云南植烟土壤和烟叶中多环芳烃含量及评价

研究调查了云南省曲靖市和玉溪市部分地区植烟土壤及烟叶中16种多环芳烃（PAHs）含量,并对二者间相关性和污染程度等进行了分析。结果表明：除苊之外,15种PAHs均在土壤样品中检出,各单体检出率在6.90%～81.03%,PAHs总量在24.30～840.30μg/kg,平均值为115.97±203.60μg/kg,以4环及4环以上PAHs为主;单项污染指数评价结果表明,研究区域植烟土壤15种PAHs的BaPeq均不超标,但2个点的总BaPeq超标,属轻微污染。除二氢苊之外,15种PAHs在烟叶样品中普遍检出,各单体检出率在13.33%～100.00%,PAHs总量在81.90～1552.70μg/kg,平均值为480.44±418.78μg/kg,以3环及3环以下PAHs为主。Spearman检验法结果表明,烟叶中PAHs含量与土壤PAHs含量无相关性。     

重金属污染土烧制水泥的模拟实验

采集湖南株洲某冶炼厂周边的土壤进行水泥烧制实验,结果表明:土壤中的重金属含量较高,其化学组成与普通黏土类似,可以代替水泥窑硅质原料。素土在100~900℃持续加热60 min后,挥发高峰为300℃以上,且随着温度的升高,重金属在残渣中的含量逐步减少,可以直接进入配料系统。添加污染土后烧制的水泥熟料,其抗压强度和抗折强度符合普通硅酸盐水泥熟料的要求。添加污染土后,水泥熟料中的f-Ca O含量降低,说明添加重金属含量较高的污染土有助于熟料烧成。     

典型废旧塑料再生基地周边农田土壤中PAHs污染特征及健康风险评价

为了解废旧塑料再生行业对周边农田土壤环境的影响，在莱州市废旧塑料再生基地内部及周边农田采集22个土壤样品，利用高效液相色谱法对样品中16种多环芳烃（PAHs）含量进行了检测，并对其污染特征及健康风险进行了分析.结果表明，基地周边农田土壤中16种PAHs总含量为60.50~303.48 μg·kg^-1，除?（Chr）、二苯并（a，h）蒽（DahA）外，其余组分的检出率均为100%.萘（Nap）、苊烯（Acy）、苊（Ace）为主要组分，分别占总量的49.57%、21.32%、14.95%.参考Maliszewska-Kordybach的土壤PAHs污染程度划分方法，仅有22.73%样品达到轻微污染且集中于基地内部.在空间分布上，基地内部农田土壤中PAHs含量显著高于外部，总体表现为距基地越远，农田土壤中PAHs含量越低.基地内部各采样点PAHs的构成具有相似性，主要以低环芳烃为主，占PAHs总量的89.56%以上，表明基地内部农田土壤有相对固定的PAHs来源.主成分分析法共提取到3个主成分，表明基地周边农田土壤中的PAHs主要与燃煤、生物质燃烧以及废旧塑料焚烧有关.健康风险评估表明，成人和儿童对PAHs的暴露风险主要通过呼吸途径，儿童的暴露剂量均高于成人，但非致癌及致癌风险水平均在可接受范围.     

