دوماه نامه

نوع مقاله : مقالات پژوهشی

نویسندگان

1 دانشجوی دکتری گروه علوم و مهندسی خاک، دانشکده کشاورزی، دانشگاه شهرکرد

2 استاد گروه علوم و مهندسی خاک، دانشکده کشاورزی، دانشگاه شهرکرد

چکیده

آلودگی خاک به کادمیم و سرب از جمله تنش­های مهم و متداول رو به گسترش در محیط است که رشد و فعالیت جمعیت میکروبی خاک را تحت تأثیر قرار می­دهند. این دو فلز سمی ممکن است به­صورت منفرد و یا هم­زمان در خاک وجود داشته باشند. گرچه اثر منفرد آن­ها بر ویژگی­های بیوشیمیایی و میکروبیولوژیکی خاک شناخته شده است، اما اثر مشترک آن­ها بر کارکرد میکروبی هنوز مشخص نیست. از این رو، هدف پژوهش حاضر بررسی اثر برهم­کنش کادمیم و سرب بر برخی ویژگی­های بیوشیمیایی و میکروبیولوژیکی در یک خاک آهکی طی 120 روز انکوباسیون بود. آزمایش به‌صورت فاکتوریل (شامل دو سطح کادمیم و دو سطح سرب) در قالب طرح کاملاً تصادفی و در شرایط آزمایشگاهی اجرا شد. نتایج نشان داد که حضور هم­زمان کادمیم و سرب موجب افزایش غلظت قابل جذب این فلزات و ضریب ویژه تنفسی در مقایسه با خاک­های تیمار شده با حضور منفرد این فلزات گردید. همچنین حضور هم­زمان دو فلز موجب کاهش بیشتر معدنی­شدن کربن و نیتروژن، آمونیفیکاسیون آرژنین، سرعت نیترات­سازی، کربن و نیتروژن زیست­توده میکروبی، تنفس پایه، تنفس ناشی از سوبسترا و فعالیت آنزیمی (اوره­آز، آریل سولفاتاز، فسفومنواستراز قلیایی، دهیدروژناز، کاتالاز و هیدرولیز فلوروسین دی­استات) در مقایسه با تیمارهای با حضور منفرد کادمیم و سرب شد. بنابراین، حضور هم­زمان دو فلز، اثرات منفی و بازدارندگی یکدیگر را بر رشد و فعالیت جمعیت میکروبی و کیفیت زیستی خاک تشدید می­کنند. این یافته­ها نشان می­دهند که هنگام ارزیابی خطر اکولوژیکی کادمیم و سرب در محیط­های آلوده باید اثر متقابل آن­ها بر جامعه خاکزیان نیز مورد توجه قرار گیرد.

کلیدواژه‌ها

عنوان مقاله [English]

Consequences of Co-contamination of Cadmium and Lead on Soil Biochemical and Microbiological Properties

نویسندگان [English]

  • N. Azadi 1
  • F. Raiesi 2

1 Ph.D. Student , Department of Soil Science and Engineering, Faculty of Agriculture, Shahrekord University, Iran

2 Professor, Department of Soil Science and Engineering, Faculty of Agriculture, Shahrekord University, Iran

چکیده [English]

