石墨烯类材料在水处理和地下水修复中的应用

作为一种性质优异的吸附材料,石墨烯类材料对有机物和重金属等多种水污染物均有出色的吸附能力,因此其在水处理和地下水修复工作中的应用前景在近几年备受关注.当前的研究总体上尚停留在实验室模拟阶段,在提高材料饱和吸附量的同时,研制出低成本、稳定性强、易于再生利用且环境友好的石墨烯类材料是今后的发展趋势.本文对石墨烯类材料的种类及制备方法进行了归纳总结,对他们在水处理和地下水修复中的应用研究情况进行了综述,对当前研究中存在的问题进行了分析,最后对未来的研究和应用前景进行了总结和展望.     

基于NSBM-Malmquist模型的中国海洋绿色经济效率时空格局演变分析

在海洋强国和生态文明建设双重背景下,海洋经济绿色发展问题受到广泛关注。为明晰中国沿海地区海洋绿色经济效率的时空格局,文章应用NSBM-Malmquist模型评估海洋经济在绿色经济效率的效率值,然后运用空间计量分布图等方法,分别从一维和二维视角分析中国沿海地区海洋绿色经济效率的时空演变趋势。研究发现,我国海洋绿色经济效率的提高主要得益于海洋环境治理效率的提高;海洋经济绿色效率增长幅度受限,海洋经济技术进步指数都出现了不同程度的技术倒退现象;海洋绿色经济效率呈现出以"高中低效率增长更迭变化、中高增长区域占主导、由北向南逐步升高"为特征的时空分布格局。     

硫化氢捕消剂的应用试验研究

针对硫化氢气体的特点,研制了在泄漏事故中用于清除硫化氢气体的硫化氢捕消剂;开展了密闭空间和开放空间硫化氢清除应用试验,结果表明,硫化氢捕消剂能够有效地清除泄漏在空气中的硫化氢气体。     

基于DED模型的挥发性有机物健康风险评价

为评估DED（Dual Equilibrium Desorption,双元平衡解吸）模型用于预测实际场地VOCs呼吸暴露健康风险的适用性,以邯郸某化工搬迁场地中危化品存储车间场地为案例,采用DED模型分别计算了二氯甲烷和苯在埋深1.5m（浅层）和3.5m（深层）处的呼吸暴露健康风险,并与基于相应深度实测土壤气中污染物浓度及采用传统J & E（Johnson and Ettinger）模型预测的呼吸暴露健康风险进行了比较验证.结果表明:①采用DED模型预测的二氯甲烷健康风险均未超过10-6,在某些点位及深度（2号点浅层、6号点浅层及深层、5号点深层）苯的健康风险超过了10-6. ②基于实测土壤气中污染物浓度计算的健康风险显示,二氯甲烷健康风险均未超过10-6,在某些点位及深度（4号和6号点浅层和深层及2号点深层）苯的健康风险超过了10-6. ③采用J & E模型预测的二氯甲烷和苯的健康风险均超过10-6. ④对比发现,对于二氯甲烷DED模型预测的风险结果与基于土壤气实测污染物浓度预测的结果总体无明显差异,但苯在部分点位前者预测结果低于后者.研究显示,DED模型基本上能适用于预测实际场地VOCs呼吸暴露健康风险,但在某些点位可能会低估实际风险,建议具体使用过程中进一步采集场地数据进行验证,而J & E模型的预测结果均过于保守;同时,对DED模型各参数进行敏感性分析发现,土壤中土壤气体积含量、污染物浓度和有机碳含量对风险结果影响相对明显,土壤容重则几乎没有影响.      

抚仙湖硅藻群落的时空变化特征及其与水环境的关系

抚仙湖是我国重要的深水型淡水湖泊且水体水质总体处于I类水平,近年来在流域开发、全球变暖等影响下其生态环境功能呈现退化的趋势,需要对湖泊生物的群落组成、分布模式及其驱动因子进行系统评价.本研究于2015年选取抚仙湖的南、中、北湖区共3个采样点开展了表层水体硅藻群落和水环境特征的逐月分析.样品中共发现硅藻31个属、166个种且以浮游类型为主,其中云南特有硅藻种Cyclotella rhomboideo-elliptica基本消失.硅藻群落结构的逐月变化在3个采样点中均呈现明显的季节演替特征,其中1、2月优势种主要为Fragilaria crotonensis,3月优势种为Aulacoseira granulata,4月C.ocellata与F.crotonensis同为优势种,而在其余月硅藻群落结构较为单一且优势物种皆为C.ocellata(相对丰度占~80%).而空间尺度上,硅藻优势属种分布和群落结构具有较高的一致性.主成分分析显示,不同湖区的硅藻群落结构组成和水体环境在时间尺度上存在较大差异,而在空间尺度上差异较小;冗余分析和变差分解等分析结果进一步表明,影响群落结构时空变化的主要驱动因子是气象与物理因子(包括水温、风速和透明度),共解释了硅藻群落变率的27.6%,表明了该深水湖泊水体热力分层的厚度与持续时间是影响硅藻群落构建的重要过程.同时,湖泊营养水平与水体离子浓度也对硅藻群落结构产生了明显影响,分别解释了硅藻群落变率的21.2%和9.4%.因此,持续的区域变暖和流域开发明显影响了抚仙湖的生物群落构建与生态系统健康,对抚仙湖的生态保护不仅需要控制营养盐等流域污染物的输入,同时应该积极应对气候变化的长期影响.     

