Beyond Biochar-Soil, Plant and Environment: Research Progress and Future Prospects

Since industrial revolution, the atmospheric CO2 concentration has kept a continuous increase by more than 2.2 ppm yr^-1, and approaches to almost 400 ppm at present （Jouzel 2012）. China has become the largest country of greenhouse gas emission （GHG）, and confronts with great challenge to mitigate GHG.

Research Progress of Soil Microbiology

This paper aims at summarized the research progress of soil microbes,in amount of soil microbes including bacteria,fungi and actinomycetes,soil microbial biomass,including microbial biomass carbon,microbial biomass nitrogen and microbial biomass phosphorus,function of microbial and screening and application of beneficial microorganisms etc.,and future research are discussed combined with our project team for many years of work.

Progress of Mid Infrared Spectroscopy in Soil Environment Research

Soil is the basis of agricultural and forestry production,and it is of great significance to obtain soil information efficiently and comprehensively for soil management.Due to the complexity of soil organic components,it is difficult to obtain the information of soil organic components comprehensively by traditional chemical analysis method.As a non-destructive,real-time and high-throughput analysis method,mid infrared spectroscopy(MIR)has the ability to obtain soil organic environmental information efficiently and accurately.It can provide a large number of basic data for soil environmental monitoring,digital mapping,agricultural and forestry production,and help to realize the real-time monitoring of soil environment and the informatization of agriculture and forestry.In this paper,the detection process of MIR obtaining soil environmental spectral information and processing methods of spectral data were briefly introduced,and the research progress on extraction and influencing factors of mid infrared spectrum characteristics of soil in recent years was reviewed.Moreover,the significance and future development direction of soil science for the technology were discussed.

A Review of REE Tracer Method Used in Soil Erosion Studies

Rare earth elements （REEs） have been proved ideal tracers for soil erosion and aggregation. REE tracer method （REETM） used to study soil erosion, as a new technique, has been developed in recent 20 yr. It is able to quantitatively monitor the temporal and spatial variation of erosion intensity, compared with traditional approaches. The applications of REETM in studying of sediment differentiation law, erosion process evolution, determination of sediment sources and sedimentation investigations, and determination of prediction parameters, were reviewed. Some application limitations were summarized.

Knowledge Map of Soil Nutrient Migration Analysis Based on WOS (Web of Science) Database

It is important to understand the research trends and hotspots of global soil nutrient migration and control. Based on the core collection of WOS (Web of Science), citespace knowledge map analysis tool was used to analyze the number of publications, cooperation networks, disciplines, research hotspots and frontier trends on nutrient migration in soil. The results showed that: the number of publications on the study of soil nutrient migration showed a good growth from 1990 to 2021. 173 countries had cooperative relationships. The number of articles published in the United States and China was significantly higher than that in other countries, while Chinese Academy of Sciences was the institution with the largest number of publications. It was a comprehensive system that permeates with agriculture, environmental science, botany and other disciplines. The research of nutrient migration in soil mainly focused on the measures of microbial community in different land types to promote nutrient transformation, improve soil fertility and reduce nutrient loss. In the future, the research trends will be the management measures of soil nutrient loss, the relationship between the change of soil nutrient and plant community diversity, and the remediation of agricultural contaminated soil. Through the above analysis, there was an overall understanding of soil nutrient migration. The research on nutrient migration may continue to increase in the future. It is suggested that Chinese research institutions, teams and universities need to strengthen international cooperation, and speed up their integration with the international community.

Occurrence and congeners specific of poiychlorinated biphenyls in agricultural soils from Southern Jiangsu, China

A total of 198 agricultural soil samples were collected from Zhangjiagang and Changshu in Southern Jiangsu for analysis of 13 polychlorinated biphenyls （PCBs） in order to assess the levels of pollution, sources, area distribution, and potential risk for the environment. All methods were rigorously tested and an adequate quality control was ensured. Only one site had no PCBs residues, and the highest total PCBs concentration in the surface soils was 32.83 ng/g. The average concentration in all the soil samples was 4.13 ng/g, signaling low-level pollution. Tetra-, penta-, and hexa-chlorinated biphenyls were dominant species in soil samples, accounting for more than 75% of ∑PCBs in the soil samples. PCB118 was the most abundant congener in all the samples. The PCB118 was about 20% of ∑PCBs. The soil organic matter content showed only a weak correlation with the levels of all PCB congeners, in which a better correlation was noted for the more volatile lighter PCB congeners than for the heavier homologues. To a certain extent, the sources and land use seemed to influence the levels of PCBs.

