Department of Environmental Science and Technology, School of Applied Sciences, Cranfield University, Bedfordshire MK43 0AL, UK.
Department of Geography, Environment and Earth Sciences, University of Hull, Cottingham Road, Yorkshire HU6 7RX, UK.
J Hazard Mater. 2014 Jul 15;276:10-8. doi: 10.1016/j.jhazmat.2014.05.006. Epub 2014 May 10.
The potential for pollution from arsenic, chromium and copper in chromated copper arsenate (CCA) treated wood waste was assessed using two lysimeter studies. The first utilised lysimeters containing soil and CCA wood waste mulch exposed to natural conditions over a five month period. The second study used the same lysimeter setup in a regulated greenhouse setting with a manual watering regime. Woodchip, soil and leachate samples were evaluated for arsenic, chromium and copper concentrations. Resultant concentration data were used to produce mass balances, an approach thus far unused in such studies. This novel analysis revealed new patterns of mobility and distribution of the elements in the system. The results suggest that CCA wood waste tends to leach on initial exposure to a leachant and during weathering of the wood. When in contact with soil, metal(loid) transport is reduced due to complexation reactions. With higher water application or where the adsorption capacity of the soil is exceeded, the metal(loid)s are transported through the soil column as leachate. Overall, there was an unexplained loss of metal(loid)s from the system that might be attributed to volatilisation of arsenic and plant uptake. This suggests a hitherto unidentified risk to both the environment and human health.
采用两种渗滤池研究，评估了铬酸铜砷酸酯（CCA）处理木材废物中砷、铬和铜的污染潜力。第一项研究利用含有土壤和 CCA 木材废物覆盖物的渗滤池，在自然条件下暴露了五个月。第二项研究使用相同的渗滤池设置在受控温室环境中，采用手动浇水制度。对木屑、土壤和渗滤液样品进行了砷、铬和铜浓度的评估。所得浓度数据用于生成质量平衡，这是迄今为止此类研究中未使用的方法。这种新颖的分析揭示了元素在系统中的迁移和分布的新规律。结果表明，CCA 木材废物在最初暴露于浸出液和木材风化时往往会浸出。当与土壤接触时，由于络合反应，金属（类）的迁移受到抑制。随着水的应用增加或土壤的吸附能力超过时，金属（类）作为渗滤液通过土壤柱进行迁移。总的来说，系统中存在金属（类）的不明原因损失，这可能归因于砷的挥发和植物吸收。这表明对环境和人类健康存在迄今未识别的风险。
