Improvement of detention ponds with respect to salinity [Elektronische Ressource] / vorgelegt von Mohie Eldeen Mohamed Ahmed Aly Omar

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• Publié par: technische_universitat_berlin
• Publié le: 01 janvier 2010
• Nombre de lectures: 10
• Langue: English
• Poids de l'ouvrage: 6 Mo

Extrait

Improvement of Detention Ponds with Respect to Salinity

vorgelegt von M.Sc. (Eng.) Mohie Eldeen Mohamed Ahmed Omar aus Kairo Von der Fakultät VI - Planen Bauen Umwelt der Technischen Universität Berlin zur Erlangung des akademischen Grades Doktor der Ingenieurwissenschaften Dr.-Ing. genehmigte Dissertation Promotionsausschuss: Vorsitzender: Prof. Dr. habil. Uwe Tröger Berichter: Prof. Dr.-Ing. Matthias Barjenbruch Berichter: Prof. Dr.-Ing. Reinhard Hinkelmann Berichterin: Dr. agr. Dagmar Balla Tag der wissenschaftlichen Aussprache: 10.08.2010 Berlin 2010 D 83

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I would like to express my great appreciation and my sincere gratitude to my supervisors Prof. Dr.Ing. M. Barjenbruch, Prof. Dr.Ing. R. Hin kelmann and Dr.agr. D. Balla for their help, advices, support and coop eration during the work and the preparation of this dissertation, which strongly encouraged me to complete this research in the best way.

Thanks for all the staff members at the Leibniz Centre for Agricultural Landscape Research (ZALF), Institute of Landscape Hydrology, Müncheberg, for their support and advices during my study in Germany.

Special thanks for Dr.Ing. J. Steidl and Ing. V. Ehlert for providing me all the required data regarding the detention pond used in the numerical simulation and for Ing. A. Jourieh for helping me to use the numerical modelling system TELEMAC  2D.

My sincere gratitude to the German Ministry of Education and Scientific Research, International Postgraduate Studies in Water Technologies (IPSWaT) for giving me the chance to carry out this postgraduate study in Germany.

Last but not the least; I would like to thank my parents who have been supporting me in every step of my life and my wife who has shared me both, the hard and nice moments during our stay in Germany.

Mohie Eldeen Omar,

June, 2010

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Dränteiche dienen dem Wasserrückhalt, der Reinigung landwirtschaftlicher Dränabflüsse und bieten eine Alternative für die Bereitstellung von Bereg- nungswasser. Hydraulische Probleme wie Totzonen, Kurzschluss-Strömungen, Verwirbelungen und, besonders in ariden und semiariden Gebieten hohe Salini- täten sowie Verdunstungsverluste sind Herausforderungen für ihre Anwendbar- keit. Im Rahmen dieser Arbeit wurde das Potenzial von Wasserlinsen(Lemna ceae) zur Stoffentnahme bei hohen Salzgehalten untersucht sowie Methoden zur Optimierung von Dränteichen getestet.

Klimakammerversuche sowie Freilandexperimente unter humiden Bedingun- gen zeigten eine Wachstumsbegrenzung mit steigender Salinität, jedoch ein zunehmendes Wachstum bis 1.6 g/l. Die Salz - Entnahme beruht auf der Kinetik 1. Ordnung und betrug 0.5 - 12 %, in Abhängigkeit von der Salinität sowie der + +2 + - + Biomasse. K , Mg , Na , Cl , und NH 4 wurden unabhängig von der Salzkon- - +2 zentration aufgenommen, Die NO 3 Ca Aufnahme  und verringerte sich. Die Verdunstung wurde zu 25 % gesenkt.

Numerische Simulationen mit TELEMAC 2D zeigten, dass sich die Anordnung der Wassereinleitung in den Dränteich, die turbulente Viskosität, sowie hohe Dränzuflüsse sowohl auf die Strömung als auch auf den Stoffabbau auswirkten. Die zusätzliche Anordnung von künstlichen Barrieren verbesserte die Effektivi- tät, wobei für den untersuchten Dränteich vier Barrieren mit ca. 70 % der Breite des Dränteiches am effektivsten waren.

Die Ergebnisse bieten Lösungen für eine Nutzung in arid/ semi-ariden Gebieten 2 an. Eine Biomasseproduktion derLemnaceae von größer als 260 g/m , eine regelmäßige Ernte sowie die individuelle Anpassung der Dränteiche mit Hilfe von Simulationsmodellen werden dabei empfohlen.

