Concurrent tellurite reduction, biogenesis of elemental tellurium nanostructures and biological nutrient removal in aerobic granular sludge sequencing batch reactor. Issue 6 (December 2022)

• Record Type: Journal Article
• Authors: Sarvajith, M.; Nancharaiah, Y.V.
• Is Part Of: Journal of environmental chemical engineering. Volume 10:Issue 6(2022)
• Publication Date: 2022-12
• Subjects: Aerobic granules -- Biological nutrient removal -- Bioremediation -- Metal(loid) oxyanions -- Metal-Microbe Interactions -- Wastewater treatment; AGS Aerobic granular sludge -- AOB Ammonium oxidizing bacteria -- Bio-Te Biogenic elemental tellurium -- BNR Biological nutrient removal -- COD Chemical oxygen demand -- EDX Energy dispersive X-ray spectroscopy -- EBPR Enhanced biological phosphoru removal -- EPS Extacellular polymeric substances -- KG killed granules -- NOB Nitrite oxidizing bacteria -- OUT Operational taxonomic unit -- PAO Polyphosphate accumulating organisms -- qPCR Quantitative polymerase chain reaction -- SEM Scanning electron microsccope -- SBR Sequencing batch reactor -- SWW Synthetic wastewater -- XRD X-ray diffraction; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2022.108511
• Languages: English
• ISSNs: 2213-2929

Abstract

Abstract: This study investigated the metabolic potential of aerobic granular sludge (AGS) to simultaneously remove tellurium oxyanion (tellurite, TeO3 2- ), COD, ammonium-nitrogen and phosphorus in a sequencing batch reactor (SBR). AGS readily converted soluble and toxic tellurite to biogenic elemental tellurium (Bio-Te 0 ) by following first-order reaction. Bio-Te 0 was dark black in colour and largely entrapped in the granules. Although endogenous substrates acted as source of electrons for tellurite reduction, it was sustained by supplying exogenous electron donor. A lab-sale SBR was seeded with AGS and operated at varied initial tellurite concentrations for 185 days to investigate tellurite reduction and biological nutrient removal (BNR). Stable removal efficiencies of > 98% Te was achieved from simulated wastewater containing 0.01–1 mM tellurite. Soluble tellurite was converted to Bio-Te 0 and retained in the AGS. SEM-EDS, XRD and Raman spectroscopy confirmed formation of Bio-Te 0 and its association with the granules. Enrichment of Bacteroidia, Petrimonas sp. and several other tellurite-reducing bacteria was confirmed by 16S rRNA gene sequencing. Enrichment of ammonium oxidizing bacteria, elimination of nitrite oxidizing bacteria and profiles of reactive-nitrogen compounds suggested occurrence of nitriation-denitriation pathway. Although ammonium removal was inhibited by tellurite, recovery occurred much quickly in the presence of up to 0.1 mM tellurite. Higher P removal under tellurite-reducing condition was linked to hydroxyapatite precipitation as confirmed by EDS and P-fractionation. Efficient BNR under toxic pollutant conditions and excellent metal(loid) immobilization capabilities implicate prospective use of AGS technology in metal-laden waste management and metal(loid) biorecovery applications. Graphical Abstract: ga1 Highlights: Complete, sustained and lactate-dependent conversion of up to 175 mg/L Te IV to Te 0 Biogenic Te 0 nanostructures were associated with aerobic granular sludge. Partial inhibition of ammonium removal and lower abundance of AOB by Te IV . Efficient nitrogen removal via nitritation-denitritation at different initial Te IV loadings. Higher P-removal in Te IV -fed reactor due to hydroxyapatite precipitation.