fa بهینه‌سازی حذف نیترات از منابع آب آشامیدنی توسط پامیس اصلاح شده با کلرید منیزیم با به کارگیری روش طراحی باکس بنکن بهداشت محیط Environmental Health پژوهشي Orginal <span style="font-size:12pt"><span style="text-justify:inter-ideograph"><span style="text-autospace:none"><span style="direction:rtl"><span style="unicode-bidi:embed"><span new="" roman="" style="font-family:" times=""><b><span b="" lang="FA" style="font-family:" yagut=""><span style="letter-spacing:-.4pt">هدف</span></span></b><span lang="FA" style="font-size:10.0pt"><span b="" style="font-family:" yagut=""><span style="letter-spacing:-.5pt">: </span></span></span><span lang="AR-SA" style="font-size:10.0pt"><span b="" style="font-family:" yagut=""><span style="letter-spacing:-.4pt">نیترات به دلیل حلالیت بالا در آب، باعث آلودگی منابع آب زیرزمینی و تهدیدی جدی برای سلامتی انسان‌ها شده و موجب اوتروفیکاسیون در منابع آب می‌گردد. این مطالعه با هدف بهینه‌سازی </span></span></span><span lang="FA" style="font-size:10.0pt"><span b="" style="font-family:" yagut=""><span style="letter-spacing:-.4pt">استفاده از</span></span></span><span lang="AR-SA" style="font-size:10.0pt"><span b="" style="font-family:" yagut=""><span style="letter-spacing:-.4pt"> پامیس اصلاح شده در حذف نیترات از آب انجام شد.</span></span></span></span></span></span></span></span></span><br> <span style="font-size:12pt"><span style="text-justify:inter-ideograph"><span style="text-autospace:none"><span style="direction:rtl"><span style="unicode-bidi:embed"><span new="" roman="" style="font-family:" times=""><b><span b="" lang="FA" style="font-family:" yagut=""><span style="letter-spacing:-.4pt">روش‌ها:</span></span></b><span lang="AR-SA" style="font-size:10.0pt"><span b="" style="font-family:" yagut=""><span style="letter-spacing:-.4pt"> این مطالعه تجربی در سال 1398 در مقیاس آزمایشگاهی و با طراحی آزمایشات به روش باکس بنکن انجام شد. متغیرهای مورد مطالعه شامل (4-2) </span></span></span><span dir="LTR" style="font-size:9.0pt"><span cg="" style="font-family:" times=""><span style="letter-spacing:-.4pt">pH</span></span></span><span lang="AR-SA" style="font-size:10.0pt"><span b="" style="font-family:" yagut=""><span style="letter-spacing:-.4pt">، غلظت اولیه نیترات (</span></span></span><span dir="LTR" style="font-size:9.0pt"><span cg="" style="font-family:" times=""><span style="letter-spacing:-.4pt">mg/L</span></span></span><span lang="AR-SA" style="font-size:10.0pt"><span b="" style="font-family:" yagut=""><span style="letter-spacing:-.4pt">100-50)، زمان تماس (</span></span></span><span dir="LTR" style="font-size:9.0pt"><span cg="" style="font-family:" times=""><span style="letter-spacing:-.4pt">min</span></span></span><span lang="AR-SA" style="font-size:10.0pt"><span b="" style="font-family:" yagut=""><span style="letter-spacing:-.4pt">45-15) و دوز پامیس (</span></span></span><span dir="LTR" style="font-size:9.0pt"><span cg="" style="font-family:" times=""><span style="letter-spacing:-.4pt">gr/L</span></span></span><span lang="AR-SA" style="font-size:10.0pt"><span b="" style="font-family:" yagut=""><span style="letter-spacing:-.4pt">5/1-5/0) اصلاح شده در سه سطح بود. در مجموع تعداد 29 آزمایش</span></span></span><span lang="FA" style="font-size:10.0pt"><span b="" style="font-family:" yagut=""><span style="letter-spacing:-.4pt"> طراحی و اجرا شد. طراحی آزمایشات و آنالیز نتایج</span></span></span><span lang="AR-SA" style="font-size:10.0pt"><span b="" style="font-family:" yagut=""><span style="letter-spacing:-.4pt"> با استفاده از نرم‌افزار</span></span></span><span dir="LTR" style="font-size:9.0pt"><span cg="" style="font-family:" times=""><span style="letter-spacing:-.4pt">Design Expert </span></span></span><span style="font-size:10.0pt"><span b="" style="font-family:" yagut=""><span style="letter-spacing:-.4pt">&nbsp;&nbsp;انجام شد. کلیه آزمایش‌ها در آزمایشگاه دانشکده بهداشت قزوین طبق دستورالعمل آخرین ویرایش کتاب روش‌های استاندارد برای آزمایشات آب و فاضلاب انجام شدند.