Common professional names of water treatment (88-118)

Common names of wastewater treatment

(88) Domestic sewage. It refers to the discharge water generated by kitchen water, washing water and toilet water used in human life. Most of them are non-toxic inorganic salts. Domestic sewage contains a lot of nitrogen, phosphorus, sulfur and pathogenic bacteria..

(89) Municipal sewage. It is a general term for sewage discharged into urban sewage system. In combined sewer system, it also includes industrial wastewater and intercepted rainwater. Municipal sewage mainly includes domestic sewage and industrial sewage, which is collected by the urban drainage network and transported to sewage treatment plants for treatment.

(90) Industrial wastewater. It refers to wastewater, sewage and waste liquid generated in the industrial production process, which contains industrial production materials, intermediates and products lost with the water, as well as pollutants generated in the production process.

(91) COD (Chemical oxygen demand). It refers to the amount of oxidant consumed in the chemical oxidation process of oxidizable substances in water under specified conditions, expressed in milligrams of oxygen consumed per liter of water sample, usually recorded as COD, and the common unit is mg/L.

(92) BOD (Biochemical oxygen demand). It refers to the amount of dissolved oxygen consumed in the process of microorganisms decomposing organic matter in surface water, usually recorded as BOD, and the common unit is mg/L.

(93) BC ratio. It indicates the biodegradability of pollutants in water, 0.1-0.25 is difficult to biodegrade, 0.25-0.5 is biodegradable, and >0.5 is easy to biodegrade.

(94) TOC. It refers to the total amount of carbon contained in dissolved and suspended organic matter in water, reflecting the content of oxidized organic compounds in water, and the unit is ppm or ppb.

(95) Ammonia nitrogen. It refers to nitrogen in water in the form of free ammonia (NH3) and ammonium ions (NH4+).

(96) Organic nitrogen. It is a general term for nitrogen-containing substances combined with carbon, such as proteins, amino acids, amides, urea, etc.

(97) Kjeldahl nitrogen (TKN). It refers to the nitrogen content measured by the Kjeldahl method. It includes ammonia nitrogen and organic nitrogen compounds that can be converted into ammonium salts under these conditions and measured.

(98) Nitrate nitrogen (NOx-). It refers to the nitrogen element contained in nitrates. The sum of nitric acid and nitrite.

(99) Total nitrogen (TN). It is the total amount of various forms of inorganic and organic nitrogen in water.

(100) Total phosphorus (TP). It is the result of converting various forms of phosphorus into orthophosphate after digestion of the water sample, and is measured in milligrams of phosphorus per liter of water sample.

(101) Hypophosphorus acid. It is a phosphate in the form of H2PO2ˉ, which cannot be removed by normal chemical phosphorus removal and needs to be converted into sulfate ions to be removed.

(102) Chroma. It refers to the degree of yellow or yellowish-brown color presented by soluble substances or colloidal substances contained in water.

(103) Grille. It is used to remove floating objects in water.

(104) Primary sedimentation tank. It is also known as a sedimentation tank, is used to remove sinkable and floating objects in sewage.

(105) Regulating tank. It is used to regulate the flow of water in and out. It mainly regulates the water quantity and quality, as well as the pH value and water temperature of sewage. It has a pre-aeration regulating effect and can also be used for emergency drainage.

(106) Accident tank, also called accident water collection tank. When treating high-concentration wastewater discharged by chemical, petrochemical and other factories, an accident tank is generally set up.

(107) Oil separation tank. The specific gravity of suspended solids and water in the sewage is different, then part of the oil can be separated by the oil separation tank.

(108) Air flotation. A large number of tiny bubbles are generated in the water, so that the air is attached to the suspended particles in the form of highly dispersed tiny bubbles, resulting in a state where the density is less than that of water. The buoyancy principle is used to make it float on the water surface, thereby achieving solid-liquid separation.

(109) Biochemical tank. It refers to the tank where bacteria metabolize during biochemical treatment.

(110) Secondary sedimentation tank. It is an important part of the activated sludge system. Its main function is to separate the sludge, clarify the mixed liquor, concentrate and return the activated sludge.

(111) Horizontal flow sedimentation tank. The tank body is rectangular in plan, with the inlet and outlet located at both ends of the tank.

(112) Vertical flow sedimentation tank. It is a sedimentation tank in which wastewater flows vertically. The plane shape of the tank is circular or square, and water enters the tank from top to bottom through the water inlet pipe located in the center of the tank. The sludge settles due to gravity.

(113) Radial flow sedimentation tank. Sewage enters the tank from the central water inlet pipe and flows slowly around the tank in the radial direction. Suspended matters will settle during the flow and enter the sludge hopper at the tank bottom, and clarified water overflows from the tank periphery to the water channel.

(114) Sludge tank. Generally, it is used to hold return sludge and excess sludge.

(115) Monitoring tank; also known as clear water tank. It is used to hold treated sewage.

(116) Condensation. It refers to the process by which a colloid loses its stability. Commonly known as colloid destabilization.

(117) Flocculation. It refers to the process by which destabilized colloids aggregate into large flocs.

(118) Coagulation. It refers to the whole process of two stages of forming large floccules through destabilization and flocculation. It is a general term for condensation and flocculation.