Albendazole (ABZ) is a benzimidazole-based veterinary anthelmintic used extensively in the treatment of intestinal parasites. Due to its high hydrophobicity, ABZ tends to accumulate in soils and sediments in the environment. This study aims to investigate ABZ’s possible degradation by manganese oxides. Minor effects from ionic strength and metal cations on ABZ degradation were observed. By contrast, decrease of pH greatly enhanced the reaction rate. Surface complexation between ABZ and MnO₂ was indicated to be the dominant control in the reaction kinetics. Suppression by the presence of co-solvents was negatively proportional to the solvent polarities (suppression from high to low: diethyl ether～n-butanol > ethanol > methanol > acetonitrile). Humic acid was found to cause significant inhibition due to the reductive dissolution of MnO₂. Four hydrolysis and six oxidative products were identified. ABZ and its hydrolysis products containing the propylthio side chain underwent the same oxidative transformation to form their corresponding sulfoxide compounds. Dehydrogenative coupling reaction between sulfoxide products and hydrolysis products could occur to generate dimers. All hydrolysis and oxidative products were eluted faster than ABZ in liquid chromatogram, suggesting that the spreading out of ABZ will be significantly enhanced if reacting with MnO₂.

阿苯达唑（ABZ）是一种基于苯并咪唑的兽用驱虫药，广泛用于治疗肠道寄生虫。由于其高疏水性，ABZ易于在环境中的土壤和沉积物中积聚。这项研究旨在研究ABZ可能被锰氧化物降解。观察到离子强度和金属阳离子对ABZ降解的较小影响。相比之下，pH的降低大大提高了反应速率。ABZ和MnO ₂之间的表面络合表明是反应动力学的主要控制因素。共溶剂的存在与溶剂极性成反比（从高到低：乙醚〜正丁醇>乙醇>甲醇>乙腈）。发现腐殖酸由于MnO ₂的还原溶解而引起明显的抑制作用。鉴定出四种水解和六种氧化产物。ABZ及其包含丙硫基侧链的水解产物进行相同的氧化转化，以形成其相应的亚砜化合物。亚砜产物和水解产物之间可能发生脱氢偶联反应，从而生成二聚体。在液相色谱图中，所有水解和氧化产物的洗脱速度均快于ABZ，这表明与MnO ₂反应可显着增强ABZ的扩散。