磁性MZF@SiO2对水中Pb(Ⅱ)的吸附

为提高吸附剂固液分离性能,以锰锌铁氧体Mn_(0.6)Zn_(0.4)Fe_2O_4为磁核,利用正硅酸乙酯水解制备了核壳结构磁性吸附剂Mn_(0.6)Zn_(0.4)Fe_2O_4@SiO_2(MZF@SiO_2),以水中重金属Pb(Ⅱ)作为探针分子,研究了其吸附动力学、吸附等温线及吸附热力学,并通过Zeta电位、FT-IR红外光谱及X射线光电子能谱,对吸附机理进行了研究.结果表明,吸附动力学数据符合准二级动力学模型,Freundlich方程能更好地描述吸附等温行为;MZF@SiO_2对Pb(Ⅱ)的吸附为自发吸热过程,MZF@SiO_2对Pb(Ⅱ)的吸附机理为静电作用、阳离子交换和配位作用.MZF@SiO_2可采用0.01 mol·L-1硝酸进行再生.     

Effects of chlortetracycline, Cu and their combination on the performance and microbial community dynamics in swine manure anaerobic digestion

Swine manure was typical for the combined pollution of heavy metals and antibiotics. The effects of widely used veterinary antibiotic chlortetracycline(CTC), Cu and their combination on swine manure anaerobic digestion performance and microbial community have never been investigated. Thus, four 2 L anaerobic digestion reactors were established including reactor A(control), B(CTC spiked by 0.5 g/kg dry weight, dw), C(Cu spiked by 5 g/kg dw) and D(combination of CTC, 0.5 g/kg dw, and Cu, 5 g/kg dw), and dynamics of bacterial and archaeal community structure was investigated using high throughput sequencing method. Results showed that addition of CTC and Cu separately could increase the total biogas production by21.6% and 15.8%, respectively, while combination of CTC and Cu severely inhibited anaerobic digestion(by 30.3%). Furthermore, corresponding to different stages and reactors, four kinds of microbes including bacteria and archaea were described in detail, and the effects of CTC, Cu and their combination mainly occurred at hydrolysis and acidification phases. The addition of Cu alone changed the dynamics of archaeal community significantly. It was genus Methanomassiliicoccus that dominated at the active methane production for A, B and D, while it was genus Methanobrevibacter and Methanoculleus for C.     

Characterizing the antibiotic resistance genes in a river catchment: Influence of anthropogenic activities

Previous studies on environmental antibiotics resistance genes(ARGs) have focused on the pollution sources such as wastewater treatment plants, aquaculture and livestock farms,etc. Few of them had addressed this issue in a regional scale such as river catchment. Hence,the occurrence and abundances of 23 ARGs were investigated in surface water samples collected from 38 sites which located from the river source to estuary of the Beijiang River.Among them, 11 ARGs were frequently detected in this region and 5 ARGs(sul I, sul II, tet B,tet C, and tet W) were selected for their distribution pattern analysis. The abundances of the selected ARGs were higher in the upstream(8.70 × 10~6 copies/ng DNA) and downstream areas(3.17 × 10~6 copies/ng DNA) than those in the midstream areas(1.23 × 10~6 copies/ng DNA), which was positively correlated to the population density and number of pollution sources. Pollution sources of ARGs along the Beijiang River not only had a great impact on the abundances and diversity, but also on the distribution of specific ARGs in the water samples. Both sul I and sul II were likely originated from aquaculture farms and animal farms,tet W gene was possibly associated with the mining/metal melting industry and the electric waste disposal and tet C gene was commonly found in the area with multiple pollution sources.However, the abundance of tet B was not particularly related to anthropogenic impacts. These findings highlight the influence of pollution sources and density of population on the distribution and dissemination of ARGs at a regional scale.     

安全与危险纠缠理论创建及其研究

针对安全概念不统一,安全科学与技术发展相对滞后,重特大安全事故频发等问题,通过借鉴量子纠缠理论,提出了安全与危险纠缠理论学说。建立了安全与危险纠缠理论模型,阐述了其纠缠机制,明确了一个系统中的安全与危险在不同时段内存在的方式和状态:通常人们所认知的安全或危险均是系统在过去时段内以“一显一隐”的方式塌缩成确定的状态,而在现在与未来时段,它们分别是以“显性”、“隐性”的方式纠缠为不确定的状态;若该系统的“安全与危险纠缠”状态向安全方向塌缩时,系统则表现为安全,若向危险转化时,则系统表现为事故。同时,分析了“安全与危险纠缠”理论建立的对安全科学及安全生产实际意义与理论价值,及其未来展望和存在问题。     

Comparison of surface water chemistry and weathering effects of two lake basins in the Changtang Nature Reserve, China

The geochemistry of natural waters in the Changtang Nature Reserve,northern Tibet,can help us understand the geology of catchments,and provide additional insight in surface processes that influence water chemistry such as rock weathering on the Qinghai–Tibet Plateau.However,severe natural conditions are responsible for a lack of scientific data for this area.This study represents the first investigation of the chemical composition of surface waters and weathering effects in two lake basins in the reserve(Lake Dogaicoring Qiangco and Lake Longwei Co).The results indicate that total dissolved solids(TDS)in the two lakes are significantly higher than in other gauged lakes on the Qinghai–Tibet Plateau,reaching 20–40 g/L,and that TDS of the tectonic lake(Lake Dogaicoring Qiangco)is significantly higher than that of the barrier lake(Lake Longwei Co).Na+and Cl-are the dominant ions in the lake waters as well as in the glacier-fed lake inflows,with chemical compositions mainly affected by halite weathering.In contrast,ion contents of inflowing rivers fed by nearby runoff are lower and concentrations of dominant ions are not significant.Evaporite,silicate,and carbonate weathering has relatively equal effects on these rivers.Due to their limited scope,small streams near the lakes are less affected by carbonate than by silicate weathering.