Study On Preparation Of Biochar Magnetic Composites And LDH And Their Sorption Mechanisms Of Heavy Metal Ni(?)

Nickel is widely used in electroplating,catalysis,batteries and other industrial fields.However,the random discharge of production wastewater has caused heavy metal nickel ions pollution in the water body,which has been a great hazard to humans and aquatic plants and animals.How to remove heavy metal pollutants represented by nickel ions from wastewater is a problem that needs to be faced in basic research and practical applications.Compared with the traditional treatment technology,sorption method has attracted great attention in the application of industrial heavy metal wastewater treatment due to its simple design,high removal efficiency and cost-effectiveness.In this paper,a simple one-pot solvothermal method was used to prepare amino functionalized biochar magnetic composites RB@MgFeAlO₄-NH₂ to improve the sorption performance and separation efficiency,while reducing cost efficiency.The demonstrated synergy and excellent sorption performance indicated potential practical applications.In addition,based on the study of LDH,the sorption of the synthesized single pure phase Mg-Al-LDH and its calcined product was studied.The effects of pH,ionic strength,contact time,initial Ni???concentration and temperature on the sorption of Ni???on the above adsorbents were studied using static batch experiments.The sorption mechanisms was explored from micro and macro levels through combining sorption isotherms and kinetic analysis with Fourier transform infrared spectroscopy?FT-IR?,X-ray photoelectron spectroscopy?XPS?and inductively coupled plasma mass spectrometry?ICP-MS?analytical detection techniques.The analyses will provide theoretical guidance and data support for the treatment of industrial heavy metal wastewater.Experimental results showed that:?1?The sorption of Ni???on RB@MgFeAlO₄-NH₂ was monolayer and rapidly,and it was obviously affected by the pH value.As the pH increased,the sorption rate increased.?2?The research based on the sorption mechanism showed that ions exchange mechanism accounted for 76.51%of the sorption of Ni???on RB@MgFeAlO₄-NH₂.In addition,the complexation of amino,carboxy and hydroxyl groups with Ni???also contributed to the sorption process.?3?Owing to the multiple advantages of environmental friendliness,low cost,easy magnetic separation and high sorption capacity,RB@MgFeAlO₄-NH₂ will be an excellent adsorbent for low cost and effective removal of Ni???from aqueous solutions.?4?The synthesized Mg-Al-LDH has the shape of pure hexagonal nanoplates and a single pure phase.The calcined product had the corresponding mixed metal oxide.?5?Mg-Al-LDO had higher Ni???sorption capacity than Mg-Al-LDH.The surface complexation and reconstructed isomorphous replacement could be the main sorption mechanism of Mg-Al-LDO towards Ni???.