1. Effect of Lake Shinji periphyton upon phosphorus sorption by concrete
WOLFE, June – Baylor University and Texas AgriLife Research
NONAKA, Tsuguhiro – Shimane University
KUWABARA, Tomoyuki
SOMURA, Hiroaki

2. Background
Periphyton :
attached benthic community consisting mainly of algae and bacteria
Periphyton removes phosphorus from water
(Craggs 2001, Dodds 2003)
Concrete sorbs phosphorus from water
(Molle et al. 2003, Sato et al. 2004, Park and Tai 2004, Takio et al. 2007)
Hypotheses:
Periphyton may prefer specific recycled concrete material (RCM)
Periphyton-covered RCM may differ in phosphorus sorption behavior
RCM may be engineered to optimize most favorable periphyton condition
Recycled Concrete Materials (RCM):
a mixture of Portland cement and various aggregates with differing sorption capacities

3. P Questions What is the phosphorus affinity of RCM?15
30.97
What is the phosphorus affinity of RCM?
What is the effect of RCM upon periphyton growth?
What is periphyton effect upon phosphorus sorption by RCM?
Is phosphorus sorbed to RCM available to periphyton?

4. Recycled Concrete Material (RCM)
Kimachi Rock
Recycled Concrete
Foamed Glass
RCM test cylinder (50mm x 50 mm)
Material
Aggregate size
Density
Portland
Aggregate
Unit Weight
(mm)
(g cm-3)
(%)
(kg m-3)
Kimachi RCM
3 - 8
1.68 19 81
1432
Concrete RCM
7 - 15
1.67 16 84
1440
Glass RCM
1.32 23 77
1186

5. Methods – Periphyton Establishment
Research site near Izumo
Attach RCM
Deploy 2-5 weeks
Harvest

6. Methods – Lab Procedures
Sample Preparation
Biomass
Taxonomy / Spectrophotometry

7. What is the phosphorus affinity of RCM?
Equilibrate RCM at 1, 5, 10, 50, 100, 500 mg P L-1 for 48 hrs
Plot equilibrium concentration vs P sorbed per gram RCM
Fit Langmuir model to describe the isotherm
Equilibrate RCM in 500 mg L-1 P for 48 hrs
Sample at 0, 6, 12, 24, and 48 hours
Plot P sorption as a function of time

8. Sorption isotherm for RCM equilibrated ºC, dashed line indicates Langmuir fit of the data

9. Sorption isotherm for RCM equilibrated 48 hrs @ 26 ºC, dashed line indicates Elovich fit of the data

10. Summary Langmuir fit Smax Material (r2) (mg/g) Foamed Glass 0.38 2.88
Kimachi Rock
0.78
2.34
Recycled Concrete
0.19
2.14

11. Lake Shinji Conditions
Date
Variable
Units
7/2/2009
7/15/2009
7/22/2009
7/29/2009
8/5/2009
8/18/2009
Weather
Descriptive
Rain
Clear
Cloudy
Sunny
Depth
(m)
0.56
0.51
1.15
0.53
0.46
0.47 pH
(n/a)
6.42
7.00
7.35
7.55
7.80
7.64
Conductivity
(sec m-1)
0.38
1.10
0.83
0.12
0.20
0.24
Turbidity
(NTU) 35 4 80 37 45 14
Dissolved O2
mg L-1
9.3
6.7
6.8
7.6
6.2
Temparature
(°C)
24.5
25.8
26.0
24.9
29.3
Salinity
(%)
0.2
0.6
0.5
0.1
Dissolved Solids
(g L-1)
2.5
7.0
5.3
0.8
1.3
1.6

12. What is the effect of RCM on periphyton growth? - Biomass

13. What is the effect of RCM on periphyton growth? - Biomass

14. What is the effect of RCM on periphyton growth? - Biomass

15. What is the effect of RCM on periphyton growth? - Biomass

16. What is the effect of RCM on periphyton growth? - Biomass

17. Periphyton common to Lake Shinji
Green filamentous algae
Rhizoclonium sp.
Enteromorpha sp.
Cladophora sp.
Diatoms
Melosira virans
Pleurosira laevis
Cymbella spp.
Navicula spp.
Nitzschia spp.
Functional groups
Green filamentous
Single pinnate diatom
Chain pinnate diatom
Chain centric diatom

18. What is the effect of RCM on periphyton growth? - Taxonomy

19. P What is periphyton effect upon phosphorus sorption by RCM? Method:
Deploy RCM into Lake Shinji for 3 weeks
Kill periphyton on half of RCM
Place RCM in 500 ml lake water
Add 1 mg L-1 phosphorus (as KH2PO4)
Collect water samples over time
Analyze water for phosphorus concentration P

20. What is periphyton effect upon phosphorus sorption by RCM?

21. P What is periphyton effect upon phosphorus sorption by RCM? Method:
Deploy RCM into Lake Shinji for 3 weeks
Place periphyton covered RCM in 500 ml lake water
Place RCM (no periphyton) in 500 ml lake water
Add 1 mg L-1 phosphorus (as KH2PO4)
Collect water samples over time
Analyze water for phosphorus concentration P

22. What is periphyton effect upon phosphorus sorption by RCM?

23. Is phosphorus sorbed to RCM available to periphyton?
Load RCM materials with SRP (as KH2PO4)
1, 5, 10, 50, 100 mg L-1
Place P-loaded materials into Lake Shinji
Allow periphyton to colonize for ~3 weeks
Analyze entire substrate for Chlorophyll a

24. Is phosphorus sorbed to RCM available to periphyton?

25. Conclusions
RCM exhibited different P sorption capacities based on composition
Lake Shinji periphyton rapidly colonized all three RCM, showing no preference
Periphyton biofilms appeared to negatively affect dissolved P sorption by RCM
Increasing amounts of P sorbed to RCM exhibited both null (rock, concrete) and positive (foamed glass)effects upon periphyton biomass accumulation

26. Acknowledgments Japan Society for the Promotion of Science - Funding
U.S.A. National ScienceFoundation - Funding
Shimane University, Matsue, Japan
Dept. of Ecology and Environmental Science
Dr. Tsughiro Nonaka – Host Researcher
Dr. Tomoyuki Kuwabara - Research advice
Dr. Hiroaki Somura – Research support
Mr. KazuhisaTakahashi – Technical support
Ms. Kanatsu Yuki – Transportation
Mr. Takahiro Fukuoka – Technical support
Texas AgriLife Research, Temple, Texas
Dr. Dennis Hoffman
Baylor University, Waco, Texas
Dr. Owen Lind

27. Questions?
Photo by Dr. Ichiro Matsumoto