What is the biofilm method?
What are its advantages over activated sludge process?
A: The biofilm method is a biological treatment technology that uses microorganisms such as bacteria and fungi, protists, and micro-animals such as metazoa to grow and breed on the filter material or some carriers to form membrane-like biological sludge (biofilm) to treat sewage.
Advantages: Because there are more types of microorganisms on the biofilm, the formed ecosystem is more stable than the activated sludge system. The food chain on the biofilm is longer than that of the activated sludge, and the amount of sludge is less than that of the activated sludge system, which reduces the cost of sludge follow-up treatment. Due to the long age of the sludge, microorganisms such as nitrifying bacteria and nitrosifying bacteria can survive on the biofilm for a long time, so that they have a certain digestive function. He has a strong adaptability to water quality and water quantity changes, even if the water intake is interrupted for a period of time, it will not have a fatal impact on the biofilm, and it is easy to recover after water passage, while activated sludge takes a longer time to recover. Due to the high inorganic composition of the biofilm and the larger proportion, its sludge sedimentation is good. Easy solid-liquid separation. The biofilm method can treat low-concentration wastewater, while the activated sludge is not suitable for treating low-concentration wastewater. If the BOD is lower than 50-60mg/L for a long time, the formation of sludge floc will be affected. Compared with activated sludge process, biofilm is easy to maintain, energy saving and low power cost. When properly run, biofilm can also achieve simultaneous nitrification and denitrification.
Characteristics and advantages and disadvantages of stable pond
Features: (1) Generally not artificial enhancement (2) similar to the self-purification process of water body (3) long residence time (4) Through the comprehensive action of microorganisms + aquatic organisms, organic matter degradation, and then purification of sewage (5) purification process includes - aerobic, facultative, anaerobic, anaerobic, anaerobic, anaerobic, anaerobic, anaerobic, anaerobic, and anaerobic. The anaerobic three states (6) DO comes from photosynthesis (7) applicable to various sewage (8) applicable to various climatic conditions (9) can achieve the whole process from level 1 to level 2 to deep treatment technology, generally equivalent to level 2
Advantages: (1) less investment, simple engineering (2) sewage resources, agricultural irrigation (3) low energy consumption
Disadvantages: (1) large footprint (2) purification effect controlled by natural factors (3) Impact on groundwater (4) poor sanitation.
