Los fabricantes de plantas de tratamiento de aguas residuales hablan sobre el proceso de tratamiento biológico anaeróbico

Los fabricantes de plantas de tratamiento de aguas residuales hablan sobre el proceso de tratamiento biológico anaeróbico

Who cut the time into fireworks, in an instant, see all the prosperity. Who turned the thoughts on the waves, turned around, and wandered the world. There are many complex organic materials in the wastewater to be treated by the sewage treatment plant. The integrated sewage treatment plant degrades it in four stages through anaerobic decomposition. Next, let's take a look at the explanation of the editor.

Hydrolysis stage: Due to its large molecular size, macromolecular organic matter cannot directly pass through the cell wall of anaerobic bacteria, and needs to be decomposed into small molecules by extracellular enzymes outside the microorganism. Typical organic substances in wastewater such as cellulose are decomposed into cellobiose and glucose by cellulase, starch is decomposed into maltose and glucose, and proteins are decomposed into short peptides and amino acids. These decomposed small molecules can enter the body of the cell through the cell wall for further decomposition. Acidification stage: Small molecular organic matter enters the cell body and is converted into simpler compounds and distributed outside the cell. The main products of this stage are volatile fatty acids (VFA), as well as some alcohols, lactic acid, carbon dioxide, etc. Hydrogen, ammonia, hydrogen sulfide and other products are produced. Acetogenic stage: In this stage, the products of the previous step are further converted into acetic acid, carbonic acid, hydrogen and new cellular material. Methanogenic stage: In this stage, acetic acid, hydrogen, carbonic acid, formic acid and methanol are all converted into methane, carbon dioxide and new cellular material. This stage is also the important stage of the whole anaerobic process and the rate-limiting stage of the whole anaerobic reaction process. Among the above four stages, some people think that the second stage and the third stage can be divided into one stage, and the reactions in these two stages are completed in the same type of bacteria. The reaction rate of the first three stages is very fast. If the Mono equation is used to simulate the reaction rate of the first three stages, Ks (half rate constant) can be below 50mg/l, and μ can reach 5KgCOD/KgMLSS.d. The fourth reaction stage is usually very slow, and it is also an important reaction process for sewage treatment plants to treat sewage. In the previous stages, the pollutants in the wastewater only changed in form, and COD was almost not removed. Only in the fourth stage In this stage, the pollutants turn into gases such as methane, which greatly reduces the COD in the wastewater. At the same time, a large amount of alkalinity is produced in the fourth stage, which is in balance with the organic acid produced in the first three stages, maintaining the pH stability in the wastewater and ensuring the continuous progress of the reaction.