Introduction: Heavy metals contamination of soils is an important environmental concern which has specially long-term hazardous effects on soil biogeochemical and microbiological properties (including microbial and enzyme activity, microbial community structure, and the contents of organic compounds). Among heavy metals, cadmium (Cd) and lead (Pb) are the two highly toxic, non-biodegradable and often coexisted anthropogenic pollutants in contaminated sites. Numerous earlier studies have demonstrated a detrimental influence of Cd and Pb, both individually and jointly, on microbial and biochemical properties through reduction of microbial activity, microbial biomass and enzyme activity in polluted soils. Metal co-contamination has a greater negative effect on soil microbial community and enzyme activity compared to individual ones. Although the individual effects of Cd and Pb on soil biological functions are generally well-known, their combined effects on microbial growth, population and functions are largely uncertain. The main aim of this study was to investigate the interactive effects of Cd and Pb pollutants on biochemical and microbiological properties in a contaminated soil. It was hypothesized that combined Cd and Pb would increase mobility and availability of Cd and Pb, which subsequently results in further reductions in soil biochemical and microbiological properties.
Materials and Methods: The study was conducted under controlled laboratory conditions. A factorial experiment with two levels of cadmium (0 and 10 mg kg-1) and two levels of lead (0 and 150 mg kg-1) was conducted using a completely randomized design with three replications. The soil was artificially spiked with cadmium chloride and lead chloride to attain the above mentioned concentrations. To reactivate the microbial population and for the aging effect, soil moisture was set at 70% of field capacity, and containers were pre-incubated at room temperature for 20 days. Soil samples were incubated under standard conditions (70% of field capacity and 25±1 oC) for 120 days. At the end of the soil incubation the concentration of DTPA-TEA (diethylene triamine penta acetic acid-triethanol amine)-extractable Cd and Pb, biochemical and microbiological properties including nitrification rate (NR), cumulative N mineralization (CNM), cumulative C mineralization (CCM), microbial biomass C (MBC), microbial biomass N (MBN), arginine ammonification (AA), basal respiration (BR), substrate (glucose)-induced respiration (SIR), metabolic quotient (qCO2) and the activities of soil urease (URE), alkaline phosphatase (ALP), arylsulphatase (ARY), dehydrogenase (DEH), catalase (CAT) and fluorescein diacetate hydrolysis (FDA) were determined. In this experiment, the Bliss independence model was used to determine the type and nature of the interaction between Cd and Pb pollution (i.e., synergistic and antagonistic).
Results and Discussion: Results showed that the DTPA-extractable metal (Cd and Pb) concentrations were considerably higher under the combined metals compared with the single-metals. In co-contaminated soils, a metal may contribute to release of other metals to soil solution and consequently would enhance the availability of the released metals. Compared to individual metal, the qCO2 was greater in Cd+Pb contaminated soil. Microbial and biochemical properties (MBC, MBN, AA, NR, CNM, CCM, BR, SIR) and enzyme activity (URE, ARY, ALP, DEH, CAT and FDA) significantly decreased in the presence of Cd or Pb pollutant than the control. Generally, the negative effects of Cd and Pb co-existence on biochemical and microbiological properties were higher than Cd or Pb alone because of synergistic interaction in the metal combinations. The results of Bliss independence model indicated the synergistic effect of Cd and Pb on microbial and biochemical functionalities in metal-co-contaminated soils. In soil ecosystem, heavy metals exhibit toxicological effects on soil microbes which may lead to the decrease of their function and activities.
Conclusion: Heavy metals can effectively change the soil biochemical and microbiological properties. This study provided strong evidence revealing that combined Cd and Pb can increase the mobility and availability of heavy metals, and intensify their toxicity effects on microbial community and enzyme activity in co-contaminated soils. The co-existence of Cd and Pb reduced soil biochemical and microbiological properties more than their individual presence. Soil microorganisms are an important indicator of soil fertility and health and thus would improve the accuracy of the ecological risk assessment of toxic metals at multi-metal contaminated sites. However, further information on responses of microbial indicators to the joint effect of heavy metals under long-term and realistic field conditions is required.