</span></span></span><span dir="LTR" style="font-size:10.0pt"><span cg="" style="font-family:" times=""><span style="letter-spacing:-.4pt"></span></span></span></span></span></span></span></span></span><br> <span style="font-size:12pt"><span style="text-justify:inter-ideograph"><span style="text-autospace:none"><span style="direction:rtl"><span style="unicode-bidi:embed"><span new="" roman="" style="font-family:" times=""><b><span b="" lang="FA" style="font-family:" yagut=""><span style="letter-spacing:-.4pt">نتایج: </span></span></b><span lang="AR-SA" style="font-size:10.0pt"><span b="" style="font-family:" yagut=""><span style="letter-spacing:-.4pt">نتایج نشان داد که معادله چند جمله‌ای درجه دوم بر داده‌های آزمایشی برازش خوبی دارد. اثرات درجه اول هر چهار متغیر شامل </span></span></span><span dir="LTR" style="font-size:9.0pt"><span cg="" style="font-family:" times=""><span style="letter-spacing:-.4pt">pH</span></span></span><span lang="AR-SA" style="font-size:10.0pt"><span b="" style="font-family:" yagut=""><span style="letter-spacing:-.4pt">، غلظت اولیه نیترات، زمان تماس و پامیس اصلاح شده و همچنین اثرات متقابل و اثرات درجه دوم هر یک از آن ها بر کارایی حذف نیترات از آب معنی‌دار بود (</span></span></span><span dir="LTR" style="font-size:10.0pt"><span cg="" style="font-family:" times=""><span style="letter-spacing:-.4pt">P-Value<0.05</span></span></span><span lang="AR-SA" style="font-size:10.0pt"><span b="" style="font-family:" yagut=""><span style="letter-spacing:-.4pt">). نتایج بهینه‌سازی عددی نشان داد که شرایط بهینه شامل </span></span></span><span dir="LTR" style="font-size:9.0pt"><span cg="" style="font-family:" times=""><span style="letter-spacing:-.4pt">pH</span></span></span><span lang="AR-SA" style="font-size:10.0pt"><span b="" style="font-family:" yagut=""><span style="letter-spacing:-.4pt"> برابر 01/2، غلظت اولیه نیترات 45/70 میلی گرم در لیتر، زمان واکنش 98/44 دقیقه و دوز پامیس اصلاح شده 21/1 گرم در لیتر بود. در این شرایط راندمان حذف نیترات، میزان مطلوبیت مدل و </span></span></span><span dir="LTR" style="font-size:9.0pt"><span cg="" style="font-family:" times=""><span style="letter-spacing:-.4pt">R²</span></span></span> <span lang="AR-SA" style="font-size:9.0pt"><span b="" style="font-family:" yagut=""><span style="letter-spacing:-.4pt">پیش بینی شده </span></span></span><span lang="AR-SA" style="font-size:10.0pt"><span b="" style="font-family:" yagut=""><span style="letter-spacing:-.4pt">به ترتیب برابر با 66/89 درصد، 100 درصد و 82/0 بود.</span></span></span></span></span></span></span></span></span><br> <span style="font-size:12pt"><span style="text-justify:inter-ideograph"><span style="text-autospace:none"><span style="direction:rtl"><span style="unicode-bidi:embed"><span new="" roman="" style="font-family:" times=""><b><span b="" lang="FA" style="font-family:" yagut=""><span style="letter-spacing:-.4pt">نتیجه‌گیری: </span></span></b><span lang="AR-SA" style="font-size:10.0pt"><span b="" style="font-family:" yagut=""><span style="letter-spacing:-.4pt">با توجه به نتایج می‌توان از پامیس اصلاح شده با منیزیم برای حذف نیترات از آب استفاده نمود. اما بایستی توجه نمود که پس از تصفیه بایستی با یک ماده قلیاء مناسب </span></span></span><span dir="LTR" style="font-size:9.0pt"><span cg="" style="font-family:" times=""><span style="letter-spacing:-.4pt">pH</span></span></span><span lang="AR-SA" style="font-size:10.0pt"><span b="" style="font-family:" yagut=""><span style="letter-spacing:-.4pt"> آب حاصل اصلاح شود.</span></span></span></span></span></span></span></span></span><br> <br> <span dir="LTR"></span> <span style="font-size:12pt"><span style="text-justify:inter-ideograph"><span new="" roman="" style="font-family:" times=""><b><span cg="" style="font-family:" times="">Introduction</span></b><b>:</b><b> </b><span style="font-size:11.0pt"><span cg="" style="font-family:" times="">Nitrate, due to its high solubility in water, causes pollution of groundwater resources, poses a serious threat to human health and causes eutrophication of water resources. The aim of this study was to optimize the use of modified pumice in the removal of nitrate from water.</span></span><b><span dir="RTL" lang="FA" style="font-size:13.0pt"><span style="font-family:"B Yagut""></span></span></b></span></span></span><br> <span style="font-size:12pt"><span style="text-justify:inter-ideograph"><span new="" roman="" style="font-family:" times=""><b><span cg="" style="font-family:" times="">Methods</span></b><b>:</b> <span style="font-size:11.0pt"><span cg="" style="font-family:" times="">This experimental study was performed in 2020 on laboratory scale. The experiments were designed using the Box-Benken method. The studied variables included pH (2-4), initial nitrate concentration (50-100 mg/L), contact time (15-45 min) and pumice dose (0.5 - 1.5 gr/L) at three levels. Thus, a total of 29 experiments were designed and performed.