Remediation of Ni toxicity by liming - field validation

通过撒石灰修复镍毒性 - 现场验证

• 批准号: 500255-2016
• 负责人: Hale, Beverley
• 金额: $ 15.74万
• 依托单位: University of Guelph
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=652832
• 关键词: Remediation; Ni; toxicity; liming; field

Remediation of soils contaminated with metals may be achieved through application of agricultural lime, which is expected to reduce plant-available metal by increasing soil pH. However, raising the pH can potentially reduce the bioavailability of essential elements, which may negatively impact crop yields. The present study will revisit a set of agricultural fields in Port Colborne (ON) elevated in Ni, Cu, Co, and As, which were amended with dolomitic lime at either 10 or 50 t/ha a decade ago and yields of oat and soybean were determined in three subsequent years. These fields will be replanted with soybean to evaluate the long-term efficacy of liming as a remediation strategy (Objective 1). These data will be compared to agronomic yield of soybean in fields more recently amended with 88 t/ha of lime (Objective 2). The effect of calcitic versus dolomitic lime on agronomic yield of soybean will be compared in two sets of fields. For both fields, agronomic response and tissue accumulation of Ni will be related to total soil Ni, soil chemistry parameters known to modify bioavailability, soil solution Ni and plant available Ni (Objective 3). An alternate to liming as a remediation strategy is reducing the Ni concentration in surface soils through phytoremediation. Using a Ni hyperaccumulator (Alyssum murale), pot and in situ field studies will provide data of soil to plant transfer which will be used to populate STELLA® models, which allow simulation of a system over time. The outcome will be estimates of the half-life of Ni in surface soils under a number of different scenarios (Objective 4). Finally, the potential for dilution of surface contamination by 'deep tilling' versus the expected loss in crop productivity by bringing less fertile B horizon soils into the root zone, will be evaluated (Objective 5). Integration of these studies will enable a decision support system for soil remediation strategies for this site, which can also be applied to other metal-contaminated areas in Canada (e.g. brownfields). The new knowledge will support the Canadian mining industry in being competitive worldwide by developing and demonstrating practical agronomic interventions suitable for large-scale use, rather than technology-intensive processes.

修复受金属污染的土壤可以通过使用农用石灰来实现，这有望通过提高土壤pH值来减少植物可利用的金属。然而，提高pH值可能会降低必需元素的生物可利用性，这可能会对作物产量产生负面影响。本研究将重新考察科尔伯恩港一组含有镍、铜、钴和砷的农田，这些农田在十年前以10吨/公顷或50吨/公顷的白云石石灰进行了改良，并在随后的三年中测定了燕麦和大豆的产量。这些田地将重新种植大豆，以评估石灰作为一种补救策略的长期效果(目标1)。这些数据将与最近用88吨/公顷石灰修正的大豆农艺产量(目标2)进行比较。在两组田间试验中，比较了钙质石灰和白云石石灰对大豆农艺产量的影响。对于这两个领域，镍的农艺反应和组织积累将与土壤总镍、土壤化学参数、土壤溶液镍和植物有效镍有关(目标3)。除石灰外，另一种修复策略是通过植物修复降低表层土壤中的镍浓度。利用镍超蓄积器(Lyssum Murale)，盆栽和现场研究将提供土壤到植物转移的数据，这些数据将被用来填充Stella®模型，从而允许随着时间的推移模拟系统。其结果将是在若干不同情景下对表层土壤中镍的半衰期的估计(目标4)。最后，将评估“深耕”冲淡地表污染的潜力，以及将肥力较低的B层土壤带入根区对作物生产力造成的预期损失(目标5)。综合这些研究将为该场地的土壤修复战略建立一个决策支持系统，该系统也可应用于加拿大其他金属污染地区(如棕地)。新知识将通过开发和示范适合大规模使用而不是技术密集型过程的实用农艺干预措施，支持加拿大采矿业在全球范围内具有竞争力。