The Treatment of Iron Containing Waste Acid in the Chemical Industry Turns Waste into Treasure

According to statistics, China generates over 100 million tons of waste acid annually, with titanium dioxide, petroleum processing, and steel pickling enterprises producing a significant amount of waste acid. These acid washes have strong acidity (pH<1) and high metal content. If they enter the natural world, they have great toxicity to aquatic organisms and microorganisms, seriously polluting the environment, posing great harm to groundwater, soil, etc., and causing catastrophic ecological damage.

The treatment of industrial waste acid has always been an important issue in environmental protection work. The traditional neutralization precipitation method is not only expensive and incomplete in treatment, but also cannot recycle acid, resulting in resource waste. The methods of recycling include heating evaporation, extraction, and membrane permeation. These methods have disadvantages such as high processing costs, high maintenance costs, and complex operating steps. Compared with these methods, the special resin adsorption method has obvious advantages. The table below provides a comprehensive comparison of the current conventional governance methods.

Table 1 Comparison of Main Treatment Methods for Iron containing Waste Acid Treatment

Our company's independently developed inorganic acid adsorbent is used for efficient separation of acids and metal ions. By utilizing the high selectivity of the adsorbent for inorganic acids, inorganic acids are adsorbed during the adsorption process, while metal ions can pass through. The adsorbed inorganic acids can be regenerated and recovered with water. The final acid and metal ions are effectively separated and recycled separately. The material has a long service life and lower operating costs compared to other adsorbents.

A chemical enterprise in Jiangsu Province produced a waste acid containing iron during production, with an iron content of about 50000mg/L, a dark yellow green appearance, and an acid content of about 0.55mmol/L. The enterprise requires separating acid from iron, recovering acid, and returning it to production for continued use. Based on the characteristics and treatment requirements of the waste acid, our company uses special acid adsorption materials for adsorption and separation treatment. The recovered acid becomes nearly colorless and transparent, and about 80% of the iron ions are separated and removed. The recovered acid can be reused in production. The separated iron containing residue can be treated harmlessly by precipitation or used as a water treatment agent. This treatment process saves acid consumption and ensures sustainable production of the enterprise, achieving a win-win situation of enterprise benefits, environmental benefits, and social benefits.

Table 2 Treatment effect of iron containing waste acid