Consultation hotline:

(+86)0532-88988868

Knowledge points of sewage treatment technology (commonly used)!

Today, we offer you the professional name of water treatment, which involves water treatment fields such as chemical water treatment, circulating water treatment, sewage treatment, etc., including activated sludge method, reverse osmosis, MBR membrane method and other related names, which are full of dry goods.

1、 Chemical water treatment

1. Surface water; It refers to water that exists on the surface of the Earth's crust and is exposed to the atmosphere. It is a collective term for four types of water bodies: rivers, glaciers, lakes, and swamps, also known as "terrestrial water".

2. Groundwater; It is the water stored in the geological voids below the Earth's surface and above the water table, including rock pores, fractures, and karst caves. Groundwater exists in crustal rock fractures or soil voids.

3. Raw water; It refers to water collected from natural sources, including but not limited to groundwater, reservoir water, and other water sources that can be seen in nature, without any artificial purification treatment.

4. PH; A numerical value representing the acidity and alkalinity of a solution, where pH=- lg [H+] is the negative logarithm of the commonly used hydrogen ion concentration.

5. Total alkalinity; The total amount of substances in water that can neutralize strong acids. This type of substance includes strong bases, weak bases, strong bases, weak acid salts, etc.

6. Phenolphthalein alkalinity; The alkalinity measured using phenolphthalein as an indicator (titration endpoint pH=8.2 to 8.4).

7. Methyl orange alkalinity; It is the alkalinity measured using methyl orange as an indicator (titration endpoint pH=3.1-4.4).

8. Total acidity; Acidity refers to the total amount of substances in water that can neutralize strong alkalis, including inorganic acids, organic acids, strong acids, weak alkaline salts, etc.

9. Total hardness; In general natural water, it is mainly composed of Ca2+and Mg2+, with little other ion content. The total content of Ca2+and Mg2+in water is usually referred to as the total hardness of water.

10. Temporary hardness; The hardness formed by the presence of Ca (HCO3) 2 and Mg (HCO3) 2 in water can be removed after boiling. This hardness is called carbonate hardness, also known as temporary hardness.

11. Permanent hardness; The hardness formed by the presence of salts such as CaSO4 (CaCl2) and MgSO4 (MgCl2) in water, which cannot be removed after boiling, is called non carbonate hardness, also known as permanent hardness.

12. Dissolved substances; It exists in the form of simple molecules or ions in water (or other solvent) solutions, with particle sizes usually only a few tenths to a few nanometers. It is not visible to the naked eye and there is no Tyndall phenomenon. It cannot be seen with an optical microscope

13. Colloid; A cluster of particles composed of several molecules or ions, typically ranging in size from tens of nanometers to tens of micrometers, that is not visible to the naked eye, but can undergo the Tindall phenomenon. Small colloidal particles cannot be seen under an optical microscope, while larger ones can be seen.

14. Suspended solids; It is a small particle visible to the naked eye formed by the combination of a large number of molecules or ions, usually several tens of micrometers in size. It can be clearly seen with an optical microscope. Suspended particles can precipitate when left standing for a long time.

15. Total salt content; The total amount of ions in water is called the total salt content. The sum of all cations and anions obtained from the comprehensive analysis of water quality is obtained, expressed in mg/L (formerly also PPM).

16. Turbidity; Also known as turbidity. From a technical perspective, turbidity is a water quality alternative parameter used to reflect the content of suspended solids in water. The main suspended substance in water is usually soil. The unit of standard turbidity is 1PPm, expressed as 1L of distilled water containing 1mg of silica.

17. Total dissolved solids; TDS, also known as total dissolved solids, is measured in milligrams per liter (mg/L), indicating how many milligrams of dissolved solids are present in 1 liter of water.

18. Resistance; According to Ohm's law, under a constant water temperature, the resistance value R of water is inversely proportional to the vertical cross-sectional area F of the electrode and directly proportional to the distance L between the electrodes.

19. Conductivity; The degree to which water has a strong or weak electrical conductivity is called conductivity S.

20. Conductivity; The conductivity of water, which is the reciprocal of its resistance, is usually used to represent the purity of water.

21. Resistivity; The electrical resistivity of water refers to the resistance between the opposite sides of a 1cm cube of water at a certain temperature, measured in ohms * centimeters (Ω * CM). It is generally a parameter representing the quality of high-purity water.

