湖南锡矿山周边土壤-农作物系统锑迁移转换特征及污染评价

Characteristics of Antimony Migration and Transformation and Pollution Evaluation in a Soil-Crop System Around a Tin Mine in Hunan Province

为了解湖南锡矿山周边土壤与农产品锑(Sb)含量特征和污染状况,为锑矿区土壤锑污染防治和农田安全利用提供科学依据.以湖南锡矿山为研究区,采集周边不同区域农田土壤及相应农产品,共计193对,通过分析土壤锑含量、基本理化性质和农产品锑含量,研究锑在土壤-农产品系统中迁移和转换特征,并且对土壤及农产品进行安全评估.结果表明,矿场中心区、矿场南区、乡镇中心区、城乡交接区和矿场北区的土壤ω(Sb)分别达到了(2348±2165)、(1298±884.1)、(311.8±526.5)、(302.5±355.9)和(215.6±183.2)mg·kg^(-1),超标倍数分别达到65.22、36.06、8.66、8.40和5.99倍.农产品中莴笋、葱、白菜、空心菜、蒜和豌豆苗的锑富集系数在0.01~0.1,对锑吸收能力相对较高;丝瓜、油麦菜、辣椒、胡萝卜、苦瓜、玉米、茄子、豇豆和芹菜的锑富集系数低于0.01,对锑吸收能力相对较低.安全评估结果表明根茎类和葱蒜类蔬菜有极高的锑污染风险;叶菜类和豆类蔬菜有较高锑污染风险;茄果类蔬菜、瓜果类蔬菜和玉米(谷类)锑污染风险较低.因此急需对矿区采取土壤锑污染治理措施,同时为实现矿区农用土地安全利用,应选择远离矿场中心区土壤锑含量较低区域的农田作为种植区,并优先选择对锑吸收能力较弱的农产品进行种植.

This study used 193 sets of farmland soil and agricultural product samples collected from around a tin mine in Hunan Province,China,to explore the antimony(Sb)content characteristics and pollution status of soil and agricultural products and to provide a scientific basis for the prevention and control of soil antimony pollution in antimony mining areas and the safe use of farmland.We analyzed the amount of antimony in the soil,basic physical and chemical properties,and antimony content in agricultural products;studied the characteristics of antimony migration and transformation in the soil-agricultural product system;and conducted safety assessments on soil and agricultural products.The results showed that the soilω(Sb)in the central area of the mine,the southern area of the mine,the central township area,the urban-rural transfer area,and the northern area of the mine reached(2348±2165),(1298±884.1),(311.8±526.5),(302.5±355.9),and(215.6±183.2)mg·kg^(-1),and the exceeding multiples reached 65.22,36.06,8.66,8.40,and 5.99 times,respectively.The antimony enrichment coefficients of lettuce,scallion,cabbage,water spinach,garlic,and pea seedlings in agricultural products were 0.01-0.1,which indicated good antimony absorption capacity.The antimony enrichment coefficients of loofah,asparagus lettuce,pepper,carrot,bitter gourd,corn,eggplant,cowpea,and celery were less than 0.01,and the antimony absorption capacity was relatively poor.The safety assessment results showed that roots,allium,and garlic vegetables had a high risk of antimony pollution;leafy vegetables and legumes had a higher risk of antimony pollution;and solanaceous vegetables,melons,and fruit vegetables and corn(cereals)had a high risk of antimony pollution.Therefore,it is urgent to take soil antimony pollution control measures in the mining area.At the same time,in order to realize the safe use of agricultural land in the mining area,the farmland far away from the low antimony content of the soil in the central area of the mine should be selected as the planting area,and the agricultural products with weak antimony absorption capacity should be planted first.