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Detention ponds can be used for storage, treatment and reuse of agricultural drainage water as one alternative for freshwater in irrigation. Generally, ponds’ hydraulic problems such as dead zones, short - circuiting and swirling and, particularly, water salinity and scarcity in arid/semi - arid areas are challenges facing the ponds’ applicability. The purpose of this work is to investigate the potential of duckweeds (Lemnaceae) for salt and nutrient uptake under different salinities as well as the methods for optimization of detention ponds.

Investigations under controlled climate conditions and under natural humid climate conditions with different water salinities showed a significant growth inhibition by salinity, but with a promoted growth up to 1.6 g/l. Salt - removal was a first - order kinetic and ranged from 0.5 - 12 % per day dependent on + +2 + - + water salinity and duckweeds’ biomass. K , Mg , Na , Cl , and NH 4 have been - +2 removed independent on water salinity, but NO 3  and Ca removal decreased significantly by salinity increase. Duckweeds saved up to 25 % of the water volume lost by evaporation.

Numerical simulations of an actual detention pond in the State of Brandenburg, Germany with the modelling system TELEMAC 2D showed that the pond inlet design, turbulent viscosity, and flood influenced both, the flow and transport processes. Design modification by baffles improved the performance. Four baffles of 70 % of pond width achieved the best performance.

In conclusion, detention ponds can be, generally, more effective, sustainable and, particularly, applicable in arid/semi - arid areas, if duckweeds’ species are 2 cultivated with intensity higher than 260 g/m , harvesting of duckweeds is done regularly, and numerical simulation of every pond is undertaken individually.

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CONTENTS .......................................................................................................I

LIST OF FIGURES ........................................................................................IV

LIST OF TABLES ..........................................................................................IX

ACRONYMS AND ABBREVIATIONS ..................................................... XII

1

2

INTRODUCTION .................................................................................... 1

PROBLEM ANALYSIS ........................................................................... 5

2.1D ETENTION PONDS .............................................................................. 5 2.2V EGETATION IN DETENTION PONDS ...................................................... 7 2.3D UCKWEEDS ....................................................................................... 7 2.3.1The principles ............................................................................. 7 2.3.2Duckweeds for water treatment .................................................. 8 2.3.3Duckweed and evapotranspiration water loss .......................... 11 2.3.4Duckweeds and other advantages............................................. 12 2.3.5Potential uses after harvesting ................................................. 12 2.3.6Duckweeds for saline water treatment...................................... 13 2.3.7Temperature influence on duckweeds ....................................... 15 2.4A SSESSMENT OF DETENTION PONDS ’ EFFICIENCY .............................. 15 2.4.1Pollutant removal ..................................................................... 15

I

CONTENTS II

2.4.2Growth of macrophytes............................................................. 16 2.4.3Residence times......................................................................... 17 2.5N UMERICAL FLOW AND TRANSPORT SIMULATIONS OF DETENTION PONDS ............................................................................................................ 18 2.6B AFFLES FOR OPTIMIZATION OF PONDS .............................................. 20 2.7L ITERATURES CONCLUSIONS .............................................................. 20

3AND STATISTICALEXPERIMENTAL, NUMERICAL METHODS….................................................................................................. 23

3.1I NVESTIGATIONS UNDER CONTROLLED CLIMATE CONDITIONS ........... 24 3.1.1Lemna growth inhibition test .................................................... 24 3.1.2............................................ 24Lemna test with respect to salinity 3.1.2.1Purpose ............................................................................................24 3.1.2.2Test procedures ................................................................................24 3.1.2.3Data analysis ....................................................................................27 3.1.3Logistic growth of Lemna minor............................................... 29 3.1.3.1Purpose ............................................................................................29 3.1.3.2Test procedures ................................................................................29 3.1.3.3....................................................................................30Data analysis 3.2I NVESTIGATIONS UNDER NATURAL CLIMATE CONDITIONS .................. 30 3.2.1Phase (1)................................................................................... 30 3.2.1.1Purpose ............................................................................................30 3.2.1.2Experimental basis ...........................................................................31 3.2.1.3Experimental procedures..................................................................32 3.2.1.4....................................................................................35Data analysis 3.2.2Phase (2)................................................................................... 36 3.2.2.1Purpose ............................................................................................36 3.2.2.2Experimental procedures..................................................................37 3.2.2.3Data analysis ....................................................................................37 3.3N UMERICAL SIMULATION OF A POND ................................................. 39 3.3.1Purpose..................................................................................... 39