کلیدواژه‌ها [English]

  • Bliss model
  • Enzymatic activity
  • Metal co-contamination
  • Microbial activity
  • Microbial functions
  1. Alef K., and Kleiner D. 1987. Applicability of arginine ammonification as indicator of microbial activity in different soils. Biology and Fertility of Soils 5: 148-151.
  2. Alef K., and Nannipieri P. 1995. Methods in Applied Soil Microbiology and Biochemistry, Academic Press, London.
  3. Alloway B.J. 2013. Sources of heavy metals and metalloids in soils. In: Alloway BJ (Ed.), Heavy Metals in Soils: Trace Metals and Metalloids in Soils, and their Bioavailability. Springer Science+Business Media Dordrecht, pp. 11–50.
  4. Amlinger F., and Boltzmann L. 1995. Biowaste compost and heavy metals: a danger for soil and environment. In: de Bertoldi P.S.M. Lemmes B. and Papi T. (eds.) Proceedings of the International Symposium on the Science of Composting. Blakie Academic and Professional. Glasgow. UK.
  5. Bonde T.A., Nielsen T.H., Miller M., and Sorenson J. 2001. Arginine ammonification assay as a rapid index of gross N mineralization in agricultural soils. Biolology and Fertility of Soils 34: 179-184.
  6. Bunemann E.K., Bongiorno G., Bai Z., Creamer R.E., de Deyn G., de Goede R., Fleskens L., Geissen V., Kuyper T.W., Mäder P., and Pulleman M. 2018. Soil quality–A critical review. Soil Biology and Biochemistry 120: 105-125.
  7. Chaperon S., and Sauve S. 2007. Toxicity interaction of metals (Ag, Cu, Hg, Zn) to urease and dehydrogenase activities in soils. Soil Biology and Biochemistry 39: 2329-2338.
  8. Christensen B.T. 2004. Tightening the nitrogen cycle. In: Schjonning S. Elmholt S. and Christensen B.T. (eds.) Managing Soil Quality Challenges in Modern Agriculture. Oxon. UK. CABI Publishing. pp. 47-67.
  9. Dai J., Becquer T., Rouiller J.H., Reversat G., Bernhard-Reversat F., and Lavelle P. 2004. Influence of heavy metals on C and N mineralization and microbial biomass in Zn-, Pb-, Cu-, and Cd-contaminated soils. Applied Soil Ecology 25: 99-109.
  10. Dick R.P. 1997. Soil enzyme activities as integrative indicators of soil health. In: Pankhurst CE, Doube BM, Gupta VVSR (eds) Biological indicators of soil health. CAB International, New York, pp 121–156.
  11. Effron D., Horra A.M., Defrieri R.L., Fontanive V., and Palma R.M. 2004. Effect of cadmium, copper and lead on different enzyme activities in a native forest soil. Communications in Soil Science and Plant Analysis, 35: 1309-1321.
  12. Fan J., Cai C., Chi H., Reid B.J., Coulon F., Zhang Y., and Hou Y. 2020. Remediation of cadmium and lead polluted soil using thiol-modified biochar. Journal of Hazardous Materials 388: 122037.
  13. Gomes P.C., Fontes M.P., Silva A.G., Mendonça E., and Netto A.R. 2001. Selectivity sequence and competitive adsorption of heavy metals by Brazilian soils. Soil Science Society of America Journal 65: 1115-1121.
  14. Green V., Stott D., and Diack M. 2006. Assay for fluorescein diacetate hydrolytic activity: optimization for soil samples. Soil Biology and Biochemistry 38: 693-701.
  15. He Z.L., Yang X.E., and Stoffella P.J. 2005. Trace elements in agroecosystems and impacts on the environment. Journal of Trace Elements in Medicine and Biology 3: 125-140.
  16. Huang S., Jia X., Zhao Y., Bai B., and Chang Y. 2017. Elevated CO2 benefits the soil microenvironment in the rhizosphere of Robinia pseudoacacia L. seedlings in Cd and Pb contaminated soils. Chemosphere 168: 606-616.
  17. Joergensen R.G. 1995. Microbial biomass estimation: the fumigation incubation method. In: Alef K., and Nannipieri P. (Eds). Methods in Applied Soil Microbiology and Biochemistry. Academic Press. pp. 376–381.
