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101. |
Which of the following option is incorrect about the sludges? |
A. | Sludges are soft, loose and slimy precipitate |
B. | They are non-adherent deposits and can be easily removed |
C. | Formed generally at heated portions of the boiler |
D. | Can be removed by blow down operation |
Answer» C. Formed generally at heated portions of the boiler |
102. |
The propulsion of water into steam drum by extremely rapid, almost explosive boiling of water at the heating surface is called ___________ |
A. | Foaming |
B. | Priming |
C. | Corrosion |
D. | Caustic embrittlement |
Answer» B. Priming |
103. |
The phenomenon during which the boiler material becomes brittle due to accumulation of caustic substances is known as ___________ |
A. | Foaming |
B. | Priming |
C. | Corrosion |
D. | Caustic embrittlement |
Answer» D. Caustic embrittlement |
104. |
Foaming is caused by the formation of ___________ |
A. | Acids |
B. | Alcohols |
C. | Oils and alkalis |
D. | Ketones |
Answer» C. Oils and alkalis |
105. |
The term ‘Sullage’ refers to: |
A. | Fresh wastewater |
B. | Septic wastewater |
C. | Wastewater from kitchen, laundry |
D. | Toxic wastewater |
Answer» C. Wastewater from kitchen, laundry |
106. |
Wastewater can become septic by the loss of: |
A. | Dissolved oxygen content |
B. | Carbon content |
C. | Organic compounds |
D. | Water content |
Answer» A. Dissolved oxygen content |
107. |
Which one of the below is not an attribute of drinking water? |
A. | Aesthetics |
B. | Economic |
C. | Safety |
D. | Source |
Answer» D. Source |
108. |
The extent of water treatment depends on how many factors? |
A. | 5 |
B. | 2 |
C. | 3 |
D. | 4 |
Answer» B. 2 |
109. |
What is added to the water treatment tank to settle the colloidal particles? |
A. | Alum |
B. | Alum and lime |
C. | Lime |
D. | Potash |
Answer» B. Alum and lime |
110. |
Disinfection of water in our country is mainly done by ____________ |
A. | Oxygenation |
B. | Hydration |
C. | Chlorination |
D. | Filtration |
Answer» C. Chlorination |
111. |
Which minerals and in what form are present in ground water? |
A. | Fe & Mn in Ferrous and Manganous |
B. | Fe & Cu in Ferric and Cupric |
C. | Fe & Mn in Ferric and manganous |
D. | Cu & Mn in Cuprous and manganous |
Answer» A. Fe & Mn in Ferrous and Manganous |
112. |
How many types of wastewater treatment plants are there based on the type of wastewater? |
A. | 5 |
B. | 4 |
C. | 2 |
D. | 3 |
Answer» D. 3 |
113. |
On how many conditions does the intervention of wastewater depend on? |
A. | 5 |
B. | 7 |
C. | 6 |
D. | 4 |
Answer» B. 7 |
114. |
The surface water quality is affected by _______ and infiltration from rainfall. |
A. | Precipitation |
B. | Run off |
C. | Wetlands |
D. | Farming |
Answer» B. Run off |
115. |
_________ are constructed for water supply, electricity generation, recreation, irrigation and others. |
A. | Swimming pools |
B. | Ponds |
C. | Reservoirs |
D. | Tanks |
Answer» C. Reservoirs |
116. |
What is the next step after water abstraction in wastewater treatment? |
A. | Supply to consumers |
B. | Treatment |
C. | Combine with stormwater |
D. | Supply to receiving body |
Answer» B. Treatment |
117. |
Which of the following requires aesthetically pleasant water? |
A. | Domestic use |
B. | Industrial use |
C. | Irrigation |
D. | Aquaculture |
Answer» B. Industrial use |
118. |
The addition of substances or energy forms that directly or indirectly alter the nature of the water body is called? |
A. | Water contamination |
B. | Water pollution |
C. | Sanitation |
D. | Water treatment |
Answer» B. Water pollution |
119. |
