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 general term for four types of water bodies: rivers, glaciers, lakes, and swamps, also known as "land water".
2. Groundwater; It is stored in geological voids below the gas bearing zone (which refers to geological media located below the Earth's surface and above the water table), including water in rock pores, fractures, and caves Groundwater exists in cracks in crustal rocks or soil voids.
3. Raw water; It refers to water collected from natural sources such as groundwater and reservoir water, without any artificial purification treatment.
4. PH; The numerical value representing the acidity or alkalinity of a solution, pH=- lg [H+], which is the negative logarithm of the commonly used concentration of hydrogen ions.
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; It is the alkalinity measured using phenolphthalein as an indicator (titration endpoint pH=8.2-8.4).
7. Alkalinity of methyl orange; 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 bases, including inorganic acids, organic acids, strong acid weak base salts, etc.
9. Total hardness; In general natural water, the main components are Ca2+and Mg2+, with very little content of other ions. 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 by boiling, and this hardness is called carbonate hardness or 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 even after boiling, is called non carbonate hardness or permanent hardness.
12. Dissolved substances; It exists in the form of simple molecules or ions in a solution of water (or other solvents), with particle sizes typically only a few tenths to a few nanometers, invisible to the naked eye, and without the Tyndall phenomenon 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 invisible to the naked eye but can undergo the Tyndall phenomenon Small colloidal particles cannot be seen with an optical microscope, while larger ones can be seen.
14. Suspended solids; It is a visible small particle formed by the combination of a large number of molecules or ions, usually with a size of several tens of micrometers or more It can be clearly seen with an optical microscope Suspended particles can precipitate after being left to stand for a long time.
15. Total salt content; The total amount of ions in water is called the total salt content. The total amount of cations and anions obtained from the comprehensive analysis of water quality is added together, expressed in mg/L (previously also PPM).
16. Turbidity; Also known as turbidity. Technically speaking, turbidity is a water quality substitute parameter used to reflect the suspended solids content in water. The main suspended solids in water are usually soil. The unit of turbidity is expressed as 1PPm, with 1mg of silica in 1L of distilled water as the standard turbidity.
17. Total dissolved solids; TDS, also known as total dissolved solids, is measured in milligrams per liter (mg/L) and indicates how many milligrams of dissolved solids are dissolved 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 strength of water's conductivity is called electrical conductivity S (or conductivity).
20. Conductivity; The conductivity of water, which is the reciprocal of its resistance, is usually used to represent the purity of water.
21. Electrical resistivity; The electrical resistivity of water refers to the resistance between the opposite sides of a cubic water with a side length of 1cm at a certain temperature, measured in ohms * centimeters (Ω * CM), and is generally a parameter representing the quality of high-purity water.
22. Softened water; It refers to water in which the hardness (mainly calcium and magnesium ions) is removed or reduced to a certain extent. During the softening process of water, only the hardness decreases, while the total salt content remains unchanged.
23. Desalinated water; It refers to water in which salts (mainly strong electrolytes dissolved in water) are removed or reduced to a certain extent. Its conductivity is generally 1.0-10.0 μ s/cm, resistivity (25 ℃) 0.1-1000000 Ω. cm, and salt content is 1.5mg/L.
24. Pure water; It refers to strong and weak electrolytes in water (such as SiO2, CO2, etc.). Remove or reduce water to a certain extent. Its conductivity is generally 1.0-0.1 μ s/cm, and its resistivity is 1.0-1000 Ω· cm. Salt content<1mg/l.
25. Ultra pure water; It refers to water in which the conductive medium is almost completely removed, while non dissociating gases, colloids, and organic substances (including bacteria, etc.) are also removed to a very low degree. Its conductivity is generally 0.1-0.055 μ s/cm, resistivity (25 ℃)>10 × 1000000 Ω· cm, and salt content<0.1mg/l. The ideal pure water has a theoretical conductivity of 0.05 μ s/cm and a resistivity of 18.3 × 1000000 μ s/cm at 25 ℃.
26. Deoxidized 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 capacity between the exchangeable groups in ion exchangers and various ions in the solution.
28. Yang resin; Having acidic functional groups. In aqueous solution, acidic groups can ionize to form H+, which can undergo ion exchange with cations in water.
29. Yin resin; Containing alkaline groups, they ionize in aqueous solution and undergo ion exchange with anions.
30. Inert resin; Without active functional groups and ion exchange, the relative density is generally controlled between the anion and cation resins to separate them and avoid cross contamination during regeneration, making the regeneration more complete.
31. Microfiltration; MF, also known as microporous filtration, belongs to precision filtration. Microfiltration can filter out micrometer or nanometer sized particles and bacteria in a solution.
