【摘要】 目的监测惠州市部分农村环境土壤重金属铅(Pb)、镉(Cd)、铬(Cr)污染水平及动态变化,客观评价农村环境土壤卫生状况。方法于2015—2017年随机抽取惠州市5个乡镇作为调查点,每个乡镇随机选取4个行政村作为采样点,共采集60份农村环境土壤进行监测Pb、Cd、Cr。采用石墨炉原子吸收分光光度法检测Pb、Cd含量;火焰原子吸收分光光度法检测Cr含量。以土壤环境质量二级标准值作为评价依据。采用单项指数法和内梅罗指数法评价Pb、Cd、Cr的污染程度。结果2015—2017年惠州市部分农村环境土壤中Pb、Cr含量均符合土壤环境质量标准中的二级标准,而Cd含量的超标率依次为15. 00%、15. 00%、10. 00%。Pb、Cd、Cr检测结果分别在7. 83～160. 0 mg/kg、0. 02～0. 85 mg/kg、0. 30～208. 0 mg/kg之间,Cd、Cr含量差异有统计学意义(分别P <0. 001,P=0. 001),而Pb含量差异无统计学意义(P=0. 057)。Pb、Cd、Cr单元素污染指数的最大值分别是0. 37、2. 05、0. 25,差异均无统计学意义(分别P=0. 531,P=0. 629,P=0. 127)。2015和2017年农村土壤综合污染指数为0. 99和0. 79,评价结果为尚清洁,而2016年农村土壤综合污染指数为1. 46,评价结果为轻污染。结论惠州市部分农村环境土壤质量整体尚可,但部分地区重金属Cd污染值得关注。更多还原

【Abstract】 Objective To monitor the level and dynamic change of heavy metal lead(Pb),cadmium(Cd),and chromium(Cr) in some rural environmental soils in Huizhou City,and assess objectively the soil sanitation status in rural areas. Methods Five rural towns in Huiyang District were randomly selected as survey sites from 2015 to 2017. Four villages in each township were randomly selected as sampling sites. A total of 60 rural soils were collected to monitor soil Pb,Cd,and Cr. The levels of Pb and Cd in soil were detected by graphite furnace atomic absorption spectrophotometry,and the level of Cr was determined by flame atomic absorption spectrophotometry. The secondary standard value of soil environmental quality was used as the evaluation basis. Single item index method and Nemerow index method were used to evaluate the pollution levels of heavy metals Pb,Cd,and Cr in rural soils. Results The content of Pb and Cr in rural environmental soil of Huiyang District from 2015 to 2017 all met the secondary standards in the soil environmental quality standards,however,the over-standard rates of Cd content were 15. 00%,15. 00%,and 10. 00%,respectively.The level of Pb in soil was between 7. 83 and 160. 0 mg/kg,Cd was between 0. 02 and 0. 85 mg/kg,Cr was between 0. 30 and 208. 0 mg/kg,and there were significant differences between Cd and Cr contents(P < 0. 001,P = 0. 001,respectively),no significant difference was observed in Pb content(P = 0. 057). The maximum values of single element pollution index of soil heavy metals Pb,Cd and Cr were 0. 37,2. 05 and 0. 25. There was no significant difference in the single element pollution index of heavy metals Pb,Cd,and Cr(P = 0. 531,P = 0. 629,P = 0. 127,respectively). The comprehensive soil pollution indexes in 2015 and 2017 were 0. 99 and0. 79,respectively. The evaluation result was still clean,while the 2016 rural soil comprehensive pollution index was 1. 46,and the evaluation result was light pollution. Conclusion The soil quality of some rural areas in Huizhou was generally acceptable,but heavy metal Cd pollution in some areas was worthy of attention.更多还原