Contamination of soil, leaves and vegetables by polychlorinated biphenyls in Xiamen region, China

The paper aimed to identify the primary of polychlorinated biphenyls(PCBs) in the Jiulong River Estuary, investigate the spatial distribution of PCBs contamination in the environment, localize the atmospheric source and evaluate ongoing PCBs emissions by analyzing soil samples collected along the Jiulong River region. In addition, the accumulation of PCBs in the human food chain was quantified by analyzing leaf of orange trees and vegetable samples collected along a gradient of soil/atmospheric contamination moving away from the source. Consequently, the impact on the human health and the ecosystem was quantified, different management options were proposedto reduce this impact and to carry out research on organic contaminants along the Jiulong River and Xiamen region.

Large-Scale Test Model of the Progressive Deformation and Failure of Cracked Soil Slopes

A large-scale test bed(LWH=6 m×3 m×2.8 m)instrumented with various sensors is used to examine the effects of rainfall infiltration and evaporation on the deformation and failure of cracked soil slopes,taking the Anhui area along the Yangtze River as a field example.The results indicate that(1)during rainfall,the soil around the shallow shrinkage fissures attains transient saturation,and the attendant decrease of matric suction is the primary cause of the shallow slope failure;(2)slope deformation continues during post-rainfall evaporation;(3)if a period of evaporation is followed by heavy rainfall,soil creep is concentrated near the deepest cracks,and two zones of steep gradients in pore pressure form at the crest and toe of the slope.Finally,a saturated zone forms near each crack base and gradually enlarges,eventually forming a continuous saturated layer that induces the slope instability or failure.

Polychlorinated biphenyis in Beijing soil of China

The concentrations of polychlorinated biphenyls （PCBs） have been determined in soils collected in Beijing of China. According to Principle Component Analysis （PCA） of PCBs, the possible sources were studied. Relationship between PCBs and soil organic materials revealed that higher chlorinated PCBs are more inclined to be adsorbed by particles rich of organic materials. But the low chlorinated homologues are dominant in Beijing soils, which is very different from the foreign studies. It was concluded that the application of relatively low chlorinated commercial PCBs in China was the main reason leading to this homologue composition character. Besides, the relatively short pollution history is also one of the main reasons. PCA of PCBs data in Beijing soil and atmospheric deposition samples revealed that some other emission sources such as atmospheric deposition, automobile exhaust; chemical and petrochemical industry and steel industry may be the important reasons of elevated PCBs concentrations in Beijing soil

Kinetic and thermodynamic studies on partitioning of polychlorinated biphenyls (PCBs) between aqueous solution and modeled individual soil particle grain sizes

The significance of soil mineral properties and secondary environmental conditions such as pH, temperature, ionic strength and time in the partitioning of eight selected polychlorinated biphenyl(PCB) congeners between aqueous solution and soil particles with different grain sizes was studied. The mineral properties of a model soil sample were determined, and Brunauer–Emmett–Teller(BET) adsorption–desorption isotherms were employed to observe the surface characteristics of the individual modeled soil particles.Batch adsorption experiments were conducted to determine the sorption of PCBs onto soil particles of different sizes. The results revealed that the sorption of PCB congeners onto the soil was dependent on the amount of soil organic matter, surface area, and pore size distribution of the various individual soil particles. Low pH favored the sorption of PCBs,with maximum sorption occurring between pH 6.5 and 7.5 with an equilibration period of 8 hr.Changes in the ionic strength were found to be less significant. Low temperature favored the sorption of PCBs onto the soil compared to high temperatures. Thermodynamic studies showed that the partition coefficient(K_d) decreased with increasing temperature, and negative and low values of ΔH° indicated an exothermic physisorption process. The data generated is critical and will help in further understanding remediation and cleanup strategies for polluted water.

The associations between the environmental exposure to polychlorinated biphenyls (PCBs) and breast cancer risk and progression

Polychlorinated biphenyls(PCBs) are chlorinated biphenyl compounds with wide applications in the industry.In spite of a ban on their production in the late 1970s,PCBs,as a group of POPs,are still persistent and widely spread in the environment,posing potential threats to human health.The role of PCBs as etiologic agents for breast cancer has been intensively explored in a variety of in vivo,animal and epidemiologic studies.Initial investigations indicated higher levels of PCBs in mammary tissues or sera corresponded to the occurrence of breast cancer,but later studies showed no positive association between PCB exposure and breast cancer development.More recent data suggested that the CYP1A1 m2 polymorphisms might add increased risk to the etiology of breast cancer in women with environmental exposure to PCBs.PCBs are implicated in advancing breast cancer progression,and our unpublished data reveals that PCBs activate the ROCK signaling to enhance breast cancer metastasis.Therefore,the correlation between PCB exposure and breast cancer risk warrants further careful investigations.