32. Ultrafiltration; UF, 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 pore size range of several nanometers for nanofiltration membranes.
34. Penetration; Penetration is the phenomenon of water molecules diffusing through a semi permeable membrane. It infiltrates from the high water molecule region (i.e. low concentration solution) into the low water molecule region (i.e. high concentration solution).
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 reverse osmosis membrane is as small as the nanometer level. 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, utilizing the selective permeability of the membrane to solutes, to achieve the separation of solutes with different properties.
37. Electrodialysis; ED, the phenomenon in which charged solute particles (such as ions) in the solution migrate 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 converted into produced water or permeate in a membrane system.
40. Desalination rate; The percentage of total soluble impurities 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 pass through the membrane. Permeation solution: Purified water produced through a membrane system.
42. Flux; The flow rate of permeate per unit membrane area is 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 part 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; The system that uses water to cool the process medium is called a cooling water system.
46. Direct current cooling water system; The cooling water only passes through the heat exchange equipment once and is discharged after use.
47. Open circulating water; Water cooling is used to remove the heat emitted by the process medium or heat exchange equipment, and then a portion of the hot water is evaporated when it comes into direct contact with air, allowing most of the hot water to be cooled and recycled.
48. Closed loop circulating water system; Also known as a closed circulating 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, in order to lower the water temperature. There are two cooling methods: natural ventilation and mechanical ventilation.
50. Water distributor; The return water is evenly distributed onto the packing material through a water distributor.
51. Filler; The return water forms a water film through the filling material, increasing the contact area with the air.
52. Water collector; Retrieve the liquid water carried in the partially evaporated water vapor.
53. Circulating water volume; The total amount of circulating water in the cooling tower of the circulating water system. N50 retained water volume: The total volume of all water in the circulating water system is equal to the total volume of the water pool, pipelines, and water cooling equipment.
54. Supplement water volume; Used to supplement the water required for evaporation/discharge/splashing losses in the circulating water system.
55. Side filter water volume; The amount of water that is separated from the circulating cooling water system and treated as required before returning to the system.
56. Evaporation water volume; The amount of water lost through evaporation during the operation of the circulating cooling water system.
57. Discharge water volume; The amount of water that needs to be discharged from the circulating cooling water system under the determined concentration factor conditions.
58. Loss of water due to wind leakage; The amount of water lost due to blowing and leakage during the operation of the circulating cooling water system.
59. Supplement water volume; The circulating cooling water system replenishes the lost water during operation.
60. Concentration factor; The ratio of the salt concentration of circulating cooling water to that of supplementary water.
61. Heat exchange; The heat exchange between objects is called heat transfer. There are three basic forms of circulating water heat transfer: heat exchange, convective heat transfer, radiative heat transfer, and evaporative heat transfer.
62. Thermal conductivity; The phenomenon of heat transfer between different parts of an object in direct contact is called thermal 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. Radiant heat transfer; Part of the thermal energy of high-temperature objects is converted into radiation energy, which is emitted in the form of electromagnetic waves to the receiving object. The radiation energy is then converted into thermal energy and absorbed. This way of transferring heat through electromagnetic waves is called radiation heat transfer.
65. Evaporative heat exchange; A form of heat transfer in which the latent heat of vaporization is carried away during the evaporation of water molecules.
66. Temperature difference between inlet and outlet of cooling water; The temperature difference of water 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 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 weather forecasts.
69. Physical cleaning; Clean the debris inside the pipeline by the flow rate of water.
70. Chemical cleaning; By the action of the agent, the surface of the metal heat exchanger is kept clean and activated, preparing for the pre membrane.
71. Pre film; Chemical conversion coating is a type of protective layer on the surface of metal equipment and pipelines, especially for pipelines that have passed acid pickling and passivation, which can be protected using pre coating methods.
72. Corrosion inhibitor; The process of inhibiting or delaying the corrosion of metals.
73. Scale inhibitor; The process of using chemical or physical methods to prevent sedimentation on the heating surface of heat exchange equipment.
74. Oxidative fungicides; A biocide with strong oxidizing properties, usually a strong oxidizing agent, has a strong killing effect on microorganisms in water.
75. Non oxidizing fungicides; It does not kill microorganisms through oxidation, but rather through toxic effects on specific parts of microorganisms, so it is not affected by reducing substances in water.
76. Effective chlorine; It refers to the amount of chlorine with equivalent oxidation ability in chlorinated compounds (especially as disinfectants), which can quantitatively represent the disinfection effect.
