دوماه نامه

نوع مقاله : مقالات پژوهشی

نویسندگان

دانشگاه تبریز

چکیده

جذب و واجذب از فرآیندهای مهم اثرگذار بر شیمی فسفر در خاک‌ها می‌باشند. این تحقیق به‌منظور بررسی تأثیر حذف ماده آلی خاک با محلول هیپوکلریت سدیم بر شاخص‌های پسماند فسفر در 12 نمونه خاک آهکی ایران با ویژگی‌های متفاوت انجام گرفت. برای این منظور 4 گرم از نمونه‌های خاک در لوله‌های سانتریفیوژ 50 میلی‌لیتری ریخته شد و پس از افزودن 40 میلی‌لیتر محلول هیپوکلریت سدیم (NaOCl) 6 درصد حجمی در pH برابر 8، به مدت 6 ساعت در دمای اتاق قرار داده شد. سپس سوسپانسیون سانتریفیوژ شده و محلول زلال رویی دور ریخته شد. بلافاصله 40 میلی‌لیتر از محلول هیپوکلریت سدیم 6 درصد اضافه و سوسپانسیون دوباره به مدت 6 ساعت در دمای اتاق قرار داده شد. این چرخه اکسایش 3 بار ادامه یافت. بعد از حذف ماده آلی، به‌منظور شست و شوی محلول هیپوکلریت سدیم اضافی، به بقایای خاک تیمار شده از مراحل فوق 40 میلی‌لیتر محلول زمینه کلرید کلسیم 01/0 مولار افزوده و سوسپانسیون تکان داده شد و پس از سانتریفیوژ محلول زلال رویی دور ریخته شد و این چرخه 3 بار ادامه یافت. پس از انجام مراحل فوق، خاک‌ها هوا خشک گردیدند. همدمای جذب فسفر در خاک‌ها با به تعادل رساندن خاک‌ها با محلول‌هایی با غلظت‌های متفاوت فسفر(5، 10، 20، 30، 40، 60، 80 و 100 میلی‌گرم فسفر بر لیتر) از منبع منو کلسیم فسفات و در محلول زمینه 01/0 مولار کلرید کلسیم به دست آمد. به‌منظور توصیف همدمای جذب و واجذب در خاک‌ها از مدل فروندلیچ استفاده شد. بر طبق نتایج حاصله در همه خاک‌ها پدیده پسماند مشاهده و جذب فسفر بعد از حذف ماده آلی برگشت‌ناپذیر شد. متوسط مقادیر فسفر واجذب‌شده در خاک‌ها بعد از حذف ماده آلی 40 درصد کاهش یافت.نتایج نشان داد که مقادیر شاخص چهارم پسماند که از ضریب توزیع (Kd) محاسبه شده بود با درصد رس (r= 0.69, p<0.05) و کربنات کلسیم فعال (p<0.05 r= 0.7,) همبستگی مثبت و معنی­دار داشت. بر طبق نتایج به دست آمده از بین هفت شاخص پسماند، شاخص چهارم (HI4) می‌تواند به‌عنوان شاخص برتر معرفی شود.

کلیدواژه‌ها

عنوان مقاله [English]

Effect of Organic Matter Removal on Phosphorus Hysteresis Indices (HI) in Calcareous Soils

نویسندگان [English]

  • M. Mahdizadeh
  • A. Reyhanitabar
  • Sh. Oustan

University of Tabriz

چکیده [English]

