Abstract

Natural bitumen was implemented as a cheap, green, available and efficient sorbent for removal of Pb(II), Cu(II) and Cd(II) ions. The effect of important parameters including time, sorbent dosage, pH and temperature was explored on adsorption process. Maximum removal for all three cations present at pH = 6.0 and 30 min for Pb(II) and Cd(II) cations and 60 min for Cu(II) cation. Also, %Removal for all three cations was decreased by increasing the temperature which is an indication of exothermic adsorption process. However, adsorption isotherms for all three cations were interpreted by Langmuir model. Also, experimental data of all three cations follows pseudosecond-order kinetic model which indicate chemisorption process. Thermodynamic parameters including ∆G, ∆H and ∆S were calculated for all three cations which present spontaneous nature of reaction. Finally, natural bitumen was presented highly adsorption–desorption property and used successfully for removal of Pb(II), Cu(II) and Cd(II) ions in wastewater real sample. Natural bitumen contains mostly carbon and oxygen elements and its good performance as a sorbent probably is due to its similar composition with other carbonaceous sorbents such as activated carbon.

Graphic Abstract

中文翻译：

---

天然沥青作为低成本的重金属阳离子修复剂

摘要

天然沥青是一种廉价，绿色，可用和高效的吸附剂，可去除Pb（II），Cu（II）和Cd（II）离子。探讨了时间，吸附剂用量，pH和温度等重要参数对吸附过程的影响。对于pH = 6.0的所有三种阳离子，Pb（II）和Cd（II）阳离子的最大去除时间为30分钟，而Cu（II）阳离子的最大去除时间为60分钟。同样，通过升高温度降低了所有三个阳离子的％去除率，这表明放热吸附过程。但是，Langmuir模型解释了所有三个阳离子的吸附等温线。同样，所有三个阳离子的实验数据均遵循伪二级动力学模型，该模型表明了化学吸附过程。热力学参数包括∆ G，∆ H和∆ S对于呈现自发反应性质的所有三个阳离子，计算其分子量。最终，天然沥青具有很高的吸附-解吸性能，并成功地用于去除废水中真实样品中的Pb（II），Cu（II）和Cd（II）离子。天然沥青主要包含碳和氧元素，其作为吸附剂的良好性能可能是由于其与其他含碳吸附剂（如活性炭）的组成相似。

图形摘要