کاهش BOD5 از آب‌های‌آلوده با استفاده از گیاه وتیور در تالاب‌مصنوعی جریان‌سطحی
محورهای موضوعی : مدیریت آب در مزرعه با هدف بهبود شاخص های مدیریتی آبیاری
1 - استادیار دانشگاه آزاداسلامی، واحد شوشتر، گروه علوم آب، شوشتر، ایران
کلید واژه: وتیور, کاهش BOD5, تالاب مصنوعی,
چکیده مقاله :
در تالاب‌های مصنوعی از نوع جریان سطحی، حجم گسترده میکروارگانیزم‌های اطراف ریشه گیاه، محیط مناسبی برای تصفیه فاضلاب فراهم می‌نمایند. به‌منظور بررسی اثر گیاه وتیور و زمان ماند فاضلاب، در کارآیی تصفیه این نوع سامانه‌ها، نه حوضچه در شرکت کشت و صنعت نیشکر کارون واقع در شهرستان شوشتر ساخته‌شد. واحدها، به‌صورت موازی در کنارهم قرارگرفته و طول هر واحد 3 متر، عرض 1 متر و ارتفاع 8/0 متر بود. جریان پیوسته فاضلاب کشاورزی حاصل از شستشوی نی، از اواسط آذرماه 1392 تا خردادماه سال 1393 برقرار شد. سه سامانه، با کشت ریشه گیاه درخاک (S)، سه سامانه با کشت گیاه روی صفحات شناور (F) و سه سامانه بدون گیاه و بستر متخلل به عنوان شاهد (C) در نظر گرفته شدند. متوسط غلظت BOD5 فاضلاب ورودی به هر واحد 69/15±115 میلی‌گرم بر لیتر و زمان‌های ماند مورد آزمایش 3، 5 و 7 روز بودند. در طی دوره آزمایش، غلظت BOD5 ورودی و خروجی هر واحد، اندازه‌گیری و با استفاده از نرم‌افزار آماری SAS آنالیز شد. نتایج حاصل از آنالیز نشان داد، اختلاف معنی‌داری بین سامانه‌های حاوی گیاه و فاقد گیاه (شاهد) در زمان‌های ماند وجود دارد. سامانه حاوی گیاه و زمان ماند 7 روز در ماه خرداد، دارای بیش‌ترین مقدار بازده حذف، با میانگین 48/68 درصد بود. به‌عبارت دیگر، شرایط بهینه برای حصول حداکثر بازده حذف BOD5 از فاضلاب کشت و صنعت نیشکر کارون، در سامانه تالاب مصنوعی شناور با کشت گیاه وتیور و در زمان ماند 7 روز به‌دست آمد.
In the free water surface flow (FW-SF) constructed wetlands, a large number of micro organisms that live around the roots of plants create a suitable environment for wastewater treatment. To study the effect of Vetiver plant and sewage retention time in treatment efficiency of such systems, nine ponds in the Karoun sugarcane Agro-industrial located in the city of Shushtar was built. Units, in parallel with each other and each unit with length 3m, width 1m and height 0.8 meters. Continuously, agricultural wastewater from the washing process of sugarcane from December 2013 until May 2014 was established. Three of the units filled with soil and were transplanted with vetiver (S), three units were cultivated with vetiver on the floating platform (F) and three units were kept unplanted as control (C). The average BOD5 concentration of the wastewater entering the unit was 115±15.69 mg/l and retention times of experiments were 3, 5 and 7 days. During the experiment, the concentration of BOD5 per unit of input and output measurements was analyzed using SAS software. The results of the analysis showed significant differences between plant and non-plant systems, including retention times. The constructed wetland system with plant cultivated and the retention time of 7 days in May had highest value of the average removal rate equal to 68.48 percent. In other words, optimum conditions for maximum BOD5 removal rate of Karoun sugarcane Agro-industrial wastewater in floating constructed wetlands systems was with vetiver cultivated and in the retention time of 7 days.
افروس، ع. ش.، منشوری، م.، لیاقت، ع. و بشلیده، ح. 1389. بررسی راندمان حذف BOD در سامانه تالاب های مصنوعی حاوی دو گونه گیاه آبزی (Typha latifolia) و (Phragmites australis) مطالعه موردی: دزفول. فصلنامه علمی پژوهشی تالاب. 2 (5): 13-19
Allen, W.C., Hook, P.B., Biederman, J.A. and Stein, O.R. 2002. Temperature and wetland plant species effects on wastewater treatment and root zone oxidation. Journal of Environmental Quality, 31: 1010-1016.
Beutel, M.W., Newton, C.D., Brouillard, E.S. and Watts, R.J. 2009. Nitrate removal in surface-flow constructed wetlands treating dilute agricultural runoff in the lower Yakima Basin. Washington. Ecological Engineering, 35: 1538–1546
Brix, H. 1997. Do macrophytes play a role in constructed treatment wetland Water Sci. Technol, 35: 11–17.
