基于改进内梅罗指数法的棕(褐)地周边土壤重金属污染评价

近年来我国棕(褐)地数量不断增加,棕(褐)地的存在给周边的居民和生态环境带来较大危害;我国土地资源紧缺,对于棕(褐)地区域需要进行再开发利用,而棕(褐)地区域在修复治理前后的污染程度需要进行评价研究,为棕(褐)地区域治理管理工作提供参考。文章主要对研究区的棕(褐)地周边的特征污染物即重金属Cu和Cd带来的污染进行评价,对传统的内梅罗方法存在的缺陷进行改进,应用到棕(褐)地周边重金属污染评价实例研究中,并利用GIS软件对评价结果进行空间表示,并分析污染程度的空间分布。     

神定河流域水质空间变化特征研究

依据2016年神定河流域20个采样点的水质调查数据,应用综合污染指数分析和聚类分析方法对神定河流域水质空间变化特征进行分析,并采用判别分析对神定河流域水质空间差异性进行检验。结果表明:将神定河流域各采样点进行水质空间聚类分析,可分为A、B、C、D 4类,其中A类为水质污染程度严重的1类污染区,B类为水质污染程度较重的2类污染区,C类为水质污染程度一般的3类污染区,D类为水质污染程度较轻的4类污染区;水质综合污染指数分析与聚类分析结果基本吻合;水质空间差异性判别分析检验结果显示,仅用氨氮、石油类污染物和高锰酸盐指数3个水质指标就能较为完整地反映神定河流域水质的空间差异性特征。     

工业废弃场地再开发的土壤环境评价与修复研究

工业废弃地（棕地）可能受原生产活动遗留的有毒有害物质的污染,因此,棕地再开发之前必须对其进行污染调查分析和环境风险评价,判断其是否需要进行土壤修复。用理化分析对首钢搬迁场址进行了土壤污染调查,采用内梅罗指数法评价土壤环境风险,分析了污染来源,并提出采用基于环境风险的土壤污染治理模式及技术经济分析。     

被遗留的“棕地”

正国际环境科学界将"棕地"作为城市中高污染、高能耗企业搬迁后遗留下来地块的统称,而在全世界的各个国家,"棕地"也有着不同的内涵和改造方式。"棕地"这个概念最早出现在美国,英文名为Brown Field,也译作"棕色地块",是指被遗弃,闲置或不再使用的前工业和商业用地及设施,这些地区的扩展或再开发会受到环境污染的影响,也因此变得复杂。如今,国际环境科学界将它作为城市中高污染、高能耗企业搬迁后遗留下来地块的统称,而在全世界的各个国家,"棕地"也有着不同的改造方式。     

张家口地区排污工业企业集聚与水污染空间耦合特征

基于排污企业污染源环境统计数据,应用水污染物排放强度和核密度分析等方法,研究张家口地区排污工业企业的空间集聚特征及其与水污染排放空间之间的空间耦合特征,结果显示：（1）张家口地区工业企业空间集聚程度存在一定的空间异质性,崇礼县、赤城县整体上几乎无污染密集型企业分布。污染密集型企业主要沿洋河流域分布。（2）农副食品加工业、黑色金属冶炼及压延加工业、食品制造业、煤炭开采和选洗业这四大行业的COD、NH₃-N、总氮等水体污染物排放量相对最大。（3）工业企业集聚度与水环境污染程度的空间正向耦合效应明显,96.23%的区域呈较强正向耦合特征。高集聚—污染高值区占比0.40%。针对四种空间耦合状态提出未来污染物排放管控方向,以期为政府部门准确锁定治理区提供决策依据。     

