| چکیده انگلیسی مقاله |
Introduction: According to the sewage exiting from any plant, the industrial complexes must observe regulations related to the standards of sewage systems. The current study tried to examine the efficiency and restrictions of the system to primary treatment operations by designing and constructing a primary treatment system entitled the "New Activated Sludge System with Falling Aeration". Materials & Methods: Designing and constructing this system is completely innovative, registered by parent office with number 40091. The main parts of this system include: the electrical connecting cable, steering circuit, miniature cap, a round-the-clock timer, contactor, control key of digested sludge pump to sandy filter, a dimmer of 2kw, adaptor, the keeping case, the electro motor, the gear box, the connector of power transferring from the gear box to main shaft, the power trans-shaft, bearings basin, the sedimentation basin, sludge pump, anaerobic digestion chamber, sand filter, pilot legs/hands, sewage transferring channels. Findings: The goal of constructing this system was offering a new model of the primary treatment operation as well as reducing the costs of primary treatment systems among industrial factories besides eliminating the need to specialists and enabling people to design such systems. Discussion & Conclusion: During the design, process the newly constructed system obtained results from sewage experiments with COD concentration 7035 mg/1, BOD5 4535 mg/1, TSS 1344 mg/1. Using this system with aeration period of about 2.74 hours per day and the average PH of 7.2 and temperature of around 21.3C proved that eliminating rates of COD, BOD5 and TSS were 73.6%, 84.2% and 85.4% respectively. These resets indicated that the operative dredges system with falling aeration enjoys the necessary efficiency to primary treatment operation |