Progress on Mercury-containing Wastewater Treatment

With the development of industry and economy in the world, a large amount of heavy metal industrial wastewater is difficult to decompose in nature and is discharged without treatment to form water pollution. It poses a major threat to the environment, ecology, and human health. Mercury is one of the highly toxic heavy metal elements in the environment. Mercury and mercury compounds are widely present in nature. This article introduces three methods for treating mercury wastewater including chemical precipitation, adsorption, and photocatalysis. Adsorbents such as activated carbon, iron oxide, and nanoparticles can remove mercury ions by adsorbing them. Precipitating agents such as sulfides and hydroxides can bind mercury ions to form precipitates, thereby achieving removal. Photocatalysis uses photocatalysts such as titanium dioxide to generate active oxygen species under light to oxidize and decompose inorganic mercury in wastewater, thereby achieving the purpose of mercury removal. Factors such as treatment efficiency, cost, sustainability, and environmental impact need to be comprehensively considered to select an appropriate method for treatment. Future research needs to further explore efficient and environmentally friendly methods for treating mercury in water.