Increasing biochar application worldwide may release more biochar-derived dissolved organic matter (BDOM) to the source water for drinking water supply. However, it is unclear how feedstock types and pyrolysis temperatures for biochar production would affect the characteristics and chlorine reactivity of BDOM. Here, we studied the spectroscopic characteristics of BDOM pyrolyzed from pine needle, wheat straw, walnut shells, alfalfa, pig manure, and sludge derived biochars at 300, 500, and 700 °C, as well as the formation potential of disinfection byproducts (DBPs) and their bulk toxicity after BDOM chlorination. The N/C ratio of biochar was higher for N-rich than C-rich feedstocks. Optical analyses indicated that BDOM aromaticity was highest at 700 °C, while the impact of pyrolysis temperature on the molecular weight of BDOM varied greatly among feedstocks. Increasing pyrolysis temperature caused consistently decreased BDOM reactivity toward haloketone formation but did not show consistent impacts on the other DBPs. Among feedstocks, the N-rich sludge showed the highest specific haloacetonitrile formation potential of BDOM at any given pyrolysis temperature. The DBP formation potential from biochar was consistently highest at 300 °C and was higher for N-rich than C-rich feedstocks. The microtoxicity of DBP mixture was highest for the BDOM derived from sludge produced at 300 °C. This study highlights the high variations in characteristics and chlorination reactivity of BDOM with varying feedstocks and pyrolysis temperatures, which implies that more attention should be paid to the environmental impacts of the intensive application of low-temperature biochar from N-rich feedstock such as sludge.

在全球范围内增加生物炭的应用可能会向饮用水源水释放更多的生物炭衍生的溶解有机物 (BDOM)。然而，目前尚不清楚生物炭生产的原料类型和热解温度将如何影响 BDOM 的特性和氯反应性。在这里，我们研究了松针、麦秸、核桃壳、紫花苜蓿、猪粪和污泥衍生生物炭在 300、500 和 700 °C 下热解 BDOM 的光谱特征，以及消毒副产物 (DBPs) 的形成潜力。 ) 及其在 BDOM 氯化后的总体毒性。富含 N 的生物炭的 N/C 比高于富含 C 的原料。光学分析表明，BDOM 芳香性在 700 °C 时最高，而热解温度对 BDOM 分子量的影响因原料而异。提高热解温度会导致 BDOM 对卤酮形成的反应性持续降低，但对其他 DBP 的影响并未显示出一致的影响。在原料中，在任何给定的热解温度下，富含 N 的污泥显示出最高的 BDOM 特定卤代乙腈形成潜力。生物炭的 DBP 形成潜力在 300 °C 时始终最高，并且富含 N 的原料高于富含 C 的原料。DBP 混合物的微毒性对 300 °C 产生的污泥产生的 BDOM 最高。本研究强调了 BDOM 在不同原料和热解温度下的特性和氯化反应性的高度变化，