Article Introduction

This article summarizes 200 basic principles of water treatment. Although brief, this knowledge is practical and will help you in your studies and work, leading to a better understanding of the water treatment industry.

 

 

1.001×7 type resin is a (strongly acidic cation exchange resin).

 

2. Regular boiler blowdown is mainly to remove (water slag).

 

3. The ion exchange process is essentially a process of gradual downward movement of the (working) layer.

 

4. When using strong and weak base resins together, the weak base resin exchanges strong acid root ions, and the strong base resin exchanges (weak acid root ions).

 

5. The chemical name of Na3PO4 is (trisodium phosphate).

 

6. The filling ratio of mixed bed anion and cation resins is (anion:cation = 2:1).

 

7. Boiler blowdown methods include continuous blowdown and (periodic blowdown).

 

8. The temperature control range for anion resin regeneration solution is (30～45℃).

 

9. The resin layer in an operating exchanger can be divided into an exhausted layer, a working layer, and a (protective layer).

 

10. When a weak base anion exchanger fails, the first ion to leak through is (chloride ion).

 

11. When a strong base anion exchanger fails, the first ion to leak through is (silicate ion).

 

12. During filtration, after contact between impurities in the water and the filter media, surface adsorption and (mechanical retention) occur.

 

13. The total mass of the substances participating in a chemical reaction is equal to the total mass of the substances produced after the reaction. This law is called the (law of conservation of mass).

 

14. The unit of conductivity is (μS/cm).

 

16. Resins are composed of two parts: a framework and (active groups).

 

17. Impurities in natural water are classified by particle size into suspended solids, colloids, and (dissolved impurities).

 

18. In thermal equipment, dissolved oxygen corrosion is most severe in the (feedwater) system.

 

19. Chemical oxygen demand is generally represented by the symbol (COD).

 

20. The molecular formula of sulfuric acid is (H2SO4).

 

21. Methods for deoxygenating feedwater include thermal deoxygenation and (chemical) methods.

 

22. Ammonia is added to feedwater to increase (feedwater pH) and prevent CO2 from causing acid corrosion of pipes.

 

23. Hydrazine is added to feedwater to (remove residual oxygen after thermal deoxygenation to prevent oxygen corrosion of pipes).

 

24. Safety generally refers to a state of (no danger, no accidents).

 

25. Work performed more than (2) meters above the ground is considered high-altitude work.

 

26. The main function of mixed bed backwashing is (separation of anion and cation resins).

 

29. For resin model 201×7, the number 2 indicates that the resin is (strongly alkaline).

 

30. In a mixed bed ion exchanger, anion and cation resins are separated based on their different (densities).

 

31. Anion resins should be protected from oil and (organic matter) contamination.

 

32. To prevent anion resin degradation, (oxidants) in the influent must be removed.

 

33. The safety production management policy determined by the "Safety Production Law" is (safety first, prevention first).

 

34. The regeneration process of ion exchange resin is actually the (reverse reaction) of the desalination process.

 

35. For motors that have been shut down for more than 15 days, contact electrical personnel to measure (insulation) before starting.

 

36. For metering pumps with a speed of 200~400r/min, the vibration value should be less than (0.15) mm.

 

37. When the temperature of the pump motor bearing exceeds (75) ℃, the backup equipment should be started, and the heating equipment should be stopped.

 

40. The criterion for judging the end point of backwashing separation of cation and anion resins in a mixed bed is (a clear separation line between cation and anion resins).

 

41. If the separation boundary line between cation and anion resins in a mixed bed backwash is not clear, (NaOH) solution with a concentration of 1～2% should be added to the mixed bed, and then the separation should be repeated.

 

42. After a new pump or an overhauled pump has been in operation for (2 weeks), the oil should be changed once if it is oil lubricated, and the solid oil should be replenished once. After that, the oil should be changed every (3 months). This work is completed by the operation notification repair.

 

43. The vibration of a centrifugal pump with a speed less than 1800 rpm should be less than (0.7㎜), and the vibration of a centrifugal pump with a speed of 1800-4500 rpm should be less than (0.06㎜).

 

44. The main factors affecting filter operation are backwashing time, intensity, (filtration rate), and (uniformity of water flow).

 

45. The main factors affecting coagulation treatment are: water temperature, water pH, (dosage), raw water quality, and contact media.

 

46. Water quality indicators for demineralized water are: YD (≈0μmol/L), SiO2 (≤20μg/L), DD (≤0.2μS/cm),

 

47. In low phosphate treatment, the phosphate content is controlled at (0.5～3mg/L), the pH value is controlled at (9.0～9.8), and the conductivity is controlled at (60us/cm).

 

48. Low phosphate treatment can reduce or eliminate the phenomenon of (phosphate hiding) in boilers.

 

When starting the chemical metering pump, the (outlet valve) must be opened first, and then the (pump) is started.