Introduction: Sorption and desorption are important processes that influence phosphorus (P) chemistry in soil. Desorption is a process more complex than sorption and usually not all that is adsorbed is desorbed. This indicates that adsorption and desorption mechanisms are not similar and it seems that such reactions are irreversible. Such irreversibility is usually called hysteresis. Major factors such as chemical changes in the structure of minerals, non-equivalent processes, inflation of adsorbent material, changes in the strength of crystals, irreversible fixation of adsorbed molecules in fine pores and equilibrium time less than its true value lead to hysteresis phenomenon. The concentration of phosphate in soil solution and thus its availability for plant are closely related to sorption processes by soil components. This relationship can be explicated by sorption isotherms. Soil organic matter (SOM) especially in arid and semiarid regions is one of the important indices of soil quality and plays important role in phosphate chemistry and fertility. Organic matter could decrease P sorption, maximum buffering capacity, and bonding energy and could increase P concentration in calcareous soils solution. Organic matter and organic acids resulted from its decomposition may coat calcium carbonate surfaces and prevent the formation of apatite precipitation. There are several methods to remove soil organic matter including using hydrogen peroxide and sodium hypochlorite solutions. It has been reported that H2O2 is penetrated into the interlayer spaces of phlogopite and vermiculite through exchange with water and cations and decomposes into H2O and O2. Therefore, this study was conducted to quantify the hysteresis indices, to investigate the effect of organic matter removal on phosphorus (P) hysteresis indices and to evaluate the relationship between hysteresis indices and soil characteristics and selection of index with the close correlation.
Materials and Methods: This study was carried out to obtain soil organic matter (SOM) removal with sodium hypochlorite solution (NaOCl, pH=8) effects on P hysteresis indices in 12 calcareous soils of Iran with different characteristics. For experiment of P sorption, 2 gr of soil subsamples was placed in separate 50 mL centrifuge tubes, to which were added 20 ml of monocalcium phosphate containing 5, 10, 15, 20, 30, 40, 60, 80 and 100 mg P L-1, which had been prepared in 0.01 M CaCl2 solution as background. Centrifuge tubes were shaken in a shaker incubator for 48-hour period to reach an equilibrium. Then, they were centrifuged at 4000 rpm for 5 minutes. The supernatant was filtered through a filter paper and the P concentration of filtrates determined using a spectrophotometer. The difference between initial and final P concentrations was assumed to be the amount of P adsorbed by the soil. Desorption experiments were assumed at the end of sorption experiments at the highest initial concentration of P with 0.01 M CaCl2 solution. The tubes were shaken to reach phosphate desorption equilibrium time (24 hours) at 25 °C in incubator shaker. Then, it was centrifuged for 5 minutes at 4000 rpm and 15 ml of the supernatant solution was pipetted and then 15 ml of solution of 0.01 M CaCl2 was added to tubes and the above steps continued to 9 steps. Freundlich model was used to describe the sorption – desorption isotherms data. DataFit 9.0.59 software (1995-2008) was used for nonlinear fitting of Freundlich to sorption data.
Results and Discussion: According to the results, P sorption and desorption data showed hysteresis which indicates adsorption and desorption mechanisms are not the same. As expected, nonlinear Freundlich equation showed a best fit (R2=0.96) to the data. The mean value of desorbed P in studied soils after SOM removal was decreased by 40%, so it was concluded that P sorption was more irreversible. In NaOCl treated soils, the mean values of seven studied hysteresis indices (HI) increased. Regression analysis indicated that the fourth hysteresis index, obtained from the distribution coefficient (Kd), had close relation with clay (r = 0.69, p < 0.05) and active calcium carbonate (r = 0.7, p < 0.05) concentration. Moreover, this hysteresis index showed significant (p<0.01) positive correlation with Kfsorb and Kfdesorb, which suggests that increasing bonding energy in sorption and desorption isotherms decreased desorption amount due to the strong interaction between adsorbed P and absorbent surface, increasing this hysteresis index.
Conclusion: It was concluded that among seven used hysteresis indices, HI4 can be introduced as the best index for the studied calcareous soils. It is predicted that using organic matter or preventing its reduction in arid and semi-arid calcareous soils may increase the efficiency of P fertilizer, given an increase in hysteresis index after the removal of the organic matter.

کلیدواژه‌ها [English]