CONTENTS III

4

5

3.3.2Study area ................................................................................. 40 3.3.3Modelling system ...................................................................... 41 3.3.4Modelling procedure................................................................. 44 3.4S TATISTICAL METHODS ...................................................................... 49

RESULTS AND DISCUSSION.............................................................. 53

4.1I NVESTIGATIONS UNDER CONTROLLED CLIMATE CONDITIONS ........... 53 4.1.1Effect of salinity on duckweeds’ growth .................................... 53 4.1.2Effect of temperature on duckweed growth ............................... 65 4.2U PTAKE OF SALT , ANIONS AND CATIONS ............................................. 69 4.3 I NVESTIGATIONS UNDER NATURAL CLIMATE CONDITIONS .................. 77 4.3.1Phase (1)................................................................................... 77 4.3.1.1..........................................77Effect of salinity on duckweeds’ growth 4.3.1.2Uptake of salts and nutrients ............................................................78 4.3.2Phase (2)................................................................................... 82 4.3.2.1Effect of salinity on duckweeds’ growth ..........................................82 4.3.2.2............................................................83Uptake of salts and nutrients 4.3.2.3Evapotranspiration and evaporation.................................................92 4.4T HE 2-D NUMERICAL SIMULATION OF THE POND ............................... 96 4.4.1............................................................. 96General and flood case 4.4.2........................................................................ 101Bottom friction 4.4.3Viscosity and diffusivity .......................................................... 103 4.4.4Inflow conditions .................................................................... 107 4.4.5Baffles ..................................................................................... 108

CONCLUSIONS AND RECOMMENDATIONS .............................. 122

5.1 5.2

C ONCLUSIONS ................................................................................. 122 R ECOMMENDATIONS ........................................................................ 124

REFERENCES ............................................................................................. 126

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Figure 2.1: Two detention ponds in east Brandenburg, Germany....................... 6

Figure 2.2: Duckweeds (Lemnaceaefamily) ...................................................... 8

Figure 3.1: Test medium (left) and groups of NaCl concentrations (right)....... 25

Figure 3.2: Main processes of salt - mass changes ........................................... 32

Figure 3.3: Mass balance in the container ........................................................ 33

Figure 3.4: Container with drainage water, initial addition of duckweeds and final duckweeds cover ...................................................................................... 34

Figure 3.5: The detention pond and its drained agricultural watershed ............ 41

Figure 3.6: The inlet with an automatic water sampler (left) and V - notch weir (right)................................................................................................................ 41

Figure 3.7: The topography of the pond ........................................................... 45

Figure 3.8: The computational mesh of the pond ............................................. 45

Figure 3.9: Un - baffled pond (a), pond with two baffles of 50 % width (b), four baffles of 50 % width (c), and four baffles of 70 % width (d) .......................... 49

IV

V LIST OF FIGURES

Figure 4.1: Influence of NaCl concentrations from 0 - 10000 mg/l on growth inhibition of frond count (a) and dry biomass (b) at temperature 25 ºC in test (1) .......................................................................................................................... 55

Figure 4.2: Influence of NaCl concentrations from 0 - 10000 mg/l on growth inhibition of frond count (a) and dry biomass (b) at temperature 25 ºC in test (2) .......................................................................................................................... 56

Figure 4.3:Lemna minorunder different NaCl concentrations in tests features (1) and (2) ......................................................................................................... 59

Figure 4.4:Lemna minor features under different NaCl concentrations in tests (3) and (4) ......................................................................................................... 61

Figure 4.5:Lemna minorfrond number (growth change) over time under NaCl concentrations................................................................................................... 64

Figure 4.6: Influence of NaCl concentrations from 0 - 10000 mg/l on growth inhibition of frond count (a) and dry biomass (b) at temperature 35 ºC in test (5) .......................................................................................................................... 66

Figure 4.7: Growth ofLemna minor... 68at different salinities and temperatures

- Figure 4.8: Influence of NaCl concentrations from 0 - 10000 mg/l on NO3 removal at temperature 25 ºC in test (1) (a) and test (2) (b) ............................. 70

- Figure 4.9: Influence of NaCl concentrations from 0 - 10000 mg/l on NO3 removal at temperature 35ºC in test (5) ............................................................ 71

+2 Figure 4.10: Ca removal under NaCl concentrations from 0 - 10000 mg/l in tests (1) and (2)................................................................................................. 73

+2 Figure 4.11: Ca removal under NaCl concentrations from 0 - 500 mg/l in test (3) ..................................................................................................................... 74