1. The Practical Application of Constructed Wetlands in the Philippines R.E. James, N. Callora, R. Inion, G. Tolentino

2. TVI Resource Development Philippines Inc. I. Review Background Constructed Wetland Types

3. TVI Resource Development Philippines Inc. Outline I.Review II.Pilot Testing and Preliminary Results –Vegetation Propagation –Pilot Anaerobic Wetland –Pilot Aerobic Wetland with Open Limestone Channel (OLC)

4. TVI Resource Development Philippines Inc. I. Review

5. TVI Resource Development Philippines Inc. Acid Mine Drainage Acid Mine Drainage (AMD) –Sulfide minerals exposed to water and oxygen 4 FeS 2 + 15 O 2 + 14 H 2 O  4 Fe(OH) 3 + 8 H 2 SO 4 Pyrite + Oxygen + Water  Iron Oxide + Sulfuric Acid –Fe oxyhydroxides smother vegetation –Acidity dissolves and mobilizes toxic metals As, Cd, Cr, Cu, Fe, Mn, Ni, Zn –Contamination of aquatic biota and drinking water

6. TVI Resource Development Philippines Inc. Constructed Wetlands Constructed Wetlands (CW) are a proven passive wastewater treatment technology Immobilization of metals as solid precipitates Generation of alkalinity Energy sources: - Photosynthesis - Topographical gradients - Microbial metabolism

7. TVI Resource Development Philippines Inc. Anaerobic Wetlands –Compost wetland Wetland Types Aerobic Wetlands –Surface reed ponds –Metal removal as Fe precipitation, heavy metal coprecipitation, adsortion, physical settling, and plant-metal uptake PROSCONS Treats acidic water Less clogging of substrate Complicated water distribution, and substrate design PROSCONS Simple design and construction Requires alkaline influent water

8. TVI Resource Development Philippines Inc. CW Modification 1 Reducing and Alkalinity Producing System (RAPS) A B C

9. TVI Resource Development Philippines Inc. CW Modification 2 Limestone Channels –Open Limestone Channels (OLC) ALD/OLC + aerobic wetland Limestone dissolution –Pretreatment of pH 3 water

10. TVI Resource Development Philippines Inc. II. Design Program and Preliminary Results

11. TVI Resource Development Philippines Inc. Wetland Components Vegetation Substrate

12. TVI Resource Development Philippines Inc. Vegetation

13. TVI Resource Development Philippines Inc. Substrate Nursery batch experiments Local substrate –Carabao manure –Forest litter –Sawdust from local sawmill –Rice straw

14. TVI Resource Development Philippines Inc. Results of Batch Experiments Successful growth of plants in pH 3 test water

15. TVI Resource Development Philippines Inc. Hydrology Water Balance: –Mean annual rainfall approximately 3,064 mm –Mean annual evaporation approximately 1,203 mm Highly variable conditions –Monthly unit base flow ranges from 800 m 3 /ha/month to nearly 2,000 m 3 /ha/month. –Short-term high intensity storm events show an even greater range of flows.

16. TVI Resource Development Philippines Inc. Erosion Controls Slope stabilization –Abaca mats –Stabilizing vegetation –Berms Water distribution –Anaerobic conditions? Constant water supply! –Trestles –3-pond water collection

17. TVI Resource Development Philippines Inc. Pilot CW Design: RAPS and OLC + Aerobic Wetland

18. TVI Resource Development Philippines Inc. Metal Analysis: Plant and Water

19. TVI Resource Development Philippines Inc. Pilot RAPS

20. TVI Resource Development Philippines Inc. OLC + Aerobic Wetland

21. TVI Resource Development Philippines Inc. Thank You!