Process and Training of Wastewater Treatment Experimental Device

1、 Working conditions

Operating at room temperature and pressure, power supply voltage: AC220V. Prior to the experiment, a certain amount of wastewater needs to be prepared and a biofilm needs to be cultivated.

2、 Experimental purpose

1. Common Unit Operation Techniques in Pilot Wastewater Treatment

2. Master the processing flow composed of these unit operations

3. Observe the behavior of wastewater, sludge, and air during the treatment process

4. The analysis of design parameters and treatment results by conducting actual treatment experiments on a certain type of wastewater.

3、 Experimental process

The experimental process includes water distribution, dosing and coagulation, inclined plate oil separation, neutralization regulation, primary sedimentation tank, anaerobic reaction tank, anoxic reaction tank, aerobic reaction tank, vertical flow secondary sedimentation tank, sludge reflux, mixed liquid reflux, ordinary fast filter (timed backwash system), active adsorption column, and ultraviolet sterilization system.

4、 Experimental principle

1. Pre treatment system: As shown in the process flow diagram, the sewage first enters pre-treatment processes such as dosing coagulation/inclined plate oil separation/PH regulation initial sedimentation, etc., to remove oil and suspended particles from the water and adjust the pH value of the wastewater.

2. Anaerobic tank: As shown in the process flow diagram, sewage first enters the anaerobic zone, where facultative anaerobic fermentation bacteria convert biodegradable organic matter in the water into low molecular weight fermentation products of volatile fatty acids (VFAs). Phosphorus removal bacteria can decompose the stored polyphosphate in their bacterial cells, releasing energy that can be used for aerobic phosphorus removal bacteria to survive in anaerobic environments. Another part of the energy can also be used for phosphorus removal bacteria to actively absorb VFA low molecular weight organic matter in the environment and store it in the form of poly ß butyric acid (PHB) in the bacterial body.

3. Hypoxia tank: Sewage enters the anoxic zone from the anaerobic tank, and denitrifying bacteria use the nitrate brought by the mixed liquid reflux in the aerobic zone, as well as the biodegradable organic matter in the sewage, to achieve simultaneous decarbonization and denitrification.

4. Aerobic tank: After the wastewater enters the aerobic zone of aeration, the phosphorus removal cells can not only absorb and utilize the remaining biodegradable organic matter in the wastewater, but also mainly decompose the PHB stored in the body, producing energy for their own growth and reproduction. In addition, it can actively absorb dissolved phosphorus from the surrounding environment and store it in the body in the form of polyphosphate. At this point, the dissolved phosphorus concentration in the discharged water is already quite low, which is conducive to the growth and reproduction of autotrophic nitrifying bacteria, and converts ammonia nitrogen into nitrate through nitrification. Although non phosphorus removing aerobic heterotrophic bacteria also exist, they are severely suppressed in the anaerobic zone and do not receive sufficient nutrition in the aerobic zone, making them relatively weak in competition with other physiological groups of microorganisms. In the remaining sludge discharged, due to the presence of a large number of phosphorus accumulating bacteria that can over store phosphorus, the phosphorus content in the sludge can reach more than 6% (dry weight), greatly improving the phosphorus removal efficiency.

5. In order to improve the water quality of the treated water, the effluent after biological treatment is sequentially passed through a fast filter and an adsorption column. The main function of a fast filter is to remove fine suspended solids. The commonly used filter material is quartz sand. After a period of operation, if the filter material is trapped and impurities accumulate or the effluent quality deteriorates, the filter needs to be backwashed. The backwashing water is also pumped from the clean water tank under the workbench, and the flushing wastewater is discharged.

6. The adsorption column is filled with granular activated carbon, whose main function is to adsorb difficult to biodegrade organic matter and remove color developing substances.

7. Further, UV sterilization is used to remove pathogens and microorganisms from the water and improve water quality.

4、 Technical parameters

Processing water volume: 10-20L/h, equipment dimensions: 9600mm × 450mm × 1200mm, power supply 220V.

5、 Product specifications and configuration

Consisting of grille, primary sedimentation tank, regulating tank, intermediate tank, regulating tank (calcium hydroxide, aluminum sulfate), flocculation settling, container pressurized air flotation, hydrolysis acidification, contact oxidation, oxidation ditch, secondary sedimentation tank, activated carbon, ion exchange, clean water tank, water pump, fan, air-water flowmeter, various fillers, 1 electric control box, leakage protection switch, button switch, connecting pipeline and ball valve, stainless steel bracket with movable wheels, etc.