Calheiros, C.S.C., Rangel, A.O.S.S. and Castro, P.M.L. 2007. Constructed wetland systems vegetated with different plants applied to the treatment of tannery wastewater. Water Res, 41: 1790–1798.
Crites, R.W., and Tchobanoglous, G. 1998. Small and Decentralized Wastewater Management Systems. McGraw-Hill Book Company,New York 1084 pages
Crites, R.W., Middlebrooks. J, and Reed, S.C. 2006. Natural Wastewater Treatment Systems. CRC press. Boca Raton.
Greenfield, J.C. 1988. Vetiver grass(Vetiveria Zizanioides): A method of vegetative soil and moisture conservation. seminar on the vetiver system presented at the World Bank. Washington D.C.
Hammer, D.A. 1992. Designing constructed wetlands systems to treat agricultural nonpoint source pollution. Ecol. Eng, 1: 49–82.
Kadlec, R.H. and Knight, R.L. 1996. Treatment Wetlands. CRC Press. Boca Raton. Florida. 893 pp.
Kadlec, R.H. and Reddy, K. R. 2001. Temperature effects in treatment wetlands. Water Environment Research, 5(73): 543-557
Kadlec, R.H. 2003. Status of treatment wetlands in North America. Proc. Conf. The Use of Aquatic Macrophytes for Wastewater Treatment in Constructed Wetlands. Lisbon. Portugal. ICN and INAG. 363-401.
Kansiime, F. and Bruggen, J.J.A.V. 2001. Distribution and retention of faecal coliforms in the Nakivubo wetland in Kampala, Uganda. Water Science and Technology, 12 (44): 199-206.
Katsenovicha, Y.P., Hummel-Batistab, A., Ravineta, A.J. and Millera. J.F. 2009. Performance evaluation of constructed wetlands in a tropical region. Ecological Engineering, 35: 1529–1537.
Klomjek P. and Nitisoravut S, 2005. Constructed treatment wetland: a study of eight plant species under saline conditions. Chemosphere 58: 585–593.
Kotti, P.I., Gikas, D.G. and Tsihrintzis, V.A. 2010. Effect of operational and design parameters on removal efficiency of pilot-scale FWS constructed wetlands and comparison with HSF systems. Ecol. Eng, 36: 862–875.
Kropfelova, L. 2008. Constructed Wetland Brehov: Three Years of Monitoring, in: Wastewater Treatment, Plant Dynamics and Management in Constructed and Natural Wetlands. Springer Science 181-190.
Greenway, M. and Woolley, A. 1999. Constructed wetlands in Queensland: Performance efficiency and nutrient bioaccumulation. Ecol. Eng, 12: 39–55.
Mitsch, W.J. 1994. Global wetlands:old world and new. Editor (ed.). Elsevier. Philadelphia. 309-324
Picard, C., Fraser, H.L. and Steer, D. 2005. The interacting effects of temperature and plant community type on nutrient removal in wetland microcosms. Biores. Technol, 96 (9): 1039-1047
Prabu, P.C. and Udayasoorian, C.U. 2007. Treatment of pulp and paper mill effluent using constructed wetland. EJEAFChe, 6: 1689–1701.
Revitt, D,M., Worrall, P. and Brewer, D. 2001. The integration of constructed wetlands into a treatment system for airport runoff. Water Science and Technology, 44: 469–476.
Steer, D., Fraser, L., Boddy, J., and Seibert, B. 2002. Efficiency of small constructed wetlands for subsurface treatment of single-family domestic effluent. Ecol. Eng, 18: 429-440.
Tanner, C.C., Clayton, J.S. and Upsdell, M.P. 1995. Effect of loading rate and planting on treatment of dairy farm wastewaters in constructed wetlands—I. Removal of oxygen demand, suspended solids and fecal coliforms. Water Res, 29: 17–26.
Tanner, C.C. and Headlby, T.R. 2011. Components of floating emergent macrophyte treatment wetlands influencing removal of stormwater pollutants. Ecological Engineering, 37: 474-486.
Truong, P.N. 2000. The Global Impact of Vetiver Grass Technology on the Environment. Proceedings of the Second International Conference on Vetiver. Bangkok.Thailand. pp 48–61.
Vymazal, J. 2002. The use of sub-surface constructed wetlands for wastewater treatment in the Czech Republic: 10 years experience. Ecol. Eng, 18: 633-646
Vymazal, J. 2010. Water and Nutrient Management in Natural and Constructed Wetlands. Springer. Dordrecht.
Weragoda, S.K., Jinadasa, K.B.S.N., Zhang, D.Q., Gersberg, R.M., Tan, S.K., Tanaka, N. and Jern, N.W. 2012. Tropical Application of Floating Treatment Wetlands. Wetlands, 32: 955–961.