 

When stopping the chemical metering pump, press the (stop) button first, and then close the (outlet valve).

 

Boiler blowdown methods are divided into two types: (continuous blowdown) and (periodic blowdown).

 

The purpose of ammonia treatment of feedwater is (to increase the pH value of feedwater and prevent carbon dioxide corrosion of feedwater pipes).

 

When the online conductivity meter measures the quality of feedwater, condensate, and steam, the water sample must first be treated with a (hydrogen ion exchange column).

 

Periodic blowdown should be carried out at the intervals specified in the boiler operation regulations. Periodic blowdown is performed by (boiler) professionals and supervised by (chemical) professionals.

 

During normal operation, adjust the chemical dosage of the ammonia pump in time according to the size of the feedwater pH value, and control the feedwater pH value within the range of (8.8～9.3).

 

There are two main reasons for steam contamination: one is (mechanical carryover), and the other is (dissolved carryover).

 

During the regeneration of the fluidized bed, the direction of the regenerant is (from top to bottom), which can better ensure that the resin layer is in a stable and compacted state, and will not cause (disordered layer) phenomenon.

 

When dry resin is first wetted, it should not be soaked in pure water. Generally, it is usually soaked in (saturated brine) to prevent the resin from cracking due to (swelling and dissolution).

 

The continuous blowdown pipe is generally installed (200～300 mm) below the normal water level of the steam drum.

 

The iron removal filter for process condensate uses (porous filter elements) to intercept suspended impurities. When the resistance increases to a certain value, it is backwashed with (water and air).

 

Methods for removing dissolved gases from water include (thermal deaeration) and (chemical methods). Our unit uses a (ultrafiltration) and (reverse osmosis) system that shares a chemical cleaning system. "Two tickets" refer to (work permits) and (operation permits).

 

If the backwashing stratification is not obvious during mixed bed regeneration, a small amount of (alkali) can be added appropriately.

 

Reverse osmosis RO chemical cleaning is divided into (alkali washing) and (acid washing).

 

The amount of resin filled in the exchanger is usually calculated by multiplying the volume of resin filled in the exchanger by the (wet apparent density).

 

The commonly referred to hardness includes (carbonate) hardness and (non-carbonate) hardness.

 

When the anion bed is in operation, to start the mixed bed, first open the (vent valve) and (inlet valve). After water comes out, open the mixed bed (bottom drain valve), close the air vent valve, and flush until the water quality is qualified. Then open the (product water valve), close the (bottom drain valve), and put it into operation.

 

Untreated water is called (raw water), and water with calcium and magnesium hard salts removed is called (softened water).

 

The chemical water treatment device monitors the (TOC) of the process condensate. Non-conforming water is directly discharged to the (wastewater collection pool) and does not enter the subsequent treatment system.

 

Activated carbon filters mainly adsorb (organic matter) and (residual chlorine) in water.

 

The indicators that characterize steam quality are (silicon) and (sodium).

 

Methods for power plant supplementary water treatment include (chemical treatment) and (heat treatment).

 

Coagulation tests generally require determining the (optimal dosage) and (optimal pH value).

 

When the anion bed is in operation, to start the mixed bed, first open the (vent valve) and (inlet valve). After water comes out, open the mixed bed (bottom drain valve), close the air vent valve, and flush until the water quality is qualified. Then open the (product water valve), close the (bottom drain valve), and put it into operation.

 

Filtration can be divided into (mechanical filtration) and (adsorption filtration).

 

Low phosphate treatment is suitable for the treatment of (feedwater with long-term no hardness).

 

Low phosphate treatment can reduce or eliminate the phenomenon of (hidden phosphate) in boilers.

 

The purpose of using an acid mist absorber is (to avoid environmental pollution).

 

Sampling devices for deaerated water, feedwater, boiler water, steam, and blowdown must be equipped with (coolers).

 

The continuous blowdown rate of the boiler shall not be less than (0.30%).

 

The purpose of continuous blowdown is to remove (suspended impurities) and (boiler water with high salt content) from the boiler water.

 

When the inlet water temperature of reverse osmosis is high, the desalination rate will (decrease) and the recovery rate will (increase). When the inlet water temperature is low, the recovery rate will (decrease).

 

In order to prevent the loss of ion exchange resin, a (resin catcher) is generally installed on the outlet pipe of the mixed bed as a preventive measure.

 

In reverse osmosis, the role of the semi-permeable membrane is to allow only (water) to pass through, but not (salt) ions or molecules.

 

The self-cleaning filter is a fully imported product and can be fully automatically operated by simply controlling the power supply. When it runs to a certain (time) or (pressure difference), it can automatically use (self-produced water) for backwashing. During backwashing, the raw water pump (continues to operate) without any changes or stops.