东北地区工业污染时空格局演变研究

基于东北地区2003—2015年地市层面工业废水、工业SO2排放数据,采用标准差椭圆、地理集中度指数,从宏观及微观两个角度分析东北地区工业污染时空格局演变特征,并对工业发展与工业污染演变协同关系展开研究.结果表明,2003—2015年间东北地区两种工业污染排放量及占全国比重均有所提升,工业污染尤其是工业SO2污染对生态环境胁迫逐渐增大;标准差椭圆结果显示,工业污染在空间上均呈南(偏西)-北(偏东)方向分布,工业污染重心轨迹迁移存在相似性,工业SO2污染空间集聚程度高于工业废水;工业污染地理集中度显示,地市层面工业污染集聚情况呈南高北低的空间分布特征,研究期内工业污染集中度高值区分布范围明显收缩,空间特征得到强化;东北地区工业发展与工业污染空间形态演变存在相似性,空间形态上的差异逐渐减弱.分地区看,东北地区中部工业环境绩效最高,而工业污染集中度较低的北部工业环境绩效偏低,局部上表现出工业发展与工业污染变化不一致的特点.最后分析了工业及工业污染空间格局演变趋势及北部地区工业发展与工业污染变化不一致的原因.     

银川市主要入黄排水沟水质时空演变特征及污染分析

运用数理统计方法,分析银川市6条主要入黄排水沟2013～2017年水环境质量特征,解析时空差异、辨识污染源及关键污染因子。结果表明:2013～2017年,银川市6条主要入黄排水沟水质整体为劣V类且时空差异显著。其中,四二干沟、灵武干沟与第二排水沟的污染主要来源于生活、农业与工业中的营养盐与石油类物质;银新干沟污染主要来源于工业及农业中的好氧有机物、石油类与营养盐;永二干沟污染主要来源于工业中的好氧有机物、石油类与表面活性剂;永宁中干沟污染主要来源于农业及工业中的氨氮、石油类与表面活性剂污染。通过对银川市水质的时空演变特征的分析以及污染物来源的识别,以期为改善银川市水环境污染问题提供一定的理论依据。     

黄河流域甘肃段工业行业水污染物空间排放特征

为研究黄河流域甘肃段工业废水污染的空间排放特征,运用系统聚类法,构建水污染物空间分类模型,引入污染综合评价指数,测算空间关联特征,揭示黄河流域甘肃段工业水污染物排放空间集聚效应.结果表明,2017年黄河流域甘肃段总工业企业数量为7 224家,企业类型以小型和微型为主.化学需氧量（COD）排放主要集中在安定区、麦积区和西固区,氨氮（NH⁺₄-N）、总氮（TN）和总磷（TP）排放主要集中在西固区、安宁区和红古区,农副食品加工业、酒/饮料和精制茶制造业、化学原料和化学制品制造业及电力/热力生产和供应业是主要贡献源.黄河流域甘肃段57个县区可分6种污染类型,水环境污染综合评价指数在空间整体上存在明显空间正相关,高值簇和低值簇集聚现象显著.研究结果可为管理部门制定差异化的水环境管控对策,实行分区分级的精细化管理提供科学支撑.     

自适应FCM土壤表层重金属污染评价——以南京市炼油厂及生活区为例

采用自适应模糊C均值聚类(FCM)挖掘土壤重金属的污染程度信息,以实现污染程度分类数的自动获取,确保类别划分的合理性,真实地反映重金属污染的空间聚集特征.以江苏省南京市炼油厂及生活区为研究对象,采集土壤中Cr、Cd、Ni、Pb、Zn、Cu重金属浓度值,首先运用自适应FCM对浓度值进行聚类分析,然后利用地统计学空间插值,揭示污染的空间聚集性.结果表明,研究区存在不同程度的污染,自适应FCM算法比传统聚类算法能更合理地划分重金属污染程度,挖掘出样本潜在的污染信息,可为分析污染成因及土壤环境治理修复提供参考.     

