ABSTRACT In this study constructed wetlands (CWs) were used to remove three heavy metals (Zn, Cu and Pb). The two tested substrates were made of coke and gravel, respectively. First order dynamic model was appropriate to describe removing of Zn and Cu. The experimental results showed that first dynamic removal rate constants of Zn in CWs with coke and gravel were 0.2326 h-1 and 0.1222 h-1, respectively. And those of Cu in CWs with coke and gravel were 0.2017 h-1 and 0.3739 h-1. However, removal efficiencies of Pb in the coke system and the gravel system were within 95-99%, so the first order dynamic model failed to fit the experimental data because the hydraulic resident times of Pb did not affect outlet concentration of Pb. From the removal rate constants, it is found that the coke and gravel system have different absorption efficiencies of heavy metal pollutants. Therefore, it is suggested that the removal efficiencies of heavy metals are influenced by the choice of substrates to some extent.
Cite this paper
nullM. CHEN, Y. TANG, X. LI and Z. YU, "Study on the Heavy Metals Removal Efficiencies of Constructed Wetlands with Different Substrates," Journal of Water Resource and Protection, Vol. 1 No. 1, 2009, pp. 22-28. doi: 10.4236/jwarp.2009.11004.
 D. B. Kosolapov, P. Kuschk, M. B. Vainshtein, A. V. Vatsourina, A. Wiessner, M. Kastner, and P. A. Muller, “Microbial processes of heavy metal removal from car-bon-deficient effluents in constructed wetlands,” Engi-neering in Life Sciences, Vol. 4, No. 5, pp. 403-411, Oc-tober 2004.
R. H. Kadlec and R. L. Knight, “Treatment wetlands,” CRC Press, 1996.
L. H. Xu and Q. Zhou, “Study on purification ability of artificial wetlands with different filler,” Shanghai Envi-ronmental Science, Vol. 21, No. 10, pp. 603-605, Octo-ber 2002.
C. A. Prochaska, A. I. Zouboulis, and K. M. Eskridge, “Performance of pilot-scale vertical-flow constructed wetlands, as affected by season, substrate, hydraulic load and frequency of application of simulated urban sewage,” Ecological Engineering, Vol. 31, No. 1, pp. 57-66, Sep-tember 2007.
China State Environmental Protection Administration, “2000 report on the state environment in China,” Envi-ronmental Education, No. 4, pp. 46-47, April 2000.
R. H. Kadlec, “Overview: Surfaceflow constructed wet-lands,” Water Science and Technology, Vol. 32, No. 3, pp. 1-12, 1995.
R. H. Kadlec, “Deterministic and stochastic aspects of constructed wetland performance and design,” Water Science and Technology, Vol. 35, No. 5, pp. 149-156, 1997.
D. P. L. Rousseau, P. A. Vanrolleghem, and N. D. Pauw, “Model-based design of horizontal subsurface flow con-structed treatment wetlands: A review,” Water Research, Vol. 38, No. 6, pp. 1484-1493, March 2004.
A. L. Simi and C. A. Mitchell, “Design and hydraulic performance of a constructed wetland treating oil refinery wastewater,” Water Science and Technology, Vol. 40, No. 3, pp. 301-307, 1999.
S. D. Huang and B. Leng, “The technique of man-made wetland treatment system,” Sichuan Environment, Vol. 12, No. 2, pp. 48-51, 1993.
Y. X. Yao and Y. J. Wang, “Application of man-made wetland in the treatment of mine wastewater,” Hunan non-ferrous metals, Vol. 21, No. 4, pp. 26-29, August 2005.
N. H. Ince, N. Dirilgen, I. G. Apikyan, G. Tezcanli, and B. Ustun, “Assessment of toxic interactions of heavy metals in binary mixtures: A statistical approach,” Archives En-vironmental Contamination and Toxicology, Vol. 36, No. 4, pp. 365-372, March 1999.
China State Environmental Protection Administration, Ed., “Water and exhausted water monitoring analysis method,” China Environmental Science Press, 2002.
D. J. Walker and S. Hurl, “The reduction of heavy metals in a stormwater wetland,” Ecological Engineering, Vol. 18, No. 4, pp. 407-414, March 2002.