Comprehensive Treatment Program Of A Sulfide Alkali Slag Field With Risk Management

Informal industrial solid waste storage yards refer to industrial solid waste disposal and disposal sites that are not constructed in accordance with national standards or technical specifications,such as the “General Industrial Solid Waste Storage and Disposal Site Pollution Control Standards”(GB18599-2001)etc.,or not complete in environmental protection facilities,Such stack yards have poor stability,complex slag composition,high pollutant concentration,and easy leakage of leachate into surface water,soil and groundwater,which will cause continuous pollution and damage to the surrounding environment,thus posing great safety and environmental risks.At present,the main remediation measures for informal industrial solid waste storage yards are divided according to the treatment methods: after-treatment,in-situ landfill,after-treatment relocation,overall in-situ remediation and overall relocation.In view of the characteristics of the uncertain hazard of the informal industrial solid waste storage yard,considering the limitation of regulation cost and time,taking corresponding risk control measures according to the size of the risk,which is the “preventive approach to the hidden dangers”.An alkali sulfide residue yard in southwest is an informal industrial solid waste storage yard left over from history,through the existing environmental pollution site investigation and risk assessment,the main environmental pollution of the sulfide alkali slag yard is the inorganic pollution problem of strong alkaline slag.According to the theoretical research and the actual characteristics of the project,limited by the time period and the cost of remediation,based on the risk management and control ideas,the best engineering control and repair-attenuation technique for the slag yard is obtained.The remediation project aims to move the slag body backwards by 150 m,and design a new sulfide alkali sealing slag bank with a horizontal-vertical anti-seepage barrier system.Firstly,the waste residue is pretreated by dehydration to reduce the migration of water-soluble pollutants in the waste residue.The humic acid is used as a buffering agent,and the waste residue is layered and backfilled and compacted,and finally the field is closed.The bottom soil exposed in the old slag field is subjected to humic acid in situ restoration and vegetation restoration,which has good effects and environmental safety.The groundwater pollution control of the slag yard adopts the risk control technology of natural attenuation and system control.Based on the above ideas and methods of remediation,Finally,the comprehensive remediation engineering design including waste residue disposalengineering,soil remediation engineering,leachate collection and drainage system,landfill construction engineering and auxiliary engineering was formed.