77. Residual chlorine; Residual chlorine refers to the effective chlorine remaining in water after disinfection with chlorine and contact for a certain period of time.
78. Compound chlorine; Refers to compounds of chlorine and ammonia in water, including NH2Cl, NHCl2, and NHCl3. Among them, NHCl2 is more stable and has good bactericidal effect, also known as bound residual chlorine
79. Free residual chlorine; ClO -, HClO, Cl2, etc. in water have fast sterilization speed and strong sterilization power, but disappear quickly, also known as free residual chlorine.
80. Orthophosphate; +5 valent phosphorus in phosphate.
81. Organic phosphorus; It is a compound containing carbon phosphorus bonds or a phosphoric acid derivative containing organic groups.
82. Total iron; Iron exists in various states, including all elements of iron.
83. Total zinc; Zinc in various states of existence contains all zinc elements.
84. Retention time of medication; The effective time of the medication in the circulating cooling water system.
85. Scaling; Calcium and magnesium bicarbonate dissolved in water undergo thermal decomposition, resulting in the precipitation of white precipitates that gradually accumulate and adhere to the container, known as scaling.
86. Corrosion; The process of loss and damage (including metal and non-metal) caused by the action of surrounding media (water, air, acid, alkali, salt, solvent, etc.).
87. Biological slime; A viscous substance that adheres to the surface of an object by mixing microorganisms and their produced mucus with other organic and inorganic impurities.
3、 Wastewater treatment
88. Domestic sewage; Mainly refers to the discharge water generated by various kitchen water, washing water, and bathroom water used in human life, which is mostly non-toxic inorganic salts. Domestic sewage contains more nitrogen, phosphorus, sulfur, and pathogenic bacteria.
89. Municipal sewage; The general term for sewage discharged into urban sewage systems. In the combined sewer 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 contain industrial production materials, intermediate products, and products that are lost with water, as well as pollutants generated during the production process.
91. COD; Chemical Oxygen Demand (COD) is 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.
92. BOD; The process of microbial decomposition of organic matter in surface water consumes the amount of dissolved oxygen in the water, known as biochemical oxygen demand, usually denoted as BOD and commonly measured in milligrams per liter.
93. BC ratio; Indicates the biodegradability of pollutants in water, with 0.1-0.25 being difficult to biodegrade, 0.25-0.5 being biodegradable, and>0.5 being easy to biodegrade.
94. TOC; The total amount of dissolved and suspended organic matter containing carbon in water, reflecting the content of oxidized organic compounds in water, measured in ppm or ppb.
95. Ammonia nitrogen; It refers to the nitrogen present in water in the form of free ammonia (NH3) and ammonium ions (NH4+).
96. Organic nitrogen; The general term for nitrogen-containing substances that combine with carbon, such as proteins, amino acids, amides, urea, etc.
97. Kjeldahl nitrogen; TKN refers to the nitrogen content measured by Kjeldahl method. It includes ammonia nitrogen and organic nitrogen compounds that can be converted to ammonium salts under these conditions.
98. Nitrate nitrogen; NOx ˉ refers to the nitrogen element contained in nitrates. Nitric acid and nitrite only coexist.
99. Total nitrogen; TN is the total amount of various forms of inorganic and organic nitrogen in water.
100. Total phosphorus; TP is the result of measuring the amount of phosphorus in milligrams per liter of water sample after various forms of phosphorus are converted into orthophosphate through digestion.
101. Secondary phosphorus; Phosphates in the form of H2PO2- cannot be removed by normal chemical phosphorus removal and need to be converted into sulfate ions for removal.
102. Chromaticity; It refers to the degree of yellowish or even yellowish brown color exhibited by soluble or gelatinous substances contained in water.
103. Grille; Used to remove floating objects in water.
104. Primary sedimentation tank; Also known as a sedimentation tank, a structure used in sewage treatment to remove sediment and floating debris.
105. Regulating pool; A structure used to regulate the inflow and outflow of water. It mainly plays a regulating role in water quantity and quality, as well as a pre aeration regulating role in sewage pH value and water temperature. It can also be used for accident drainage.
106. Accident pool; Accident water collection tank is a type of structure required in the sewage treatment process. When treating high concentration wastewater discharged from factories such as chemical and petrochemical industries, accident tanks are generally installed.
107. Oil separation tank; To achieve separation by utilizing the difference in specific gravity between suspended solids and water in wastewater.
108. Air flotation; 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.
109. Biochemical pool; The field pool where bacterial metabolism occurs in biochemical treatment.
110. Secondary sedimentation tank; The secondary sedimentation tank is an important component of the activated sludge system. Its main function is to separate the sludge, clarify, concentrate, and reflux the mixed liquid with activated sludge.
