Department of Biology & CESAM (Centre for Environmental and Marine Studies), University of Aveiro, 3810-193, Aveiro, Portugal,
Ecotoxicology. 2014 Nov;23(9):1784-93. doi: 10.1007/s10646-014-1344-1. Epub 2014 Sep 12.
It is vital to address potential risks to aquatic ecosystems exposed to runoff and leachates from biochar-amended soils, before large scale applications can be considered. So far, there are no established approaches for such an assessment. This study used a battery of bioassays and representative aquatic organisms for assessing the acute toxicity of water-extractable fractions of biochar-amended soil, at reported application rates (80 t ha(-1)). Biochar-amended aqueous soil extracts contained cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), manganese (Mn), zinc (Zn), nickel (Ni), lead (Pb), arsenic (As) and mercury (Hg) (Σmetals 96.3 µg l(-1)) as well as the 16 priority PAHs defined by the U.S. Environmental Protection Agency (Σ16PAHs 106 ng l(-1)) at contents in the range of current EU regulations for surface waters. Nevertheless, acute exposure to soil-biochar (SB) extracts resulted in species-specific effects and dose-response patterns. While the bioluminescent marine bacterium Vibrio fischeri was the most sensitive organism to aqueous SB extracts, there were no effects on the growth of the microalgae Pseudokirchneriella subcapitata. In contrast, up to 20 and 25% mobility impairment was obtained for the invertebrate Daphnia magna upon exposure to 50 and 100% SB extract concentrations (respectively). Results suggest that a battery of rapid and cost-effective aquatic bioassays that account for ecological representation can complement analytical characterization of biochar-amended soils and risk assessment approaches for surface and groundwater protection.
在大规模应用之前，必须解决生物炭改良土壤的径流和淋滤液对水生生态系统的潜在风险。到目前为止，还没有建立这种评估的既定方法。本研究使用了一系列生物测定法和有代表性的水生生物，以评估以报告的应用率（80 t ha(-1)）添加生物炭的土壤的水可提取部分的急性毒性。生物炭改良的水基土壤提取物含有镉（Cd）、钴（Co）、铬（Cr）、铜（Cu）、锰（Mn）、锌（Zn）、镍（Ni）、铅（Pb）、砷（As）和汞（Hg）（Σ 金属 96.3 µg l(-1)）以及美国环境保护署（U.S. Environmental Protection Agency）定义的 16 种优先多环芳烃（Σ16PAHs 106 ng l(-1)），含量在欧盟目前对地表水的规定范围内。尽管如此，土壤-生物炭（SB）提取物的急性暴露导致了物种特异性的影响和剂量反应模式。虽然发光海洋细菌发光杆菌是对水基 SB 提取物最敏感的生物，但对微藻斜生栅藻的生长没有影响。相比之下，在接触 50%和 100%SB 提取物浓度时，无脊椎动物大型溞的移动能力分别下降了 20%和 25%。结果表明，一系列快速且具有成本效益的水生生物测定法，能够反映生态代表性，可以补充生物炭改良土壤的分析特性和地表水及地下水保护的风险评估方法。