 

"Three violations" refer to: violation of command, violation of operation, (violation of labor discipline).

 

The items generally monitored during the normal operation of the anion bed are the conductivity and (silicon content) of the effluent.

 

For anion exchangers, the greater the (acidity) of the influent, the better.

 

100. A pneumatic diaphragm valve consists of two parts: a diaphragm valve and a pneumatic actuator.

 

101. The key reason for poor regeneration of mixed ion exchangers is poor backwashing stratification.

 

102. pH is the negative logarithm of the (H-) concentration.

 

103. If the dissolved oxygen in the feed water is unqualified, it can be considered that the (deaerator) is not operating well.

 

104. If the water pump does not pump water and the outlet pressure gauge indicates a high pressure, after ruling out valve problems, the (outlet pipe) should be considered to be blocked.

 

105. The main reason for the deterioration of cation resin is that it is easily eroded by (oxidants). 106. The greater the water permeability of the reverse osmosis membrane, the greater its (desalination rate). 107. When selecting ion exchange resin, the more uniform the resin (particles), the better. 108. Cation resin often has a lower wet true density than anion resin.

 

109. For boiler steam drums, poor water quality will cause scaling, salt accumulation, and (metal corrosion) in the steam-water system.

 

110. When adding ammonia to the feed water, an (excessive) amount of ammonia may cause corrosion of copper pipes.

 

111. When the boiler load increases sharply, PO43- in the boiler water decreases, and phenolphthalein alkalinity increases, because a temporary (disappearance) phenomenon of salts has occurred.

 

112. When the cation exchanger fails, the conductivity will temporarily (decrease).

 

113. The pH value of demineralized water is generally between (6.5-7.5).

 

115. Generally speaking, the chemical stability of anion resin is (worse) than that of cation resin.

 

116. The smaller the crosslinking degree of ion exchange resin, the greater the water content of the resin, and the (stronger) the anti-pollution performance.

 

117. Phosphate treatment can both prevent corrosion and (scaling).

 

118. When the pH of water ≥8.3, it indicates that (no) CO2 exists in natural water.

 

119. After being contaminated by iron, aluminum, and their oxides, the color of ion exchange resin (darkens).

 

120. In natural water, the most common metal ions that form water hardness are (Ca2+, Mg2+).

 

121. In natural water, the alkalinity of water is mainly composed of salts of (HCO3-).

 

122. Substances usually have three states of aggregation: (solid), (liquid), and (gaseous). Under certain conditions, these three states can be transformed into each other.

 

123. The reaction of an acid and a base to produce salt and water is a (neutralization) reaction.

 

124. A solution is composed of a (solvent) and a (solute).

 

125. A solution that can resist changes in pH when strong acids or strong bases are added is called a (buffer solution).

 

126. pH=7 indicates that water is (neutral), pH<7 indicates that water is (acidic), and pH>7 indicates that water is (alkaline).

 

127. The smaller the pH value, the (higher) the concentration of (hydrogen) ions.

 

128. In redox reactions, the substance that loses electrons is called a (reducing agent), and the substance that gains electrons is an (oxidizing agent).

 

129. The pH value of a solution is equal to the (negative) logarithm of its (hydrogen ion concentration).

 

130. The role of filling a certain height of inert white balls in the floating bed is to (protect the resin and prevent broken resin from blocking the water outlet device).

 

131. When the pressure difference between the inlet and outlet water of the floating bed reaches (0.2) MPa or more, the resin should be cleaned.

 

132. After the boiler is ignited, when the pressure rises to (1.0 MPa), start the phosphate dosing pump and start adding chemicals to the boiler water. When the boiler water has hardness, the phosphate content in the boiler water should be controlled at the (upper limit).

 

133. After the boiler is ignited, when the pressure rises to (1.0 MPa), continuous blowdown is put into operation; if the boiler water appears turbid visually, appropriate (periodic blowdown) should be carried out.

 

134. During normal operation, the oil level in the oil chamber of the metering pump should be (1/3 to 2/3) of the oil window.

 

135. The online instrument cabinet is equipped with an automatic temperature control device to maintain the water sample temperature at (25+2℃).

 

136. When the unit starts up, the content of various impurities in the water sample is high, and (blowdown) should be carried out for each steam and water sample.

 

137. Ammonia solution is added to the feed water of the (deaerator downcomer).

 

138. When the unit is running normally, the ammonia pump should be kept running (continuously).

 

139. When the stroke of the ammonia pump is adjusted to a very small value, but the pH value of the feed water is still high, the operators should (add water to dilute) the ammonia solution in the ammonia solution tank.

 

140. There are two main reasons for steam contamination: one is, and the other is (dissolved carryover).

 

141. Increasing the (temperature) of the regenerant can increase the degree of regeneration, mainly because it accelerates the rate of internal diffusion and membrane diffusion.

