Abstract:

Sulfuric acid has long been known as an“industrial yeas”.As an important basic chemical raw material，sulfuric?acid is widely used in various industrial sectors such as textile，chemical engineering，metallurgy and medicine.The litho?phile and sulfophilic characteristics of thallium determine that the process of producing sulfuric acid with pyrite and heavy metal ore as raw materials，such as sulfuric acid from pyrite and smelting flue gas，has become an important source of heavy metal thallium emission.A recent survey from the typical pyrite sulfuric acid producers was found that the thallium content in the raw pyrite ores used for sulfuric acid production was ranged from 2 mg/kg to 30 mg/kg，and the thallium concentration in the waste acids was ranged from 6.01 μg/L to 400 μg/L，with the average concentration of 203 μg/L.Controlling status of thallium in wastewater of sulfuric acid industry was analysed from several aspects，such as methods of establishing the standards for pollutant discharge，technologies for the treatment of wastewater with thallium，economic cost invested，as well as administrative vulnerabilities in environment protection etc..It was presented that 1）implementation of standards related to the treatment of thallium wastewater should be accelerated by carrying out special rectification of thallium wastewater；2）training on the monitoring of total thallium in wastewater should be strengthened；3）the sites of the discharge holes of the “plants and production facilities” should be well?defined to prevent discharge of dilute waste，and 4）the management of the responsibilities on notifying comprehensive utilization of“waste acids” should be set up to prevent shift of thallium in waste acids among different industries.These suggestions are of great importance to the prevention of environmental risks and the protection of the safety of water environment.

Key words: pyrite sulfuric acid production, heavy metal thallium, pollutant discharge standards, risk prevention andcontrol