Whitening of sludge is a common problem in the sewage treatment process, which has a negative impact on the effectiveness of sewage treatment and the operation of sludge treatment equipment. The reasons for its occurrence include lack of nutrition, excessive proliferation of filamentous bacteria or fixed ciliates, and poor growth of bacterial colonies; High or low pH values can cause a large growth of filamentous bacteria, resulting in loose sludge and larger volume. One important reason for the whitening of sludge is the lack of nutrients. In the process of sewage treatment, microorganisms require sufficient nutrients to maintain their life activities. If there is insufficient nutrition in the water, it will lead to poor growth of microorganisms, resulting in the sludge turning white in color. Specifically manifested in the following two aspects:
1. Insufficient carbon source: Carbon source is an important nutrient for microbial growth. If there is insufficient carbon source in the influent, microorganisms cannot grow normally, resulting in sludge turning white.
2. Insufficient nutrients such as nitrogen and phosphorus: Nutrients such as nitrogen and phosphorus also play an important role in the growth of microorganisms. If the nitrogen, phosphorus and other elements in the influent are insufficient, it will affect the growth and reproduction of microorganisms, thereby causing the sludge to turn white. Filamentous bacteria or fixed ciliates proliferate in large numbers. Under suitable growth conditions, filamentous bacteria or fixed ciliates will multiply in large numbers, causing the sludge structure to become loose and the color to turn white.
1. Large scale reproduction of filamentous bacteria: filamentous bacteria have long hyphae that are easy to entangle into clumps, making the sludge structure loose. When filamentous bacteria multiply in large numbers, the color of the sludge will gradually turn white.
2. Large scale reproduction of fixed ciliates: Fixed ciliates form biofilms on the surface of sludge, causing the sludge to lose its original structure and turn white in color. Poor growth of bacterial colonies. Microbial flocs are an important component of sludge, with the ability to adsorb and degrade pollutants. If the growth of microbial flocs is poor, it will cause the sludge to turn white in color. The reasons are as follows:
1. Reduction in the number of microbial flocs: The reduction in the number of microbial flocs causes the sludge to lose its ability to adsorb and degrade pollutants, resulting in a white color. 2. Loose structure of microbial flocs: The loose structure of microbial flocs reduces their ability to adsorb and degrade pollutants, resulting in the sludge turning white in color. High or low pH value. The pH value has a significant impact on the growth of sludge. When the pH value is high or low, it can cause a large growth of filamentous bacteria, resulting in loose sludge, larger volume, and white color.
The specific reasons are as follows: 1. High pH value: When the pH value exceeds 9, filamentous bacteria multiply in large numbers, the sludge structure becomes loose, and the color turns white. 2. Low pH value: When the pH value is below 5, microbial growth is inhibited, the number of microbial flocs decreases, and the sludge color turns white. The solution is to adjust the inflow load and ammonia nitrogen drip rate according to the nutrient ratio, and maintain the color of the sludge for several days to restore it; Adjust the pH value of the inlet water and maintain the pH value of the aeration tank between 6-8. Only by maintaining the pH value range for a long time can sludge expansion be effectively prevented. Adjust the influent load and nutrient ratio to address the cause of sludge whitening, ensuring that microorganisms receive sufficient nutrition.
1. Increase carbon source: Increase the carbon source content in the influent, such as adding glucose, methanol, etc., to meet the needs of microbial growth.
2. Adjust the nitrogen and phosphorus ratio: Based on the actual water quality, adjust the nitrogen and phosphorus ratio in the influent to ensure the necessary nutrients for microbial growth. Adjustment of ammonia nitrogen drip dosage. Appropriately increasing the amount of ammonia nitrogen added can help improve the color of sludge.
1. Monitor the influent ammonia nitrogen concentration: Adjust the ammonia nitrogen drip dosage based on the influent ammonia nitrogen concentration.
2. Maintain the color of the sludge for several days: After adjusting the amount of ammonia nitrogen added, observe the color change of the sludge. Maintaining the color of the sludge for several days can restore normal. Adjusting the pH value of the influent and maintaining the pH value of the aeration tank between 6-8 is beneficial for microbial growth and prevents sludge expansion.
1. Monitor the pH value of the incoming water: Regularly check the pH value of the incoming water and adjust it promptly if any abnormalities are found.
2. Adjust the pH value of the aeration tank: By adding acidic and alkaline substances, adjust the pH value of the aeration tank to maintain it between 6-8. Whitening of sludge is a common problem in the sewage treatment process. By analyzing the causes and adopting corresponding solutions, the color of sludge can be effectively improved. In practical operation, attention should be paid to adjusting the inlet load, nutrient ratio, ammonia nitrogen drip rate, and pH value to ensure the normal operation of the sewage treatment system.
