Identification of inorganic and organic species of phosphorus and its bio-availability in nitrifying aerobic granular sludge
Journal
Water Research
Journal Volume
68
Pages
423-431
Date Issued
2015
Author(s)
Abstract
Phosphorus (P) recovery from sewage sludge is necessary for a sustainable development of the environment and thus the society due to gradual depletion of non-renewable P resources. Aerobic granular sludge is a promising biotechnology for wastewater treatment, which could achieve P-rich granules during simultaneous nitrification and denitrification processes. This study aimed to disclose the changes in inorganic and organic P species and their correlation with P mobility and bio-availability in aerobic granules. Two identical square reactors were used to cultivate aerobic granules, which were operated for 120 days with influent ammonia nitrogen (NH4-N) of 100mg/L before day 60 and then increased to 200mg/L during the subsequent 60 days (chemical oxygen demand (COD) was kept constant at 600mg/L). The aerobic granules exhibited excellent COD removal and nitrification efficiency. Results showed that inorganic P (IP) was about 61.4-67.7% of total P (TP) and non-apatite inorganic P (NAIP) occupied 61.9-70.2% of IP in the granules. The enrichment amount of NAIP and apatite P (AP) in the granules had strongly positive relationship with the contents of metal ions, i.e. Fe and Ca, respectively accumulated in the granules. X-ray diffraction (XRD) analysis and solution index calculation demonstrated that hydroxyapatite (Ca5(PO4)3(OH)) and iron phosphate (Fe7(PO4)6) were the major P minerals in the granules. Organic P (OP) content maintained around 7.5mg per gram of biomass in the aerobic granules during the 120 days' operation. Monoester phosphate (21.8% of TP in extract), diester phosphate (1.8%) and phosphonate (0.1%) were identified as OP species by Phosphorus-31 nuclear magnetic resonance (31P NMR). The proportion of NAIP+OP to TP was about 80% in the granules, implying high potentially mobile and bio-available P was stored in the nitrifying aerobic granules. The present results provide a new insight into the characteristics of P species in aerobic granules, which could be helpful for developing P removal and recovery techniques through biological wastewater treatment. ? 2014 Elsevier Ltd.
Subjects
Aerobic granules
Nitrification
P fractionation
Phosphorus-31 nuclear magnetic resonance (31P NMR)
Other Subjects
Ammonia; Apatite; Biological water treatment; Chemical oxygen demand; Granular materials; Hydroxyapatite; Iron compounds; Metal ions; Metals; Nitrification; Nuclear magnetic resonance; Phosphorus; Sewage sludge; Sustainable development; Wastewater treatment; X ray diffraction analysis; 31P-NMR; Aerobic granular sludges; Aerobic granules; Biological waste water treatment; Index calculation; P fractionation; Phosphorus-31 nuclear magnetic resonance; Simultaneous nitrification and denitrification; Granulation; ammonia; apatite; calcium; calcium phosphate; diester phosphate; DNA; ferric phosphate; hydroxyapatite; iron; magnesium; monoester phosphate; nitrogen; phosphate; phosphonic acid derivative; phosphorus; polyphosphate; unclassified drug; mineral; organophosphate; phosphorus derivative; sewage; apatite; bioavailability; biotechnology; denitrification; identification method; metal; nitrification; nuclear magnetic resonance; oxic conditions; phosphate; phosphorus; sewage treatment; sludge; sustainable development; activated sludge; aeration; aerobic granular sludge; Article; bioavailability; biomass; cell membrane; chemical oxygen demand; crystal; cyanobacterium; fractionation; lake sediment; microbial activity; nitrification; nitrifying bacterium; nonhuman; oxidation reduction reaction; pH; phosphorus nuclear magnetic resonance; pollutant; scanning electron microscopy; sludge; solubilization; waste water; waste water treatment plant; X ray diffraction; aerobic metabolism; biochemical oxygen demand; bioreactor; chemistry; nitrification; procedures; sewage; Aerobiosis; Biological Oxygen Demand Analysis; Bioreactors; Minerals; Nitrification; Organophosphates; Phosphorus Compounds; Sewage; Waste Disposal, Fluid
Type
journal article