22. Softened water; It refers to the removal or reduction of water hardness (mainly referring to calcium and magnesium ions) to a certain extent. During the softening process of water, only the hardness decreases, while the total salt content remains unchanged.

23. Demineralized water; It refers to the water to which salts (mainly strong electrolytes soluble in water) are removed or reduced to a certain extent. Its conductivity is generally 1.0-10.0 μ S/cm, resistivity (25 ℃) 0.1-100000 Ω. cm, salt content 1.5mg/L.

24. Pure water; It refers to the strong and weak electrolytes in water (such as SiO2, C02, etc.). Remove or reduce water to a certain extent. Its conductivity is generally 1.0-0.1 μ S/cm, resistivity 1.0-100000 Ω. cm. The salt content is less than 1mg/l.

25. Ultra pure water; It refers to the almost complete removal of conductive media from water, while non dissociating gases, colloids, and organic substances (including bacteria) are also removed to a very low level of water. Its conductivity is generally between 0.1-0.055 μ S/cm, resistivity (25 ℃) > 10 × 1000000 Ω. cm, with a salt content of<0.1mg/l. The ideal pure water (theoretically) has a conductivity of 0.05 μ S/cm, resistivity (25 ℃) is 18.3 × one million μ S/cm.

26. Deaerated water; Also known as deoxygenated water, it removes dissolved oxygen from water and is generally used for boiler water.

27. Ion exchange; A method of separation that utilizes the difference in ion exchange ability between exchangeable groups in ion exchange agents and various ions in solution.

28. Cation resin; Having acidic groups. In aqueous solutions, acidic groups can ionize to form H+, which can undergo ion exchange with cations in water.

29. Anion resin; They contain alkaline groups that ionize in aqueous solutions and undergo ion exchange with anions.

30. Inert resin; No active groups, no ion exchange, and the relative density is generally controlled between the anion and cation resins to separate them and avoid cross contamination during regeneration, making regeneration more complete.

31. Microfiltration; MF, also known as microporous filtration, belongs to precision filtration. Microfiltration can filter out micro or nano sized particles and bacteria in the solution.

32. Ultrafiltration; UF is one of the membrane separation technologies driven by pressure. For the purpose of separating large and small molecules, the membrane pore size is between 20-1000A °.

33. Nanofiltration; NF is a pressure driven membrane separation process between reverse osmosis and ultrafiltration, with a nanofiltration membrane pore size range of several nanometers.

34. Penetration; Permeation is the phenomenon of water molecules diffusing through a semi permeable membrane. It infiltrates from high water molecule regions (i.e. low concentration solutions) into low water molecule regions (i.e. high concentration solutions).

35. Osmotic pressure; For semi permeable membranes with different concentrations of aqueous solutions on both sides, the minimum additional pressure applied on the high concentration side to prevent water from penetrating from the low concentration side to the high concentration side is called osmotic pressure.

36. Reverse osmosis; RO, reverse osmosis, is the process of manually pressurizing water from a concentrated solution to a low concentration solution. The pore size of the RO membrane is as small as nanometers, and under a certain pressure, water molecules can pass through the RO membrane, while impurities such as inorganic salts, heavy metal ions, organic matter, colloids, bacteria, viruses, etc. in the source water cannot pass through the RO membrane.

36. Dialysis; Also known as dialysis. A membrane separation operation driven by concentration difference, which utilizes the selective permeability of the membrane to solutes and achieves the separation of solutes with different properties.

37. Electrodialysis; ED, the phenomenon of charged solute particles (such as ions) in the solution migrating through the membrane during dialysis under the action of an electric field, is called electrodialysis.

38. EDI; Also known as continuous electric desalination technology, it is a pure water manufacturing technology that combines ion exchange technology, ion exchange membrane technology, and ion electromigration technology.

39. Recovery rate; The percentage of water supply in a membrane system that is converted into permeate or permeate.

40. Desalination rate; The percentage of total soluble impurity concentration removed from the system inlet through reverse osmosis membrane, or the percentage of specific components such as divalent ions or organic matter removed through nanofiltration membrane.

41. Salt penetration rate; The opposite value of desalination rate is the percentage of dissolved impurities in the influent that penetrate the membrane. Permeation liquid: Purified water produced through the membrane system.

42. Flux; The flow rate of liquid through a unit membrane area, usually expressed in liters per square meter per hour (l/m2h) or gallons per square foot per day (gfd).