What is the type of pollution where the pollutants reach the water body in points called? |
A. | Point-source pollution |
B. | Diffuse pollution |
C. | Point-source contamination |
D. | Diffuse contamination |
Answer» A. Point-source pollution |
120. |
What percentage of solids does wastewater contain? |
A. | 0.5% |
B. | 5% |
C. | 0.1% |
D. | 1% |
Answer» C. 0.1% |
121. |
What is the growth of huge amounts of algae and other aquatic plants leading to the deterioration of the water quality called? |
A. | Eutrophication |
B. | Algae growth |
C. | Nitrification |
D. | Denitrification |
Answer» A. Eutrophication |
122. |
The optimum temperature for bacterial activity is in what range? |
A. | 25-35 degree Celsius |
B. | 50 degree Celsius |
C. | 20 degree Celsius |
D. | 40 degree Celsius |
Answer» A. 25-35 degree Celsius |
123. |
The fluoride concentration for prevention of dental caries is ____________ |
A. | 1mg/l |
B. | 2mg/l |
C. | 3mg/l |
D. | 4mg/l |
Answer» A. 1mg/l |
124. |
In which process, the fluoride content of water is raised? |
A. | Chlorination |
B. | Fluoridation |
C. | Defluoridation |
D. | Flocculation |
Answer» B. Fluoridation |
125. |
Which of the following is not used as a fluoride compound? |
A. | Sodium fluoride |
B. | Sodium silico fluoride |
C. | Hydrofluosilicic acid |
D. | Sodium fluro carbonate |
Answer» D. Sodium fluro carbonate |
126. |
Which of the following is the pure compound? |
A. | Sodium fluoride |
B. | Sodium silico fluoride |
C. | Hydrofluosilicic acid |
D. | Sodium fluro carbonate |
Answer» A. Sodium fluoride |
127. |
As far as safer handling is considered, which of the following is used for fluoridation? |
A. | Sodium fluoride |
B. | Sodium silico fluoride |
C. | Hydrofluosilicic acid |
D. | Sodium fluro carbonate |
Answer» C. Hydrofluosilicic acid |
128. |
What happens when water contains 8-20 ppm of fluoride concentration? |
A. | Blue baby disease |
B. | Crippling fluorosis |
C. | Dental fluorosis |
D. | Mottling of teeth |
Answer» B. Crippling fluorosis |
129. |
The process of reducing the fluoride content from water is called _____ |
A. | Chlorination |
B. | Fluoridation |
C. | Defluoridation |
D. | Flocculation |
Answer» C. Defluoridation |
130. |
Which of the following is not used for defluoridation? |
A. | Calcium phosphate |
B. | Copper sulfate |
C. | Alum |
D. | Bone charcoal |
Answer» B. Copper sulfate |
131. |
At which temperature, the bone is calcinated during defluoridation with calcium phosphate? |
A. | 100-200oC |
B. | 200-300oC |
C. | 400-600oC |
D. | 500-800oC |
Answer» C. 400-600oC |
132. |
One cubic metre of bone can treat how much quantity of water containing 3.5 ppm of fluoride? |
A. | 10m3 |
B. | 100m3 |
C. | 1000m3 |
D. | 10000m3 |
Answer» B. 100m3 |
133. |
Which material is used in contact filters for the removal of fluorides? |
A. | Calcium phosphate |
B. | Copper sulfate |
C. | Synthetic tri-calcium phosphate |
D. | Bone charcoal |
Answer» C. Synthetic tri-calcium phosphate |
134. |
Which material is used for removing fluorides from hard water containing 3ppm of fluorides? |
A. | Lime |
B. | Copper sulfate |
C. | Synthetic tri-calcium phosphate |
D. | Bone charcoal |
Answer» A. Lime |
135. |
Fluorex is a special mixture of ____________ |
A. | Di-calcium phosphate and carbon |
B. | Tri-calcium phosphate and hydroxyapatite |
C. | Di-calcium phosphate and phosphoric acid |
D. | Tri-calcium phosphate and carbon |
Answer» B. Tri-calcium phosphate and hydroxyapatite |
136. |
Which of these materials is not added to iron for improving its oxidation resistance? |
A. | Nickel |
B. | Chromium |
C. | Aluminum |
D. | Silicon |
Answer» D. Silicon |
137. |
How much chromium is required to provide oxidation resistance for use over 1000oC? |
