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نوع مقاله : مقالات پژوهشی

نویسندگان

1 دانشگاه گیلان

2 گروه علوم خاک، دانشکده علوم کشاورزی، دانشگاه گیلان، رشت، ایران.

چکیده

افزایش فعالیت‌های کشاورزی و به دنبال آن رهاسازی آلاینده‌ها از سامانه‌های کشاورزی و همچنین گسترش صنایع سبب ورود یون‌های فلزهای سنگین از جمله کادمیوم به محیط زیست می‌شود. کاربرد جاذب‌ها از روش‌های مناسب برای ناپویاسازی فلزهای سنگین در خاک‌های آلوده می‌باشند. این پژوهش با هدف بررسی پیامد جاذب‌های طبیعی و اصلاح شده در ناپویاسازی کادمیوم در خاک آلوده و پیامد آن بر برخی ویژگی‌های زیستی و شاخص‌های اکوفیزیولوژیک خاک در قالب طرح کاملا تصادفی با 13 تیمار و سه تکرار انجام شد. تیمارها شامل بنتونیت (B)، بنتونیت اصلاح شده با آهن (B-Fe)، بنتونیت اصلاح شده با منگنز (B-Mn)، بنتونیت اصلاح شده با آهن و منگنز (B-Fe Mn)، شلتوک برنج (RH)، شلتوک برنج اصلاح شده با اسید فسفریک (RH-P)، هرکدام در دو سطح 2 و 5 درصد و تیمار شاهد بودند. نتایج آزمایش نشان داد که تنفس پایه میکروبی و فعالیت آنزیم فسفاتار در تیمار RH-P 5% به ترتیب به 6/2 و 25/2 برابر تیمار شاهد رسید. تنفس برانگیخته با سوبسترا و فعالیت آنزیم اوره‌آز در تیمار RH-P 5% بیشترین مقدار بود. فعالیت آنزیم دهیدروژناز نیز در تیمارهای RH-P 5% و 5% و B-FeMn 2 بیشترین مقدار را نشان داد. نتایج همچنین نشان داد که مقدار کادمیوم محلول و تبادلی با افزودن جاذب‌ها کاهش یافت و در تیمار RH-P 5% نسبت به شاهد 5/2 برابر کاهش مشاهده شد. شاخص‌های اکوفیزیولوژیک خاک نیز که از شاخص‌های سلامت و کیفیت خاک می‌باشند در حضور جاذب‌ها بهبود یافتند، به گونه‌ای که سهم متابولیک در تیمارهای همراه با جاذب بنتونیت و شلتوک برنج بیشترین مقدار بود. بنابراین کاربرد جاذب‌ها می‌تواند یکی از راه‌کارهای مدیریتی موثر برای ناپویاسازی کادمیوم و بهبود شرایط زیستی خاک باشد.

کلیدواژه‌ها

عنوان مقاله [English]

Efficiency of Natural and Modified Bentonite and Rice Husk on Immobilization of Cadmium and Its Effect on Some Biological Properties of Soil

نویسندگان [English]

  • Samaneh Abduolrahimi 1
  • Nasrin Ghorbanzadeh 1
  • Hasan Ramezanpour 1
  • Mohammad Bagher Farhangi 2

1 University of Guilan

2 Soil science departement, Faculty of agricultural sience, University of Guilan, Rasht, Iran.

چکیده [English]

