| With the development of industry and rapid increase of energy demand,exploitation and utilization of coal,the main energy resource in China,has increased dramatically.Coal has brought a large number of coal wastes,accounting for 1/4 of the industrial solid waste annual discharge in China,and has become one of the largest solid wastes in China.Coal reserves in Xinjiang account for more than 40%of the whole country,and the associated coal waste is huge.It is of great practical significance for the safe disposal of coal waste and the realization of resource utilization.The main contents of this paper are as follows:Biomimetic preparation of humic acid（HA）from different carbon sources.Faced all kinds of waste,such as weathered coal,coal,coal gangue and oil sludge.We applied a common resource utilization route to invent into humic acid,help to promote the recycling of solid waste in more areas.The technological process of extracting humic acid was as follows,with the oxidation temperature 250oC and 2 h,mass ratio of raw materials to KOH:10:1,under 70oC reaction temperature and 1 h.The Extraction rates of HA-W,HA-C,HA-G and HA-OS were 67.58%,34.33%,25.62%and 14.41%,respectively.Through FT-IR spectrum,UV-vis spectrum,XRD diffraction,SEM and other techniques,found that the molecular structure of humic acid has high degree of condensation,less fatty structure,rich functional groups and strong activity.The detection results of potassium humate showed that except for OS-HAK,other potassium humates met to II standard of GB/T 33804-2017.Highly efficient adsorption of Pb（Ⅱ）by humic acid derived carbon nanoparticles（CNPs）.The adsorption mechanism of humic acid on Pb（Ⅱ）was studied by using modified Hummers method to prepare CNPs from HA.The results showed that the maximum adsorption capacity of CNPs on Pb（Ⅱ）was 297.85 mg g-1 at pH=6.0.Mechanism of HA is a spontaneous exothermic process,can be explained as electrostatic attraction attracted Pb（Ⅱ）to its surface,and the surface functional groups were complexed with lead ions by ion exchange.Preparation of hierarchical porous carbon（HPC）from organic residues of coal gangue after removal of HA.Using coal gangue residue after extracting HA as raw materials,under the optimal process,coal gangue:KOH:urea=1:2:2,and the obtained HPC with the largest specific surface area and rich functional groups,and doped a certain amount of nitrogen.By means of XPS spectrum,FT-IR spectrum,XRD diffraction and so on,found that the mass of N-doped increased with the increased of temperature,and the carbon lattice was divided into small pieces due to different density of electron cloud and the effect of temperature,which led to the collapse of carbon spatial network structure,the increase of defects and unseparation of a small part of nitrogen doped in carbon net rather than shed from the system.Thus the carbon material becoming more stable and diversified.Adsorption performance of coal gangue based HPC for RhB and Cr（Ⅵ）in wastewater.The results of adsorption of simulated wastewater showed that the maximum adsorption capacity of HPC4 for RhB can reach to 3086.42 mg g-1.And was controlled by both physical adsorption and chemical action,the functional groups on the surface of protonated adsorbent combined with RhB through hydrogen bond,and the adsorption became easier with the increase of temperature.With the increase of temperature,more violent the molecular movement is,and stronger the ability to destroy the solvation,easier to diffuse into the pore structure.The adsorption of Cr（VI）first attracts anions to the surface of the material by electrostatic attraction,and then reduce them to Cr（III）by chemical reaction through active functional groups on the surface,such as C=C,C-OH,-NH2,etc.And Cr（III）are fixed on the functional groups such as C=O,C-O to form Cr-O bonds.This work provides a theoretical basis for removal and application of heavy metals in the environment.In this paper,Coal Wastes is taken as the research object,the route and transformation mechanism of full resource utilization are fully studied.And adsorption mechanism of its products in wastewater is explored,which provides a reference for the deep resource utilization and application of solid waste in more fields. |