老工业基地棕地开发环境管理体系建立的一般程序

本文以武汉市老工业基地搬迁企业腾退遗留场地开发再利用为切入点,结合地区的经济发展目标、城市总体规划要求,对棕地开发再利用过程中污染防治与环境管理机制进行了探索,并制定了棕地再利用环境管理体系的一般程序,包括如何设置场地环境调查与修复单位准入标准、如何开展场地环境调查与修复中的监管工作、如何规范棕地开发再利用过程中的环境管理,为我国出台相关法律、法规提供基础依据,为其他地区、城市老工业基地转型中的棕地开发再利用环境管理工作提供参照。     

Effects of two sludge application on fractionation and phytotoxicity of zinc and copper in the soil

The potential harm of heavy metals is a primary concern in application of sludge to the agricultural land. A pot experiment was conducted to evaluate the effect of two sludges on fractionation of Zn and Cu in soil and their phytotoxicity to pakchoi. The loamy soil was mixed with 0%, 20%, 40%, 60% and 80% (by weight) of digested sewage sludge (SS) and composted sludge (SC). The additions of both sludges caused a significant raise in all fractions, resulting in that exchangeable (EXCH) and organic bound (OM) became predominance of Zn and organic bound Cu occupied the largest portion. There was more available amount of Zn and Cu in SS treatments than SC treatments. During the pot experiment, the concentration of Zn in EXCH, carbonate (CAR) and OM and Cu in EXCH and OM fractions decreased in all treatments, so their bioavailability reduced. Germination rate and plant biomass decreased when the addition rate was high and the best yield appeared in 20% mixtures at the harvest of pakchoi. The two sludges increased tissue contents of Zn and Cu especially in the SS treatments. Zn in pakchoi was not only in relationship to ΔEXCH and ΔCAR forms but also in ΔOM forms in the sludge-soil mixtures. Tissue content of Cu in pakchoi grown on SC-soils could not be predicted by ΔEXCH. These correlation rates between Zn and Cu accumulation in pakchoi and variation of different fractions increased with time, which might indicate that sludges represented stronger impacts on the plant in long-term land application.     

Intraspecific differences in effects of co-contamination of cadmium and

A hydroponic experiment was carried out to study intraspecific differences in the effects of different concentrations of cadmium (Cd)(0-10 mg/L) and arsenate (As(V)) (0-8 mg/L) on the growth parameters and accumulation of Cd and As in six wheat varieties Jing-9428, Duokang-1, Jingdong-11, Jing-411, Jingdong-8 and Zhongmai-8. The endpoints of wheat seedlings, including seed germination,biomass, root length and shoot height, decreased with increasing the Cd and As concentrations. Significant differences in seed germination, biomass, root length, shoot height and the accumulation of Cd and As were observed between the treatments and among the varieties (p ＜ 0.05). The lethal dosage 50% were about 20, 80, 60, 60, 80 and 20 mg As/L for Jing-9428, Duokang-1, Jingdong-11,Jing-411, Jingdong-8 and Zhongmai-8, respectively, and the corresponding values for Cd were about 30, 80, 20, 40, 60 and 10 mg Cd/L, respectively. Among the six varieties, Duokang-1 was found to be the most resistant to Cd and As toxicity, and Zhongmai-8 was the most sensitive to Cd and As co-contamination. The resistance of the six varieties was found dependant on the seedling uptake of Cd and As. Duokang-1 was the most suitable for cultivation in Cd and As co-contaminated soils.     

Toxic effects of acetochlor, methamidophos and their combination on nifH gene in soil

Toxic effects of two agrochemicals on nifH gene in agricultural black soil were investigated using denaturing gradient gel electrophoresis （DGGE） and sequencing approaches in a microcosm experiment. Changes of soil nifH gene diversity and composition were examined following the application of acetochlor, methamidophos and their combination. Acetochlor reduced the nifH gene diversity （both in gene richness and diversity index values） and caused changes in the nifH gene composition. The effects of acetochlor on nifH gene were strengthened as the concentration of acetochlor increased. Cluster analysis of DGGE banding patterns showed that nifH gene composition which had been affected by low concentration of acetochlor （50 mg/kg） recovered firstly. Methamidophos reduced nifH gene richness that except at 4 weeks. The medium concentration of methamidophos （150 mg/kg） caused the most apparent changes in nifH gene diversity at the first week while the high concentration of methamidophos （250 mg/kg） produced prominent effects on nifH gene diversity in the following weeks. Cluster analysis showed that minimal changes of nifH gene composition were found at 1 week and maximal changes at 4 weeks. Toxic effects of acetochlor and methamidophos combination on nifH gene were also apparent. Different nifH genes （bands） responded differently to the impact of agrochemicals： four individual bands were eliminated by the application of the agrochemicals, five bands became predominant by the stimulation of the agrochemicals, and four bands showed strong resistance to the influence of the agrochemicals. Fifteen prominent bands were partially sequenced, yielding 15 different nifH sequences, which were used for phylogenetic reconstructions. All sequences were affiliated with the alpha- and beta-proteobacteria, showing higher similarity to eight different diazotrophic genera.     