43. Product water; The purified aqueous solution is the water produced by reverse osmosis or nanofiltration systems.

44. Concentrated water; The portion of the solution that passes through the membrane, such as concentrated water from reverse osmosis or nanofiltration systems.

2、 Circulating water treatment

45. Circulating water; A system that uses water to cool the process medium is called a cooling water system.

46. DC cooling water system; The cooling water only passes through the heat exchange equipment once, and after use, the water is discharged.

47. Open circulating water; Remove the heat emitted by the process medium or heat exchange equipment through water cooling, and then evaporate a portion of the hot water when it comes into direct contact with air, allowing most of the hot water to be cooled and reused.

48. Closed circulating water system; Also known as a closed cycle cooling water system. In this system, the cooling water is not immediately discharged after use, but is recycled and reused.

49. Cooling tower; It is a device that uses water as a circulating coolant to absorb heat from a system and discharge it into the atmosphere to lower the water temperature. There are two cooling methods: natural ventilation and mechanical ventilation.

50. Water distributor; The return water is evenly distributed on the filler through a water distributor.

51. Filler; The backwater passes through the filler to form a water film, increasing the contact area with the air.

52. Water collector; Recycle the liquid water carried in the partially evaporated water vapor.

53. Circulating water volume; Refers to the total circulating water volume of the cooling tower on the circulating water system. N50 retained water volume: The total volume of all water in the circulating water system, equal to the total volume of the pool and the volume of water in pipelines and cooling equipment.

54. Supplementary water volume; Used to supplement the water required in the circulating water system due to evaporation/discharge/splashing losses.

55. Side filter water volume; The amount of water that flows out of the circulating cooling water system and is treated as required before being returned to the system.

56. Evaporated water volume; The amount of water lost by evaporation during the operation of the circulating cooling water system.

57. Sewage discharge volume; The amount of water that needs to be discharged from the circulating cooling water system under the determined concentration factor conditions.

58. Water loss due to wind leakage; The amount of water lost due to wind blowing and leakage during the operation of the circulating cooling water system.

59. Supplementary water quantity; The circulating cooling water system replenishes the lost water during operation.

60. Concentration ratio; The ratio of the salt concentration of circulating cooling water to the salt concentration of supplementary water.

61. Heat exchange; The heat exchange between objects is called heat exchange. There are three basic forms of heat transfer in circulating water: heat exchange, convective heat transfer, radiation heat transfer, and evaporation heat transfer.

62. Heat conduction; The phenomenon of heat transfer between parts of an object in direct contact is called heat conduction.

63. Convective heat transfer; In a fluid, the heat transfer between fluids is mainly due to the motion of the fluid, which transfers a portion of the heat in the heat flow to the cold fluid. This heat transfer method is called convective heat transfer.

64. Radiation heat transfer; Part of the thermal energy of a high-temperature object is converted into radiant energy, which is emitted outward in the form of electromagnetic waves to the receiving object. The radiant energy is then converted into thermal energy and absorbed. This type of electromagnetic wave transfer of heat is called radiation heat transfer.

65. Evaporation heat exchange; A form of heat transfer in which the latent heat of vaporization is carried away when water molecules evaporate.

66. Temperature difference between inlet and outlet of cooling water; The temperature difference between the inlet of the cooling tower and the outlet of the water tank.

67. Wet bulb temperature; It refers to the air temperature at which water vapor in the air reaches saturation under the same enthalpy value air state.

68. Dry bulb temperature; It is the temperature measured by a thermometer in ordinary air, which is commonly referred to as the temperature in our general weather forecast.

69. Physical cleaning; Clean debris from the pipeline through the flow rate of water.

70. Chemical cleaning; By the action of chemicals, the surface of the metal heat exchanger is kept clean and activated, preparing for the pre film.

71. Pre film; Chemical conversion film is a type of surface protection layer for metal equipment and pipelines, especially for pipelines that have passed acid cleaning and passivation, which can be protected by pre coating methods.

72. Corrosion inhibitors; The process of inhibiting or delaying metal corrosion.

73. Scale inhibitor; The process of using chemical or physical methods to prevent the formation of deposits on the heating surface of heat exchange equipment.

74. Oxidative fungicides; A highly oxidizing biocide, usually a strong oxidant, has a strong killing effect on microorganisms in water.

