1.Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences;2.College of Environment, Hohai University;3.State Key Laboratory of Soil & Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences
Supported by the Key-Area Research and Development Program of Guangdong Province, China (No.2020B0202010006), the Postdoctoral Science Fecundation of China (No. 2021M703301), and the Youth Innovation Promotion Association of the Chinese Academy of Sciences (No. 2019312)
土壤重金属污染快速诊断与评价是污染防控与风险管理的前提。以广东省典型设施蔬菜产地土壤为研究对象，采用便携式X射线荧光光谱法(portable X-ray fluorescence spectroscopy, PXRF)原位快速获取土壤重金属（镉（Cd）、铜（Cu）、铬（Cr）、铅（Pb）、锌（Zn）、砷（As）、镍（Ni）及汞（Hg））含量，在传统实验室方法验证PXRF的准确性和稳定性的基础上，对广东省设施菜地表层土壤重金属的污染状况进行快速诊断，并对土壤重金属污染风险进行评价。结果表明：(1) 异位PXRF法对土壤Cd、Cu、Cr、Pb、Zn、As及Ni的测定值与传统实验室方法测定值极显著相关(P<0.01)，土壤Pb和As含量的PXRF原位测定值与传统实验室方法测定值极显著相关(P<0.01)；(2) 土壤含水量为150 g?kg-1~200 g?kg-1时，Cr、Pb、Zn和As的PXRF原位测定值与实验室测定值的相关性达到了极显著水平(P<0.01)；(3) 土壤Cd和Cu的超标现象较为突出，其点位超标率分别为20.9%和10.0%。设施菜地土壤Cd的平均含量为0.21 mg?kg-1，约为露天农田土壤的1.2倍。珠江三角洲地区设施土壤中各重金属的含量整体较其他地区高；(4) 土壤Cd、Cu、Cr、Pb、Zn、As、Ni及Hg的单项污染指数均小于1，由高到低依次为Cd>Cu>Pb>Zn>Cr>As>Ni>Hg，内梅罗综合污染指数的均值为0.69。就整体平均值而言，土壤重金属污染程度处于清洁水平。PXRF实现了广东省设施菜地土壤重金属污染的快速诊断，并快速识别出Cd和Cu为设施菜地污染风险较高的潜在污染元素，研究结果可为设施农业土壤重金属污染快速诊断与评价提供方法和数据支撑。
【Objective】Guangdong is a major province of vegetable production and consumption in China, and is also an important vegetable production base for Hong Kong, Macao, and the "Southern Vegetables and Northern Transportation". Therefore, rapid diagnosis and assessment of soil heavy metal pollution is the premise of soil pollution prevention and control and risk management. This study aimed to investigate the applicability of in situ and ex situ portable X-ray fluorescence spectroscopy (PXRF) for rapid detection of heavy metals in greenhouse vegetable production soils of Guangdong Province and to diagnose and evaluate heavy metal pollution in greenhouse vegetable production soils based on portable X-ray fluorescence spectroscopy. 【Method】A total of 110 greenhouse vegetable production soil sampling sites and 26 open-field soil sampling sites were set up in the study area. PXRF was used in situ to rapidly detect soil heavy metal contents (Cd, Cu, Cr, Pb, Zn, As, Ni and Hg). The accuracy of the PXRF method was verified by analyzing the correlation between the values of soil heavy metals measured by the PXRF and the traditional laboratory analysis and based on this, the soil heavy metal pollution status was quickly diagnosed. The risk of soil heavy metal pollution was evaluated by the single factor pollution index and the Nemerow composite pollution index method. 【Result】The results indicated that: (1) the concentrations of Cd, Cu, Cr, Pb, Zn, As and Ni detected by the ex situ PXRF method were significantly correlated with those determined by traditional laboratory methods (P < 0.01), and the R2 were 0.69, 0.50, 0.56, 0.58, 0.47, 0.54 and 0.62, respectively. Also, the results of in situ determination of Pb and As in soil by the PXRF method were significantly correlated with those by traditional laboratory methods (P < 0.01), and the R2 were 0.73 and 0.74, respectively. (2) When the soil moisture content was 150 g?kg-1-200 g?kg-1, the results of in situ determination of Cr, Pb, Zn and As in soil by the PXRF method were significantly correlated with those by traditional laboratory methods (P < 0.01), and the R2 were 0.77, 0.94, 0.72 and 0.93, respectively. (3) Soil Cd and Cu pollutions were prominent in greenhouse vegetable production soils of Guangdong Province. The point exceeding rates were 20.9% and 10.0%, respectively, according to the Soil Environmental Quality Risk Control Standard for Soil Contamination of Agricultural Land (GB 15618-2018). In addition, the average content of Cd in greenhouse vegetable production soil was 0.21 mg?kg-1, which was 1.2 times greater than that in open-field soil. The contents of Cd, Cu, Cr, Pb, Zn, As and Ni in the greenhouse vegetable production soil in the Pearl River Delta were generally higher than those in other areas. (4) The single pollution index of Cd, Cu, Cr, Pb, Zn, As, Ni and Hg were all less than 1, and the order was Cd > Cu > Pb > Zn > Cr > As > Ni > Hg. The mean value of the Nemerow comprehensive pollution index was 0.69. From the overall average, the degree of soil heavy metal pollution was at a clean level.【Conclusion】In summary, PXRF is an effective method for the rapid diagnosis of heavy metal pollution in greenhouse vegetable production soils in Guangdong Province. Furthermore, Cd and Cu can be quickly identified as the primary pollution elements with high risk in greenhouse vegetable production soils of Guangdong Province. The results of this study will serve as a reference for the evaluation of soil environmental quality and sustainable development of greenhouse agriculture.
DENG Yuan, FAN Yanan, WU Qiumei, HU Wenyou, YU Yueming, WANG Hua, ZHU Chunwu, LI Xun, TIAN Kang, HUANG Biao. Rapid Diagnosis and Assessment of Heavy Metal Pollution in Greenhouse Vegetable Production Soils Based on Portable X-ray Fluorescence Spectroscopy[J]. Acta Pedologica Sinica, DOI:10.11766/trxb202206130187,[In Press]