Research On Synthesis Of Attapulgite Clay@Carbon Nanocomposite And Application In The Removal Of Pollutants In Water

With the rapid development of economy, water pollution in China has been more and more serious. Industrial wastewater is the main source of water pollution, which contains a variety of pollutants. Some pollutants in industrial wastewater, such as organic compounds and heavy metal ions are poisonous, which are difficult to remove. However, some conventional treatment methods, such as activated carbon adsorption method, biological treatment, chemical oxidation and membrane separation method can not effectively to meet the requirements of the water treatment. Research and development on new and low-cost materials with multiple functions has become an important and urgent task. Clay mineral adsorbent, especially the attapulgite clay adsorbent was concerned as a new and low-cost adsorbent material at home and abroad. Due to the advantages of low cost, better effect of treatment, simple regeneration, treatment of industrial wastewater by attapulgite clay has shown broad application and development prospects.Food wastewater is rich in carbohydrates, protein and lipids and other organic matter, and it is the main source of organic phase of municipal solid waste, accounting for about40%to60%. The high content of water,organic compounds, and ease of deterioration make it both a pollutant and a recyclable resource.Attapulgite is widely used in industrial wastewater treatment due to its own excellent structure and properties. Attapulgite clay has strong hydrophilic, and weak organophilic. Current organically modified methods are usually high cost, also may cause environmental pollution and destruction. To solve this problem, we prepared multi-function attapulgite clay@carbon composite material with excellent adsorption by hydrothermal synthesis reaction. In this study, attapulgite clay@carbon composite material were prepared by organically modification, in oder to make it remove organic pollutants and heavy metal ions in wastewater more effectively. Using the hydrothermal synthesis reaction, attapulgite clay@carbon composite material I was prepared with low-grade attapulgite clay and sucrose, and attapulgite clay@carbon composite material II was preared with high-grade attapulgite clay and Food wastewater. The influence of preparation conditions on composite materical structures, surface properties and adsorption performance have been studied by a variety of characterization techniques (SEM,IR,XRD). After that, simulated absorption experiments of two attapulgite clay@carbon composite materials for wastewater have been conductedThe results showed that the carbon in the form of amorphous was coated on the surface of attapulgite crystal, some organic group existed in the material, such as-CH,-C=C-and-C=O。 So the organophilic performance was largely improved. It also showed that the reaction time, temperature and pH in the hydrothermal reaction process had a great influence on the adsorption properties of the attapulgite clay@carbon composite material.In the simulated absorption experiments, the adsorption rate of attapulgite clay@carbon composite Ⅰ on5mg/L phenol reached79%, which was9.16times of the adsorption rate of low-grade attapulgite clay; the adsorption rate of attapulgite clay@carbon composite Ⅰ on100mg/L Cr6+reached99.5%, which was14.14times of the adsorption rate of low-grade attapulgite clay. The adsorption rate of attapulgite clay@carbon composite Ⅱ on5mg/L phenol reached75.4%%, while the adsorption rate of high-grade attapulgite clay was9.08%; the adsorption rate of attapulgite clay@carbon composite Ⅱ on100mg/L Cr6+reached99.4%, while the adsorption rate of high-grade attapulgite clay was20.72%. Thereofore, the adsorption performance of attapulgite clay@carbon composites on trace organic pollutants and toxic heavy metal ions was largely improved. Meanwhile, Solid-liquid ratio, pH value, the initial solution concentration and some other factors had great impacts on the adsorption performance. The adsorption on phenol and Cr6+of attapulgite@carbon composite fitted the Langmuir model very well which proved that the adsorption process was the surface adsorption of the monomolecular layer.