75. Non oxidizing fungicides; It is not through oxidation that microorganisms are killed, but rather through toxic effects on specific parts of microorganisms, thus it is not affected by reducing substances in water.

76. Effective chlorine; It refers to the amount of chlorine in chlorinated compounds (especially when used as disinfectants) with equivalent oxidation capacity, which can quantitatively represent the disinfection effect.

77. Residual chlorine; Residual chlorine refers to the effective chlorine left in water after being disinfected with chlorine and exposed to it for a certain period of time.

78. Combined chlorine; Refers to the compounds of chlorine and ammonia in water, including NH2Cl, NHCl2, and NHCl3. NHCl2 is more stable and has good bactericidal effects, also known as binding residual chlorine

79. Free residual chlorine; Refers to ClO -, HClO, Cl2, etc. in water, which have fast sterilization speed and strong bactericidal power, but disappear quickly, also known as free residual chlorine.

80. Orthophosphate; The+5 valent phosphorus in phosphate.

81. Organic phosphorus; It is a compound containing carbon phosphorus bonds or a phosphate derivative containing organic groups.

82. Total iron; Iron in various states of existence, including all iron elements.

83. Total zinc; Zinc in various states of existence contains all zinc elements.

84. Reagent retention time; The effective time of the agent in the circulating cooling water system.

85. Scaling; Calcium and magnesium bicarbonate dissolved in water decompose under heat, precipitate white precipitates, and gradually accumulate and adhere to the container, called scaling.

86. Corrosion; Refers to the process of loss and destruction (including metal and non-metal) under the action of surrounding media (water, air, acid, alkali, salt, solvent, etc.).

87. Biological slime; A viscous substance produced by microorganisms and their mucus, mixed with other organic and inorganic impurities, that adheres to the surface of an object.

3、 Sewage treatment

88. Domestic sewage; The discharge water mainly comes from various types of kitchen water, washing water, and bathroom water used in human life, which are mostly non-toxic inorganic salts. Domestic sewage contains a lot of nitrogen, phosphorus, and sulfur, and there are many pathogenic bacteria.

89. Municipal sewage; The general term for sewage discharged into urban sewage systems. In the combined flow drainage system, it also includes production wastewater and intercepted rainwater. Municipal sewage mainly includes domestic sewage and industrial sewage, which are collected by urban drainage networks and transported to sewage treatment plants for treatment.

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

91. COD; Chemical oxygen demand, the amount of oxidant consumed during the chemical oxidation process of substances that can be oxidized in water under specified conditions, expressed in milligrams of oxygen consumed per liter of water sample, usually recorded as COD.

92. BOD; The process of microbial decomposition of organic matter in surface water bodies consumes the amount of dissolved oxygen in the water, known as biochemical oxygen demand, usually referred to as BOD, commonly measured in milligrams per liter.

93. BC ratio; Denotes the degree of biodegradability of pollutants in water, with values ranging from 0.1 to 0.25 being difficult to degrade, from 0.25 to 0.5 being biodegradable, and>0.5 being easy to degrade.

94. TOC; Refers to the total amount of carbon in dissolved and suspended organic matter in water, reflecting the content of oxidized organic compounds in water, expressed in ppm or ppb.

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

96. Organic nitrogen; A general term for nitrogen-containing substances that bind to carbon, such as proteins, amino acids, amides, urea, etc.

97. Kjeldahl nitrogen; TKN refers to the nitrogen content measured using the Kjeldahl method. It includes ammonia nitrogen and organic nitrogen compounds that can be converted into ammonium salts under this condition and measured.

98. Nitrate nitrogen; NOx ˉ, It refers to the nitrogen element contained in nitrates. Nitric acid is only mixed with nitrite.

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

100. Total phosphorus; TP, measured in milligrams of phosphorus per liter of water sample, converts various forms of phosphorus into orthophosphate after digestion.

101. Secondary phosphorus; With H2PO2 ˉ Phosphates in their form cannot be removed by normal chemical phosphorus removal and need to be converted into sulfate ions to be removed.

102. Chromaticity; It refers to the degree to which soluble or colloidal substances contained in water exhibit a yellowish or even yellowish brown color.

103. Grille; Used to remove floating objects in water.

104. Initial sedimentation tank; Also known as a sedimentation tank, a structure used in sewage treatment to remove settleable and floating debris.

