بررسی تأثیر میدان‌های مغناطیسی بر شاخص حجمی لجن رقیق‌شده فاضلاب شهری

نوع مقاله : مقاله پژوهشی

نویسندگان

1 استاد، مرکز تحقیقات عوامل اجتماعی مؤثر بر سلامت، گروه مهندسی بهداشت محیط، دانشکده بهداشت، دانشگاه علوم پزشکی همدان، همدان، ایران

2 دانشجوی دکترا، مرکز پژوهش دانشجویان، گروه مهندسی بهداشت محیط، دانشکده بهداشت، دانشگاه علوم پزشکی همدان، همدان

3 دانشجوی کارشناسی، مرکز پژوهش دانشجویان، گروه مهندسی بهداشت محیط، دانشکده بهداشت، دانشگاه علوم پزشکی همدان، همدان، ایران

4 کارشناسی ارشد، مسئول آزمایشگاه تصفیه‌خانه فاضلاب شهر سنندج، شرکت مهندسی آب و فاضلاب کردستان، سنندج، ایران

چکیده

یکی از مهم‌ترین مشکلات فرایند تصفیه فاضلاب به روش لجن فعال اختلاط کامل، تولید حجم زیادی از لجن است که آمایش و مدیریت لجن تولیدی را با مشکلات زیادی مواجه می‌سازد. از آنجایی‌که حدود 60 درصد هزینه‌های بهره‌برداری از تصفیه‌خانه‌های فاضلاب مربوط به مدیریت لجن است، بنابراین هر فرایند اصلاحی که بتواند میزان لجن کمتری را تولید کند، می‌تواند در کاهش هزینه‌ها و مدیریت بهتر لجن مؤثر باشد. استفاده از میدان مغناطیسی برای تصفیه فاضلاب به‌دلیل عدم‌استفاده از مواد شیمیایی در سال‌های اخیر مورد توجه پژوهشگران قرارگرفته است. در این پژوهش با استفاده از شدت میدان 19/0 تا 21/3 میلی‌تسلا بر روی شاخص حجمی لجن رقیق‌شده در مدت ‌زمان 30 دقیقه میزان کاهش این شاخص در نمونه‌های مورد نسبت به نمونه‌های شاهد با هم مقایسه شدند. کاهش میزان این شاخص از 10 تا 100 میلی‌لیتر برگرم متفاوت بود. در این بازه زمانی میزان تفاوت دمایی نمونه‌های مورد در مقایسه با نمونه‌های شاهد از نظر آماری معنی‌دار و از 4/0 تا 20 درجه سلسیوس برآورد شد. تفاوت pH نمونه‌های مورد در مقایسه با نمونه‌های شاهد معنی‌دار ولی غلظت اکسیژن محلول نمونه‌های مورد و شاهد به‌عنوان متغیر دیگر مؤثر بر فرایند، ازنظر آماری معنی‌دار نبودند (05/0< p).

کلیدواژه‌ها


عنوان مقاله [English]

Investigation of the Effect of Magnetic Fields on the Volume Index of Diluted Municipal Wastewater Sludge

نویسندگان [English]

  • Ghorban Asgari 1
  • Ramin Khoshniyat 2
  • Mahtab Nazifi 3
  • Hana Shabrandy 4
1 Prof., Social Determinants of Health Research Center (SDHRC), Dept. of Environmental Health Engineering, Faculty of Public Health, Hamadan University of Medical Sciences, Hamadan, Iran
2 PhD. Student, Student Research Committee, Dept. of Environmental Health Engineering, Faculty of Public Health, Hamadan University of Medical Sciences, Hamadan, Iran
3 BSc. Student, Student Research Committee, Dept. of Environmental Health Engineering, Faculty of Public Health, Hamadan University of Medical Sciences, Hamadan, Iran
4 MSc., Supervisor of Sanandaj Wastewater Treatment Laboratory, Kurdistan Water and Wastewater Engineering Company, Sanandaj, Iran
چکیده [English]

One of the most important problems in the process of wastewater treatment by the complete mix activated sludge method is the production of a large volume of sludge, which poses many problems in the management and conditioning of sludge. Since about 60% of the operating costs of wastewater treatment plants are related to sludge management, so any modified process that can produce less sludge can be effective in reducing costs and better sludge management. The use of magnetic fields to treat wastewater has been considered by researchers in recent years due to the lack of application of chemicals in these processes. This study considered the use of MFs strength in the range of 0.19 to 3.21 mT on diluted sludge volume index for 30 minutes. The rate of reduction of this index in the case samples compared to the control samples from 10 to 100 mL/g was different. During this period, the difference between the temperatures of the case samples compared to the control samples was statistically significant and was estimated from 0.4 to 20 °C. The difference between mean pH of the case and control samples was significant but the dissolved oxygen concentration of them, similar to other variables’ factors that affect the process, was not statistically significant (p> 0.05).

کلیدواژه‌ها [English]

  • Magnetic Fields
  • Diluted Sludge Volume Index
  • Municipal wastewater
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