As we all know, stench refers to unpleasant odors, and the odorous substances mostly come from industries such as petroleum refining, pharmaceuticals, papermaking, leather making, fertilizers, food, foundry, automobile manufacturing, and textiles. The stench has different degrees of damage to the human respiratory system, circulatory system, digestive system, endocrine system and nervous system. At the same time, VOCs and inorganic odors emitted from sewage pools are one of the VOCs emission sources currently controlled by environmental protection, and need to be collected and treated.
The VOCs escape from the open liquid surface of the sewage tank is one of the twelve major emission sources of VOCs in chemical enterprises. Generally speaking, the VOCs management of chemical enterprises starts from LDAR (dynamic and static sealing point VOCs emission control), the sewage tank is covered with deodorization and VOCs removal and The four parts of VOCs emission sources, such as tank farms and loading vehicles, have begun to be treated.
The total odor air volume collected by the odor treatment facility shall be calculated according to the following formula:
Q=Q1+Q2+Q3
Q3=K(Q1+Q2）
In the formula: Q—the total odor air volume collected by the odor treatment facility (m3/h);
Q1—the amount of odor collected by the structure (m3/h);
Q2—the amount of odor collected by the equipment (m3/h);
Q3 - the infiltration air volume of the collection system (m3/h);
K—infiltration air volume coefficient, which can be taken as 5%-10%.
The odor air volume of sewage and sludge treatment structures should be determined according to factors such as the type of structure, the area of the water surface that emits odor, and the volume of the odor space. The odor air volume of the equipment should be determined according to factors such as the type of equipment, the degree of enclosure, and the volume of the enclosed space. The calculation of the odor air volume of structures and equipment shall meet the following requirements:
①The odor air volume entering the water pump suction well or grit chamber can be calculated according to the odor air volume index per unit water surface area of 10m3/(m2·h), and the space ventilation volume can be increased by 1/h-2 times/h;
②The odor air volume of structures such as primary sedimentation tank or concentration tank can be calculated according to the odor air volume index per unit water surface area of 3m3/(m2·h), and the space ventilation volume of 1 time/h-2 times/h can be added;
③ The odor air volume of aeration treatment structures can be calculated as 110% of the aeration volume;
④The odor air volume of the semi-sealing equipment can be calculated according to the smaller of the two calculation results of the ventilation times in the cover of 8 times/h and the extraction flow rate of 0.6m/s at the opening of the cover;
It should be noted that when it is difficult to separate the odor treatment system from the ventilation system, people need to enter for a short time and the number of ventilation is difficult to meet, natural ventilation or temporary forced ventilation should be adopted when people enter.
