Why is the sewage station so smelly? I believe this issue is a concern for many sewage station managers and operators. During the treatment process of sewage and the sewage itself, some unpleasant gases are released, which we collectively refer to as odor. In addition to inorganic gases such as hydrogen sulfide and ammonia, there are also a large amount of VOCs gases. Most of the unpleasant gases that are inhaled into our bodies can cause harm. The hazards of odorous gases mainly manifest in their impact on the respiratory system, circulatory system, nervous system, digestive system, endocrine system, and mental state. The common inorganic odors in sewage treatment plants are hydrogen sulfide and ammonia. There are three main sources of odors in sewage treatment plants.

1. Odor of sewage: Sewage itself has an unpleasant odor, which is caused by the substances carried in the sewage. The typical odor is the rotten egg odor produced by the reduction of sulfate to hydrogen sulfide by anaerobic bacteria.

2. Odor generated by sewage treatment units: In the sewage treatment process, the grid residue filtered out, the bottom sand deposited in the sedimentation tank, the floating oil collected in the oil separation tank, and the sludge deposited in the primary sedimentation tank all produce unpleasant odors.

3. Odor generated by the sludge treatment unit: The sludge treatment and disposal system usually produces a strong odor, especially in uncovered sludge storage tanks and sludge concentration tanks. Different types, characteristics, dewatering methods, and chemical substances added during pretreatment of sludge can also lead to varying degrees of odor.