105. Regulating tank; A structure used to regulate the inlet and outlet flow rates. It mainly regulates the water quantity and quality, as well as the pH value and water temperature of sewage. It also has the function of pre aeration and can be used for accident drainage.

106. Accident pool; Accident water collection tank is a type of structure required in the sewage treatment process. When dealing with high concentration wastewater discharged by chemical, petrochemical and other factories, accident tanks are generally set up.

107. Oil separation tank; The purpose of separation is achieved by utilizing the different specific gravity of suspended solids and water in wastewater.

108. Air flotation; A large number of micro bubbles are generated in water, causing air to adhere to suspended particles in the form of highly dispersed micro bubbles, resulting in a density less than water. The principle of buoyancy is used to float it on the water surface, thus achieving solid-liquid separation.

109. Biochemical pool; The field where bacteria metabolize in biochemical treatment.

110. Secondary sedimentation tank; The secondary sedimentation tank is an important component of the activated sludge system, mainly used to separate the sludge, clarify, concentrate, and reflux the mixed liquid.

111. Horizontal flow sedimentation tank; The plane of the pool body is rectangular, with the inlet and outlet located at both ends of the pool length.

112. Vertical flow sedimentation tank; Also known as a vertical sedimentation tank, it is a sedimentation tank in which wastewater flows vertically. The plane shape of the pool body is circular or square, and water enters the pool from top to bottom through the inlet pipe located in the center of the pool. Sedimentation occurs through the weight of the sludge itself.

113. Amplitude flow sedimentation tank; The wastewater enters the pool from the inlet pipe in the center of the pool and flows slowly towards the circumference of the pool along the radius direction. Suspended solids settle in the flow and enter the sludge hopper along the slope of the pool bottom, while clarified water overflows from the pool perimeter and flows out of the water channel.

114. Sludge tank; Generally, it is a pool used to hold reflux sludge and excess sludge.

115. Monitoring pool; Also known as a clean water tank, it is used to hold treated sewage.

116. Coagulation; The process of losing stability of colloids. Commonly known as colloidal instability.

117. Flocculation; The process of unstable colloids coalescing with each other to form large flocs.

118. Coagulation; The entire process of two stages of forming large particles of flocculent through destabilization and flocculation. The general term for coagulation and flocculation

119. Metabolism; The exchange of material and energy between the body and the external environment, as well as the self-renewal process of material and energy within the organism, is called metabolism. Metabolism includes anabolism (assimilation) and catabolism (alienation).

120. Bacterial micelles; Some bacteria, due to their genetic characteristics, adhere to each other in a certain arrangement and are surrounded by a common capsule to form a certain shaped bacterial group, called a bacterial gel group.

121. Filamentous bacteria; A class of bacteria with a filamentous structure. The skeleton of the bacterial gel.

122. Autotrophic bacteria; Bacteria using inorganic carbon sources as carbon sources

123. Heterotrophic bacteria; Bacteria using organic carbon sources as carbon sources

124. Anaerobic environment; In theory, anaerobic refers to the absence of molecular oxygen and nitrate nitrogen. But it is impossible to achieve it in practical work. In engineering, DO<0.2 is considered anaerobic,,

125. Aerobic environment; There is both dissolved oxygen and nitrate nitrogen. In engineering, DO>0.5 or above is considered aerobic.

126. Hypoxic environment; It refers to the absence of molecular oxygen and the presence of nitrate nitrogen. In engineering, DO ranges from 0.2 to 0.5, indicating hypoxia.

127. Activated sludge method; A continuous sewage treatment method achieved through the adsorption, metabolism, and separation of sludge and water through microbial micelles.

128. Biofilm method; A method of treating organic wastewater using microorganisms (i.e. biofilms) that adhere to the surface of certain solids.

129. Hydraulic retention time; Abbreviated as HRT, a water treatment process term, hydraulic retention time refers to the average residence time of the treated wastewater in the reactor, which is the average reaction time between the wastewater and microorganisms in the bioreactor.

130. Mud age; Refers to the average residence time of microbial cells in the aeration tank. For the activated sludge method with reflux, the sludge age is the average time (in days) required for the entire aeration tank to update the sludge once.

