情况一致的方法,以及"工况谱"编制的主要内容.将"积木式"试验流程应用到橡胶材料中,为新型航空发动机成附件橡胶件的设计研制提供帮助.     

某地加油站土壤地下水现状调查与分析

通过对某地10个加油站所在场地土壤及地下水现场采样、实验室检测,分析加油站对土壤与地下水污染原因,结合国家政策法规以及加油站土壤地下水调查现状,针对加油站污染状况提出加强加油站土壤及地下水污染隐患排查力度、强化加油站土壤地下水方面日常管理、污染加油站风险管控及修复工作、加快推进防渗池及双层罐等设施改造工作等建议。     

Elemental mercury (Hg0) removal from coal syngas using magnetic tea-biochar: Experimental and theoretical insights

Mercury is ranked 3^rd as a global pollutant because of its long persistence in the environment. Approximately 65% of its anthropogenic emission (Hg⁰) to the atmosphere is from coal-thermal power plants. Thus, the Hg⁰ emission control from coal-thermal power plants is inevitable. Therefore, multiple sorbent materials were synthesized using a one-step pyrolysis method to capture the Hg⁰ from simulated coal syngas. Results showed, the Hg⁰ removal performance of the sorbents increased by the citric acid/ultrasonic application. T5CUF_0.3 demonstrated the highest Hg⁰ capturing performance with an adsorption capacity of 106.81 µg/g within 60 min at 200 °C under complex simulated syngas mixture (20% CO, 20% H₂, 10 ppmV HCl, 6% H₂O, and 400 ppmV H₂S). The Hg⁰ removal mechanism was proposed, revealing that the chemisorption governs the Hg⁰ removal process. Besides, the active Hg⁰ removal performance is attributed to the high dispersion of valence Fe₃O₄ and lattice oxygen (α) contents over the T5CUF_0.3 surface. In addition, the temperature programmed desorption (TPD) and XPS analysis confirmed that H₂S/HCl gases generate active sites over the sorbent surface, facilitating high Hg⁰ adsorption from syngas. This work represented a facile and practical pathway for utilizing cheap and eco-friendly tea waste to control the Hg⁰ emission.