1. Recovery of Zinc fromTreatment of Spent Acid Solutions from the Pickling Stage of Galvanizing Plants
- Author
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Valentina Corradini, Svetlana B. Zueva, Valentina Innocenzi, Nicolò Maria Ippolito, Francesco Ferella, Ida De Michelis, and Francesco Vegliò
- Subjects
hydrochloric acid ,Geography, Planning and Development ,TJ807-830 ,chemistry.chemical_element ,Hydrochloric acid ,02 engineering and technology ,Zinc ,010501 environmental sciences ,Management, Monitoring, Policy and Law ,precipitation ,TD194-195 ,01 natural sciences ,Renewable energy sources ,chemistry.chemical_compound ,symbols.namesake ,Precipitation ,Spent pickling solution ,Wastewater ,Pickling ,GE1-350 ,wastewater ,0105 earth and related environmental sciences ,Calcium hydroxide ,Environmental effects of industries and plants ,spent pickling solution ,Renewable Energy, Sustainability and the Environment ,zinc ,021001 nanoscience & nanotechnology ,Pulp and paper industry ,Galvanization ,Environmental sciences ,chemistry ,Sodium hydroxide ,symbols ,Sewage treatment ,0210 nano-technology - Abstract
Typical methods for the treatment of waste pickling solutions include precipitation by alkaline reagents, most commonly calcium hydroxide. As a result, large volumes of galvanic sludge form, containing iron, calcium, sulphates, and a relatively small quantity of zinc (<, 20%), making Zn recovery not profitable. In summary, state-of-the-art Zn galvanization processes entail the loss of valuable metals and the irrational and expensive handling of spent pickling solutions (SPSs). The resulting conclusion is that there is room for a significant improvement in the way SPSs are treated, with the double goal of enhancing Zn galvanization methods&rsquo, economic viability and achieving a lesser impact on the environment&rsquo, s processes. The experimental results show that it is possible to use SPS as a coagulant to treat the process wastewaters, kept separated, and added with sodium hydroxide. The results in obtaining precipitates with Zn contents higher than 40%, increasing the added advantage of making Zn recovery profitable. The results show the possibility of using SPS as a coagulant in the process of physical-chemical wastewater treatment and sodium hydroxide to obtain a precipitate with a zinc content of more than 40%.
- Published
- 2021
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