Methods to Identify Hazardous Waste Sludge

Electroplating wastewater and sludge with excessive heavy metals:

Electroplating sludge belongs to hazardous waste, and the waste category often belongs to HW17, HW21, HW22, HW23 at the same time. Electroplating wastewater with excessive heavy metals belongs to the scope of prevention and control of wastewater pollution and is included in wastewater management. It is not applicable to the scope of the Law of the People's Republic of China on the Prevention and Control of Environment Pollution Caused by Solid Wastes. And it is not classified as hazardous waste. Although the excessive wastewater is not included in the management of hazardous waste, according to the Two High Judicial Interpretation (2016 edition), if one type of heavy metal in the wastewater (eg lead, mercury, chromium, cadmium, arsenic) exceeds the standard by 3 times, or the second type of heavy metal (such as nickel, copper, zinc, manganese, vanadium) exceeds the standard by more than 10 times, in addition to the administrative penalty, the company will still be held criminally liable.

Sludge from domestic wastewater treatment plants:

This kind of sludge is solid waste, not hazardous waste. However, the management level should be improved, especially the ledgers management should be strengthened to prevent spills and illegal dumping during transportation. However, the sludge produced in the wastewater treatment process of industrial enterprises is often too toxic, or contains other toxic and hazardous substances and dangerous characteristics, so most of them should belong to the category of hazardous waste.

Fly ash from household waste incineration:

It is classified as hazardous waste (HIW18). However, after meeting the requirements of Section 6.3 of the Standard for Pollution Control on the Landfill Site of Municipal Solid Waste (GB16889-2008), landfill in domestic waste landfills is not included in hazardous waste management. In another case, if the pretreatment meets the relevant requirements of the Standard for pollution control on co-processing of solid wastes in cement kiln (GB30485-2013), the coordinated disposal process is also included in the scope of exemption management.

Sludge produced during the wastewater treatment of medical institutions:

Most of it is hazardous waste. According to the regulations on the administration of medical wastes (State Council Order No. 380), medical waste means waste that is directly or indirectly infectious, toxic or other hazardous produced by medical and health institutions in the course of medical treatment, prevention, health care and other related activities. According to the national catalogue of hazardous wastes, medical waste is hazardous waste. The classification of medical waste shall be carried out in accordance with the medical waste classification catalogue. The infectious waste in the medical waste classification catalogue lists other articles contaminated by the patient's blood, body fluids and excreta. The grid slag, precipitated sludge and septic tank sludge generated in the wastewater treatment process of medical institutions should be included in this category.

In the environmental assessment, the wastewater treatment process of a medical institution has been specially designed, and it has made a judgment on the properties of sludge. If the management believes that this kind of sludge should be included in the hazardous waste management, then the final judgment should be made through the hazardous waste identification procedure.