Which treatment process can be applied to rural domestic sewage treatment to meet the standard of Class A A.
There may be several reasons for the black color of the effluent from the sewage treatment plant:
1.The raw water quality is unstable and dark.
2.The sludge return flow is unstable, resulting in insufficient sludge activity.
3.Insufficient dissolved oxygen causes the death of microorganisms and presents a black substance.
4.The sludge precipitation is incomplete, resulting in some residual substances with a black color, such as copper and iron plasma.
5.Chemical hypoxia, which affects the balance of redox reactions.
6.The oxygen content is too low, which affects the oxygen supply required in the sewage treatment process.
7.The lack of activated sludge accumulates suspended solids, organic matter, and humus in sewage.
8.The quality of the wastewater treatment is too low, and the sewage treatment equipment and processes do not meet the sewage treatment standards.
To solve this problem, it is necessary to take corresponding measures for different factors, such as strengthening pretreatment, increasing sludge activity, increasing aeration equipment, accelerating the sedimentation process, etc. At the same time, preventive measures are also very important, such as adding depth filters, installing automatic pH regulators, increasing dissolved oxygen content, and cleaning sedimentation tanks regularly, which can effectively reduce the probability of water turning black.
The solution to the black color of the effluent of the sewage treatment equipment is as follows:
1.Increase aeration capacity: If the dissolved oxygen is too low, the integrated sewage treatment plant will produce black sludge. The amount of oxygen available at pressure can be increased by increasing the amount of aeration and to 4 to 5 mg l if the mass concentration of dissolved oxygen exceeds 2 mg l. As the oxygen content increases, the sludge will gradually return to normal within a few hours.
2.Improvement of influent water quality: Black sludge appears in the integrated sewage treatment plant caused by influent water quality. For example, when the influent contains a large amount of iron ions, the dissolved oxygen in the aeration tank is insufficient, and hydrogen sulfide is released due to the anaerobic decomposition of organic matter, and the interaction between hydrogen sulfide and iron ions produces dark brown ferrous sulfide that blackens the sludge in the aeration tank of the entire integrated sewage treatment plant. The solution is to test the water quality to determine the cause of the sludge blackening and then apply the right chemicals. At the same time, by increasing the aeration volume and reflux ratio, the blackening of the sludge in the aeration tank can be improved.
3.Check the quality of the influent water: If the influent water contains substances that are toxic to microorganisms and kill microorganisms, the sludge in the aeration tank of the integrated sewage treatment equipment will also turn black. The solution is to first check the influent quality. If the influent water contains substances that are harmful to microorganisms, they need to be controlled at the beginning.