中国危险废物管理的历史沿革——从"探索起步"到"全面提升"

如何对危险废物进行有效管理已成为当今世界各国政府环境管理部门共同面临的一个重要问题,也是减少危险废物产生量、降低危险废物危害性的关键.回顾了中国危险废物管理法规、制度和利用处置行业的建立和发展过程,并根据对危险废物的认识过程,将中国危险废物管理分为探索起步阶段、体系构建阶段、能力构筑阶段和全面提升阶段,分析了不同阶段的主要特征和重要事件,阐明了当代危险废物管理模式产生的现实必要性和历史必然性,最后提出了中国建设现代化危险废物管理体系的重要意义.本研究可为我国建立设现代化的危险废物管理体系、提升危险废物监管水平提供参考.     

Intensification,regulation and diversification: The changing face of inland aquaculture in China

Trends in aquatic food consumption were matched against farm production surveys within Hubei province and compared to official production data and statistics. Surveys showed that consumer tastes were changing to a much broader aquatic food menu as their spending power increased. Traditional aquaculture species were becoming less profitable due to reduced profit margins as input costs increased and consumption preferences changed. Consequently, many producers were diversifying their production to meet local demand. Some farmers were also de-intensifying by reducing commercial aquafeed inputs and reverting to more traditional methods of dyke-crop culture to optimise trade-offs between input costs and labour, and manage their risk more effectively. In addition, analysis of local data showed that wholesale changes were occurring to aquaculture production as environmental protection legislation took effect which reduced the growing area for carps considerably.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01503-3.     

甲基丙烯酸树脂吸附微生物降解与演化石油烃特性

为了提高石油污染土壤的生物降解效率,以甲基丙烯酸丁酯制备的树脂为载体吸附石油降解菌进行生物降解,利用GC-MS“指纹图谱”对TPH（total petroleum hydrocarbon,总石油烃）的降解程度及生物演化特性进行分析.结果表明:树脂吸附菌剂后TPH的半衰期为24.23 d,比单纯菌剂降解缩短7.28 d;其中正构烷烃的降解性能表明,高碳数高达92.03%,中、低碳数皆超过75%,高于TPH的56.67%,较好地解释了TPH降解率比单纯菌剂提高的内在原因;在演化特征方面,正构烷烃的生物演化参数——w（∑C₂₁）/w（∑C₂₂₊）（C_21-、C₂₂₊分别指C₁₄~C₂₁和C₂₂~C₃₉）、姥植比〔w（pr）/w（ph）〕和OEP（奇/偶碳数质量比）分别为0.643 3、0.486 5和1.111 9,均高于单纯菌剂演化程度.研究显示,树脂吸附菌剂后对较难降解的偶数碳正构烷烃和类异戊二烯烃类物质的氧化还原能力增强,从生物演化的角度有力地佐证了降解的优势所在.      

Pd/silicalite-1: An highly active catalyst for the oxidative removal of toluene

Catalytic combustion is thought as an efficient and economic pathway to remove volatile organic compounds, and its critical issue is the development of high-performance catalytic materials. In this work, we used the in situ synthesis method to prepare the silicalite-1 (S-1)-supported Pd nanoparticles (NPs). It is found that the as-prepared catalysts displayed a hexagonal prism morphology and a surface area of 390−440 m²/g. The sample (0.28Pd/S-1-H) derived after reduction at 500°C in 10 vol% H₂ showed the best catalytic activity for toluene combustion (T_50% = 180°C and T_90% = 189°C at a space velocity of 40,000 mL/(g·hr), turnover frequency (TOF_Pd) at 160°C = 3.46 × 10⁻³ sec⁻¹, and specific reaction rate at 160°C = 63.8 µmol/(g_Pd·sec)), with the apparent activation energy (41 kJ/mol) obtained over the best-performing 0.28Pd/S-1-H sample being much lower than those (51−70 kJ/mol) obtained over the other samples (0.28Pd/S-1-A derived from calcination at 500°C in air, 0.26Pd/S-1-im derived from the impregnation route, and 0.27Pd/ZSM-5-H prepared after reduction at 500°C in 10 vol% H₂). Furthermore, the 0.28Pd/S-1-H sample possessed good thermal stability and its partial deactivation due to CO₂ or H₂O introduction was reversible, but SO₂ addition resulted in an irreversible deactivation. The possible pathways of toluene oxidation over 0.28Pd/S-1-H was toluene → p-methylbenzoquinone → maleic anhydride, benzoic acid, benzaldehyde → carbon dioxide and water. We conclude that the good dispersion of Pd NPs, high adsorption oxygen species concentration, large toluene adsorption capacity, strong acidity, and more Pd⁰ species were responsible for the good catalytic performance of 0.28Pd/S-1-H.     

Utilization of coal gangue for the production of brick

Journal of Material Cycles and Waste Management - Coal gangue, an industrial solid waste discarded from coal mining and processing, was used as the sole raw material to prepare brick. The coal...     