土壤环境中的多氯联苯(PCBs)及其修复技术

本文着重介绍了土壤中PCBs污染的现状及其产生的危害,总结了土壤中持久性污染物PCBs的迁移转化规律,回顾并比较了近年来国内外PCBs污染土壤的修复技术,最后对多氯联苯污染土壤的修复技术的发展趋势进行了预测和展望。

上海农村及郊区土壤中PCBs污染特征及来源研究

2007年3月采集上海市农村及郊区36个表层土壤样品,采用气相色谱法对土壤中的多氯联苯(PCBs)残留进行了分析,揭示了土壤中PCBs的残留水平、分布、组成特征及来源。结果表明,试区土壤中共检出62种PCB,总浓度最高2530ng·kg-1,最低71.7ng·kg-1,平均含量534ng·kg-1。较高污染浓度主要是编号为BS2、SJ6、JS4和FX4的土壤样品,但从整体采样区域来看,其污染可能主要来源于城区污染导致的区域大气沉降或是全球大气传输所致。上海农村及郊区土壤PCBs污染物以Tri-CBs和Tetra-CBs为主,主要以工业Aroclor1242来源为主。相关性分析显示,土壤中PCBs与TOC具有显著相关性,尤其是对于挥发性较强的低氯代PCBs,表明TOC是影响上海市土壤中PCBs持留的重要因素之一。聚类分析显示,部分采样点PCBs污染与工业品使用有关,但可能还存在其他来源。

北京土壤中的PCBs含量与组成

利用高分辨率气质联用仪（HRGC-HRMS）测定了北京土壤中的多氯联苯（PCBs）含量．结果表明，PCBs总含量平均为3．1ng·g^-１（范围为0．39～13ng·g^-1）。毒性当量TEQ为0．37pg·g^-1（范围为0．72～1．8pg·g^-1），与其它研究结果相比处于较低水平．类二噁英PCBs含量最大的3种为118＞105＞77（IUPAC编号），约90％的TEQ由异构体126产生．PCBs同族体含量以低氯取代为主。虽然与国内环境介质相似。但与国外不同,国内对低氯取代PCBs化学品的使用可能是造成这种不同的主要原因．高氯取代PCBs更容易吸附在土壤有机质中．PCBs总含量的高低顺序为：路边土壤＞公园土壤＞农田土壤＞山地土壤，城区与近郊土壤＞远郊土壤，推测城市机动车尾气的排放和农用化学品的使用等是造成北京土壤PCBs含量升高不可忽视的原因．

上海市某工业区表层土壤中PCBs分布特征研究

为了探讨上海市某典型工业区表层土壤中PCBs的来源和分布以及行业间的分布差异,本文参考EPA方法采用GC/ECD及GC/MS初步建立了环境样品中PCBs测定的方法,同时得到了工业区和对照区域内表层土壤中PCBs的浓度和组成,其浓度分布在0.05～586.85 ng/g间.结果表明:研究区域内呈现由工业区、近效区到远郊区表层土壤中PCBs浓度的显著降低以及高氯取代PCBs占PCBs同类物百分比升高的趋势,从而推断工业区内可能存在着一定程度的PCBs,同时也再次证明了PCBs同类物相对不同迁移转化途径.

环境样品中PCBs的测定

通过碱解、酸洗、萃取、净化、浓缩、脱硫等步骤处理实际样品 ,利用毛细管柱 GC/ ECD进行 PCBs的定性和定量。方法定性准确 ,定量良好 ,具有较高的回收率。各同系物的方法检出限 ,水样为 0 .0 1～ 0 .0 8ng/ L;土壤样为 0 .0 0 3～0 .0 3μg/ kg,可以应用于土壤、沉积物、水样、油样等环境样品中