  • Desorption
  • Hypochlorite
  • Isotherm
  • oxidation
  • Sorption
1- Allison L.E., and Moodie C.D. 1965. Carbonates. In: Black, C. A. (ED). Methods of Soil Analysis. Pares, ASA: Madison, WI. 1379-1396.
2- Angeluz O., Pierre B., Enrique B., and Laura O. 2008. Sorption and desorption of organophosphate pesticides, parathion and cadusafos, on tropical agricultural soils. Agronomy for Sustainable Development, Springer Verlag/ EDP Sciences/ INRA 28: 231-238.
3- Barrow N.J., Bowden J.W., Posner A.M., and Quirk J.P. 1980. Describing the effects of electrolyte on adsorption of phosphate by a variable charge surface. Australian Journal of Soil Research 18: 395-404.
4- Berkowitz B., Dror I., and Yaron B. 2009. Contaminant Geochemistry: Interactions and transport in the subsurface environment. Springer, Berlin, Germany, Pp: 120-123. ISBN 978-3-540-74381-1.
5- Braida W.J., Pignatello J.J., Lu Y., Ravikovitch P.I., Neimark A.V., and Xing B. 2003. Sorption hysteresis of benzene in charcoal particles. Environment Science Technology 37: 409-4170.
6- Celis R., Carnejo H., Hermosin M.C., and Koskinen W.C. 1997. Sorption – desorption of atrazine and simazine by model soil colloidal components. Soil Science Society of America Journal 61: 436-443.
7- Datafit version 9.0.59. (1995-2008). Oakdal engineering.
8- Essington M.E. 2004. Soil and Water chemistry: an Integrative Approach. CRC Press, Boca Raton, Florida.
9- Farrell J., and Reinhard M. 1994. Desorption of halogenated organics from model solids, sediments, and soils under unsaturated conditions: 2. Kinetics. Environmental. Science and Technology 28: 63–72.
10- Filippo F., Markus E., Paolo Ch., Giacomo S., Wilfried H., and Evelyne D. 2008. Comparison of different methods of obtaining a resilient organic matter fraction in Alpine soils. Geoderma 145: 355–369.
11- Fox. R.L. 1981. External phosphorus requirements of crops. In M. Stelly(ed) Chemistry in the Soil Environment. SSSA. Madison, WI. p.223-239.
12- Gee G.W., and Bauder J.W. 1986. Particle size analysis. Pp.383-412. In: A. Klute (ed). Methods of Soil Analysis. Part 1. 2nd ed. ASA, SSSA. Madison, WI. USA: 201-214.
13- Guppy C.N., Menzies N.W., Moody P.W., and Blamey F. 2005. Competitive sorption reactions between phosphorus and organic matter in soil: a review. Australian Journal of Soil Research 43: 189-202.
14- Havlin J.L., Tisdale S.L., Nelson W.L., and Beaton J.D. 2004. Soil Fertility and Fertilizers. An introduction to nutrient management. 5th ed. Macmillan Publishing Company New York, Inc.750p.
15- Havlin J.L., Tisdale S.L., Nelson W.L., and Beaton J.D. 2002. Soil Fertility and Ffertilizers. An introduction to nutrient management 4th ed. Macmillan Publishing Company New York, Inc.750p.
16- Hu H.Q., He J.Z., Li X.Y., and Liu F. 2001. Effect of several organic acids on phosphate adsorption by variable charge soils of central China. Environmental International Journal 26: 353-358.
17- Huang W., Yu H., and Weber W.J. 1998. Hysteresis in the sorption and desorption of hydrophobic organic contaminants by soils and sediments. 1. A comparative analysis of experimental protocols. Journal of Contaminant Hydrology 31: 215-225.
18- Huang W.L., Schlautman M.A., and Weber W.J. 1996. A distributed reactivity model for sorption by soils and sediments. 5. The influence of near-surface characteristics in mineral domain. Environmental Science and Technology 30: 2993-3000.
19- Ingrid K., Thomsen. Sander B., Lars S., Jensen Be., and Christensen T. 2009. Assessing soil carbon lability by near-infrared spectroscopy and NaOCl oxidation. Soil Biology and Biochemistry 41: 2170–2177.
20- Inskeep W.P., and Silvertooth J.C. 1998. Inhibition of hydroxyapatite precipitation in the presence of fulvic, humic and tannic acids. Soil Science Society of America Journal 52: 941-946.
21- Kaiser K., and Guggenberger G. 2003. Mineral surfaces and soil organic matter. European Journal of Soil Science 54: 219-236.
22- Karimian N., and Moafpourian G.R. 1999. Zinc adsorption characteristics of selected calcareous soils of Iran and their relationship with soil properties. Communications in Soil Science and Plant Analysis 30: 1721-1731.
23- Khedri E., Oustan Sh., and Reyhanitabar A. 2016. Hysteresis Indices of Potassium Sorption-Desorption Isotherms in Some Soils of East Azarbaijan Province, Iran. Iranian Journal of Soil Research (Formerly Soil and Water Science) 30: 427-442. (In Persian with English abstract)
24- Laird D.A., Yen P.Y., Koskinen W.C., Steinheimer T.R., and Dowdy R.H. 1994. Sorption of atrazine on soil clay components. Environment Science Technology 28: 1054-1061.
25- Leoppert R.h., and Suarez L. 1996. Methods of Soil Analysis. Part 3.Chemical Methods. Soil Science Society of America and American Society of Agronomy Madison.WI.
26- Leytem A.B., and Westermann D.T. 2003. Phosphate sorption by Pacific Northwest calcareous soils. Journal of Soil Science 168: 368-375.
27- Ma L., Southwick L.M., Willis G.H., and Selim H.M. 1993. Hysteretic characteristics of atrazine adsorption-desorption by a sharkey soil. Weed Science Society of America 41: 627-633.