Introduction: Rapid development of industrialization, heavy metal and radionuclide contaminants from industrial activities have posed a major threat to the environment owing to their toxicity, non-biodegradability and persistent accumulation. So various ecosystems are continuously contaminated with high levels of high-risk chemicals with different structures and levels of toxicity. Cadmium is one of the high-risk elements that enters the environment and can accumulate in the body of fish and other aquatic organisms, plants and livestock and be transferred to the human body. Therefore, the remediation of contaminated soils with cadmium in order to protect human health is very important. One method for remediation of pollutants is immobilization of them in the soil by adsorbents. Among the absorbents, bentonite has been identified for its unique properties, including high surface area and cation exchange capacity and adsorptive affinity for organic and inorganic ions, low cost and ease of access. If the physical and chemical properties of natural bentonites are improved by a special modification process, the adequate supplies for environmental purposes can be obtained. Among the biosorbents, rice husk has also been reported to be suitable for adsorption of cadmium and other heavy metals. This research was designed with the aim of decreasing the amount of cadmium in the soluble and exchangeable phase of a polluted soil under laboratory conditions in the presence of bentonite and rice husk. Considering that biological properties of the soil are an indicator of soil health and quality, so, after application of adsorbents, biological properties and some soil ecophysiological indices were also investigated.
Materials and Methods: The experiment was done with 13 treatments and 3 replications in a completely randomized design. Treatments were bentonite (B) and modified bentonite with iron (B-Fe), manganese (B-Mn), iron and manganese together (B-Fe-Mn), rice husk (RH), modified rice husk with phosphoric acid (RH-P) in two levels (2 and 5%) and control treatment (without adding adsorbent). Modification of bentonite was done with iron chloride (FeCl3.6H2O), manganese chloride (MnCl2.6H2O) and a mixture of FeCl3.6H2O and MnCl2.6H2O. Some of the characteristics of bentonite and rice husk adsorbents including pH, electrical conductivity, cation exchange capacity and organic carbon were measured. The contaminated soil with CdCl2 was treated with adsorbents and incubated for 2 months under constant lab conditions. After the incubation time, soil biological properties such as basal respiration, substrate-induced respiration (SIR), microbial biomass carbon (MBC), activity of some enzymes and also some ecophysiological indexes were measured.
Results and Discussion: The results showed that the basal respiration, SIR, MCB, activity of phosphatase, dehydrogenase and urease were less in the control treatment. The basal respiration and phosphatase activity in RH-P 5% treatment were 2.6 and 2.25 times more than those in the control, respectively. SIR and urease activity were highest in RH-P 5% treatment. The application of adsorbents to contaminated soil reduced soluble and exchangeable cadmium fraction. The lowest amount of soluble and exchangeable fraction of cadmium was in RH-P 5% treatment that showed 2.5 times reduction in comparison to control. In other words, immobilization of cadmium from these fractions improved soil conditions and caused increasing of biological soil properties and activity of microorganisms. The metabolic quotient was higher in the control treatment, probably due to lower microbial content, and decreased by adding adsorbents. Microbial quotient in control treatment was lower than other treatments which prove again the lower biomass carbon of control treatment. Carbon availability that is the ratio of basal respiration to SID, also was more in control in comparison to other treatments, perhaps due to the suppress or inhibition of dormant or zymogenous microbes by cadmium in the control treatment which can be stimulated to growth in the SIR experiment.
Conclusions: The results of this study revealed that cadmium with concentration of 30 mg kg-1has a toxic and inhibitory effect on the microbial activity of the soil. The addition of bentonite and rice husk adsorbents in particular modified form reduced mobility of cadmium and thus improved the biological properties of the soil and also had a positive effect on ecophysiological indexes.
The use of these adsorbents can be a cost effective, succeeded, and operative management strategy for immobilization of cadmium in contaminated soils that reducing the risk of plant reclamation, washing and entry into groundwater and food cycle.

کلیدواژه‌ها [English]