多氯联苯(PCBs)污染土壤的生物修复

多氯联苯(PCBs)是一类持久性有机污染物(POPs),因氯原子取代位置和数量的不同共有209种同系物。近年来,土壤中的PCBs污染问题已引起人们的广泛关注。由于PCBs具有高分子稳定性、低水溶性和颗粒相高吸附势,土壤基质中PCBs的去除极其困难。此外,PCBs的高憎水性和亲脂性使之易于在动物体脂肪组织和母乳富集。生物修复技术是指利用生物有机体(绿色植物、微生物和动物)的作用将环境中污染物转化为无害或低毒产物的过程。生物修复技术具有成本低、高效和环境安全等特征,被认为是可替代传统的土壤污染修复技术的最佳选择之一。因此,通过综述国内外土壤PCBs污染现状和健康效应,以及土壤PCBs污染的生物修复最新研究进展和相关修复机理,对微生物修复、植物修复和蚯蚓修复目前存在的问题和后续研究方向进行了讨论及展望,以期为今后生物修复PCBs污染土壤提供有益参考。

土壤中PCDD/Fs、PBDD/Fs、PCBs与PBDEs同步分离测试方法的研究

建立了土壤样品中氯代二（噁）英、溴代二（噁）英、多氯联苯和多溴联苯醚四类化合物的同步分离前处理方法.应用硝酸银复合硅胶柱将四类化合物分成含氯（PCBs和PCDD/Fs）和含溴（PBDEs和PBDD/Fs）两大类,再用弗罗里硅土柱分别对PCBs和PCDD/Fs、PBDEs和PBDD/Fs进行两两分离,最终实现四类结构、性质相近化合物的完全分离.该方法的回收率和相对标准偏差（RSD）分别为PCDD/Fs：61％～83％,1.4％～14.2％; PBDD/Fs：71％～110％,2.8％～14.9％; PCBs：68％～92％,3.6％～15.2％; PBDEs：81％～87％,10.9％～17.4％.方法应用于土壤样品中四类化合物的同步分析,并与目前常用的分析方法进行比对,两者间的分析结果相差不大于12.5％,验证了方法的准确性和可靠性.

生物表面活性剂鼠李糖脂对PCBs污染土壤的修复作用研究

利用生物表面活性鼠李糖脂(RL)洗脱土壤,再通过紫外光预照射与生物降解协同去除洗脱液中的PCBs的组合方法对多氯联苯(PCBs)污染土壤进行修复,旨在研究RL在修复PCBs污染土壤中的作用及其机理。结果表明,RL对PCBs的洗脱具有显著的促进作用,PCBs的总洗脱率与RL的质量浓度呈正相关。当洗脱液中加入2 000 mg.L-1的RL,在3次批洗脱后,人工污染土样和陈化土样的PCBs总洗脱率分别达到了90.1%和47.1%。PCBs降解菌P.LB400在以RL或联苯为碳源的驯化培养基中均能够快速生长。当土壤洗脱液中的PCBs被P.LB400的生长细胞菌液降解时,RL对PCBs的生物降解具有显著的促进作用;而在P.LB400的休眠细胞降解体系中,RL对PCBs的生物降解有一定的抑制作用。紫外光预照射对土壤洗脱液中PCBs的生物降解有一定的促进作用。紫外光预照射和生物降解的耦合有利于提高PCBs的降解速率。

Polychlorinated Biphenyls-contaminated Soil Washing with Mixed Surfactants Enhanced by Electrokinetics

On the basis of comparing the adsorption loss of different surfactants[single nonionic surfactant sorbitanmonooleatepolyoxyethylene ether（Tween 80）, anionic surfactant sodium dodecyl benzene sulfonate（SDBS）, and mixed surfactants Tween 80/SDBS（3：2）, Tween 80/SDBS（4：1）] and their performance in the enhancement of polychlorinated biphenyls（PCBs） desorption from soil, the impact of electric field intensity on the desorption of PCBs and the transport of surfactants in washing resulted solution were investigated in this study. With regard to the remedia- tion cost, 1000 mg/L mixed Tween 80/SDBS（3.＇2） was recognized as an optimum concentration in the remediation of PCBs-contaminated soil, because Tween 80/SDBS（3：2） had the highest washing capacity and relatively low adsorp- tion loss onto soil. Electrokinetics can enhance the washing efficiency of PCBs-contaminated soil by Tween 80/SDBS（3：2） effectively and safely at an electric field intensity of 1.5 V/cm for 10 d, for the desorption of PCBs was 1.57 times more than that without electrokinetics, and the most of organic residue in washing resulted solution was removed in an electrical field to avoid the possible secondary contamination risk.