</span></span> <span style="font-size:11.0pt"><span cg="" style="font-family:" times="">Experimental design and statistical analysis were performed using Design Expert 7.0 software.</span></span> <span style="font-size:11.0pt"><span cg="" style="font-family:" times="">All examinations were performed according to the instructions provided in the latest edition of the Standard Methods for the Examinations of Water and Wastewater. </span></span><b><span b="" dir="RTL" lang="FA" style="font-family:" yagut=""><span style="letter-spacing:-.4pt"></span></span></b></span></span></span><br> <span style="font-size:12pt"><span style="text-justify:inter-ideograph"><span new="" roman="" style="font-family:" times=""><b><span cg="" style="font-family:" times="">Results</span></b><b><span dir="RTL" lang="AR-SA" style="font-size:11.0pt">:</span></b><span style="font-size:11.0pt"><span cg="" style="font-family:" times=""> The results</span></span> <span style="font-size:11.0pt"><span cg="" style="font-family:" times="">showed that the quadratic polynomial equation fitted well with the experimental data.</span></span> <span style="font-size:11.0pt"><span cg="" style="font-family:" times="">Also, the liner effects of all four variables (including pH, initial nitrate concentration, contact time and modified pumice dose), as well as interactions effects and quadratic effects of each variable on the nitrate removal efficiency from water were significant </span></span>(P-Value <0.05)<span style="font-size:11.0pt"><span cg="" style="font-family:" times="">.</span></span> <span style="font-size:11.0pt"><span cg="" style="font-family:" times="">The results of numerical optimization showed that the optinal conditions included pH of 2.01, initial nitrate concentration of 70.45 mg/L, reaction time of 44.98 min, and modified pumice dose of 1.21 gr/L. </span></span>Under these conditions, nitrate removal efficiency, model desirability, and predicted R² were 89.66%, 100% and 0.82, respectively.<span style="font-size:11.0pt"><span style="font-family:"CG Times","serif""></span></span></span></span></span><br> <span style="font-size:12pt"><span style="text-justify:inter-ideograph"><span new="" roman="" style="font-family:" times=""><b><span cg="" style="font-family:" times="">Conclusion</span></b><b>:</b><span style="font-size:11.0pt"><span cg="" style="font-family:" times=""> According to the results, magnesium-modified pumice can be applied to remove nitrate from water. However, it should be mentioned that the pH of the water, after purification, must be modified with a suitable alkaline substance.</span></span></span></span></span><br> &nbsp; تصفیه آب, آب‌های زیرزمینی, حذف نیترات, پامیس اصلاح شده Water Treatment, Groundwaters, Nitrate Removal, Modified Pumice. 56 68 http://jpm.hums.ac.ir/browse.php?a_code=A-10-182-8&slc_lang=fa&sid=1 Kavoos Dindarloo کاووس دیندارلو kdindarloo@yahoo.com 10031947532846007355 10031947532846007355 No PhD, Environmental Health Engineering, Department of Environmental Health, Social Determinants on Health Promotion Research Center, Hormozgan University of Medical Sciences, Bandar Abbas, Iran دکترای تخصصی، مهندسی بهداشت محیط، مرکز تحقیقات سلامت مواد غذایی، دانشگاه علوم پزشکی هرمزگان، بندرعباس، ایران. Hamideh Sheikh Mohammadi حمیده شیخ محمدی alijamali758@yahoo.com 10031947532846007356 10031947532846007356 No BSc, Environmental Health Engineering, Student Research Committee, Qazvin University of Medical Sciences, Qazvin, Iran. کارشناسی، مهندسی بهداشت محیط، کمیته تحقیقات دانشجویی، دانشگاه علوم پزشکی قزوین، قزوین، ایران. Hamzeh Ali Jamali حمزه علی جمالی jamalisadraei@yahoo.com 10031947532846007357 10031947532846007357 Yes PhD, Environmental Health Engineering, Department of Health Education and Health Promotion, Social Factors in Health Promotion Research Center, Qazvin University of Medical Sciences, Qazvin, Iran دکترای تخصصی، گروه مهندسی بهداشت محیط، مرکز تحقیقات عوامل اجتماعی مؤثر بر سلامت، دانشگاه علوم پزشکی قزوین، قزوین، ایران.