en عمومى General مقاله اصیل Original Article <p>Background: Yazd waste stabilization pond facilities consist of three stabilization pond systems, module 1, module 2 and module 3 that AWSP module 1 has started its operation. The existing facilities have had several problems in their operation. The objectives of this research were to evaluate the performance of stabilization ponds in wastewater treatment of the city of Yazd, due to several problems in their operation, and to prepare a scheme of its upgrading, if necessary. Methods: During the period from December to June 2010, data analysis were carried out for both raw and treated wastewater. Results: Results of these investigations showed that the average effluent concentrations of Biochemical Oxygen Demand 5 (BOD5), Chemical Oxygen Demand (COD) and Suspended Solid (SS) taken from anaerobic pond and secondary facultative ponds of module 1 were 306.9, 135.18, 139.75 and 136.75, 69.025, 136.5 mg/L, respectively. Conclusion: These results indicated that the effluent of the anaerobic pond of module 1 was complied with the Iranian treated wastewater standards for agricultural reuse in terms of BOD5 and COD concentrations hence the secondary facultative ponds could be changed to other primary facultative ponds in order to increase the capacity of wastewater treatment plant.</p> Biological wastewater treatment, Stabilization pond, Yazd 7 12 http://ehemj.com/browse.php?a_code=A-10-27-8&slc_lang=en&sid=1 Mahdi Farzadkia 10031947532846001826 10031947532846001826 No Department of Environmental Health Engineering, Iran University of Medical Sciences, Tehran, Iran Mohamad Hassan Ehrampoush 10031947532846001827 10031947532846001827 No Department of Environmental Health Engineering, Shahid Sadoughi University of Medical Sciences, Yazd, Iran Shahram Sadeghi 10031947532846001828 10031947532846001828 No Environmental Health Engineering, Student Research Committee, Kurdistan University of Medical Sciences, Sanandaj, Iran Majid Kermani 10031947532846001829 10031947532846001829 No Department of Environmental Health Engineering, Iran University of Medical Sciences, Tehran, Iran Mohammad Taghi Ghaneian 10031947532846001830 10031947532846001830 No Department of Environmental Health Engineering, Shahid Sadoughi University of Medical Sciences, Yazd, Iran Vahid Ghelmani 10031947532846001831 10031947532846001831 No Civil Engineering, Manager of Wastewater Treatment Plant in Yazd, Iran Ehsan Abouee Mehrizi 10031947532846001832 10031947532846001832 Yes Environment Research Center, Iran University of Medical Sciences, Department of Environmental Health Engineering, Faculty of Public Health, North Khorasan University of Medical Sciences- Bojnurd, Bojnurd, Iran