Synthetic azo dyes such as Orange I represent a significant cause of environmental contamination. Their discharge into the aquatic medium creates tremendous concerns for the environment and living organisms as most of them are recalcitrant, toxic, and carcinogenic. In this context, Algerian dolomite treated at 900 °C (D900), characterized by thermal analysis, laser granulometry, and zetametry, was applied in the adsorption of Orange I from aqueous solutions. Several parameters influencing adsorption were investigated. The mechanism of Orange I-D900 interaction was also explored by infrared spectroscopy. Thermal analysis showed that 900 °C is a sufficient temperature to decompose dolomite [CaMg(CO₃)₂] into CaO and MgO. An initial concentration of 200 mg L⁻¹, pH of 5, solid/solution concentration of 3 g L⁻¹, and temperature of 55 °C, were found to be the optimum conditions, for a maximum amount adsorbed by D900 of 36.8 versus 11.5 mg g⁻¹ for dolomite. The equilibrium data were suitably fitted by the Redlich–Peterson model, with values of coefficient of determination and average relative error ≥ 0.98 and < 10.0%, respectively. Thermodynamic parameters show that the adsorption process switches from non-spontaneous for dolomite to spontaneous for D900. The Orange I-D900 interaction mechanism involves two phenomena: an electrostatic attraction between the negative charge of Orange I embodied by the sulfonate group and the positive charge of D900 represented by MgOH⁺, and a hydrogen bonding between Ca(OH)₂ and Mg(OH)₂, evidenced by infrared spectroscopy, and the hydroxyl group of the azo-molecule. The mechanistic approach is essential to expand the application of dolomite in wastewater remediation.

合成偶氮染料（例如Orange I）是造成环境污染的重要原因。它们排放到水生介质中给环境和生物造成了极大的关注，因为它们大多数是难降解的，有毒的和致癌的。在这种情况下，以900°C（D900）处理的阿尔及利亚白云石为特征，通过热分析，激光粒度分析和Zeta法进行了表征，将其从水溶液中吸附橙I。研究了影响吸附的几个参数。还通过红外光谱研究了Orange I-D900相互作用的机理。热分析表明，900°C足以将白云石[CaMg（CO ₃）₂ ]分解为CaO和MgO。初始浓度为200 mg L ^-1发现pH值为5，固/溶液浓度为3 g L ^-1和温度为55°C是最佳条件，D900吸附的最大量为36.8，而白云石的最大吸附量为11.5 mg g ^-1。平衡数据通过Redlich-Peterson模型进行了适当拟合，测定系数的值和平均相对误差分别≥0.98和<10.0％。热力学参数表明，吸附过程从对白云石的非自发转变为对D900的自发。Orange I-D900的相互作用机理涉及两种现象：由磺酸盐基团体现的Orange I的负电荷与以MgOH ⁺表示的D900的正电荷之间的静电吸引，以及Ca（OH）之间的氢键通过红外光谱法证实了₂和Mg（OH）₂以及偶氮分子的羟基。机械方法对于扩大白云石在废水修复中的应用至关重要。