A. | 1% |
B. | 6% |
C. | 12% |
D. | 17% |
Answer» D. 17% |
138. |
Molybdenum with hydrogen can be used up to ________ |
A. | 1000oC |
B. | 1500oC |
C. | 2000oC |
D. | 4000oC |
Answer» B. 1500oC |
139. |
% chromium mixed with ______ can be used up to 1100oC. |
A. | Nickel |
B. | Chromium |
C. | Aluminum |
D. | Silicon |
Answer» A. Nickel |
140. |
Which of these metals does not require alloying for oxidation resistance? |
A. | Iron |
B. | Copper |
C. | Aluminum |
D. | Molybdenum |
Answer» C. Aluminum |
141. |
_________ is used to prevent duralumin from corrosion. |
A. | Iron |
B. | Kynal |
C. | Titanium |
D. | Alclad |
Answer» D. Alclad |
142. |
Galvanized ion is made by dipping low carbon steel in molten zinc at ________ |
A. | 100oC |
B. | 150oC |
C. | 200oC |
D. | 450oC |
Answer» D. 450oC |
143. |
Which of these is not a way to prevent intergranular corrosion? |
A. | Reduction of carbon level |
B. | Quenching |
C. | Addition of carbide forming elements |
D. | Reduction of alloying elements |
Answer» D. Reduction of alloying elements |
144. |
Dezincification of brass is prevented by addition of ________ |
A. | Nickel |
B. | Zinc |
C. | Arsenic |
D. | Tungsten |
Answer» C. Arsenic |
145. |
Season-cracking can be prevented by cold-working of brass at _________ |
A. | 15oC |
B. | 100oC |
C. | 300oC |
D. | 550oC |
Answer» C. 300oC |
146. |
How can caustic embrittlement be avoided? |
A. | Addition of nickel |
B. | Increasing potential |
C. | Decreasing carbon |
D. | Adding tannins |
Answer» D. Adding tannins |
147. |
A grit chamber is usually installed ______ primary sedimentation tanks. |
A. | Before |
B. | After |
C. | In between |
D. | In |
Answer» A. Before |
148. |
At what velocity will the particles settle down? |
A. | 0.5 m/s |
B. | 0.3 m/s |
C. | 0.1 m/s |
D. | 0.25 m/s |
Answer» B. 0.3 m/s |
149. |
Grit chambers are constructed to prevent their accumulation in _______ |
A. | Sedimentation tank |
B. | Sludge digesters |
C. | Coagulation tank |
D. | Sand filter |
Answer» B. Sludge digesters |
150. |
What is the cleaning period for manual grit chambers? |
A. | 3 days |
B. | 5 days |
C. | 48 hours |
D. | 1 week |
Answer» D. 1 week |
151. |
Grit chamber is similar to which of the following? |
A. | Screening unit |
B. | Sedimentation tank |
C. | Coagulation tank |
D. | Sand bed |
Answer» B. Sedimentation tank |
152. |
What is the specific gravity of settleable particles in the grit chamber? |
A. | 2.98 |
B. | 2.56 |
C. | 2.65 |
D. | 2.89 |
Answer» C. 2.65 |
153. |
Stoke’s law holds good for Reynolds’s number ______ |
A. | Less than 1 |
B. | Equal to 1 |
C. | Greater than 1 |
D. | Nearer to 1 |
Answer» A. Less than 1 |
154. |
What is the horizontal velocity considered for grit chamber? |
A. | 0.25-0.4m/sec |
B. | 0.6-0.9 m/sec |
C. | 1-2 m/sec |
D. | 3-4m/sec |
Answer» A. 0.25-0.4m/sec |
155. |
What is the detention time considered for aerated grit chamber? |
A. | 5-6 mins |
B. | 2-5 mins |
C. | 1-2 mins |
D. | 3-4 mins |
Answer» B. 2-5 mins |
156. |
Which of these is not a grit removal equipment installed in the aerated grit chamber? |
A. | Screw conveyers |
B. | Tubular conveyers |
C. | Jet pumps |
D. | Communitors |
Answer» D. Communitors |
157. |
What is the amount of air supplied for these grit chambers? |
A. | 1-2 m3/m.min |
B. | 0.2-0.5 m3/m.min |
C. | 0.5-0.8 m3/m.min |
D. | 0.8-1 m3/m.min |
Answer» B. 0.2-0.5 m3/m.min |
158. |
At what depth are the air diffusers placed in the grit chamber? |
A. | 0.6-0.9 m |
B. | 1-2 m |
C. | 0.1-0.4m |
D. | 0.45-0.6 m |
Answer» D. 0.45-0.6 m |
159. |
What is the amount of grit quantities captured by the aerated grit chamber? |