  18. Kabata-Pendias A., and Mukherjee A.B. 2007. Trace Elements from Soil to Human. Springer Science. Heidelberg, 550p.
  19. Khan S., Hesham A.E.L., Qiao M., Rehman S., and He J.Z. 2010. Effects of Cd and Pb on soil microbial community structure and activities. Environmental Science and Pollution Research 17: 288–296.
  20. Lei S., Shi Y., Qiu Y., Che L., and Xue C. 2019. Performance and mechanisms of emerging animal-derived biochars for immobilization of heavy metals. Science of the Total Environment 646: 1281-1289.
  21. Lindsay W.L., and Norvell W.A. 1978. Development of a DTPA soil test for zinc, iron, manganese, and copper. Soil Science Society of America Journal 42: 421-428.
  22. Liu J., Xie J., Chu Y., Sun C., Chen C., and Wang Q. 2008. Combined effect of cypermethrin and copper on catalase activity in soil. Soils and Sediments 8: 327-332.
  23. Long S.M., Reichenberg F., Lister L.J., Hankard P.K., Townsend J., Mayer P., Wright J., Holmstrup M., Svendsen C., and Spurgeon D.J. 2009. Combined chemical (Fluoranthene) and drought effects on Lumbricus rubellus demonstrate the applicability of the independent action model for multiple stressor assessment. Environmental Toxicology and Chemistry 28: 629–636.
  24. Lu M., Xu K., and Chen J. 2013. Effect of pyrene and cadmium on microbial activity and community structure in soil. Chemosphere 91: 491–497.
  25. Lu S.G., and Xu Q.F. 2009. Competitive adsorption of Cd, Cu, Pb and Zn by different soils of Eastern China. Environmental Geology 57: 685–693.
  26. Luo L.Y., Xie L.L., Jin D.C., Mi B.B., Wang D.H., Li X.F., Dai X.Z., Zou X.X., Zhang Z., Ma Y.Q., and Liu F. 2019. Bacterial community response to cadmium contamination of agricultural paddy soil. Applied Soil Ecology 139: 100-106.
  27. Moreno J.L., García C., and Hernández T. 2003. Toxic effect of cadmium and nickel on soil enzymes and the influence of adding sewage sludge. European Journal of Soil Science 54: 377–386.
  28. Nannipieri P. 1994. The potential use of soil enzymes as indicators of productivity, sustainability and pollution.In: Pankhurst, C.E., Doube, B.M., Gupta, V.V.S.R., Grace, P.R. (Eds.), Soil Biota, Management in Sustainable Farming Systems. CSIRO Publications, Australia, pp.238–244.
  29. Palansooriya K.N., Shaheen S.M., Chen S.S., Tsang D.C.W., Hashimoto Y., Houg D., Bolanh N.S., Rinklebeb J., and Oka Y.S. 2020. Soil amendments for immobilization of potentially toxic elements in contaminated soils: A critical review. Environment International 134: 105046.
  30. Pan J., and Yu L. 2011. Effects of Cd or/and Pb on soil enzyme activities and microbial community structure. Ecological Engineering 37: 1889-1894.
  31. Park J.H., Cho J.S., Ok Y.S., Kim S.H., Heo J.S., Delaune R.D., and Seo D.C. 2016. Comparison of single and competitive metal adsorption by pepper stem biochar. Archives of Agronomy and Soil Science 62: 617-632.
  32. Raiesi F. 2007. The conversion of overgrazed pastures to almond orchards and alfalfa cropping system may favor microbial indicators of soil quality in central Iran. Agriculture, Ecosystems and Environment 121: 309-318.
  33. Raiesi F., Razmkhah M., and Kiani S. 2018. Salinity stress accelerates the effect of cadmium toxicity on soil N dynamics and cycling: Does joint effect of these stresses matter? Ecotoxicology and Environmental Safety 153: 160-167.