Arsenic uptake by arbuscular mycorrhizal maize （Zea mays L.） grown in an arsenic-contaminated soil with added phosphorus

The effects of arbuscular mycorrhizal (AM) fungus (Glomus mosseae) and phosphorus (P) addition (100 mg/kg soil) on arsenic (As) uptake by maize plants (Zea mays L.) from an As-contaminated soil were examined in a glasshouse experiment.Non-mycorrhizal and zero-P addition controls were included.Plant biomass and concentrations and uptake of As,P,and other nutrients,AM colonization,root lengths,and hyphal length densities were determined.The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium.Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments,but shoot and root biomass of AM plants was depressed by P application.AM fungal inoculation decreased shoot As concentrations when no P was added,and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition,respectively.Shoot and root uptake of P,Mn,Cu,and Zn increased,but shoot Fe uptake decreased by 44.6%,with inoculation, when P was added.P addition reduced shoot P,Fe,Mn,Cu,and Zn uptake of AM plants,but increased root Fe and Mn uptake of the nonmycorrhizal ones.AM colonization therefore appeared to enhance plant tolerance to As in low P soil,and have some potential for the phytostabilization of As-contaminated soil,however,P application may introduce additional environmental risk by increasing soil As mobility.     

Degradation of metabolites accumulated of benzo[a]pyrene by coupling Penicillium Chrysogenum with KMnO4

Several main metabolites of benzo[a]pyrene （BaP） formed by Penicillium chrysogenum, Benzo[a]pyrene-1,6-quinone （BP 1,6- quinone）, trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene （BP 7,8-diol）, 3-hydroxybenzo[a]pyrene （3-OHBP）, were identified by high-performance liquid chromatography （HPLC）. The three metabolites were liable to be accumulated and were hardly further metabolized because of their toxicity to microorganisms. However, their further degradation was essential for the complete degradation of BaP. To enhance their degradation, two methods, degradation by coupling Penicillium chrysogenum with KMnO4 and degradation only by Penicillium chrysogenum, were compared; Meanwhile, the parameters of degradation in the superior method were optimized. The results showed that （1） the method of coupling Penicillium chrysogenum with KMnO4 was better and was the first method to be used in the degradation of BaP and its metabolites; （2） the metabolite, BP 1,6-quinone was the most liable to be accumulated in pure cultures; （3） the effect of degradation was the best when the concentration of KMnO4 in the cultures was 0.01% （w/v）, concentration of the three compounds was 5 mg/L and pH was 6.2. Based on the experimental results, a novel concept with regard to the bioremediation of BaP-contaminated environment was discussed, considering the influence on environmental toxicity of the accumulated metabolites.     

Impact of atrazine and nitrogen fertilizers on the sorption of chlorotoluron in soil and model sorbents

Sorption of chlorotoluron in ammonium sulfate, urea and atrazine multi-solutes system was investigated by batch experiments. The results showed application of nitrogen fertilizers to the soil could affect the behavior of chlorotoluron. At the same concentration of N, sorption of chlorotoluron decreased as the concentration of atrazine increased on the day 0 and 6 in soil, respectively. The sorption of chlorotoluron increased from 0 to 6 d when soils were preincubated with deionized water, ammonium sulfate and urea solution for 6 d. That indicated incubation time was one of the most important factors for the sorption of chlorotoluron in nitrogen fertilizers treatments. The individual sorption isotherms of chlorotoluron in rubbery polymer and silica were strictly linear in single solute system, but there were competition sorption between pesticides or between pesticides and nitrogen fertilizers. That indicated the sorption taken place by concurrent solid-phase dissolution mechanism and sorption on the interface of water-organic matter or water-mineral matter.     

