تعیین ضرایب بیوسینتیکی فرایند بیولوژیکی واحد لجن فعال با هوادهی گسترده در شرایط آب و هوایی گرم در تصفیه فاضلاب بیمارستانی

نوع مقاله: یاداشت‌ فنی

نویسندگان

1 دانشیار گروه مهندسی بهداشت محیط و عضو مرکز تحقیقات فناوری‌های زیست محیطی دانشگاه علوم پزشکی جندی شاپور اهواز، اهواز، ایران

2 کارشناس ارشد مهندسی بهداشت محیط ، دانشگاه علوم پزشکی جندی شاپور اهواز، اهواز، ایران

3 استادیار گروه مهندسی بهداشت محیط و عضو مرکز تحقیقات فناوری های زیست محیطی دانشگاه علوم پزشکی جندی شاپور اهواز، اهواز، ایران

4 استادیار گروه مهندسی محیط زیست، واحد اهواز، دانشگاه آزاد اسلامی اهواز، اهواز، ایران

چکیده

فاضلاب بیمارستانی جزو فاضلاب شهری ناخالص محسوب میشود که با توجه به گستردگی بیمارستان و تنوع بخشهای درمانی آن و در نتیجه آلاینده‌های مختلف موجود در فاضلاب‌های بیمارستانی، تعیین ضرایب سینتیکی و راهبری تصفیه‌خانه فاضلاب بیمارستان از اهمیت زیادی برخوردار است. یکی از مهم‌ترین روش‌های تصفیه فاضلاب بیمارستانی، سیستم لجن فعال با هوادهی گسترده است. این پژوهش با هدف انتخاب مناسب ضرایب سینتیکی و راهبری تصفیه‌خانه فاضلاب بیمارستان در شرایط آب و هوای گرم انجام شد.در این پژوهش نمونه‌برداری در طی 6 ماه در فاصله دی 1392 تا خرداد 1393 انجام شد و پارامترهای TSS، COD، BOD5، pHوکدورت در فاضلاب خام ورودی و خروجی از تصفیه‌خانه و MLVSS و MLSSو اکسیژن محلول در حوض هوادهی و میزان لجن برگشتی به راکتور اندازه‌گیری و با تعیین پارامترهای راهبری و بهره‌برداری از قبیلSVI، F/M، qcدرحوضچه هوادهی، در نهایت ضرایب سینتیکی Kd، KS، Yو µmaxبا استفاده از معادلات اصلاح شده مونود محاسبه شد. نتایج این مطالعه نشان داد که میانگین ضرایب سینتیکی در فرایند بیولوژیکی لجن فعال با هوادهی گسترده در فاضلاب بیمارستانی مورد مطالعه برابر با : K=2.19d-1، Ks= 9.74(mg/L) ، Y=0.39gBiomass/gBOD5، Kd=0.06d-1،mmax=0.85d-1محاسبه شد. از ضرایب سینتیکی به‌دست آمده در این تحقیق می‌توان به‌منظور طراحی و همچنین راهبری و بهره‌برداری تصفیه‌خانه‌های فاضلاب بیمارستان‌ها به روش لجن فعال هوادهی گسترده به‌ویژه در مناطق گرمسیری استفاده نمود.

کلیدواژه‌ها


عنوان مقاله [English]

Determination of Biokinetic Coefficients for the Extended Aeration Activated Sludge System Treating Hospital Effluents in Hot Climate Conditions

نویسندگان [English]

  • Afshin Takdastan 1
  • Bahareh Kordestani 2
  • Abdolkazem Neisi 3
  • Reza Jalilzadeh Yangejeh 4
1 Assoc. Prof. of Environmental Health Engineering, and Member of Environmental Technologies Research Center, Ahvaz Judishapur University of Medical Sciences, Ahvaz, Iran
2 MSc of Environmental Health Engineering, Ahwaz Jundishapur University, Ahvaz, Iran
3 Assist. Prof. of Environmental Health Engineering, and Member of Environmental Technologies Research Center, Ahvaz Judishapur University of Medical Sciences, Ahvaz, Iran
4 Assist. Prof of Environmental Health Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran
چکیده [English]

Hospital effluents are regarded as a kind of municipal wastewater laden with additional pollutants due to the variety of wards and therapeutic activities in a hospital. This makes the determination of kinetic coefficients and parameters of utmost importance for the successful operation and maintenance of hospital wastewater treatment facilities. Extended aeration activated sludge is one of the most important processes employed in such facilities. The present study is an effort to determine these parameters for the operation of such a facility operating in hot climate conditions. For this purpose, samples of both hospital raw wastewater and plant effluent were taken during a 6-month period from January to June 2014 to determine their BOD5, COD, TSS, PH, and Turbidity. Moreover, MLSS, MLVSS, and DO in the aeration tank as well as the sludge return ratios were measured. Such operation and maintenance parameters as θc, F/M, and SVI were then calculated and the equations of the modified Monod Model were used to calculate the values of the kinetic coefficients such as Y, K, KS, Kd, and µmax for the extended aeration activated sludge process at the hospital wastewater treatment plant as follows: K= 2.19 d-1, Ks=90.74 mg/l, Y = 0.39 g Biomass/g BOD5, Kd = 0.06 d-1, and  µmax =0.85 d-1. The results obtained can be usefully exploited for designing similar extended aeration activated sludge processes for the treatment of hospital effluents, especially for those operating in hot climates.

کلیدواژه‌ها [English]

  • Hospital Wastewater Treatment
  • Activated sludge
  • Extended Aeration
  • Kinetic Coefficients
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