Work

“Treating Waste with Waste”: Utilizing Phosphogypsum to Synthesize Porous Calcium Silicate Hydrate for Recovering of Fe2+ from Pickling Wastewater

Year: 2024

Type: article

Abstract: Phosphogypsum is a by-product of the wet-process phosphoric acid production, and it is rich in Ca and S. Long-term storage of Phosphogypsum can cause serious pollution to the environment; therefore, promoting the sustainable utilization of Phosphogypsum is crucial. This study proposes the use of Phosphogypsum and silicic acid in a sodium hydroxide solution for the hydrothermal synthesis of porous calcium silicate hydrate adsorbent, which is used for adsorbing Fe2+ from simulated hydrochloric acid pickling wastewater. Under the optimal synthesis conditions (37.5 g/L of NaOH, calcium/silicon ratio of 1.0, liquid/solid ratio of 15:1 mL/g, 110 °C, and 4 h), the conversion rate of SO42− in Phosphogypsum is 87.41%. Porous calcium silicate hydrate exhibits excellent OH− release capability in Fe2+-containing pickling wastewater. The adsorption process for Fe2+; is mainly chemical adsorption, involving ion exchange between Ca2+ and Fe2+, as well as complexation reactions of O-Si-O group, -OH group, and Si-O group with Fe2+. This technology aims to provide a solution for the sustainable utilization of Phosphogypsum and the recovery of Fe2+ from pickling wastewater, which has significant practical importance.

Source: Sustainability

DOI: 10.3390/su16177796

Authors: Pan Liang, Chaoyi Chen, Junqi Li, Jiahang Chen

Institution: Guizhou University

Language: English

Topic: Recycling and utilization of industrial and municipal waste in materials production

Subfield: Building and Construction

Field: Engineering

Domain: Physical Sciences

SDGs: Responsible consumption and production, Clean water and sanitation, Climate action

Open Access status: gold

Estimated APC paid: $2,728