Rural sewage treatment projects and township sewage treatment projects now use more decentralized sewage treatment equipment.For remote areas,the government pipe network cannot reach them,so there is a great need for treatment methods adapted to local conditions.What are the basic common sense that must be known about sewage treatment?Let's find out together.

1.What is self-purification of water bodies?

Self-purification of water bodies:Polluted rivers undergo physical,chemical,biological and other effects to reduce or transform the concentration of pollutants,and the water body is restored to its original state,or from the initial exceeding the water quality standard to equal to the water quality standard.

2.What are the basic methods of sewage treatment?

The basic method of sewage treatment:it is to use various means and technologies to separate and remove pollutants from sewage,recycle them,or convert them into harmless substances to purify the sewage.It is generally divided into water treatment and sewage treatment.

3.What are the current sewage treatment technologies?

Modern sewage treatment technology can be divided into physical treatment method,chemical treatment method,and biological treatment method according to the principle of action.

4.Five water measurement indicators

Biochemical oxygen demand(BOD):Refers to the amount of oxygen required to degrade organic matter due to the action of microorganisms under aerobic conditions.It is a comprehensive index indicating that sewage is polluted by organic matter.

Theoretical oxygen demand(thOD):The theoretical oxygen demand of a certain organic matter in water.It usually refers to the theoretical value of the oxygen required to completely oxidize the carbon and hydrogen in organic matter to carbon dioxide and water(that is,the oxygen demand calculated according to the complete oxidation reaction formula.

Total oxygen demand(TOD):Refers to the substances in water that can be oxidized,mainly the amount of oxygen required when organic substances become stable oxides in combustion.The result is expressed in mg/L of O2.

Chemical oxygen demand(COD):It is a chemical method to measure the amount of reducing substances that need to be oxidized in a water sample.The oxygen equivalent of substances(generally organic matter)that can be oxidized by strong oxidants in wastewater,effluent from wastewater treatment plants,and contaminated water.

Total organic carbon(TOC):Refers to the total amount of carbon contained in soluble and suspended organic matter in a water body.

5.Under what circumstances is biochemical treatment used?

It is generally believed that sewage with a BOD/COD value greater than 0.3 is suitable for biochemical treatment.

6.What are the hygiene standards for drinking water?

Physical indicators of sanitary standards for drinking water:color,turbidity,odor and taste.

7.What is eutrophication of water bodies?

Eutrophication of water bodies is a natural phenomenon that occurs in fresh water and is caused by the excessive content of nitrogen,phosphorus,and potassium in water bodies,which leads to the sudden hyperproliferation of algae.

The main reason for the formation of eutrophication of water bodies is that nitrogen,phosphorus,potassium and other elements are discharged into surface waters with slow flow rates and long renewal cycles,causing algae and other aquatic organisms to grow and reproduce in large quantities,so that the rate of organic matter production far exceeds the rate of consumption,and the accumulation of organic matter in water bodies destroys the process of aquatic ecological balance.

8.What is dissolved oxygen?

Oxygen dissolved in water bodies is called dissolved oxygen.Organisms and aerobic microorganisms in water bodies,the oxygen on which they depend for survival is dissolved oxygen.Different microorganisms have different requirements for dissolved oxygen.

9.What are the basic methods of modern sewage treatment?

Modern sewage treatment technology can be divided into physical treatment method,chemical treatment method,and biological treatment method according to the principle of action.