A. | 0.004-0.20 m3/103.m3 |
B. | 0.25 m3/103.m3 |
C. | <0.004 m3/103.m3 |
D. | 0.5 m3/103.m3 |
Answer» A. 0.004-0.20 m3/103.m3 |
160. |
Usually while designing what is the range of the width of the aerated grit chamber assumed? |
A. | 0.5-2 m |
B. | 8-10 m |
C. | 2.5-7.0m |
D. | 12m |
Answer» C. 2.5-7.0m |
161. |
Usually while designing what is the range of length of the aerated grit chamber assumed? |
A. | 7.5-20 |
B. | 4-6 m |
C. | 25 m |
D. | 50 m |
Answer» A. 7.5-20 |
162. |
Usually while designing what is the range of depth of the aerated grit chamber assumed? |
A. | 0.5-2 m |
B. | 8-10 m |
C. | 2-5 m |
D. | 12 m |
Answer» C. 2-5 m |
163. |
Aerated grit chambers are usually designed to remove particles in which range of size? |
A. | 0.1mm diameter |
B. | 0.35 mm diameter |
C. | 0.21 mm diameter |
D. | 0.41 mm diameter |
Answer» C. 0.21 mm diameter |
164. |
Activated sludge process degrade organics and _________ |
A. | Improve nutrients |
B. | Remove nutrients |
C. | Remove odour |
D. | Remove taste |
Answer» B. Remove nutrients |
165. |
What is required to keep the activated sludge suspended? |
A. | Carbon-dioxide |
B. | Nitrogen |
C. | Oxygen |
D. | Ammonia |
Answer» C. Oxygen |
166. |
What does the bacterium use to grow? |
A. | Oxygen |
B. | Organic pollutants |
C. | Water |
D. | Carbon-dioxide |
Answer» B. Organic pollutants |
167. |
________ combines aeration basin and secondary clarifier into single unit. |
A. | Primary clarifier |
B. | Aerobic unit |
C. | Sequential batch reactor |
D. | Secondary clarifier |
Answer» C. Sequential batch reactor |
168. |
What does SBR stand for? |
A. | Secondary batch reactor |
B. | Sequential biological reactor |
C. | Secondary biological reactor |
D. | Sequential batch reactor |
Answer» D. Sequential batch reactor |
169. |
SBR operates as ________ process. |
A. | Batch |
B. | Continuous |
C. | Semi-continuous |
D. | Discontinuous |
Answer» A. Batch |
170. |
When the aeration system shuts off, the basin begins to perform as a ______ |
A. | Primary clarifier |
B. | Secondary clarifier |
C. | Anaerobic unit |
D. | Aeration unit |
Answer» B. Secondary clarifier |
171. |
_______ provides the dual purpose of providing DO and mixing of the mixed liquor and wastewater. |
A. | Flocculation |
B. | Aeration |
C. | Sedimentation |
D. | Clarification |
Answer» B. Aeration |
172. |
Ion-exchange resin is ____________ |
A. | Linear |
B. | Low molecular weight |
C. | Organic polymer with porous structure |
D. | Soluble |
Answer» C. Organic polymer with porous structure |
173. |
Which of the following ion get released from the cation exchange column? |
A. | H+ |
B. | Na+ |
C. | K+ |
D. | Ca+2 |
Answer» A. H+ |
174. |
Which of the following ion get released from the anion exchange column? |
A. | CO3-2 |
B. | OH– |
C. | Cl– |
D. | SO4-2 |
Answer» B. OH– |
175. |
Ion-free water coming out from the exchanger is known as ____________ |
A. | Potable water |
B. | Disinfected water |
C. | Coagulated water |
D. | Demineralised water |
Answer» D. Demineralised water |
176. |
Which of the following statement is incorrect about the demineralised water? |
A. | It is as pure as distilled water |
B. | It is very good for use in high pressure boilers |
C. | It is fit for domestic use |
D. | It can be made either by distillation or by using cation and anion exchangers |
Answer» C. It is fit for domestic use |
177. |
The exhausted cation exchange column is regenerated by passing a solution of ____________ |
A. | Dil. HCl |
B. | Dil. NaCl |
C. | Conc. HCl |
D. | Conc. NaCl |
Answer» A. Dil. HCl |
178. |
The exhausted anion exchange column is regenerated by passing a solution of ____________ |
A. | Dil. KOH |
