title: Stabilization/solidification of mercury-contaminated waste ash using calcium sodium phosphate (CNP) and magnesium potassium phosphate (MKP) processes.
abstract: This study examined the stabilization and solidification (S/S) of mercury (Hg)-contaminated waste ash generated from an industrial waste incinerator using chemically bonded phosphate ceramic (CBPC) technology. A magnesium potassium phosphate (MKP; MgKPO4 · 6H2O) ceramic, fabricated from MgO and KH2PO4, and a calcium sodium phosphate (CNP; CaNaPO4) ceramic, fabricated from CaO and Na2HPO4, were used as solidification binders in the CBPC process, and Na2S or FeS was added to each solidification binder to stabilize the Hg-contaminated waste ash. The S/S processes were conducted under various operating conditions (based on the solidification binder and stabilization reagent, stabilization reagent dosage, and waste loading ratio), and the performance characteristics of the S/S sample under each operating condition were compared, including the Hg leaching value and compressive strength. The Hg leaching value of untreated Hg-contaminated waste ash was 231.3 μg/L, whereas the S/S samples treated using the MKP and CNP processes exhibited Hg leaching values below the universal treatment standard (UTS) limit (25 μg/L). Although the compressive strengths of the S/S samples decreased as the sulfide dosage and waste loading ratio were increased, most of the S/S samples fabricated by the MKP and CNP processes exhibited good mechanical properties.
authors.affiliation: Department of Chemical and Biomolecular Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749, Republic of Korea.
authors.forename: Jae Han
authors.initials: JH
authors.lastname: Cho
authors.affiliation: Department of Chemical and Biomolecular Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749, Republic of Korea.
authors.forename: Yujin
authors.initials: Y
authors.lastname: Eom
authors.affiliation: Department of Chemical and Biomolecular Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749, Republic of Korea. Electronic address: teddy.lee@yonsei.ac.kr.
authors.forename: Tai Gyu
authors.initials: TG
authors.lastname: Lee
mesh_terms: D002130:Calcium Phosphates / Q000737:chemistry*; D019245:Compressive Strength; D005296:Ferrous Compounds / Q000737:chemistry; D017745:Incineration; D007220:Industrial Waste / Q000032:analysis; D017616:Magnesium Compounds / Q000737:chemistry*; D008628:Mercury / Q000737:chemistry*; D017680:Potassium Compounds / Q000737:chemistry*; D013440:Sulfides / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D002130:Calcium Phosphates; D005296:Ferrous Compounds; D007220:Industrial Waste; D017616:Magnesium Compounds; D017680:Potassium Compounds; D013440:Sulfides; D014874:Water Pollutants, Chemical; C076375:rhenanite; D008628:Mercury; C022597:ferrous sulfide; C033479:sodium sulfide
keywords: CBPC; Calcium sodium phosphate; Compressive strength; Mercury; TCLP