  34. Raiesi F., and Sadeghi E. 2019. Interactive effect of salinity and cadmium toxicity on soil microbial properties and enzyme activities. Ecotoxicology and Environmental Safety 168: 221-229.
  35. Raiesi F., and Dayani L. 2020. Compost application increases the ecological dose values in a non-calcareous agricultural soil contaminated with cadmium. Ecotoxicology1-14.
  36. Rieuwerts J.J., Thornton I., Farago M.E., and Ashmore M.R. 1998. Factors influencing metal bioavailability in soils: preliminary investigations for development of a critical loads approach for metals. Chemical Speciation and Bioavailability 10: 61-75.
  37. Singh B.K., Quince C., Macdonald C.A., Khachane A., Thomas N., Al-Soud W.A., Sorensen S.J., He Z., White D., Sinclair A., Crooks B., Zhou J., and Campbell C.D. 2014. Loss of microbial diversity in soils is coincident with reductions in some specialized functions. Environmental Microbiology 16: 2408–2420.
  38. Smolders E., and Mertens J. 2013. Cadmium. In: Alloway BJ (Ed.), Heavy Metals in Soils: Trace Metals and Metalloids in Soils, and their Bioavailability. Springer Science+Business Media Dordrecht, pp. 283–311.
  39. Steinnes E. 2013. Lead. In: In: Alloway BJ (Ed.), Heavy Metals in Soils: Trace Metals and Metalloids in Soils, and their Bioavailability. Springer Science+Business Media Dordrecht, pp. 395–409.
  40. Tabatabai M.A., and Bremner J.M. 1969. Use of p-nitrophenyl phosphate for assay of soil phosphatase activity. Soil Biology and Biochemistry 1: 301–307.
  41. Tabatabai M.A., and Bremner J.M. 1970. Arylsulphatase activity of soils. Soil Science Society of America Journal 34: 225–229.
  42. Thalmann A. 1966. The determination of the dehydrogenase activity in soil by means of TTC (Triphenyltetrazolium). Soil Biology and Biochemistry 6: 46-49.
  43. Usman A.R.A. 2008. The relative adsorption selectivites of Pb, Cu, Zn, Cd and Ni by soils developed on shale in New Valley Egypt. Geoderma 144: 334-343.
  44. Veeresh H., Tripathy S., Chaudhuri D., Hart B.R., and Powell M.A. 2003. Competitive adsorption behavior of selected heavy metals in three soil types of India amended with fly ash and sewage sludge. Environmental Geology 44: 363-370.
  45. 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.
  46. Wang Y., Liu Y., Zhan W., Zheng K., Wang J., Zhang C., and Chen R. 2020. Stabilization of heavy metal-contaminated soils by biochar: Challenges and recommendations. Science of the Total Environment 729: 139060.
  47. Wang Y.P., Shi Y.J., Wang H., Lin Q., Chen X.C., and Chen Y.X. 2007. The influence of soil heavy metals pollution on soil microbial biomass, enzyme activity, and community composition near a copper smelter. Ecotoxicology and Environmental Safety 67: 75–81.
  48. Xin J.L., Huang B.F., Yang Z.Y., Yuan J.G., Dai H.W., and Qiu Q. 2010. Responses of different water spinach cultivars and their hybrid to Cd, Pb and Cd-Pb exposures. Journal of Hazardous Materials 175: 468–476.
  49. Xu Y., Seshadri B., Bolan N., Sarkar B., Ok Y.S., Zhang W., Rumpel C., Sparks D., Farrell M., Hall T., and Dong Z. 2019. Microbial functional diversity and carbon use feedback in soils as affected by heavy metals. Environment International 125: 478–488.
  50. Zhan J., Li T., Zhang X., Yu H., and Zhao L. 2018. Rhizosphere characteristics of phytostabilizer Athyrium wardii (Hook.) involved in Cd and Pb accumulation. Ecotoxicology and Environmental Safety 148: 892-900.
  51. Zhao W., Sachsenmeier K., Zhang L., Sult E., Hollingsworth R.E., and Yang H. 2014. A new bliss independence model to analyze drug combination data. Journal of Biomolecular Screening 19: 817-821.
CAPTCHA Image