本研究旨在评估矿井水回用,阐明与痕量金属生物地球化学有关的潜在问题,重点是水中的Cu动力学,土壤,和植物。水样是从铜矿和用于储存矿井水的水库中收集的。从未开垦地区的土壤和香蕉果园(用矿井水灌溉至少10年)和灌溉地区的植物中采集了其他样品。分析了以下参数:pH,氧化还原电位,水样中的溶解离子(例如,Ca2+,Mg2+,Na+,K+,Cu2+,SO42-,andCl-),生物可利用的Cu和Cu固相分馏(在土壤和储层沉积物样品中),以及香蕉植物中的铜含量。矿井水中溶解铜浓度高(平均2.3±0.0mgL-1),限制其用于灌溉。水库蓄水提高了水质,降低溶解的铜浓度(平均0.2±0.0mgL-1),由于吸附/沉淀为碳酸盐(平均131.8±24.6mgkg-1),有机物(平均1526.2±4.7mgkg-1)和硫化物(平均158.4±56.9mgkg-1)。尽管水库水质较高,矿井水的使用增加了土壤中生物可利用铜的含量,主要与有机物有关。土壤中生物可利用性Cu的增加并没有增加香蕉叶片的Cu含量,但导致根和果的Cu含量高。增加了人群的毒性风险。
This study aimed to evaluate mine water reuse, elucidating the potential problems related to trace metal biogeochemistry focusing on Cu dynamics in water, soil, and plants. Water samples were collected from a Cu mine and a reservoir used to store mine water. Additional samples were taken from soils from an uncultivated area and a banana orchard (irrigated with mine water for at least 10 years) and plant from the irrigated area. The following parameters were analyzed: pH, redox potential, dissolved ions in water samples (e.g., Ca2+, Mg2+, Na+, K+, Cu2+, SO 4 2- , and Cl-), bioavailable Cu and Cu solid-phase fractionation (in soils and reservoir sediments samples), as well as Cu content in banana plants. Mine water presents high dissolved Cu concentration (mean 2.3 ± 0.0 mg L-1), limiting its use for irrigation. Water storage at the reservoir increased water quality, reducing dissolved Cu concentration (mean 0.2 ± 0.0 mg L-1), due to adsorption/precipitation as carbonates (mean 131.8 ± 24.6 mg kg-1), organic matter (mean 1526.2 ± 4.7 mg kg-1) and sulfides (mean 158.4 ± 56.9 mg kg-1). Despite higher water quality at the reservoir, the use of mine water increased the amount of bioavailable Cu in soils, which was primarily associated with organic matter. Increased bioavailable Cu in the soil did not increase the Cu content of banana leaves but resulted in high Cu content of roots and fruit, increasing the risk of toxicity for the population.