111. Horizontal 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 where wastewater flows vertically in the tank. The planar shape of the pool is circular or square, and water enters the pool from top to bottom through the inlet pipe located at the center of the pool. Settling by the weight of the sludge itself.
113. Stream sedimentation tank; Wastewater enters the pool through the inlet pipe at the center of the pool and flows slowly along the radius towards the periphery of the pool. Suspended solids settle in the flow and enter the sludge hopper along the slope of the pool bottom, while clarified water overflows from the surrounding water channel.
114. Sludge tank; It is generally used as a tank to hold returned sludge and residual sludge.
115. Monitoring pool; Also known as a clear water tank, it is used to hold treated wastewater.
116. Condensation; The process by which colloids lose stability. Commonly known as colloidal destabilization.
117. Flocculation; The process of destabilization colloids aggregating into large particle flocs.
118. Coagulation; The entire process of forming large particle flocs through two stages of destabilization and flocculation. The general term for coagulation and flocculation
119. Metabolism; The exchange of substances and energy between the body and the external environment, as well as the self-renewal process of substances and energy within the body, is called metabolism. Metabolism includes synthetic metabolism (assimilation) and catabolic metabolism (alienation).
120. Microbial flocs; 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 shaped bacterial group called a bacterial colony.
121. Filamentous bacteria; A type of bacteria with a filamentous structure. The skeleton of a bacterial colony.
122. Autotrophic bacteria; Bacteria using inorganic carbon sources as carbon sources
123. Heterotrophic bacteria; Bacteria that use 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 in actual 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 is considered aerobic.
126. Oxygen deficient environment; It refers to the absence of molecular oxygen and nitrate nitrogen. In engineering, a DO range of 0.2~0.5 indicates hypoxia.
127. Activated sludge process; The continuous sewage treatment method is achieved through the adsorption, metabolism, and sludge water separation of microbial flocs.
128. Biofilm method; The method of treating organic wastewater using microorganisms (i.e. biofilms) attached to the surface of certain solid objects.
129. Hydraulic retention time; Abbreviated as HRT, hydraulic retention time refers to the average residence time of wastewater in a reactor, which is the average reaction time between wastewater and microorganisms in a bioreactor.
130. Mud age; The average residence time of microbial cells in the aeration tank. For the activated sludge process with reflux, the sludge age is the average time (in days) required for the entire aeration tank to renew the sludge once.
131. SV; The 30 minute settling ratio refers to the volume ratio of the settled sludge to the mixed liquid obtained by quickly pouring the mixed activated sludge from the aeration tank into a 1000ml measuring cylinder until it reaches the full mark, and allowing it to settle for 30 minutes. It is also known as the sludge settling volume (SV30) and is expressed in mL/L. Because the sludge can generally reach or approach its maximum density after settling for 30 minutes, this time is commonly used as the standard time for measuring this indicator.
132. MLSS; Sludge concentration, weight of dry sludge contained in a 1-liter aeration tank sludge mixture
133. MLVSS; The concentration of volatile suspended solids in a mixed solution refers to the concentration of organic solid substances in the activated sludge of the mixed solution.
134. RSS; The sludge concentration of the returned sludge.
135. SVI; The sludge volume index is an indicator for measuring the settling performance of activated sludge. The volume (in mL) occupied by 1g of dry sludge after 30 minutes of static settling of the mixed liquid in the aeration tank, i.e. SVI=sludge volume (mL) after 30 minutes of static settling of the mixed liquid/sludge dry weight (g), i.e. SVI=SV30/MLSS.
136. Internal reflux ratio; The ratio of the reflux flow rate of nitration solution to the inflow flow rate is generally expressed as a percentage, with the symbol r.
137. External reflux ratio; Also known as sludge return ratio, the ratio of the flow rate of returned sludge to the inflow flow rate. Generally expressed as a percentage, with the symbol R.
138. Vaccination; The process of adding activated sludge or granular sludge to a biochemical treatment system.
139. Domestication; The transformation 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 mass of activated sludge in a unit time.
141. Volume load; Unit aeration tank volume, the weight of pollutants that can be removed in a unit time.
142. Impact load; In the operation of sewage treatment, the sludge volume is generally maintained at a certain level, and the volume of reactors (aeration tanks, anaerobic reactors, etc.) will not change. However, if there is a significant change in the incoming water quality (COD surge or significant decrease), it will cause a significant change in sludge load and volumetric load, which will have an impact on sludge microorganisms, known as impact load.
143. ORP; The oxidation-reduction potential is a measurement indicator of the oxidation-reduction ability of an aqueous solution, measured in mV.
