National Guard SBR/STP

National Guard SBR/STP National Guard SBR/STP National Guard SBR/STP National Guard SBR/STP National Guard SBR/STP National Guard SBR/STP

This project purpose is to treat the waste water for National Guard. Both of suspended solids and biodegradable organic matter will be reduced through treatment systems to acceptable limits. The plant is capable to produce treated water of volume and quality for agriculture purposes. The scope of the project is described briefly below: The SBR process is designed and will be operated based on the fill and draw activated sludge process with plant capacity of 2 x 500 m3/day. The raw wastewater inlet is force main. The force main opens into equalization tank where raw sewage is screened by automatic screen to remove solids from sewage flow. The equalization tank is designed to equalize flow rate variations and is provided with odor control dosing system to control production of odors around equalization/equalization tank. The submersible aerator installed in the equalization tank mix contents of tank and avoid septicity of sewage water creating aerobic (aseptic) condition in equalization tank. The raw sewage is lifted by means of sewage submersible lifting pumps installed in the equalization tank. The sewage flow is passed through comminutor where it cuts and grinds up coarse solids in wastewater to about 6.35 mm, so that solids will not harm subsequent treatment equipment or process. Then sewage flows into Sequencing Batch Reactor tanks. SBR process operates in a true batch mode with aeration and sludge settlement both occurring in same tank. The major differences between SBR and conventional continuous – flow, activated sludge system is that SBR tank carries out the functions of aeration and sedimentation in a time sequence rather than in the conventional space sequence of continuous – flow systems. The operating principles of a batch activated sludge process, or SBR, are characterized in five discrete periods/phases 1) Fill, 2) Aerate/react, 3) Settle, 4) Decant & 5) Idle. The process is designed for BOD removal & nitrification only. Total cycle or batch time is 8.0 hrs of which 2.7 hrs is fill phase, 2.47 hrs aerate/react, 1.0 hr settling phase, 1.33 hrs decanting phase & 0.5 hr idle phase. Sewage lifting pumps lift sewage according to fill phase timing. When one tank is in fill phase other tank will be in aerate, react, settle or decant phase. Submersible aerator ,four per each tank is used for aeration purpose. After aeration gravity separation of solids from liquid occur in the SBR unit during settle phase of SBR operation cycle. The clear liquid is decanted by means of decanting pumps. The excess waste sludge which is produced during process is transferred to sludge holding tank where it is partially digested. Sludge holding tank is provided with diffusers. The secondary treated effluent is than chlorinated using sodium hypochlorite solution giving good contact time in Chlorine Contact Tank. Chlorinated effluent then is filtered by multimedia sand filtration process. Media filtration of treated effluent removes maximum suspended solids and gives required quality of effluent. Filtered effluent is then transferred to treated water tank for final storage.