Preparation of adsorbent from coal gasification slag for the treatment of waste water from lanchar and its adsorption mechanism

Solid waste coal gasification slag has certain hardness, porosity, pore structure and specific surface area, etc. which can be utilized in environmental protection materials and other areas of high value. Yulin City, high-quality coal resources derived from the excellent quality of charcoal products, but its processing will produce a large number of high chemical oxygen demand (COD), high volatile phenol, high ammonia nitrogen 'three high' wastewater, the ecological environment is very harmful. The results of the modification of the refined coal gasification fine residue showed that the removal rates of the three were enhanced to 91%, 89% and 83%, respectively, after adsorption at a pH of 9.5, an injection ratio of 1:5 and 25 ℃ for 25 min. The reason is that the modification treatment significantly increased the specific surface area of the adsorbent from 103 m²/g to 606 m²/g, which effectively increased the adsorption active sites for the pollutant molecules. The adsorption process of COD from modified refining coal gasification slag for the treatment of charcoal wastewater was thermodynamically investigated. The thermodynamic study shows that the adsorption process of modified refining coal gasification slag on pollutants in the charcoal wastewater is an exothermic and spontaneous process.