Wastewater Treatment Process Design

The construction and operation of sewage treatment projects are costly and constrained and influenced by various factors. Among them, the optimization and selection of sewage treatment process proposal have a particularly critical impact on the investment and operation management of sewage treatment. Therefore, it is necessary to start from the perspective of overall optimization, comprehensively consider the properties of sewage and the requirements for treated effluent, and propose the best sewage treatment process plan. 

Principles of wastewater treatment process selection:

(1) The process technology is required to be advanced and mature, with high safety, strong oxygenation capacity, high dissolved oxygen concentration, strong oxidation ability, high oxygen utilization rate, and reliable operation, meeting the requirements for treating effluent.

(2) Convenient operation and management, flexible operation, and corresponding impact resistance and adaptability to changes in inflow and water quality.

(3) Economically reasonable, saving infrastructure investment and operational management costs while meeting processing requirements.

(4) The process supporting equipment has advanced technology, reliable quality, small footprint, low investment, and good treatment effect.

(5) The automation control of the process is reasonable and reliable, reducing labor intensity.

(6) The selection of sludge treatment process and equipment should consider operational flexibility to improve the operability of the sludge treatment process.

 Process Description

The sewage enters the sewage plant, intercepts suspended solids through the grid, and then flows into the sedimentation tank by gravity; Due to the different water quality and quantity from different periods, the peak flow rate of domestic sewage is generally 3-6 times the average treatment capacity. To ensure continuous operation of the system, a regulating tank is used to regulate the water quantity and homogenize the water quality, while also removing and reducing some pollutant loads.

After being collected by the drainage system, the sewage enters the grid well of the sewage treatment plant. After removing particles and debris, it enters the regulating tank for homogenization and equalization. A liquid level controller is installed in the regulating tank, and then the signal is transmitted by the liquid level controller. It is pumped by the lifting pump to the A-level biological contact oxidation tank for acidification, hydrolysis, nitrification and denitrification, reducing the concentration of organic matter, removing some ammonia nitrogen, and then flows into the O-level biological contact oxidation tank for aerobic biochemical reaction, The vast majority of organic pollutants in the O-level biological tank are degraded through biological oxidation and adsorption, and the effluent flows to the secondary sedimentation tank for solid-liquid separation.