Distribution and ecological effect of mercury in Laogang landfill, Shanghai, China

Laogang landfill near Shanghai is the largest landfill in China, and receives about 10000 t of daily garbage per day, Samples of topsoil and plants were analyzed to evaluate mercury pollution from the landfill. For topsoil samples, there were significant correlations among total mercury （HgT）, combinative mercury （Hgc） and gaseous mercury （HgG）, and content of total organic carbon （TOC）, but, no significantly relationship was found between Hg content and filling time. Hg content changes in vertical profiles with time showed that the average Hgv of profiles 1992, 1996, and 2000 was similar, but their average HgG was quite different. HgT was significantly correlated with Hgc in profile 1992 and 2000, and Hgv was significantly correlated with Hg6 in profile 1996. HgG/Hgv ratio in profile samples decreased in the order of （HgG,/HgT）1992〉（HgG/HgT）1996〉〉（HgG/HgT）2000. A simple outline of Hg release in landfill could be drawn： with increasing of filling time, degradation undergoes different biodegradation, accordingly, gaseous mercury goes through small, more, and small proportion to total mercury. Distribution of Hg in plants was inhomogeneous, following the order of leaf〉root〉stem. The highest value of leaf may be associated with higher atmospheric Hg from landfill. Ligneous plants （e.g. Phyllostachys glanca, Prunus salicina and Ligustrum lucidum） are capable of enriching more Hg than herbaceous plants.     

EDTA-enhanced phytoremediation of lead contaminated soil by Bidens maximowicziana

Phytoremediation is a potential cleanup technology for the removal of heavy metals from contaminated soils.Bidens maximowicziana is a new Pb hyperaccumulator,which not only has remarkable tolerance to Pb but also extraordinary accumulation capacity for Pb.The maximum Pb concentration was 1509.3 mg/kg in roots and 2164.7 mg/kg in overground tissues.The Pb distribution order in the B. maximowicziana was:leaf>stem>root.The effect of amendments on phytoremediation was also studied.The mobility of soil Pb and the Pb concentrations in plants were both increased by EDTA application.Compared with CK(control check),EDTA application promoted translocation of Pb to overground parts of the plant.The Pb concentrations in overground parts of plants was increased from 24.23-680.56 mg/kg to 29.07-1905.57 mg/kg.This research demonstrated that B.maximowicziana appeared to be suitable for phytoremediation of Pb contaminated soil,especially,combination with EDTA.     

Decomposition of alachlor by ozonation and its mechanism

Decomposition and corresponding mechanism of alachlor, an endocrine disruptor in water by ozonation were investigated. Results showed that alachlor could not be completely mineralized by ozone alone. Many intermediates and final products were formed during the process, including aromatic compounds, aliphatic carboxylic acids, and inorganic ions. In evoluting these products, some of them with weak polarity were qualitatively identified by GC-MS. The information of inorganic ions suggested that the dechlorination was the first and the fastest step in the ozonation of alachlor.     

Enzymatic oxidation of aqueous pentachlorophenol

The influence of the nonionic surfactant Tween 80 on pentachlorophenol （PCP） oxidation catalyzed by horseradish peroxidase was studied. The surfactant was tested at concentrations below and above its critical micelle concentration （CMC）. Enhancement of PCP removal was observed at sub-CMCs. The presence of Tween 80 in the reaction mixture reduced enzyme inactivation which occurred through a combination of free radical attack and sorption by precipitated products. A simple first-order model was able to simulate time profiles for enzyme inactivation in the presence or absence of Tween 80. At supra-CMCs, the surfactant caused noticeable reductions in PCP removal, presumably through micelle partitioning of PCP which precluded the hydrophobic PCP molecule from interacting with the enzyme.