ABSTRACT
Introduction: sequential batch reactor [SBR] is one of the modified biological treatment systems which is able to remove BOD[5], Nitrogen, and phosphorus from wastewater. The object of this study is to determine the removal efficiency of nitrogen, phosphorus, and heavy metals from municipal wastewater by the advanced SBR system
Methods: This descriptive-analytical and cross-sectional study was conducted on advanced SBR in Yazd city wastewater treatment plant during a one-year period [from September, 2014 until August, 2015]
The samples were collected from the influent and effluent of the advanced SBR as a composite in order to measure BOD[5] TKN, NH[+4], TP parameters, and heavy metals monthly
Also, statistical t-test was used to compare heavy metals quantities with standard ones
Results: The results showed that the mean of removal efficiency of BOD[5], TKN, NH[+4], and TP were 92.24, 80.36, 90.41, and 66.41 percent, respectively. Also, the removal efficiency of Iron [Fe], Plumbum [Pb], Nickel [Ni], Zink [Zn], Chromium [Cr], and Cadmium [Cd] were 47.77%, 40.71%, 24.79%, 12.29%, 5.70%, and 5.65%, respectively
Conclusion: The high removal efficiency of BOD[5], TKN, and NH[+4] showed that this advanced SBR system had an appropriate efficiency for nitrification. Phosphorus removal [TP] had a lower efficiency than those of NH[+4] and TKN, but it was within the environmental standard limits. On the other hand, in the advanced SBR the removal efficiency of heavy metals for Cd was not within the standard limits
ABSTRACT
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 [BOD[5]], 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 BOD[5] 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