近20年中国表层土壤中多环芳烃时空分布特征及源解析

随着中国经济社会的快速发展,表层土壤多环芳烃（polycyclic aromatic hydrocarbons,PAHs）污染问题受到了全社会的高度关注.本研究通过搜集2000~2020年间有关我国表层土壤PAHs污染的相关研究,并对筛选得到的166篇文献采样数据综合运用统计学、空间插值分析和污染物特征比值源解析方法,定量分析了我国表层土壤PAHs污染水平、时间变化特征、空间分布特征以及来源特征.结果表明,我国表层土壤普遍存在人为因素的PAHs污染,其含量中位值为675.70 μg·kg^-1,总体情况良好但部分采样点位污染情况较为严重,单体含量中荧蒽（Fla）和芘（Pyr）含量较高,而苊烯（Acy）和二氢苊（Ace）含量较低;调查时段中,表层土壤PAHs含量数据大体稳定在313.10~1070.45 μg·kg^-1的中度污染水平范围内,其年度变化受石油生产与消费的影响相对较小,且不存在明显波动;统计学以及空间插值结果表明,我国表层土壤PAHs污染存在明显区域特征,地区含量从西北、华北、华东、东北、西南和中南依次递减,多数省份的PAHs污染水平处于"中度污染"或"轻度污染";源解析结果表明,我国大部分地区表层土壤PAHs污染来源于石油、生物质和煤等化石燃料的高温燃烧,但黑龙江以及新疆、西藏等西北地区主要表现为石油源污染.本研究对我国土壤环境管理和PAHs污染治理工作开展有一定参考价值.     

北京东南郊污灌区PAHs垂向分布规律

采用Eijkelkamp土壤采样器对北京东南郊污灌区进行了3个钻孔剖面采样,分析了土壤样品的理化参数,并且采用气相色谱-质谱联用仪对土壤样品的多环芳烃（PAHs）进行了定量分析,研究了土壤理化参数和16种PAHs从表层到5.5 m深的范围内垂向变化规律.结果表明,污灌区表层土壤中有14种PAHs检出,检出浓度在4～428 μg/kg之间,表层以下PAHs的检出种类显著减少,主要以2环和3环的萘、菲、芴、苊烯、二氢苊、荧蒽6种为主.粘粒含量、粘土矿物总量、阳离子交换容量以及总有机碳4个理化参数相互之间在垂向变化上具有一致性,均在0.05水平上显著相关.表层以下粘粒含量与低环PAHs在垂向含量变化也有较好的一致性,粘粒含量高的层位,PAHs含量也较高.从剖面PAHs含量变化可以判断,低环PAHs较易迁移,它们的迁移性强弱顺序为：二氢苊>芴>萘>菲>苊烯>荧蒽,其它高环PAHs难以迁移,仅在表层土壤中检出,说明在长期污灌条件下,迁移性较好的低环PAHs能够迁移到较深的土层中,有可能导致浅层地下水的污染.     

变电站场地土壤环境调查与评价

该文对变电站场地土壤中7种重金属和16优先控制的多环芳烃(PAHs)含量进行了检测和分析。结果表明,变电站场地土壤中重金属及PAHs浓度在垂直断面上均符合国家土壤环境质量标准,且随着深度增加浓度逐渐减小,土壤深度约为60 cm后基本达到天然背景值。站内表层土壤中重金属元素含量是站外对照点1.40～2.63倍,是河北省中南部平原土壤背景值的1.03～3.85倍,表明该区域表层土壤存在一定程度的重金属污染。变电站表层土壤中PAHs总含量为899.45μg/kg,站内土壤中、高环(4～6环)PAHs是主要污染物,占PAHs的89.66%。变电站表层土壤重金属潜在生态危害处在轻微水平,而PAHs处于中度污染水平,变电站场地土壤污染主要是由生产运行导致的污染物长时间积累所致,同时也受周边环境、交通状况、生产活动等因素影响。就变电站场地土壤而言,场地内PAHs和重金属的污染风险整体处于较低水平。     

城市污泥对通菜-水稻土中有机污染物的累积效应

在水稻土上施用城市污泥及化肥盆栽通菜,应用GC/MS对通菜植株和土壤中的邻苯二甲酸酯(PAEs)和多环芳烃(PAHs)等7类43有机污染物进行系统分析,探讨通菜植株和土壤中其累积效应.结果表明,通菜植株中检出邻苯二甲酸酯、多环芳烃、氯苯类、硝基苯类、醚类和卤代烃类共6类28种化合物(胺类未检出),土壤中检出上述7类33种化合物,均以PAEs和PAHs为主,其总含量是其他类污染物的几倍或数十倍.不同处理的通菜和土壤中各类有机污染物的含量差别较大,均以个别或少数污染物为主.施用城市污泥增加了植株和土壤中PAEs和PAHs等污染物的含量.强致癌性化合物苯并(a)芘在通菜中被检出,在部分土壤中的含量超过加拿大土壤质量控制标准(1.0mg/kg).除佛山污泥处理的通菜对氯苯类和醚类的生物浓缩系数(BCF)大于1外,其余均小于1.0.     