131. SV; The 30 minute settling ratio refers to the rapid pouring of the mixed activated sludge mixture from the aeration tank into a 1000ml measuring cylinder to the full scale. After settling for 30 minutes, the volume ratio of the precipitated sludge to the selected mixture is the sludge settling ratio (%), also known as the sludge settling volume (SV30), expressed in mL/L. Due to the fact that after 30 minutes of sludge settling, the maximum density can generally be reached or approached, so this time is commonly used as the standard time for measuring this indicator.

132. MLSS; Sludge concentration, weight of dry sludge contained in 1 liter aeration tank sludge mixture

133. MLVSS; The concentration of volatile suspended solids in the mixed liquid represents the concentration of organic solid substances in the activated sludge of the mixed liquid.

134. RSS; The sludge concentration of the returned sludge.

135. SVI; The sludge volume index is an indicator that measures the settling performance of activated sludge. Refers to the volume (in mL) of 1g dry sludge corresponding to the mixed liquid in the aeration tank after 30 minutes of static settling, i.e. SVI=sludge volume (mL)/sludge dry weight (g) after 30 minutes of static settling of the mixed liquid, i.e. SVI=SV30/MLSS.

136. Internal reflux ratio; The ratio of the reflux flow rate of nitrifying liquid to the inflow flow rate, usually expressed as a percentage, with the symbol r.

137. External reflux ratio; Also known as sludge reflux ratio, the ratio of the reflux sludge flow rate to the inflow flow rate. Generally expressed as a percentage, with the symbol R.

138. Inoculation; The process of adding activated sludge or granular sludge to a biochemical treatment system.

139. Domestication; The conversion process of gradually developing mature fecal sewage activated sludge with the ability to treat specific industrial wastewater.

140. Organic load; It refers to the amount of pollutants removed per unit of activated sludge per unit time.

141. Volume load; The weight of pollutants that can be removed per unit time in a unit aeration tank volume.

142. Impact load; During the operation of sewage treatment, the sludge volume is generally maintained at a certain level, and the volume of reactors (such as aeration tanks and anaerobic reactors) will not change. However, if there is a significant change in the inflow water quality (such as a surge or significant decrease in COD), it will cause significant changes in sludge load and volumetric load, which will have an impact on sludge microorganisms, known as impact load.

143. ORP; The redox potential is a measurement indicator of the redox ability of an aqueous solution, measured in mV.

144. DO; The molecular oxygen dissolved in water is called dissolved oxygen, usually referred to as DO, expressed in milligrams of oxygen per liter of water.

145. Aeration; A method of making air in strong contact with water, with the aim of dissolving oxygen in the air in water or expelling unwanted gases and volatile substances from the water into the air.

146. Oxygen filling rate; In wastewater treatment, the ability of an aerator to supply liquid oxygen is called oxygenation capacity, expressed in kg/(m3 ˙ h) Calculate [10 ℃ or 20 ℃, 101.3kPa]. The oxygenation capacity of a liquid per kilowatt hour is called oxygenation efficiency.

147. Pushing flow activated sludge method; The sewage flows evenly, entering from the head of the pool and exiting from the tail of the pool. The front and rear liquid flows do not mix.

148. Sequential batch activated sludge method; An activated sludge wastewater treatment technology that operates through intermittent aeration. Its main feature is orderly and intermittent operation during operation.

149. Microscopic examination; Abbreviation for Microscopic Examination. It means taking samples and making sections of the specimens to be tested, and observing, analyzing, and judging them under a microscope.

150. Protozoa; Protozoa are the lowest class of eukaryotic single-celled animals in the animal kingdom, with individuals composed of individual cells.

151. Metabiotics; The general term for all animals except protozoa (metazoan subfamily).

152. Expansion of non filamentous bacteria; Non filamentous bacterial swelling caused by the accumulation of a large amount of highly viscous substances in the bacterial body, such as glucose, mannose, arabinose, rhamnose, and deoxyribose.

153. Filamentous bacteria swelling; The expansion of filamentous bacteria in activated sludge caused by the proliferation of a large number of filamentous bacteria.

154. Peroxide; Microorganisms continue to oxidize themselves when there is sufficient oxygen but insufficient nutrition, which means that the carbon source in sewage is insufficient.

155. Exogenous respiration; Under normal circumstances, microorganisms use externally supplied energy for respiratory metabolism, which is called exogenous respiration.

156. Endogenous respiration; If there is no energy supply from the outside, but instead uses the energy stored within oneself for respiratory metabolism, it is called endogenous respiration.