 

142. The conductivity of a water sample has a certain relationship with the temperature of the water sample. As the temperature of the water sample increases, the conductivity of the water sample will (increase), and as the temperature of the water sample decreases, the conductivity of the water sample will (decrease).

 

143. The speed of a reaction, in addition to being related to the chemical properties of the reactants themselves, is also related to the reaction conditions such as (temperature), (concentration), and (catalyst).

 

144. Boiler blowdown rate refers to the percentage of blowdown water to (boiler evaporation).

 

145. Cooling water scale prevention usually adopts (water quality stabilization treatment).

 

146. As the boiler pressure increases, the dissolved carryover of saturated steam (increases).

 

147. The ability of saturated steam to dissolve and carry silicon compounds is related to (boiler pressure).

 

148. When scale samples are dissolved with sulfuric acid, if the solution turns blue, the scale is (copper scale).

 

149. During static sodium determination, it is best to use a calomel electrode filled with (0.1 mol/L) KCl solution.

 

150. (Metal corrosion rate) is one of the important evaluations of chemical cleaning effect.

 

151. Boiler water is heated into saturated steam in (water wall tubes).

 

152. In the power plant production process, water mainly plays the role of heat transfer and (cooling).

 

153. Superheated steam refers to steam with (pressure greater than 1 atmosphere).

 

154. The function of the chemical sampling constant temperature device is (to ensure accurate analysis results).

 

155. The main pollutants in the flue gas discharged from thermal power plants that cause air pollution are (sulfur dioxide).

 

156. After coagulation treatment of natural water, the hardness of the water (is reduced).

 

157. As the temperature and pressure of water increase, the solubility of air in water will (decrease).

 

158. When sulfuric acid is used for regeneration in the cation bed, high sulfuric acid concentration will produce (calcium sulfate) precipitation.

 

159. Floating bed resin is cleaned (externally).

 

160. The water used for floating bed resin transport is (demineralized water).

 

161. When the pressure difference between the inlet and outlet water of the floating bed increases, the resin should be (cleaned).

 

162. The floating bed regeneration uses (counter-current regeneration).

 

163. High (chlorine) content in water will have a negative impact on cation exchange resin.

 

164. Sodium hydroxide solution often contains a small amount of (sodium carbonate).

 

165. Glass containers cannot hold (strong alkalis).

 

166. Chemical oxygen demand is an indicator used to represent the (organic matter concentration) in water.

 

167. Condensate refers to the steam condensate in (various steam pipes) and steam-using equipment.

 

168. Alkaline water refers to water with alkalinity greater than (hardness).

 

169. After titration, if there are droplets hanging outside the burette nozzle, the titration result will be (too high).

 

170. When different types of resins are mixed together, they can be easily separated by using their different (densities).

 

171. If someone is found to be electrocuted, immediately (cut off the power) and then rescue.

 

172. When measuring the conductivity of water samples with an online conductivity meter, it is often necessary to measure it after passing through a (hydrogen ion exchange column).

 

173. Thermal power generation uses (heat energy) to convert into mechanical energy for power generation.

 

174. (Strong base anion resin) can effectively remove silicon compounds from water.

 

175. The color of acid-base indicators changes with the change of solution (pH value).

 

176. An element is the general term for the same type of atoms with the same (nuclear charge number).

 

177. The main production systems of thermal power plants are water and steam systems, electrical systems, and (coal conveying systems).

 

178. When filling out record forms, the filling should be clear, the handwriting should be clear, and (pencils) should not be used.

 

179. The water production of reverse osmosis is (proportional) to the temperature of the inlet water.

 

180. Increasing the regeneration liquid temperature can increase the regeneration degree, mainly because it accelerates the speed of (internal diffusion and membrane diffusion).

 

190. The pH value of reverse osmosis outlet water is generally around (6).

 

191. After the resin is dehydrated, it should be treated with (10% brine).

 

192. In the demineralization system, in order to remove all cations except H+ in the water, the strongly acidic H-type ion exchange must be stopped immediately when (Na+) exceeds the standard.

 

193. When the mixed bed starts to produce water after regeneration and cleaning, the water conductivity (drops rapidly).

 

194. The characteristic of counter-current regeneration ion exchanger is (good water quality).

 

195. In the blow-type decarbonator, the water and air enter in the way that water enters from the (top) of the decarbonator and air enters from the (bottom).

 

196. The role of the compacted resin layer in the counter-current regeneration ion exchanger is to (prevent layer disorder during regeneration).

 

197. When the electrocuted person's heart stops beating, (external cardiac compression) should be used for rescue.

 

198. When working with acids and alkalis, operators need to wear (acid and alkali resistant) gloves.

 

199. In case of acid burns, rinse with (5% sodium bicarbonate) solution.

 

200. Gauge pressure should be equal to (absolute pressure minus atmospheric pressure).