28- Marzadori C., Vittori Antisari L., Ciavatta C., and Sequi P. 1991. Soil organic matter influence on adsorption and desorption of boron. Soil Science Society of America Journal 55: 1582-1585.
29- Mc Gechan, M.B., and Lewis, D.R. 2002. Sorption of phosphorus by soil, part 1: Principles, equations, and models. Biosystems Engineering 82: 1-24.
30- Mikutta R., Kleber M., Kaiser K., and John R. 2005. Review: Organic matter removal from soils using hydrogen peroxide, sodium hypochlorite, and disodium peroxodisufat. Soil Science Society of America Journal 69: 120-135.
31- Murphy J., and Rilley H.P. 1962. A modified single solution method for the determination of phosphate in natural waters. Analytica Chimica Acta 27: 31-36.
32- Mustafa G., Kookana R.S., and Singh B. 2006. Desorption of cadmium from goethite: Effect of pH, temperature and aging. Chemosphere 64: 856-865.
33- Nelson D.W., and Sommers L.E. 1982. Total carbon, organic carbon and organic matter. P. 539-580. Methods of Soil Analysis: Part 2. Chemical and Microbiological Methods, 2nd ed. Agronomy Monograph. 9. ASA and SSSA. Madison, USA.
34- Olsen S.R., and Sommer L.E. 1982. Phosphorus. In: Klute, A. (Ed). Methods of Soil Analysis: Chemical and microbiological properties, part2. 2nd Ed. Agronomy Monograph. No. 9. ASA and SSSA , Madison WI, pages 403-430.
35- Perez-Novo C., Pateiro M., Osorio F., Novoa-Munoz J.C., Lopez-Periago E., and Arias-Estevez M. 2008. Influence of organic matter removal on competitive and noncompetitive adsorption of copper and zinc in acid soils. Journal of Colloid and Interface Science 322: 33-40.
36- Ran Y.B., Rao P.S.C., and Fu J. 2004. Importance of adsorption (hole-filling) mechanism for hydrophobic organic contaminants on an aquifer kerogen isolate. Environmental Science Technology 38: 4340-4348.
37- Rhoades J.D. 1996. Salinity. Electrical conductivity and total dissolved solids. In: Sparks, Dl. Methods of soil analysis. part3. Chemical methods. (Ed). SSSA. Madison WI. 417-435.
38- Sakadevan K., and Bavor H.J. 1998. Phosphate adsorption characteristics of soils, slages and zeolite to be used as substrates in constructed wetland systems. Water Resource 32: 393-399.
39- Sander M., Lu Y., and Pignatello J.J. 2005. A thermodynamically based method to quantify true sorption hysteresis. Journal of Environmental Quality 34: 1063-1072.
40- Shirvani M., Kalbasi M., Shariatmadari H., Nourbakhah F., and Najafi B. 2006. Sorption-desorption of cadmium in aqueous palygorskite, sepiolite, and calcite suspensions: Isotherm hysteresis. Chemosphere 65: 2178–2184.
41- Shirvani M., and Shariatmadari H. 2002. Application of sorption isotherms for determining the phosphorus buffering indices and the standard P requirement of some calcareous soils in esfahan. Journal of Science and Technology of Agriculture and Natural Resources, Water and Soil Science 6: 121-130. (In Persian with English abstract)
42- Siregar A., Kleber M., Mikutta R., and John R. 2004. Sodium hypochlorite oxidation reduces soil organic matter concentrations without affecting inorganic soil constituents. European Journal of Soil Science 56: 481-490.
43- Sparks D.L. 1995. Environmental Soil Chemistry, Academic Press, San Diego.
44- Swanson R.A., and Dutt G.R. 1 973. Chemical and physical processes that affect atrazine and distribution in soil systems. Soil Science Society of America Proceeding 37: 872-876.
45- Theng B.K.G., Ristori G.G., Santi C.A., and Percival H.J. 1999. An improved method for determining the specific surface areas of topsoils with varied organic matter content, texture and clay mineral composition. European Journal of Soil Science 50: 309-316.
46- Thomas G.W. 1996. Soil pH and soil acidity. In: Sparks, D.L. (Ed), Methods of Soil Analysis, Chemical Methods. SSSA.Madison, Wisconsin, PP: 475-483.
47- Tvardovski A.V., Fomkin A.A., Tarasevich Y.Ui., and Zhukova A.I. 1997. Hysteresis phenomena in the study of sorptive deformation of sorbents. Journal of Colloid and Interface Science 191: 117-119.
48- Van Genuchten M.T., Wierenga P.J., and O'Connor G.A. 1977. Mass transfer studies in sorbing porous media: III. Experimental evaluation with 2,4,5-T. Soil Science Society of America Journal 41: 278-285.
49- Varinderpal S., Dhillon N.S., and Brar B.S. 2006. Influence of long-term use of fertilizers and farmyard manure on the adsorption-desorption behavior and bioavailability of phosphorus in soils. Nutrient Cycling Agro Ecosystems 75: 67-78.
50- Vega F.A., Covelo E.F., and Andrade M.L. 2009. Hysteresis in the individual and competitive sorption of cadmium, copper, and lead by various soil horizons. Journal of Colloid and Interface Science 331: 312-317.
51- Zemmerman M., Leifeld J., Abiven S., Schmidt M.W.I., and Fuhrer J. 2007. Sodium hypochlorite separates an older soil organic matter fraction than acid hydrolysis. Geoderma 139: 171–179.
52- Zhu H., and Selim HM. 2000. Hysteretic behavior of metolachlor adsorption-desorption in soils. Soil Science 165:632-645.
CAPTCHA Image