The total and available (water extracted) content of selected metal were determined in co-pyrolyzed SSL with willow (8:2, 6:2 w/w) at 500, 600, and 700 °C using two different carrier gases (N₂ or CO₂). The study investigated the relationship of metal content and bioavailability to toxicity of biochars towards bacteria (Vibrio fischeri), plants (Lepidium sativum), and arthropods (Folsomia candida).

For the biochar produced at a ratio of 6:4 (SSL:willow), the content of most metals significant decrease (P ≤ 0.05) from 5.9% to 28.9%. Co-pyrolysis of SSL with willow decreased water extractable metal concentrations (Ba, Cd, Cu, Fe, Mn, Ni, and Zn) from 8.0% to 100%. The CO₂ resulted from 6 to 200 % increase (P ≤ 0.05) of metal content relative to the biochar pyrolyzed in N₂. An increase in pyrolysis temperature caused a higher concentration of the metals in the biochars. The available content of most metals decreased from 9 to 100 %. The adverse effect of these biochars on living organisms was reduced due to a stronger binding of the metals (especially Cu and Cd) with the biochar matrix. The negative impact of Cd, Cr, and Cu on living organisms was also confirmed by principal component analysis (PCA).

使用两种不同的载气（N ₂）在500、600和700°C下与柳树（8：2、6：2 w / w）共热解SSL中测定选定金属的总含量和可用水提取量或CO ₂）。该研究调查了金属含量和生物利用度，以向细菌生物炭的毒性（关系费氏弧菌），植物（独行菜豌豆），和节肢动物（Folsomia念珠菌）。

对于比例为6：4（SSL：柳树）的生物炭，大多数金属的含量从5.9％降至28.9％（P≤0.05）。SSL与柳树的共热解将可提取水的金属浓度（Ba，Cd，Cu，Fe，Mn，Ni和Zn）从8.0％降低到100％。相对于在N _2中热解的生物炭，CO ₂是由于金属含量增加了6％至200％（P≤0.05）。热解温度的升高导致生物炭中金属的浓度更高。大多数金属的有效含量从9％降至100％。由于金属（特别是Cu和Cd）与生物炭基质的牢固结合，减少了这些生物炭对活生物体的不利影响。主成分分析（PCA）也证实了Cd，Cr和Cu对生物的负面影响。