Kinetics and mechanisms of reactions for hydrated electron with chlorinated benzenes in aqueous solution

The reactions between chlorinated benzenes (CBzs) and hydrated electron (eaq-) were investigated by the electron beam (EB) and laser flash photolysis (LFP) experiments. Under the EB irradiation, the effects of irradiation dose, initial concentration and the number of Cl atoms on the removal efficiencies were further examined. At 10 kGy, the removal efficiencies of mono-CB, 1,3-diCB, 1,2-diCB and 1,4-diCB were 41.2%, 87.2%, 84.0%, and 84.1%, respectively. While irradiation dose was 50 kGy, the removal efficiencies increased to 47.4%, 95.8%, 95.0%, and 95.2%, respectively. Irradiation of CBzs solutions has shown that the higher the initial concentration, the lower the percentage of CBzs removal. In addition to this, the dechlorination efficiencies of 1,2-dichlorobenzene (1,2-diCB), 1,3-dichlorobenzene (1,3-diCB) and 1,4-dichlorobenzene (1,4-diCB) were much higher than that of chlorobenzene (mono-CB). The kinetics of the reactions was achieved with nanosecond LFP. The rate constants of second-order reaction between eaq- with mono-CB, 1,2-diCB, 1,3-diCB and 1,4-diCB were (5.3±0.4) × 10⁸, (4.76±0.1) × 10⁹, (1.01±0.1) × 10¹⁰ and (3.29±0.2) × 10⁹ L·mol^-1·s^-1, respectively. Density functional theory (DFT) calculations were performed to determine the optical properties of unstable CBzs anion radicals, and the main absorption peaks lied in the range of 300–550 nm. The primary reaction pathway of CBzs with eaq- was gradual dechlorination, and the major products were Cl^- and benzene (CBzs(-Cl^-)). Furthermore, biphenyl (or chlorobiphenyl) was observed during the LFP, which was probably formed by recombination of benzene radicals.     

基于SOFM神经网络的京津冀地区水源涵养功能分区

为探讨水源涵养功能空间分异在水资源分区管理方面的应用,以京津冀地区为研究区,根据水源涵养功能的5个主要影响要素——海拔、降水量、蒸散量、土壤饱和含水率、森林覆盖度,构建SOFM(self-organizing feature map,自组织特征映射)神经网络,并对该区水源涵养功能进行区域划分. 结果表明:京津冀地区可划分为6个水源涵养功能区域,分别为冀西北高原-间山盆地草原水源涵养中能力区、坝上高原-冀北山地草原-森林水源涵养中低能力区、燕山-太行山中低山森林-草原水源涵养中高能力区、冀中南部平原农田水源涵养低能力区、燕山-太行山低山森林水源涵养中高能力区和冀东平原农田-草原水源涵养高能力区. 方差分析结果显示,各分区之间具有显著差异,表明用SOFM神经网络对水源涵养功能进行分区效果良好. 在水源涵养功能分区基础上,归纳和总结了各分区水源涵养功能影响要素的主要特征. 京津冀地区作为一个统一的水资源生态环境区,其内部的水源涵养功能存在明显的区域差异,建议依据各分区水源涵养功能的强弱及其主要控制因子特征,科学制订适应当地自然环境的水资源管理方案.      

广州市居民食品砷摄入的健康风险评价

从暴露途径来看,食物是人体砷暴露的主要途径之一。从饮食结构来看,广州市居民膳食主要来源于谷类食品,同时鱼虾类总体平均摄入量约为全国总体平均摄入量的2倍。因此,在分析广州市市场大米和海鲜这2种典型食品中砷含量的基础上对广州市居民食品砷摄入的健康风险进行了评价。分析了广州市场上的26种不同品牌的大米中的总砷含量,其含量范围为0.082～0.171μg·g~(-1),平均浓度为(0.127±0.027)μg·g~(-1),满足绿色食品大米标准(≤0.40μg·g~(-1))。在14种鱼虾蟹贝类海鲜中的砷含量分析基础上,计算得出广州市场上鱼类中总砷的平均含量为0.488μg·g~(-1),虾蟹贝类中总砷的平均含量为3.44μg·g~(-1),相比较国内外,广州市场鱼虾蟹中砷的含量整体处于中间水平。最后综合文献调研中其他主要食品中砷的含量,计算得出广州市成人通过食品每日摄入总砷的量为5.08μg·kg~(-1)BW·d~(-1)。建议日常饮食需要特别控制每日海鲜的摄入量,尤其是砷含量较高的濑尿虾、红虾及红蟹、花蟹。     

基于鱼类生物完整性指数的拒马河北京段河流健康评价

拒马河是北京周边具有独特生物多样性的河流,目前面临很多水生态环境问题.鱼类生物完整性指数(F-IBI)是评价河流生态健康的重要方法.本研究于2018年5月和10月,在拒马河北京段设置9个采样点,利用地笼和刺网进行调查,共获得鱼类样本2001尾,隶属于4目9科.根据采样情况,初步设置了5大类21个初选指标,经过对指标完整性、相关性和取值范围分析,筛选得出6个评价指标:鱼类总物种数(M1)、鲤科占总种数的百分比(M3)、中上层鱼种类数百分比(M9)、杂食性鱼类种类数百分比(M13)、产粘性卵鱼类种类数百分比(M19)和鱼类总个体数(M20),构建了适用于拒马河的F-IBI指标体系,运用该体系对拒马河北京段的河流健康状况进行了评价,并将F-IBI与几个主要水环境参数和拦河坝相关数据进行了相关性分析.研究结果表明,拒马河北京段河流健康整体处于较差水平,F-IBI与水质理化因子无显著相关性,与参数"采样点与上游最近拦河坝的距离"呈显著相关.结果表明,拒马河北京段河流健康指数的关键影响因素不是水质理化因子,可能与拦河坝导致的河流片段化有关.     

环渤海渔港沉积物多环芳烃的污染特征和生态风险评价

2019年5-6月采集了环渤海20个渔港的沉积物样品,采用高效液相色谱紫外成光检测器串联方法对16种多环芳烃(PAHs)进行检测,分析了其分布和组成特征,采用比值法和正定矩阵因子模型法(PMF)对PAHs进行定量源解析,采用效应区间中低值法和中值商法评估其生态风险.10种PAHs的检出率达到100％,表明PAHs在沉积...