fa تأثیر کلسیت زیستی بر برخی ویژگی‌های فیزیکی خاک‌های شنی عمومی Ggeneral پژوهشي Research <strong><span style="FONT-FAMILY: Lotus FONT-SIZE: 11pt mso-fareast-font-family: 'Times New Roman' mso-bidi-language: FA mso-ansi-font-size: 9.0pt mso-ansi-language: EN-US mso-fareast-language: EN-US mso-ascii-font-family: 'Times New Roman' mso-hansi-font-family: 'Times New Roman' mso-no-proof: yes" dir="rtl" lang="FA">پرشدگی منافذ و اتصال ذرات یک خاک شنی توسط رسوب میکروبی کلسیت در پژوهش حاضر مورد مطالعه قرار گرفت. تأثیر دو گونه باکتری (</span><i><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 9pt mso-bidi-font-family: Lotus mso-fareast-font-family: 'Times New Roman' mso-bidi-language: FA mso-bidi-font-size: 11.0pt mso-ansi-language: EN-US mso-fareast-language: EN-US mso-no-proof: yes">Sporosarcina</span></i><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 9pt mso-bidi-font-family: Lotus mso-fareast-font-family: 'Times New Roman' mso-bidi-language: FA mso-bidi-font-size: 11.0pt mso-ansi-language: EN-US mso-fareast-language: EN-US mso-no-proof: yes"> <i>pasteurii</i></span><span dir="rtl"></span><span style="FONT-FAMILY: Lotus FONT-SIZE: 11pt mso-fareast-font-family: 'Times New Roman' mso-bidi-language: FA mso-ansi-font-size: 9.0pt mso-ansi-language: EN-US mso-fareast-language: EN-US mso-ascii-font-family: 'Times New Roman' mso-hansi-font-family: 'Times New Roman' mso-no-proof: yes" dir="rtl" lang="FA"><span dir="rtl"></span> و</span><i><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 9pt mso-bidi-font-family: Lotus mso-fareast-font-family: 'Times New Roman' mso-bidi-language: FA mso-bidi-font-size: 11.0pt mso-ansi-language: EN-US mso-fareast-language: EN-US mso-no-proof: yes">Sporosarcina</span></i><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 9pt mso-bidi-font-family: Lotus mso-fareast-font-family: 'Times New Roman' mso-bidi-language: FA mso-bidi-font-size: 11.0pt mso-ansi-language: EN-US mso-fareast-language: EN-US mso-no-proof: yes"> <i>ureae</i></span><span dir="rtl"></span><span style="FONT-FAMILY: Lotus FONT-SIZE: 11pt mso-fareast-font-family: 'Times New Roman' mso-bidi-language: FA mso-ansi-font-size: 9.0pt mso-ansi-language: EN-US mso-fareast-language: EN-US mso-ascii-font-family: 'Times New Roman' mso-hansi-font-family: 'Times New Roman' mso-no-proof: yes" dir="rtl" lang="FA"><span dir="rtl"></span>)، سه غلظت واکنش­گر (مخلوط اوره و کلرید کلسیم در غلظت­های 5/0، 1 و 5/1 مولار) و شش زمان واکنش (12، 24، 48، 96، 192 و 288 ساعت) بر میزان هدایت هیدرولیکی اشباع و مقاومت مکانیکی، در یک خاک شنی در قالب آزمایش فاکتوریل مورد بررسی قرار گرفت. نمونه خاک از تپه­های شنی منطقه جوپار در استان کرمان برداشت شد. مایه تلقیح باکتری­ها و محلول­های­ واکنش­گر روزانه به ستون­های خاک اضافه شدند. نتایج نشان داد، استفاده از گونه </span><i><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 9pt mso-bidi-font-family: Lotus mso-fareast-font-family: 'Times New Roman' mso-bidi-language: FA mso-bidi-font-size: 11.0pt mso-ansi-language: EN-US mso-fareast-language: EN-US mso-no-proof: yes">S. pasteurii</span><span dir="rtl"></span><span style="FONT-FAMILY: Lotus FONT-SIZE: 11pt mso-fareast-font-family: 'Times New Roman' mso-bidi-language: FA mso-ansi-font-size: 9.0pt mso-ansi-language: EN-US mso-fareast-language: EN-US mso-ascii-font-family: 'Times New Roman' mso-hansi-font-family: 'Times New Roman' mso-no-proof: yes" dir="rtl"><span dir="rtl"></span> </span></i><span style="FONT-FAMILY: Lotus FONT-SIZE: 11pt mso-fareast-font-family: 'Times New Roman' mso-bidi-language: FA mso-ansi-font-size: 9.0pt mso-ansi-language: EN-US mso-fareast-language: EN-US mso-ascii-font-family: 