多环芳烃类污染土壤热脱附修复技术应用研究

针对传统热脱附工艺脱附时间长、处理成本高、尾气处理工艺不完善等问题,进行了电加热回转窑热脱附实验。研究发现:随着温度增高、时间增长,总PAHs去除率增加;10 min条件下350℃与500℃时总PAHs的去除率分别为98.83%和98.94%,土壤中PAHs可达到修复目标值;500℃时多环芳烃的去除率表现为低环PAHs>高环PAHs。在此基础上,通过集成形成1套集污染土壤预处理、热脱附、尾气净化、余热利用、自动化控制于一体的工艺技术,并建成年处理有机污染土壤18万t的热脱附生产线。在350和500℃条件下对1万余吨污染土壤进行热脱附处理后(≥10 min),总PAHs去除率分别为98.92%和99.95%,尾气排放指标均低于DB 11/501—2007《大气污染物综合排放标准》。     

某油泥堆放场地中多环芳烃的污染及其垂向分布特征

通过采集某油田油泥堆放场地及其周边24个表层土壤样品和2个剖面土壤样品,采用超声波萃取-气相色谱/氢火焰离子化检测分析方法,对美国环境保护局(USEPA)优控的16种多环芳烃(PAHs)进行定量分析.结果表明:该研究区域的PAHs污染已较为严重,污染场地内16种PAHs的检出率为100%,w(PAHs)平均值为7 770.7 ng/g;周边土壤的16种多环芳烃的检出率为58.3%～100%,二苯并［a,h］蒽及茚并［1,2,3-cd］芘的检出率相对较低,w(PAHs)平均值为2 038.8 ng/g.研究区域内主要污染物为萘、苊、二氢苊、芴、菲、蒽、荧蒽、、芘、苯并［a］蒽和苯并［a］芘.从母体PAHs与污染物来源的关系和单组分比值可以看出,污染场地内及周边土壤的污染源是石油源和燃烧源的混合源.w(PAHs)在土壤剖面中的峰值出现在40～60及20～40 cm处,不同组分的PAHs在土壤剖面中的迁移能力表现为2～3环PAHs＞4环PAHs＞5～6环PAHs.      

银川市湖泊、河流沉积物中PAHs污染特征及风险评价

为了解银川市湖泊及城市河流沉积物中多环芳烃（PAHs）污染状况及生态风险,于2018年4~5月在银川市各湖泊及城市河流采集17个表层沉积物样品,采用气相色谱质谱（GC-MS）检测样品中PAHs含量.结果表明,银川市湖泊及城市河流表层沉积物中16种PAHs总含量范围为767.35~3961.53ng/g,平均值为2129.86ng/g,与国内外沉积物中PAHs污染状况相比,银川市湖泊及城市河流沉积物中PAHs污染处于较高水平.来源解析表明,银川市湖泊及城市河流沉积物中主要的污染来源为石油及煤炭等生物质的不完全燃烧.通过效应区间低中值法分析沉积物中PAHs的生态风险评价结果显示,部分采样点表层沉积物中菲的含量超过效应区间中值（ERM）;沉积物质量标准法（SQSs）分析沉积物中PAHs生态风险结果表明,萘、苊检测含量在可能效应浓度值（PEL）与频繁效应浓度值（FEL）之间,菲的检测含量高于FEL;风险商值法分析显示苊烯、苊、菲、荧蒽风险熵值RQ>1.综合分析认为沉积物中多环芳烃的污染可能会造成一定程度的生态风险.     