157. Aging; The phenomenon of sludge disintegration caused by excessive sludge age, prolonged low load, or peroxidation.

158. Excess sludge; It refers to the activated sludge discharged from the secondary sedimentation tank (or sedimentation zone) outside the system in the activated sludge system.

159. Ammoniation; It refers to the process of microbial decomposition of nitrogen-containing organic compounds such as proteins and urea into ammonia.

160. Nitrification; The process of ammonia being oxidized to nitric acid by microorganisms.

161. Denitrification; The biochemical process in which bacteria reduce nitrogen (N) from nitrate (NO3 −) to nitrogen (N2) through a series of intermediate products (NO2 −, NO, N2O).

162. Short range nitrification and denitrification; Short term nitrification refers to the production of nitrite by NH3, which no longer produces nitrate; The direct generation of N2 from nitrite is called short-range denitrification.

163. Simultaneous nitrification and denitrification; Nitrification and denitrification reactions often occur under the same treatment conditions and within the same treatment space, therefore, these phenomena are called synchronous nitrification/denitrification (SND).

164. Anaerobic ammonia oxidation; The biological reaction process in which anaerobic ammonia oxidizing bacteria use nitrite as an electron acceptor to oxidize ammonia nitrogen to nitrogen under anaerobic conditions.

165. Chlorination at break point; NH3-N in wastewater can be oxidized to chloramine (NH2Cl, NHCl2, NCl3) using chlorine based oxidants (such as Cl2, NaOCl) at an appropriate pH value, and then oxidized and decomposed into N2 gas to achieve removal.

166. Bird manure stone method; The method of using magnesium ions, ammonium ions, and phosphates in water to form ammonium magnesium phosphate precipitation to remove ammonia nitrogen and total phosphorus.

167. Biological phosphorus removal; The process of phosphorus removal is achieved by utilizing the excessive phosphorus absorption characteristics of phosphorus accumulating bacteria.

168. Chemical phosphorus removal; The process of removing phosphorus by utilizing the principle of precipitation formed by phosphate ions and certain metal ions.

169. Gasification for phosphorus removal; The process of phosphate forming phosphine under the action of microorganisms.

170. Sludge drying; The process of removing most of the water content from sludge through infiltration or evaporation.

171. Anaerobic reactor; A specialized reactor designed for anaerobic treatment technology.

172. Anaerobic granular sludge; The granular sludge produced by upflow anaerobic sludge beds and similar reactors is hollow and nearly circular, mainly composed of inorganic precipitates and extracellular polysaccharides. Various microorganisms living together can effectively remove pollutants from wastewater.

173. Aerobic granular sludge; It is a granular activated sludge formed by the self coagulation of microorganisms in an aerobic environment.

174. MBR; Also known as membrane bioreactor, it is a new type of water treatment technology that combines membrane separation unit and biological treatment unit. Replace the secondary sedimentation tank with a membrane.

175. Advanced oxidation; The process of oxidative degradation of pollutants in wastewater that cannot be oxidized by ordinary oxidants by generating hydroxyl radicals.

176. Hydroxyl radicals; It is an important reactive oxygen species, which is formed by the loss of an electron from the hydroxyl radical (OH -) in terms of molecular formula. Hydroxyl radicals have extremely strong electron harvesting ability, also known as oxidation ability, with an oxidation potential of 2.8v. It is the second only oxidant to fluorine in nature.

177. Evaporative crystallization; Heat and evaporate the solvent, causing the solution to change from unsaturated to saturated. Continuing to evaporate, the excess solute will form crystals and precipitate, called evaporative crystallization.

178. Salt eating bacteria; Refers to a class of bacteria and microorganisms with specific physiological structures that can only survive in saline environments.

179. Reclaimed water reuse; It refers to the deep technical treatment of domestic sewage (or urban sewage) or industrial wastewater to remove various impurities, toxic and harmful substances and certain heavy metal ions that pollute the water body, and then disinfect and sterilize it. The water body is colorless, odorless, and the water quality is clear and transparent, and meets or exceeds the national standards for miscellaneous water use (or relevant regulations). It is widely used in enterprise production or residential life.

180. Zero emissions; It refers to the recycling and reuse of industrial water after repeated use, which is concentrated into wastewater with high salt content and pollutants (over 99%), or the use of a filter press to filter out insoluble substances and recycle them, without any waste liquid discharged from the factory.


(Source: New Horizon of Water Treatment)