Settleable algal-bacterial culture for municipal wastewater treatment

128 Pages·2012·2.05 MB·English

Settleable algal-bacterial culture for
municipal wastewater treatment

Der Fakultät Nachhaltigkeit der Leuphana Universität Lüneburg zur Erlangung des
Grades Doktorin der Naturwissenschaften
-Dr. rer. nat.-

vorgelegte Dissertation von

Yanyan Su
geb. Mai 02.1982 in: Dalian, China
Eingereicht am: 11.09.2012

Betreuerin und Gutachterin: Prof. Dr. Brigitte Urban

Betreuerin und Erstgutachterin: Prof. Dr. Brigitte Urban
Zweitgutachter: Prof. Dr.-Ing. R. Otterpohl
Drittgutachter: Prof. Dr.-Ing. habil. Thomas Dockhorn
Viertgutachter: Prof. Dr.-Ing. Artur Mennerich

Tag der Disputation: 07.12.2012
Nature does not hurry, yet everything is accomplished…
- Lao Tzu

Table of contents
Table of contents I
List of tables V
List of figures VII
List of Abbreviations IX
Summary XI
Chapter 1
Background and aims of the study
1.1 Background and aims of the study 1
1.2 References 4
Chapter 2
Microalgae
2.1 The advantages and potentials of microalgae 9
2.2 Microalgal metabolism 9
2.2.1 Autotrophic metabolism 9
2.2.2 Heterotrophic metabolism 12
2.3 Microalgal cultivation 13
2.4 References 14
Chapter 3
Municipal wastewater treatment and microalgae
3.1 Municipal wastewater treatment 19
3.1.1 Primary treatment 19
3.1.2 Second treatment 20
3.1.3 Tertiary treatment 21
I
3.1.4 Disinfection 23
3.2 Municipal wastewater treatment with microalgae 23
3.2.1 Pretreated municipal wastewater treatment with algal-bacterial culture 23
3.2.2 Tertiary treatment with microalgae based technology 25
3.2.3 Other advanced treatments based on microalgae technology 25
3.3 References 26
Chapter 4
Microalgae harvesting strategies
4.1 Physical based methods 31
4.2 Chemical based methods 32
4.3 Biological based methods 32
4.4 Immobilization systems 34
4.5 Other methods 36
4.6 References 36
Chapter 5
Process factors in algal-bacterial systems
5.1 Abiotic factors 41
5.1.1 Temperature 41
5.1.2 pH 42
5.1.3 Dissolved oxygen (DO) 42
5.1.4 Light 43
5.1.5 Mixing 45
5.1.6 The concentration and ratio of nitrogen and phosphorus 45
5.2 Biotic factors 46
5.2.1 Microalgae species selection 46
5.2.2 Microalgal-bacterial symbiotic system 49
5.2.3 Inoculum concentration 50
5.3 References 50
II
Chapter 6
Conclusions 57
Acknowledgements 61
Curriculum Vitae 63
List of publications 65
Selbständigkeitserklärung 67
Declaration 1 69
Declaration 2 70
Appendices 71
Paper I: Municipal wastewater treatment and biomass accumulation with a
wastewater-born and settleable algal-bacterial culture. Water Research
45(11), 3351-3358 (2011).
Paper II: Synergistic cooperation between wastewater-born algae and activated
sludge for wastewater treatment: Influence of algae and sludge
inoculation ratios. Bioresource Technology 105, 67-73 (2012).
Paper III: Comparison of nutrient removal capacity and biomass settleability of four
high-potential microalgal species. In press. DOI:
10.1016/j.biortech.2012.08.037.
Paper IV: Coupled nutrient removal and biomass production with mixed algal
culture: Impact of biotic and abiotic factors. Bioresource Technology 118,
469-476 (2012).

III
IV
List of tables
2.1 Summary of microalgal applications in different areas 10
2.2 N-assimilation processes with different N sources 12
2.3 Advantages and disadvantages of open ponds and closed photobioreactors 14
4.1 Wastewater treatment with immobilized microalgae 35
5.1 Wastewater treatment efficiency, biomass production or lipid content
with different microalgae species 48
5.2 The positive and negative interactions between microalgae and bacteria 49

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VI