بررسی تأثیر گیاهان آبزی در کاهش فسفر و هدایت الکتریکی پساب شهری

نوع مقاله: مقاله پژوهشی

نویسندگان

1 کارشناس ارشد خاکشناسی، دانشگاه شاهرود

2 استادیار گروه آب و خاک، دانشکده کشاورزی، گروه پژوهشی زیست فناوری، دانشگاه شاهرود

چکیده

فسفر یک عنصر غذایی برای موجودات زنده محسوب می‌شود, اما مقادیر زیاد آن در آبهای زیرزمینی و سطحی سبب بروز مشکلات محیط زیستی نظیر پدیده پرغذایی می‌گردد. لذا باید قبل از تخلیه پساب به منابع آبی مقدار فسفر آن تا حد امکان کاهش یابد. از‌ روشهای مؤثر برای پالایش آبهای آلوده استفاده از گیاهان آبزی است. آزمایشی بر روی دو گیاه الودئا و عدسک ‌آبی با چهار تیمار در سه تکرار در پایلوت‌های آزمایشی با جریان بسته انجام ‌شد. تیمارها شامل: پساب اولیه همراه و بدون گیاه و پساب رقیق ‌شده (با درجه رقت‌2/1) همراه و بدون گیاه بود. مقدار pH ، EC و فسفر کل محلول در زمان ماندهای 8، 16 و 24 روز در نمونه‌های پساب ‌اندازه‌گیری ‌شد. نتایج نشان ‌داد که مقدار pH پساب در طول زمان تا 2/0 واحد کاهش یافت، اما بین تیمارها تفاوت معنی‌داری (05/0 p≤) در مقدارpH  مشاهده نشد. گیاهان، EC پساب را پس از 24 روز 7 درصد نسبت به شاهد کاهش دادند. غلظت فسفر کل محلول در تمام تیمارها با گذشت زمان روند کاهشی داشت و مقدار کاهش فسفر در تیمارهای عدسک ‌آبی و الودئا به‌ترتیب 49 و 7 درصد بود. به‌طور کلی عدسک آبی نسبت به الودئا توانایی بیشتری در کاهش فسفر پساب داشت.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Effect of Aquatic Plants on Phosphorus Removal and Electrical Conductivity Decrease in Municipal Effluent

نویسندگان [English]

  • Sara Samimi Loghmani 1
  • Ali Abbaspour 2
2 Shahrood university of technology
چکیده [English]

Phosphorus (P) is one of essential elements for living organisms, though its critical concentration in surface and ground waters impose a serious problem such as eutrophication. So treatment of polluted waters is required before discharging to water resources. One of effective ways to decrease water pollution is using aquatic plants. An experiment was conducted in pilots with a closed flowing system on two plants, elodea (egria densa) and duck weed (lemna minor) with four treatments and three replications. Data were analyzed in a factorial completely randomized design. Treatments included effluent with and without the plants, and effluent diluted (dilution grade 1/2) with and without the plants. Total dissolved P, electrical conductivity (EC) and pH value were measured after 8, 16 and 24 days in effluent samples. The results showed that pH value decreased up to 0.2 units during of 24 days of the experiment, but there was found no significant difference (p≤0.05) in pH values among the treatments. Both plants decreased EC about 7 % relative to the control (without plant) after 24 days. The plants were also effective in reducing total dissolved phosphorus, so that duck weed and elodea decreased total dissolved P in the effluent about 49 and 7%, respectively. It is concluded that duck weed is more effective in the P removal from the effluent than the other plant.

کلیدواژه‌ها [English]

  • Duck Weed
  • Elodea
  • Eutrophication
  • Effluent
  • Water Pollution
1. Shigaki, F., Sharpley, A., and Prochnow, L.I. (2007). “Rainfall intensity and phosphorus, source effects on phosphorus transport in surface runoff from soil trays.” Sci. Total Environ., 373, 334-343.

2. Shokouh Saljoghi, Z., Malekpour, A., Rafiee, Gh., Imani, A., and Bakhtiari, M. (2011). “Removal of nitrite and nitrate from recirculation aquaculture system effluent (RAS) by modified bentonites.” J. of Water and Wastewater, 78, 46-54. (In Persian)

3. Javanshir, A., and Jandaghi, M. (2008). “Evaluation of phosphate and nitrate removal capacity of anodonta cygnea (unionidae) in open and closed systems.” J. of Water and Wastewater, 66, 25-33. (In Persian)

4. Zimmo, O.R., Van der Steen, N.P., and Gijzen, H.J. (2004). “Nitrogen mass balance across pilot-scale algae and duckweed-based wastewater stabilisation ponds.” Wat. Res., 38, 913-920.

5. Reddy, K.R. (1983). “Fate of nitrogen and phosphorus in a wastewater retention reservoir containing aquatic macrophytes.” J. Environ Qual.,12, 137-141.

6. Gurtekin, E., and Sekerdag, N. (2008). “The role of duckweed (lemna minor) in secondary clarifier tank.” Environ. Engineering, 12, 28-31.