'Times New Roman' mso-hansi-font-family: 'Times New Roman' mso-no-proof: yes" dir="rtl" lang="FA">نسبت به </span><i><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 9pt mso-bidi-font-family: Lotus mso-fareast-font-family: 'Times New Roman' mso-bidi-language: FA mso-bidi-font-size: 11.0pt mso-ansi-language: EN-US mso-fareast-language: EN-US mso-no-proof: yes">S. ureae</span></i><span dir="rtl"></span><span style="FONT-FAMILY: Lotus FONT-SIZE: 11pt mso-fareast-font-family: 'Times New Roman' mso-bidi-language: FA mso-ansi-font-size: 9.0pt mso-ansi-language: EN-US mso-fareast-language: EN-US mso-ascii-font-family: 'Times New Roman' mso-hansi-font-family: 'Times New Roman' mso-no-proof: yes" dir="rtl" lang="FA"><span dir="rtl"></span> موجب کاهش بیشتر هدایت هیدرولیکی نمونه­های تیمار شده (</span><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 9pt mso-bidi-font-family: Lotus mso-fareast-font-family: 'Times New Roman' mso-bidi-language: FA mso-bidi-font-size: 11.0pt mso-ansi-language: EN-US mso-fareast-language: EN-US mso-no-proof: yes">cm/h</span><span dir="rtl"></span><span style="FONT-FAMILY: Lotus FONT-SIZE: 11pt mso-fareast-font-family: 'Times New Roman' mso-bidi-language: FA mso-ansi-font-size: 9.0pt mso-ansi-language: EN-US mso-fareast-language: EN-US mso-ascii-font-family: 'Times New Roman' mso-hansi-font-family: 'Times New Roman' mso-no-proof: yes" dir="rtl" lang="FA"><span dir="rtl"></span>57/11) نسبت به شاهد (</span><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 9pt mso-bidi-font-family: Lotus mso-fareast-font-family: 'Times New Roman' mso-bidi-language: FA mso-bidi-font-size: 11.0pt mso-ansi-language: EN-US mso-fareast-language: EN-US mso-no-proof: yes">cm/h</span><span dir="rtl"></span><span style="FONT-FAMILY: Lotus FONT-SIZE: 11pt mso-fareast-font-family: 'Times New Roman' mso-bidi-language: FA mso-ansi-font-size: 9.0pt mso-ansi-language: EN-US mso-fareast-language: EN-US mso-ascii-font-family: 'Times New Roman' mso-hansi-font-family: 'Times New Roman' mso-no-proof: yes" dir="rtl" lang="FA"><span dir="rtl"></span>61/41) گردیده است. افزایش زمان واکنش (از 12 تا 288 ساعت) و غلظت واکنش­گرها (از 5/0 تا 5/1 مولار) به‌ترتیب موجب کاهش 49 و 16درصدی هدایت هیدرولیکی شد. گونه </span><i><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 9pt mso-bidi-font-family: Lotus mso-fareast-font-family: 'Times New Roman' mso-bidi-language: FA mso-bidi-font-size: 11.0pt mso-ansi-language: EN-US mso-fareast-language: EN-US mso-no-proof: yes">S. pasteurii</span><span dir="rtl"></span><span style="FONT-FAMILY: Lotus FONT-SIZE: 11pt mso-fareast-font-family: 'Times New Roman' mso-bidi-language: FA mso-ansi-font-size: 9.0pt mso-ansi-language: EN-US mso-fareast-language: EN-US mso-ascii-font-family: 'Times New Roman' mso-hansi-font-family: 'Times New Roman' mso-no-proof: yes" dir="rtl"><span dir="rtl"></span> </span></i><span style="FONT-FAMILY: Lotus FONT-SIZE: 11pt mso-fareast-font-family: 'Times New Roman' mso-bidi-language: FA mso-ansi-font-size: 9.0pt mso-ansi-language: EN-US mso-fareast-language: EN-US mso-ascii-font-family: 'Times New Roman' mso-hansi-font-family: 'Times New Roman' mso-no-proof: yes" dir="rtl" lang="FA">نسبت به </span><i><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 9pt mso-bidi-font-family: Lotus mso-fareast-font-family: 'Times New Roman' mso-bidi-language: FA mso-bidi-font-size: 11.0pt mso-ansi-language: EN-US mso-fareast-language: EN-US mso-no-proof: yes">S. ureae</span></i><span dir="rtl"></span><span style="FONT-FAMILY: Lotus FONT-SIZE: 11pt mso-fareast-font-family: 'Times New Roman' mso-bidi-language: FA mso-ansi-font-size: 9.0pt mso-ansi-language: EN-US mso-fareast-language: EN-US mso-ascii-font-family: 'Times New Roman' mso-hansi-font-family: 'Times New Roman' mso-no-proof: yes" dir="rtl" lang="FA"><span dir="rtl"></span> مقاومت نمونه­های تیمار شده را تا فشار 6/2 مگاپاسکال افزایش داد. غلظت واکنش­گرها و زمان واکنش باعث افزایش معنی­دار مقاومت خاک شد (به‌ترتیب 13/2 و1/4 مگاپاسکال). مطالعات میکرومورفولوژی نشانگر بلورهای کلسیت به‌صورت پل در بین ذرات خاک و پرکننده خلل و فرج بود.