Marchand Lilian, Brunel-Muguet Sophie, Lamy Isabelle, Mench Michel, Pelosi Celine
BIOGECO, INRA, Univ. Bordeaux, Pessac, 33615, France.
UNICAEN, INRA, EVA, Normandie Univ., Caen, 14000, France.
Ecotoxicology. 2017 Dec;26(10):1378-1391. doi: 10.1007/s10646-017-1862-8. Epub 2017 Oct 11.
Biochars are used as amendments to improve soil quality, but their effects on edaphic organisms such as earthworms remain controversial. This study aimed to assess the effects of adding a poultry manure-derived biochar into a contaminated technosol on trace element (TE) (i.e. As, Cd, Cu, Pb, and Zn) bioavailability for two earthworm species, Aporrectodea icterica and Aporrectodea longa. Three components of the bioavailability concept were determined using a pot experiment: (1) total soil TE (potentially reactive) and TE concentrations in the soil pore water (environmental availability), (2) TE concentrations in depurated whole earthworm bodies (environmental bioavailability) and (3) ecophysiological and biochemical effects on earthworms (toxicological bioavailability). Biochar addition increased TE concentrations in the soil pore water respectively from 1.8, 2.7, 9.4, 0.7 and 959 to 6, 6.2, 19.3, 6.9, and 3003 µg L for As, Cd, Cu, Pb and Zn. Biochar addition did not influence TE environmental bioavailability for earthworms, except a decreased As concentration (32.5 to 15.2 µg g) in A. icterica. This suggests an inter-specific variability in As homeostasis in the Aporrectodea genus. In line with this internal As decrease, the Glutathione-S-transferase (GST) activity decreased by 42% and protein and lipid contents slightly increased (14 and 25%, respectively) in A. icterica tissues. The body weight of both earthworm species decreased for the biochar-amended soil. Environmental TE availability depended on both the biochar addition and the earthworm activity in the contaminated soil, while environmental and toxicological bioavailabilities resulted from the earthworm species, the targeted TE and biochar supply to the soil.
生物炭被用作改良剂来改善土壤质量，但其对蚯蚓等土壤生物的影响仍存在争议。本研究旨在评估向受污染的技术土壤中添加家禽粪便衍生生物炭对两种蚯蚓（黄色爱胜蚓和长爱胜蚓）的微量元素（TE，即砷、镉、铜、铅和锌）生物有效性的影响。通过盆栽试验确定了生物有效性概念的三个组成部分：（1）土壤总TE（潜在反应性）和土壤孔隙水中的TE浓度（环境有效性），（2）净化后的蚯蚓整体组织中的TE浓度（环境生物有效性），以及（3）对蚯蚓的生态生理和生化影响（毒理学生物有效性）。添加生物炭后，土壤孔隙水中砷、镉、铜、铅和锌的TE浓度分别从1.8、2.7、9.4、0.7和959增加到6、6.2、19.3、6.9和3003μg/L。添加生物炭对蚯蚓的TE环境生物有效性没有影响，除了黄色爱胜蚓体内的砷浓度降低（从32.5降至15.2μg/g）。这表明爱胜蚓属中砷稳态存在种间变异性。与这种体内砷含量降低一致，黄色爱胜蚓组织中的谷胱甘肽-S-转移酶（GST）活性降低了42%，蛋白质和脂质含量略有增加（分别为14%和25%）。两种蚯蚓在添加生物炭的土壤中的体重均下降。环境TE有效性取决于生物炭的添加和受污染土壤中蚯蚓的活动，而环境和毒理学生物有效性则取决于蚯蚓种类、目标TE以及生物炭向土壤中的供应情况。
