Performance of Combined Vertical and Horizontal Flow Sub-Surface Constructed Wetlands
AbstractThe present study demonstrates wetland projects to treat industrial wastewater for reuse implemented for different hydraulic & organic loadings. The combination of vertical and horizontal flow wetland treatment system with fill and draw controls provides a design for effective contact of wastewater with the root system to achieve higher treatment efficiencies by creating necessary environments for nitrification-denitrification removal of organic materials, and phosphorus adsorption reactions. Systems have been implemented for large scale applications in automobile, sand reclamation, municipal leachate and other industries for process and domestic wastewater treatment & reuse. The results show that there is a marked removal efficiency using Typha species & several other indigenous plants. The percentage reductions in various physicochemical parameters such as Total Suspended Solids (TSS), Biochemical Oxygen Demand (BOD), Nitrate (N), Phosphate (P), and Fecal Coliforms (FC) are 85%, 90%, 70%, 60% and 95% respectively. The study further reveals the effect of variable hydraulic loading rates on treatment efficiencies. The system has been successfully adopted for the past 3 years reducing electrical, mechanical operations and maintenance requirements for wastewater treatment by almost 70% benefiting industries to a great extent and exploring opportunities for application in other industrial sectors for implementation of such technologies which were not in practice earlier.
2. APHA-AWWA-WPCF, 1989, ‘Standard Methods for the Examination of water and wastewater’, eds . Clesceri, L. S., Greenberg, A. E., Trussell, R. R., Baltimore, MD.
3. Bastian, R.K. and Hammer, D.A., 1993. The use of constructed wetlands for wastewater treatment and recycling. Constructed wetlands for water quality improvement, pp.59-68.
4. Brix, H., 1987. Treatment of wastewater in the rhizosphere of wetland plants–the root-zone method. Water Science and Technology, 19(1-2), pp.107-118.
5. Cole, S., 1998. The emergence of treatment wetlands. Environmental science & technology, 32(9), pp.218A-223A.
6. Crites, R., Techobanoglous, G., 1998. Small and decentralized wastewater management systems. McGraw-Hill, Boston.
7. Drizo, A.F.C.A., Frost, C.A., Smith, K.A. and Grace, J., 1997. Phosphate and ammonium removal by constructed wetlands with horizontal subsurface flow, using shale as a substrate. Water Science and Technology, 35(5), pp.95-102.
8. Gersberg, R.M., Elkins, B.V., Lyon, S.R. and Goldman, C.R., 1986. Role of aquatic plants in wastewater treatment by artificial wetlands. Water research, 20(3), pp.363-368.
9. House, C.H., Bergmann, B.A., Stomp, A.M. and Frederick, D.J., 1999. Combining constructed wetlands and aquatic and soil filters for reclamation and reuse of water. Ecological Engineering, 12(1-2), pp.27-38.
10. Juwarkar, A.S., Oke, B., Juwarkar, A. and Patnaik, S.M., 1995. Domestic wastewater treatment through constructed wetland in India. Water Science and Technology, 32(3), pp.291-294.
11. Kadlec, R. H. & Knight, R. L., 1996. Treatment wetlands. Boca Raton: Lewis Publishers.
12. McIntyre, B.D. and Riha, S.J., 1991. Hydraulic conductivity and nitrogen removal in an artificial wetland system. Journal of environmental quality, 20(1), pp.259-263.
13. Pullin, B.P. and Hammer, D.A., 1989. Comparison of plant density and growth forms related to removal efficiencies in constructed wetlands treating municipal wastewater. Tennessee Valley Authority, Valley Resource Center, Waste Technology Program, Knoxville, TN, USA.
14. Sauer, P. and Kimber, A., 2001. Technical assessment of constructed wetlands for wastewater treatment in Iowa. IOWA: Associate of Municipal Utilites.
15. U.S. EPA, 1999. Constructed Wetlands Treatment of Municipal Wastewaters. National Risk Management Research Laboratory, Office of Research and Development, Cincinnati.
16. Wathugala, A.G., Suzuki, T. and Kurihara, Y., 1987. Removal of nitrogen, phosphorus and COD from waste water using sand filtration system with Phragmites australis. Water research, 21(10), pp.1217-1224.
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