B. | Conc. KOH |
C. | Conc. NaOH |
D. | Dil. NaOH |
Answer» D. Dil. NaOH |
179. |
In ion-exchange process, the capital cost is _________ and the operational expenses are ______________ |
A. | Low, high |
B. | High, low |
C. | High, high |
D. | Low, low |
Answer» C. High, high |
180. |
The residual hardness in ion-exchange process is ____________ |
A. | 0-2 ppm |
B. | 5-10 ppm |
C. | 10-15 ppm |
D. | 20-30 ppm |
Answer» A. 0-2 ppm |
181. |
How many oxygen atoms are present in the ozone? |
A. | 1 |
B. | 2 |
C. | 3 |
D. | 4 |
Answer» C. 3 |
182. |
_______ is produced by subjecting oxygen to high electric voltage. |
A. | Carbon-monoxide |
B. | Carbon-dioxide |
C. | Pure oxygen |
D. | Ozone |
Answer» D. Ozone |
183. |
Which of the following can be inactivated using ozone? |
A. | Algae |
B. | Fungi |
C. | Protozoa |
D. | All microbes |
Answer» C. Protozoa |
184. |
Which of these is not an advantage of Ozonation? |
A. | Reaction with bacteria |
B. | Organics degradation |
C. | Equipment costs |
D. | Chemicals |
Answer» C. Equipment costs |
185. |
Which of the following is not a disadvantage of Ozonation? |
A. | Chemicals |
B. | Costs |
C. | Energy |
D. | Fire hazard |
Answer» A. Chemicals |
186. |
Which of the following is not removed by Ozonation? |
A. | Iron |
B. | Manganese |
C. | Magnesium |
D. | Bacteria |
Answer» C. Magnesium |
187. |
What is the maximum time required for ozone degradation? |
A. | 15 minutes |
B. | 30 minutes |
C. | 45 minutes |
D. | 60 minutes |
Answer» B. 30 minutes |
188. |
What is the average ozone concentration created during Ozonation? |
A. | 1000 mg/l |
B. | 5000 mg/l |
C. | 10000 mg/l |
D. | 15000 mg/l |
Answer» C. 10000 mg/l |
189. |
Which of the following is not correct regarding Ozonation? |
A. | Does not requires chemicals |
B. | Eliminates bad taste |
C. | Eliminates odour |
D. | Operational costs are low |
Answer» D. Operational costs are low |
190. |
What is the colour of ozone? |
A. | Violet |
B. | White |
C. | Grey |
D. | Colourless |
Answer» D. Colourless |
191. |
Ozone is formed by the interaction of _______ |
A. | UV or O2 |
B. | O and O2 |
C. | O and UV |
D. | O2 and CO |
Answer» A. UV or O2 |
192. |
In which year was the structure of ozone determined? |
A. | 1865 |
B. | 1875 |
C. | 1885 |
D. | 1895 |
Answer» A. 1865 |
193. |
In which year was the ozone named? |
A. | 1829 |
B. | 1839 |
C. | 1849 |
D. | 1859 |
Answer» B. 1839 |
194. |
At what pH ozonation is carried out? |
A. | 8 |
B. | 9 |
C. | 11 |
D. | 7 |
Answer» A. 8 |
195. |
Photo catalysis uses which of the following methods to produce free radicals? |
A. | UV rays |
B. | UV + TiO2 |
C. | Ozone + UV |
D. | TiO2 |
Answer» B. UV + TiO2 |
196. |
How is the electrical requirement for the ozonation process expressed mathematically? |
A. | EE/O =EEt/ Vlog(Ci-Cf) |
B. | EE/O =EEt/ (Ci-Cf) |
C. | EE/O =EEt Vlog(Ci-Cf) |
D. | EE/O =EEt(Ci-Cf) |
Answer» A. EE/O =EEt/ Vlog(Ci-Cf) |
197. |
What are the byproducts of the breakdown of the organic compounds by UV rays? |
A. | CO |
B. | CO2 + H2O |
C. | H2CO3 and water |
D. | CO + H2O |
Answer» B. CO2 + H2O |
198. |
In what range is the EE/O present in order to reduce one log of reduction? |
A. | 0-20 KWH |
B. | 20-265 KWH |
C. | 265-365 KWH |
D. | 365-650 KWH |
Answer» B. 20-265 KWH |
199. |
Primary sludge includes __________ |
A. | Total suspended solids |
B. | Suspended solids |
C. | Removable solids |
D. | Settleable solids |
Answer» D. Settleable solids |
200. |
Which of the following methods are used in rural communities? |
A. | Aerobic digestion |
B. | Mechanical dewatering |
C. | Dewatering |
D. | Composting |
Answer» D. Composting |
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