  • Adsorbente
  • Ecophysiological index
  • Enzyme Activity
  • Microbial respiration
1- Ajmal M., Rao R.A.K., Anwar Sh., Ahmad J., and Ahmad R. 2003. Adsorption studies on rice husk: removal and recovery of Cd (II) from wastewater, Bioresource Technology, 86: 147–149.
2- Anderson T.H. and Domsch K.H. 1990. Application of eco-physiological quotients (qCO2 and Dq) on microbial biomasses from soils of different cropping histories, Soil Biology and Biochemistry, 22(2): 251-255.
3- Anderson T.H., and Domsch K.H. 1993. The metabolic quotient from CO2 (qCO2) as a specific activity parameter to assess the effects of environmental conditions, such as pH, on the microbial biomass of forest soils, Soil Biology and Biochemistry, 25: 393-395.
4- Anderson J.P.E. 1982. Soil respiration. In: Methods of Soil Analysis, Part 2: Chemical and Microbiological Properties, Page A.L., and Miller, R.H. (Eds.), American Society of Agronomy Madison, 831-871.
5- ASTM D 422 (American Society for Testing and Materials), 2007, Standard test method for particle-size analysis of soil, Annual Book of ASTM Standards, 2-7 pp.
6- Bao S.D. 2005. Soil Agricultural Chemistry Analysis. China Agriculture Press, Beijing, pp. 257–270.
7-Bhattacharyya K.G. and Gupta S.S. 2008. Adsorption of a few heavy metals on natural and modified kaolinite and montmorillonite: A review, Advances in Colloid and Interface Science, 140(2): 114–131.
8- Borchardt, G. 1989. Minerals in Soil Environments, SSSA Book Series, Smectites. vol. 1, pp. 675-727.
9- Brigatti M.F., Galan E. and Theng B.K.G. 2006. Structures and mineralogy of clay minerals, Developments in Clay Science, 1: 19-86.
10- Cruz-Guzman M., Celis R., Hermosın M.C., Koskinen W.C., Nater E.A. and Cornejo J. 2006. Heavy metal adsorption by montmorillonites modified with natural organic cations, Soil Science Society of America Journal, 70(1): 215–221.
11- Cheng W., Coleman D.C., Carroll C.R. and Hoffman C.A. 1993. In situ measurement of root respiration and soluble c concentrations in the rhizosphere, Soil Biology and Biochemistry, 25(9): 1189- 1196.
12-Doelman P. and Haanstra L. 1989. Short and long term effects of heavy metals on phosphatase activity in soils: An ecological dose response model approach, Biology and fertility of soils, 8: 235-241.
13- Ebrahimzad S.A., Asgharzad N.A. and Najafi N.A. 2013. Influence of some soil ecophysiological indexes on land use change in the Seddouz plain (Naghdeh - West Azerbaijan), Journal of Agricultural Science and Sustainable Production, 23(4): 133-149. (In Persian with English abstract).
14- Gianfreda L. and Rao M.A. 2004. Potential of extra cellular enzymes in remediation of polluted soils: a review, Enzyme and Microbial Technology, 35: 339–354.
15- Hartley W. and Lepp N. 2008. Remediation of arsenic contaminated soils by CaO application, evaluated in terms of plant productivity, arsenic and phytotoxic metal uptake, Science of the Total Environment, 390: 35-44.
16- Horvath B., Opara-Nadi O., and Beese F. 2005. A simple method for measuring the carbonate content of soils, Soil Science Society of America journal, 69: 1066–1068.
17- Jenkinson D.S., and Ladd J.N. 1981. Microbial Biomass in Soil: Measurement and Turnover. In E. A. Paul, and J. N. Ladd (Eds.), Soil Biochemistry. vol. 5, pp. 415-471.
18- Jimenez-Cedillo M.J., Olguin M.T., Fall C.H., and Colin A. 2011. Adsorption capacity of iron- or iron manganese-modified zeolite-rich tuffs for As(III) and As(V) water pollutants, Applied Clay Science, 54(3): 206-216.
19- Kumpiene J., Ore S., Renella G., Mench M., Lagerkvist A. and Maurice C. 2006. Assessment of zerovalent iron for stabilization of chromium, copper, and arsenic in soil, Environmental Pollution, 144(1): 62-69.
20- Kizilkaya R., Askin T., Bayrakli B. and Saglam M .2004. Microbological characteristics of soils contaminated with heavy metals, European Journal of Soil Biology, 40: 95-102.
