TY - JOUR
T1 - Variation in Phosphorus Speciation of Sewage Sludge throughout Three Wastewater Treatment Plants
T2 - Determined by Sequential Extraction Combined with Microscopy, NMR Spectroscopy, and Powder X-ray Diffraction
AU - Wang, Qian
AU - Raju, Chitra S.
AU - Almind-Jørgensen, Nina
AU - Laustrup, Mikkel
AU - Reitzel, Kasper
AU - Nielsen, Ulla Gro
N1 - Publisher Copyright:
© 2022 American Chemical Society. All rights reserved.
PY - 2022/6/21
Y1 - 2022/6/21
N2 - The variation in phosphorus (P) speciation of sewage sludge throughout three wastewater treatment plants (WWTPs) was obtained by combining sequential P extraction with optical and scanning electron microscopy (SEM), chemical analyses, powder X-ray diffraction (PXRD), and 27Al and 31P nuclear magnetic resonance (NMR) spectroscopy. The WWTPs combine chemical P removal (CPR) and enhanced biological P removal (EBPR) and were compared to understand the effect of iron (Fe) dosing with and without codosing of aluminum (Al) and thermal hydrolysis on the P speciation. 31P NMR showed comparable inorganic orthophosphate (ortho-P, 53-60% of total P) and organophosphate (organic-P, 37-45%) in primary sludge, whereas polyphosphate (poly-P, 23-44%) from poly-P accumulating organisms (PAOs) was mainly observed in the secondary sludge. Inorganic ortho-P (90-98%) dominated after anaerobic digestion, which degraded poly-P and most organic-P. The inorganic ortho-P was mainly Fe bound P (Fe-P), especially after anaerobic digestion (71%). Codosing of Fe and Al led to two comparable fractions: Fe-P (38%) and P sorbed on amorphous Al (hydr)oxides (38%). Vivianite was identified in all samples by microscopy and chemical extraction but was PXRD amorphous in 12 out of 17 samples. Thus, vivianite may be more common in sewage sludge than previously known.
AB - The variation in phosphorus (P) speciation of sewage sludge throughout three wastewater treatment plants (WWTPs) was obtained by combining sequential P extraction with optical and scanning electron microscopy (SEM), chemical analyses, powder X-ray diffraction (PXRD), and 27Al and 31P nuclear magnetic resonance (NMR) spectroscopy. The WWTPs combine chemical P removal (CPR) and enhanced biological P removal (EBPR) and were compared to understand the effect of iron (Fe) dosing with and without codosing of aluminum (Al) and thermal hydrolysis on the P speciation. 31P NMR showed comparable inorganic orthophosphate (ortho-P, 53-60% of total P) and organophosphate (organic-P, 37-45%) in primary sludge, whereas polyphosphate (poly-P, 23-44%) from poly-P accumulating organisms (PAOs) was mainly observed in the secondary sludge. Inorganic ortho-P (90-98%) dominated after anaerobic digestion, which degraded poly-P and most organic-P. The inorganic ortho-P was mainly Fe bound P (Fe-P), especially after anaerobic digestion (71%). Codosing of Fe and Al led to two comparable fractions: Fe-P (38%) and P sorbed on amorphous Al (hydr)oxides (38%). Vivianite was identified in all samples by microscopy and chemical extraction but was PXRD amorphous in 12 out of 17 samples. Thus, vivianite may be more common in sewage sludge than previously known.
KW - P and Al NMR
KW - P recovery
KW - analytical chemistry
KW - chemical P removal
KW - phosphorus speciation
KW - vivianite
UR - http://www.scopus.com/inward/record.url?scp=85131835413&partnerID=8YFLogxK
U2 - 10.1021/acs.est.2c01815
DO - 10.1021/acs.est.2c01815
M3 - 文章
C2 - 35623015
AN - SCOPUS:85131835413
SN - 0013-936X
VL - 56
SP - 8975
EP - 8983
JO - Environmental Science and Technology
JF - Environmental Science and Technology
IS - 12
ER -