</span></strong> <span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 10pt mso-fareast-font-family: 'Times New Roman' mso-bidi-language: FA mso-ansi-language: EN-US mso-fareast-language: EN-US">Biocalcite infilling and bridging in a sandy soil was studied in the present research. Effects of 2 bacterial species (<i>Sporosarcina pasteurii and Sporosarcina ureae</i>), 3 reactant concentrations (0.5, 1.0, and 1.5 M of urea and CaCl₂ mixture), and 6 reaction times (12, 24, 48, 96, 192, and 288 hr) on saturated hydraulic conductivity and mechanical<span dir="rtl"></span><span dir="rtl"><span dir="rtl"></span><font size="2" face="Times New Roman"> </font></span>strength of a sandy soil were studied as a factorial experiment. Soil samples were selected from sand dunes of Joopar<span dir="rtl"></span><span dir="rtl"><span dir="rtl"></span><font size="2" face="Times New Roman"> </font></span>area, Kerman Province. Bacterial inoculums and reactant solutions were daily added to soil columns. Results of the<span dir="rtl"></span><span dir="rtl"><span dir="rtl"></span><font size="2" face="Times New Roman"> </font></span>study showed that <i>S. pasteuriihad</i> had a higher effect on decreasing hydraulic conductivity of the treated samples (11.57 cm/h)<span dir="rtl"></span><span dir="rtl"><span dir="rtl"></span><font size="2" face="Times New Roman"> </font></span>compared to the blank (41.61 cm/h) than <i>S. ureae</i>. Increasing reaction times (from 12 to 288 hrs) and reactant<span dir="rtl"></span><span dir="rtl"><span dir="rtl"></span><font size="2" face="Times New Roman"> </font></span>concentrations (from 0.5 to 1.5 M) decreased hydraulic conductivity by 49 and 16 %, respectively. <i>S. pasteurii</i> increased strength of treated samples up to 2.6 Mpa pressure compared to <i>S. ureae</i>. Reactant concentrations and<span dir="rtl"></span><span dir="rtl"><span dir="rtl"></span><font size="2" face="Times New Roman"> </font></span>reaction times increased soil strength significantly (2.13 and 4.1 Mpa, respectively). Micromorphological observation<span dir="rtl"></span><span dir="rtl"><span dir="rtl"></span><font size="2" face="Times New Roman"> </font></span>showed calcite crystals bridging soil particles and filling pore spaces<span dir="rtl"></span><span dir="rtl" lang="FA"><span dir="rtl"></span><font size="2" face="Times New Roman">. </font></span></span> Sporosarcina pasteurii, Sporosarcina ureae, سیمانی شدن زیستی, مسدود شدن زیستی, مقاومت خاک, هدایت هیدرولیکی اشباع Sporosarcina pasteurii, Sporosarcina ureae, Biocementation, Bioclogging, Soil strength, Saturated hydraulic conductivity. 69 78 http://jstnar.iut.ac.ir/browse.php?a_code=A-10-1-14&slc_lang=fa&sid=1 M. Sarmast معصومه سرمست No Shahid Bahonar Univ. Kerman, Iran دانشکده کشاورزی، دانشگاه شهید باهنر، کرمان M. H. Farpoor محمد هادی فرپور Yes Shahid Bahonar Univ. Kerman, Iran دانشکده کشاورزی، دانشگاه شهید باهنر، کرمان M. Sarcheshmehpoor مهدی سر‌چشمه‌پور No Shahid Bahonar Univ. Kerman, Iran دانشکده کشاورزی، دانشگاه شهید باهنر، کرمان M. Karimian Eghbal مصطفی کریمیان اقبال No Tarbiat Modares Univ., Tehran, Iran. دانشکده کشاورزی، دانشگاه تربیت مدرس، تهران