21- KazemAlilo S., RasuoliSedghiyani M.H. 2013. Evaluation of some biological indices of soil in presence of microorganisms stimulating plant growth and soil cadmium contamination, Iranian Journal of Soil and Water Research. 44(1): 57-68. (In Persian)
22- Landi L., Renella G., Moreno J.L., Flachini L. and Nannipieri P. 2000. Influence of cadmium on the metabolic quotient, L: D-glutamic acid respiration ratio and enzyme activity; microbial biomass ratio under laboratory conditions, Biology and Fertility of Soils, 32: 8–16.
23- Mulvaney R.L. 1996. Nitrogen-inorganic forms. In: Sparks D.L., editor. Methods of Soil Analysis, Part 3. Chemical Methods. SSSA Book Ser. 5. Soil Science Society of America; Madison, WI. pp. 1123–1184.
24- Moore D.M., Reynolds R.C. 1997. X-ray Diffraction and the Identification and Analysis of Clay Minerals, Oxford University Press, pp. 378.
25- Neto A.F.A., Vieira M.G.A. and Silva M.G.C. 2012. Cu(II) adsorption on modified bentonitic clays: different isotherm behaviors in static and dynamic systems, Materials Research, 15(1): 114 124.
26- Page, A.L., R.H. Miller, D.R. Keeney. 1992. Methods of Soil Analysis. Part 2. Chemical and Microbiological Methods Soil Sci. Soc. Am. Agron. Monograph, 2nd ed., vol. 9, pp. 325–340.
27- Qiang L., Xu-lai Y. and Xi-feng Z. 2008. Analysis on chemical and physical properties of bio-oil pyrolyzed from rice husk, Journal of Analytical and Applied Pyrolysis, 82: 191-198.
28- Sparks D.L., Page A., Helmke P. and Loeppert R.H. 1996. Methods of Soil Analysis. Part 3-Chemical methods, Soil Science Society of America. Inc.
29- Schutz T., Dolinska S. and Mockovciakova A. 2013. Characterization of bentonite modified by manganese oxides, Universal Journal of Geoscience, 1(2): 114–119.
30- Shirzadeh N., Aliasgharzad N. and Najafi N. 2013. Changes in carbonation, ecophysiological identifiers, base and induced respiration soil in incubation with different lead levels, Journal of Water and Soil Science. 23(2): 111-124. (In Persian with English abstract).
31- Ionescu C., Hoeck V. and Simon V. 2011. Effect of the temperature and the heating time on the composition of an illite-rich clay: an XRPD study, Study of. University Babes-Bolyai Physics, 56(2): 70.
32- Tabatabai M.A. and Bremner J.M. 1969. Use of p-nitrophenylphosphate for assay of soil phosphatase activity, Soil Biology Biochemistry, 1: 301–307.
33- Tabatabai M.A. 1982. Soil enzymes Methods of soil analysis. Part 2. American Society of Agronomy, Madison, WI, USA, pp. 539–579.
34- Tan X., Liu Y., Yan K., Wang Z., Lu G., He Y. and He W. 2007. Differences in the response of soil dehydrogenase activity to Cd contaminated are determined by the different substrates used for its determination, Soil Science, 169: 324-332.
35- Vieira M.G.A., Almeidaneto A.F., Dasilva M.G.C., Carneiro C.N. and Melofilho A.A. 2014. Adsorption of lead and copper ions from aqueous effluents on rice husk ash in a dynamic system, Brazilian Journal of chemical engineering, 31(2): 519–529.
36- Vig K., Megharaj M., Sethunathan N. and Naidu R. 2003. Bioavailability and toxicity of cadmium to microorganisms and their activities in soil: a review, Advances in Environmental Research, 8: 121-135.
37- Walkley A. and A.I. Black. 1934. Examination of the degtjareff method for determining soil organic matter and a proposed modification of the chromic and titration method, Soil Science, 34: 29–38.
38- Wan Ngah W.S. and Hanafiah M.A.K.M. 2008. Removal of heavy metal ions from wastewater by chemically modified plant wastes as adsorbents: A review, Bioresource Technology, 99: 3935-3948.
39- Wu P., Wu W., Li S., Xing N., Zhu N., Li P., Wu J., Yang C. and Dang, Z. 2009. Removal of Cd2+ from aqueous solution by adsorption using Fe-montmorillonite, Journal of Hazardous Materials. 169(1): 824–830.
40- Zhang Y., Zheng R., Zhao J., Ma F., Zhang Y. and Meng Q. 2014. Characterization of H3PO4 treated rice husk adsorbent and adsorption of copper (II) from aqueous solution. Hindawi Publishing Corporation BioMed Research International Volume, Article ID 496878, 8 pages.
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