7. Schwarz, A., and Haves, I. (1997). “Effect of changing water clarity on characean biomass and species composition in alarge oligotrophic lake.” Aquat. Bot., 56, 169- 181.

8. Amelie, K., and Kivaisi, A. (2001). “The potential for constructed wetlands for wastewater treatment and reuse in developing countries: A review.” Ecological Engineering, 16, 545-560.

9. Skillicorn, P., and Spira, W. (1993). Duckweed aquaculture, World Bank Pub., Washington, D.C, USA.

10. El-Shafai, S.A., El-Gohary, F.A., and Van der Steen, N.P. (2004). “Chronic ammonia toxicity to duckweed fed tilapia.” Aquaculture, 232, 117-127.

11. Barrat-Segretain, M.H. (2005). “Competition between invasive and indigenous species: Impact of spatial pattern and developmental stage.” Plant Ecol., 180, 153-160.

12. Bowmer, K., Jacobs, S.W.L., and Sainty, G.R. (1995). “Identification, biology, and management of Elodea Canadensis, Hydrocharitaceae.” Aquatic Plant Management, 33, 13-19.

13. USDA, A.R.S. (2009). “Taxon: Elodea canadensis michx. national genetic resources program.” Germplasm Resources Information Network- (GRIN) [Online Database]. National Germplasm Resources Laboratory, Beltsville, Maryland.

14. Reddy, K.R., and Debusk, W.F. (1985). “Nutrient removal potential of selected aquatic macrophytes.” J. Environ. Qual., 14, 459-462.

15. Iamchaturapatr, J., Won, Y. S., and Rhee, J. S. (2007). “Nutrient removals by 21 aquatic plants for vertical free surface-flow (VFS) constructed wetland.” J. Ecology Engineering, 29, 287-293.

16. Page, A.L. (1982). Methods of soil analysis (part 1), Madison, Wisconsin: Am. Soc. Argon.

17. Abbaspour, A.,  Arocena, J.M., and Kalbasi, M. (2012). “Uptake of phosphorus by Brassica juncea and Medicago sativa in chloropyromorphite- and apatite-treated sand cultures.” Int. J. Phytoremediation, 14, 531-542.

18. Shan, B., Ao, L., Hu, C., and Song, J. (2011). “Effectiveness of vegetation on phosphorus removal from reclaimed water by a subsurface flow wetland in a coastal area.” J. Environ. Sci.,  23(10) 1594-1599.

19. Lin, Y.F., Jing, S.R., Wang, T.W., and Lee, D.Y. (2002). “Effects of macrophytes and external carbon sources on nitrate removal from groundwater in constructed wetlands.” J. Environ. Pollut., 119, 413-420.

20. Bezbaruah, A.N., and Zhang, T.C. (2004). “pH, redox and oxygen microprofiles in rhizosphere of bulrush (Scirpus validus) in a constructed wetland treating municipal wastewater.” J. Biology Technol., 88, 60-70.

21. Ayyasamy, P.M., Rajakumar, S., Sathishkumar, M., and Swaminathan, K. (2009). “Nitrate removal from synthetic medium and groundwater with aquatic macrophytes.” J. Desalination, 242, 286-296.

22. Lantzke, I.R., Mitchell, D.S., Heritage, A.D., and Sharma, K.P. (1999). “A model of factors controlling orthophosphate removal in planted vertical flow wetland.” Ecological Engineering, 12, 93-105.

23. Xiang, W., Xiao, Y., and Rengel, Z. (2009). “Phytoremediation facilitates removal of nitrogen and phosphorus from eutrophicated water and release from sediment.” Environ. Monit. Assess., 157, 1-4.

24. Hunter, R. G., Combs, D. L., and George, D. B. (2001). “Nitrogen, phosphorous, and organic carbon removal in sitmulated wetland treatment systems.” Environ. Contamination Toxicology, 41, 274-281.

25. Gao, J., Xiong, Z., Zhang, J. Zhang, W., and Mba, F. O. (2009).” Phosphorus removal from water of eutrophic Lake Donghu by five submerged macrophytes.” Desalination, 242, 193-204.

26.Wen, L., and Recknage, F. (2002). “In situ removal of dissolved phosphorus in irrigation drainage water by planted floats: Preliminary results from growth chamber experiment.” Agriculture, Ecosystems and Environment, 90, 9-15.

27. Werker, A.G., Dougherty, J.M., McHenry, J.L., and Van Loon, W.A. (2002). “Treatment variability for wetland wastewater treatment design in cold climates.” Ecological Engineering, 19, 1-11.

28. Tang, X., Huang, S., and Scholz, M. (2009). “Nutrient removal in pilot-scale constructed wetlands treating eutrophic river water: Assessment of plants, intermittent artificial aeration and polyhedron hollow polypropylene balls.” Water Air Soil Pollut., 197, 61-73.

29. Vermmat, J.E., and Hanif, M.K. (1998). “Performance of common duckweed species (Lemnaceae) and the water fern Azolla Filiculoides on different types of wastewater.” Wat. Res., 32, 256-257.