Phosphorus Species, Distribution and Bio-availability in Sewage Sludge and Aerobic Granular

97 Pages·2015·3.72 MB·English

Phosphorus Species, Distribution and
Bio-availability in Sewage Sludge and Aerobic
Granular Sludge
著者 黄 文力
year 2015
その他のタイトル 下水汚泥および好気性汚泥顆粒中におけるリンの種
類、分布及びその生物学的利用性
学位授与大学 筑波大学 (University of Tsukuba)
学位授与年度 2015
報告番号 12102甲第7539号
URL http://hdl.handle.net/2241/00135001
Phosphorus Species, Distribution and Bio-availability in
Sewage Sludge and Aerobic Granular Sludge

June 2015

Wenli HUANG
Phosphorus Species, Distribution and Bio-availability in
Sewage Sludge and Aerobic Granular Sludge

A Dissertation Submitted to
the Graduate School of Life and Environmental Sciences,
the University of Tsukuba
in Partial Fulfillment of the Requirements
for the Degree of Doctor of Environmental Studies
(Doctoral Program in Sustainable Environmental Studies)

Wenli HUANG
Abstract
Phosphorous (P) is an essential and limiting element for living organisms and
human beings, especially for the growth of plants. However, phosphate rock, raw
material used for P fertilizers, is a non-renewable resource. Thus P resource protection
and P recovery is prerequisite for a sustainable agriculture and society on a global
scale. On the other hand, sewage sludge generated from wastewater treatment is
regarded as a potential P reservoir due to its high production amount and high P
content. Moreover, aerobic granular sludge (AGS) is a promising technology for
wastewater treatment and the generated AGS contains a high level of P. As not all the
forms of P exhibit similar mobility and bio-availability in the sludge, detailed
information about P fraction is necessary for both activated sludge and AGS,
especially when land application of sludge is taken into consideration. According to
the Standards, Measurements and Testing (SMT), total P (TP) in sludge can be
fractionated into inorganic P (IP), organic P (OP), non-apatite inorganic P (NAIP) and
apatite P (AP). OP and NAIP are considered as potentially mobile and bio-available P.
In addition, identification of P species in sludge is helpful to understand the
characteristics and function of P in sludge and thus the mechanisms of P removal
through biotechnology. Recent research indicates that phosphorus-31 nuclear
magnetic resonance spectroscopy (31P NMR) can be used for analyzing IP
(orthophosphate(ortho-P), pyrophosphate(pyro-P) and polyphosphate(poly-P)) and OP
species (monoester phosphate(monoester-P), diester phosphate(dister-P) and
phosphonates) in sediments, soil and activated sludge since it is able to distinguish
multiple P compounds among complex substances.
Therefore, this study aims to fractionate P forms in primary sludge, secondary
sludge, digested sludge, nitrifying AGS and enhanced biological P removal (EBPR)-
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AGS and evaluate their bio-availability. The IP and OP species in those sludges were
also analyzed and discussed. Major results are summarized as follows:
(1) IP was the primary P fraction in the secondary sludge and digested sludge,
while OP was the dominant P composition in primary sludge. About 87.7%, 94.8%
and 76.2% of TP in primary sludge, secondary sludge and digested sludge,
respectively, possessed high potential mobility and bio-availability. Monoester-P and
ortho-P were the major P species in primary sludge and digested sludge, respectively,
and poly-P was the mainly P species in secondary sludge.
(2) IP was the primary P fraction in nitrifying AGS, in which NAIP amounted to
61.9-70.2%. About 80.9% of TP in nitrifying AGS possessed high potential mobility
and bio-availability. Hydroxyapatite [Ca (PO ) (OH)] and iron phosphate [Fe (PO ) ]
5 4 3 7 4 6
patterns were the main IP species in the nitrifying AGS. Monoester-P was the
dominant P in OP, and less amount of poly-P was detected in the granules, probably
attributable to the inhibition of free ammonia on the activity of phosphorus
accumulating organisms (PAOs).
(3) 92.4 - 96.4% of TP in the mature EBPR-AGS exhibited high mobility and
bio-availability. The microbial cells, extracellular polymeric substances (EPS) and
mineral precipitates respectively contributed 73.7%, 17.6% and 5.2 - 6.4% to the TP
of EBPR-AGS. Poly-P occupying 59.2 - 64.1% of TP was the major P species in
EBPR-AGS, cells and EPS. Monoester-P and diester-P were identified as the OP
species in the AGS and cells. Furthermore, hydroxyapatite [Ca (PO ) OH] and
5 4 3
calcium phosphate [Ca (PO ) ] were the dominant P minerals accumulated in the core
2 4 3
of the granules. Cells along with poly-P were mainly in the outer layer of EBPR-AGS
while EPS were distributed in the whole granules. Based on the above results, the
distribution of IP and OP species in EBPR-AGS has been conceived.
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This work would not only be useful for P utilization and recovery from sewage
sludge and AGS but also provide insight into the characteristics of P in those sludge,
which will help to develop applicable technologies for P removal and recovery
through wastewater treatment.