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.     

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.     

Potential of plant polyphenol oxidases in the decolorization and removal of textile and non-textile dyes

In this study an effort has been made to use plant polyphenol oxidases; potato （Solanum tuberosum） and brinjal （Solanum melongena）, for the treatment of various important dyes used in textile and other industries. The ammonium sulphate fractionated enzyme preparations were used to treat a number of dyes under various experimental conditions. Majority of the treated dyes were maximally decolorized at pH 3.0. Some of the dyes were quickly decolorized whereas others were marginally decolorized. The initial first hour was sufficient for the maximum decolorization of dyes. The rate of decolorization was quite slow on long treatment of dyes. Enhancement in the dye decolorization was noticed on increasing the concentration of enzymes. The complex mixtures of dyes were treated with both preparations of polyphenol oxidases in the buffers of varying pH values. Potato polyphenol oxidase was significantly more effective in decolorizing the dyes to higher extent as compared to the enzyme obtained from brinjal polyphenol oxidase. Decolorization of dyes and their mixtures, followed by the formation of an insoluble precipitate, which could be easily removed simply by centrifugation.     

Removal of heavy metals from sewage sludge by low costing chemical method and recycling in agriculture

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Single and joint effects of pesticides and mercury on soil urease

The influence of two pesticides including chlorimuron-ethyl and furadan and mercury （Hg） on urease activity in 4 soils （meadow burozem and phaeozem） was investigated. The soils were exposed to various concentrations of the two pesticides and Hg individually and simultaneously. Results showed that there was a close relationship between urease activity and organic matter content in soil. Chlorimuron-ethyl and furadan could both activate urease in the 4 soils. The maximum increment of urease activity by chlorimuronethyl was up to 14%-18%. There was almost an equal increase （up to 13%-21%） in the urease activity by furadan. On the contrary, Hg markedly inhibited soil urease activity. A logarithmic equation was used to describe the relationship （P〈0.05） between the concentration of Hg and the activity of soil urease in the 4 tested soils. Semi-effect dose （ED50） values by the stress of Hg based on the inhibition of soil urease in the 4 soils were 88, 5.5, 24 and 20 mg/kg, respectively, according to the calculation of the corresponding equations. The interactive effect of chlorimuron-ethyl or furadan with metal Hg on soil urease was mainly synergic at the highest tested concentrations.     

Isolation and preliminary characterization of a 3-chlorobenzoate degrading bacteria

A study was conducted to compare the diversity of 2-, 3-, and 4-chlorobenzoate degraders in two pristine soils and one contaminated sewage sludge. These samples contained strikingly different populations of mono-chlorobenzoate degraders. Although fewer cultures were isolated in the uncontaminated soils than contaminated one, the ability of microbial populations to mineralize chlorobenzoate was widespread. The 3- and 4-chlorobenzoate degraders were more diverse than the 2-chlorobenzoate degraders. One of the strains isolated from the sewage sludge was obtained. Based on its phenotype, chemotaxonomic properties and 16S rRNA gene, the organism S-7 was classified as Rhodococcus erythropolis. The strain can grow at temperature from 4 to 37℃. It can utilize several （halo）aromatic compounds. Moreover, strain S-7 can grow and use 3-chlorobenzoate as sole carbon source in a temperatures range of 10-30℃ with stoichiometric release of chloride ions. The psychrotolerant ability was significant for bioremediation in low temperature regions. Catechol and chlorocatechol 1,2-dioxygenase activities were present in cell free extracts of the strain, but no （chloro）catechol 2,3- dioxygenase activities was detected. Spectral conversion assays with extracts from R. erythropolis S-7 showed accumulation of a compound with a similar UV spectrum as chloro-cis,cis-muconate from 3-chlorobenzoate. On the basis of these results, we proposed that S-7 degraded 3-chlorobenzoate through the modified ortho-cleave pathway.