A novel and sustainable approach for biotransformation of phosphogypsum to calcium carbonate using urease producing Lysinibacillus sphaericus strain GUMP2. Issue 2 (15th January 2023)

• Record Type: Journal Article
• Authors: Patil, Prajakta Pratap; Prabhu, Meghanath; Mutnuri, Srikanth
• Is Part Of: Environmental technology. Volume 44:Issue 2(2023)
• Page Start: 226
• Page End: 239
• Publication Date: 2023-01-15
• Subjects: Environmental hazard -- phosphogypsum -- transformation -- crystallization -- calcite; Environmental engineering -- Periodicals; Environmental protection -- Periodicals; 628.05
• DOI: 10.1080/09593330.2021.1968506
• Languages: English
• ISSNs: 0959-3330

Abstract

ABSTRACT: Phosphogypsum (CaSO4 ) is produced as a waste by-product during phosphoric acid production in the fertilizer industry. Only 15% of worldwide phosphogypsum production is recycled, while 85% is stored in the vicinity of factories as huge piles resulting in environmental and health hazards. An extensively studied biotransformation of phosphogypsum to calcium carbonate or calcite (CaCO3 ) using sulfate reducing bacteria (SRBs) is a prolonged process and results in the formation of extremely hazardous H2 S gas. Here we report for the first time a novel approach for biotransformation of phosphogypsum to CaCO3 using urease producing Lysinibacillus sphaericus strain GUMP2. The strain could effectively transform phosphogypsum to crystalline, bead-shaped CaCO3 precipitates. In a batch reactor with the PG loading rate of 60 g/L, 100% biotransformation was observed within seven days. After calcite recovery, the ammonium sulfate formed in the supernatant was recovered by precipitation. Urease-producing L. sphaericus strain GUMP2 could be used to remove the hazardous phosphogypsum from the environment by converting it to the industrially useful CaCO3 and ammonium sulfate, a valuable agricultural fertilizer. This novel and sustainable approach could be a promising solution for the hazardous phosphogypsum in the phosphoric acid industries. GRAPHICAL ABSTRACT: UF0001