Key words: Sewage sludge; aerobic granular sludge (AGS); phosphorus recovery;

phosphorus removal; phosphorus species.
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Contents

Chapter 1 Introduction ................................................................................... 1

1.1. P resource ................................................................................................................. 1
1.2. Sludge production and disposal in conventional wastewater treatment plants ........ 2
1.3. Granulation technology ............................................................................................ 3
1.3.1. Anaerobic granular sludge ............................................................................. 3
1.3.2. Aerobic granular sludge ................................................................................. 4
1.4. P fraction and species .............................................................................................. 5
1.5. Research objectives and thesis structure .................................................................. 7
Chapter 2 P species and bio-availability analysis in sewage sludge .......... 10

2.1. Introduction ............................................................................................................ 10
2.2. Materials and methods ........................................................................................... 10
2.2.1. Sewage sludge sample ................................................................................. 10
2.2.2. P fractionation in sludge .............................................................................. 11
2.2.3. Extraction of P from sludge. ........................................................................ 11
2.2.4. Analytical method ........................................................................................ 12
2.3. Results and discussion ........................................................................................... 13
2.3.1. Variation in solid content of the sludge samples ......................................... 13
2.3.2. P fractionation in sludge by SMT protocol .................................................. 13
2.3.3. Identification of P species in sludge by 31P NMR analysis ......................... 15
2.4. Summary ................................................................................................................ 16
Chapter 3 Identification of inorganic and organic species of P and its
bio-availability in nitrifying AGS ........................................................... 26

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3.1. Introduction ............................................................................................................ 26
3.2. Materials and methods ........................................................................................... 27
3.2.1. Experimental set-up and operation .............................................................. 27
3.2.2. Chemical and physical analysis ................................................................... 28
3.2.3. P fractionation in AGS ................................................................................. 29
3.2.4. P extraction from AGS and analysis by 31P NMR ....................................... 29
3.3. Results and discussion ........................................................................................... 29
3.3.1. Formation and characterization of nitrifying AGS ...................................... 29
3.3.2. Overall pollutants removal performance ..................................................... 30
3.3.3. P fractionation in nitrifying AGS by SMT protocol .................................... 31
3.3.4. Species of IP in nitrifying AGS by XRD ..................................................... 33
3.3.5. Identification of P species in nitrifying AGS by 31P NMR analysis ............ 35
3.4. Summary ................................................................................................................ 37
Chapter 4 Distribution and bio-availability of IP and OP species in
EBPR-AGS ............................................................................................... 48

4.1. Introduction ............................................................................................................ 48
4.2. Materials and methods ........................................................................................... 49
4.2.1. Experimental set-up and operation .............................................................. 49
4.2.2. P fractionation in EBPR-AGS ..................................................................... 50
4.2.3. Extraction and species analysis of P in EBPR-AGS.................................... 50
4.2.4. Extraction and analysis of P from EPS and cells ......................................... 50
4.2.5. CLSM observation of EBPR-AGS .............................................................. 51
4.2.6. Analytical methods ...................................................................................... 52
4.3. Results and discussion ........................................................................................... 52
4.3.1. Characterization of EBPR-AGS .................................................................. 52
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4.3.2. P fractionation in EBPR-AGS by SMT protocol ......................................... 54
4.3.3. Species of IP in the core of granules by using EDX and XRD ................... 55
4.3.4. Identification and distribution of P species in granules by 31P NMR
analysis ........................................................................................................... 57
4.3.5. Possible distribution of P in EBPR-AGS ..................................................... 59
4.4. Summary ................................................................................................................ 60
Chapter 5 Conclusions and future research ................................................ 75

5.1. Conclusions ............................................................................................................ 75
5.2. Future research ....................................................................................................... 76
References ....................................................................................................... 77

Acknowledgements ........................................................................................ 85

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Abbreviations
AGS: Aerobic granular sludge
AP: Apatite phosphorus
CLSM: Confocal laser scanning microscope
COD: Chemical oxygen demand
DAPI: 4, 6-diamidino-2-phenylindole
Diester-P: Diester phosphate
EBPR: Enhanced biological phosphorus removal
EDX: Energy dispersive X-ray
EPS: Extracellular polymeric substances
IP: Inorganic phosphorus
MLSS: Mixed liquor suspended solids
Monoester-P: Monoester phosphate
NAIP: Non-apatite inorganic phosphorus
31P NMR 31 phosphorus nuclear magnetic resonance spectroscopy
OP: Organic phosphorus
Ortho-P: Orthophosphate
P: Phosphorus
PAOs: Phosphate accumulating organisms
PCA : Cold perchloric acid
PN: Protein
Poly-P: Polyphosphate
PS: Polysaccharides
Pyro-P: Pyrophosphate
SBRs: Sequencing batch reactors
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