144. DO; The molecular oxygen dissolved in water is called dissolved oxygen, usually denoted as DO, expressed in milligrams of oxygen per liter of water.
145. Aeration; A means of strongly contacting air with water, aimed at dissolving oxygen in the air into water or expelling unwanted gases and volatile substances from water into the air.
146. Oxygenation rate; In wastewater treatment, the ability of aerators to supply oxygen to liquids is called oxygenation capacity, measured in kg/(m3 · h) [10 ℃ or 20 ℃, 101.3kPa). The oxygenation capacity of liquids per kilowatt hour is called oxygenation efficiency.
147. Push flow activated sludge process; The sewage flows evenly, and the wastewater enters from the head of the pool and flows out from the tail of the pool, without mixing the front and rear streams.
148. Sequential batch activated sludge process; An activated sludge wastewater treatment technology that operates in an intermittent aeration mode. Its main feature is orderly and intermittent operation during operation.
149. Microscopic examination; The abbreviation for microscopic examination. It is to sample and prepare the specimen to be tested, observe, analyze, and judge it under a microscope.
150. Primitive organisms; Protozoa are the lowest class of eukaryotic unicellular animals in the animal kingdom, consisting of individual cells.
151. Epigenetic organisms; The general term for all animals other than protozoa (subphylum of metazoa).
152. Non filamentous bacterial expansion; Non filamentous bacterial swelling caused by the accumulation of highly viscous substances such as glucose, mannose, arabinose, xylose, and deoxyribose in the bacterial body.
153. Expansion of filamentous bacteria; The expansion of filamentous bacteria in activated sludge caused by the proliferation of a large number of filamentous bacteria.
154. Peroxide; Microorganisms continue to undergo oxidation reactions when there is sufficient oxygen but insufficient nutrients, such as carbon sources in wastewater.
155. External respiration; Under normal circumstances, microorganisms utilize externally supplied energy for respiratory metabolism, which is called exogenous respiration.
156. Endogenous respiration; If there is no external energy supply, but instead uses the stored energy substances within oneself for respiratory metabolism, it is called endogenous respiration.
157. Aging; The phenomenon of sludge disintegration caused by long 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) of the activated sludge system outside the system.
159. Ammoniation; It refers to the process in which nitrogen-containing organic compounds such as proteins and urea are decomposed by microorganisms and converted 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) in nitrate (NO3-) to nitrogen (N2) through a series of intermediate products (NO2-, NO, N2O).
162. Short range nitrification denitrification; Short range nitrification refers to the production of nitrite from NH3 and the cessation of nitrate production; 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 in 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. Add chlorine at the inflection point; NH3-N in wastewater can be removed by using chlorine based oxidants (such as Cl2, NaOCl) at an appropriate pH to oxidize it into chloramines (NH2Cl, NHCl2, NCl3), which are then oxidized and decomposed into N2 gas.
166. Bird droppings stone method; The method of using magnesium ions, ammonium ions, and phosphate in water to form ammonium magnesium phosphate precipitate to remove ammonia nitrogen and total phosphorus.
167. Biological phosphorus removal; The process of utilizing the excessive phosphorus uptake characteristics of polyphosphate accumulating bacteria to achieve phosphorus removal.
168. Chemical phosphorus removal; The process of using phosphate ions to form precipitates with certain metal ions to remove phosphorus.
169. Gasification 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 filtration 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. Multiple 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 water treatment technology that combines membrane separation units with biological treatment units. Replace the secondary sedimentation tank with a membrane.
175. Advanced oxidation; The process of oxidizing and degrading 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 hydroxide (OH -) in terms of molecular formula. Hydroxyl radicals have extremely strong electron donating ability, also known as oxidation ability, with an oxidation potential of 2.8v. It is the second largest oxidant in nature after fluorine.
177. Evaporative crystallization; Heating and evaporating the solvent causes the solution to change from unsaturated to saturated, and further evaporation results in the precipitation of excess solutes into crystals, known as evaporative crystallization.
178. Salt eating bacteria; A type of bacterial microorganism that has a specific physiological structure and can only survive in saline environments.
179. Reuse of reclaimed water; 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 water bodies, and then disinfect and sterilize them. The water body is colorless, odorless, clear and transparent, and meets or exceeds the national standard for miscellaneous water use (or relevant regulations). It is widely used in enterprise production or residential life.
180. Zero emissions; After repeated use, industrial water is highly concentrated into wastewater with a salt content and pollutants of over 99%, which is then recycled and reused. Alternatively, insoluble substances can be filtered out using a filter press and reused without any waste liquid being discharged from the factory.