1. What is (physical) wastewater treatment method?
Physical treatment method is a treatment method that separates and recovers insoluble and suspended pollutants in wastewater through physical actions.
2. What is (chemical) wastewater treatment method?
Chemical treatment is a treatment method that involves adding chemical agents to wastewater, using chemical reactions to separate and recover pollutants from the wastewater, or converting them into harmless substances.
3. What is (biological) wastewater treatment method?
Biological treatment is a treatment method that uses microorganisms to adsorb, decompose, and oxidize organic matter in wastewater, degrading unstable organic matter into stable and harmless substances, thereby purifying wastewater.
4. What are the common biological treatment processes?
Activated sludge process, biofilm process, biological contact oxidation process, MBR process, SBR process, etc. are commonly used process systems for wastewater treatment.
5. What is the function of the grille in Wastewater treatment?
The main function of the grille is to intercept larger suspended solids or floating impurities, in order to reduce the processing load of subsequent water treatment processes.
6. What is the role of air flotation in Wastewater treatment?
A large number of fine bubbles are generated in water, causing air to adhere to suspended particles in the form of highly dispersed small bubbles, resulting in a state of lower density than water. The principle of buoyancy is used to make it float on the water surface, thereby achieving solid-liquid separation. 7. What is the function of coagulation sedimentation tank in Wastewater treatment?
By adding some chemicals (usually referred to as coagulants and coagulants) to the water, particles that are difficult to precipitate in the water can aggregate with each other to form flocs. Then, the flocs adsorb and increase in volume, causing some pollutants in the Wastewater to coagulate and precipitate, and the supernatant flows into the lower treatment tank.
7. What is pH value?
PH represents the acidity or alkalinity of wastewater. It is the logarithmic value of the reciprocal of hydrogen ion concentration in water, ranging from 0 to 14. If the pH value is 7, water is neutral, and if it is less than 7, it is acidic. The smaller the value, the stronger the acidity, and if it is greater than 7, it is alkaline. The larger the value, the stronger the alkalinity. The pH value of Wastewater treatment plants that mainly treat domestic Wastewater is usually between 7.2 and 7.8.
8. What is dissolved oxygen?
The oxygen dissolved in water is called dissolved oxygen. The organisms and aerobic microorganisms in water rely on dissolved oxygen for their survival. Different microorganisms have different requirements for dissolved oxygen.
9. Does water temperature affect the operation of Wastewater treatment?
have The water temperature has a significant impact on the operation of the aeration tank. The water temperature of a Wastewater treatment plant gradually changes slowly with the seasons, and there is almost no change within a day. If significant changes are found within a day, a check should be conducted. The common temperature range is 8-30 ℃, and the treatment efficiency of the aeration tank decreases when the water temperature is below 8 ℃.
10. What are the main factors affecting the coagulation effect?
The main factors affecting the coagulation effect are water temperature, pH and alkalinity of water, suspended solids concentration in water, and hydraulic conditions.
11. What is the relationship between COD and BOD?
Some organic compounds can be biodegraded by biological oxidation (such as glucose and ethanol), some organic compounds can only be partially biodegraded by biological oxidation (such as methanol), and some organic compounds cannot be biodegraded by biological oxidation and are also toxic (such as ginkgolides, ginkgolic acids, and certain surfactants). Therefore, we can divide the organic matter in water into two parts, namely biodegradable organic matter and non biodegradable organic matter. It is generally believed that COD can basically represent all organic matter in water. And BOD is the organic matter that can be biodegraded in water, so the difference between COD and BOD can represent the non biodegradable organic matter in wastewater.
