Back to Search
Start Over
Metal oxyanion removal from wastewater using manganese-oxidizing aerobic granular sludge.
- Source :
-
Chemosphere . Dec2019, Vol. 236, pN.PAG-N.PAG. 1p. - Publication Year :
- 2019
-
Abstract
- As, Sb, and Cr are redox-sensitive and toxic heavy metal(loid)s, and redox reactions are usually involved in the treatment of substrates containing these elements. In this study, manganese-oxidizing aerobic granular sludge (Mn-AGS) was obtained by continuously adding Mn(II) to the sludge in a sequencing batch reactor (SBR). Morphological observations, and analyses of extracellular polymeric substances (EPS), Mn valence-states, and microbial communities were performed on the resulting sludge. After 50 days of cultivation, biogenic Mn(III,IV) oxides (bio-MnO x) accumulated up to approximately 25 mg Mn/g suspended solids (SS). X-ray photoelectron spectroscopy (XPS) revealed that the percentage of Mn(III,IV) was 87.6%. The protein (PN) component in EPS increased from 80.3 to 87.8 mg/g volatile suspended solids (VSS) during cultivation, which might be favorable for sludge granulation and heavy metal(loid) removal. Batch experiments showed that Mn-AGS was better at oxidizing As(III)/Sb(III) into less toxic As(V)/Sb(V) than traditional AGS. Remarkably, the results indicated that Mn-AGS did not oxidize Cr(III) but was able to reduce Cr(VI) into relatively harmless Cr(III). This work provided a new promising method with which to treat As(III), Sb(III), and Cr(VI) in wastewaters. Image 1 • Manganese-oxidizing aerobic granular sludge (Mn-AGS) was successfully obtained. • A high level of biogenic MnO x accumulation was observed in aerobic granules. • Oxidation of As(III)/Sb(III) into less toxic forms was largely improved by Mn-AGS. • Cr(III) was not oxidized but Cr(VI) was reduced into harmless Cr(III) by Mn-AGS. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00456535
- Volume :
- 236
- Database :
- Academic Search Index
- Journal :
- Chemosphere
- Publication Type :
- Academic Journal
- Accession number :
- 138984152
- Full Text :
- https://doi.org/10.1016/j.chemosphere.2019.124353