environmental engineering

Column I presents common air pollutants, and column II presents treatment technologies commonly employed to control air pollutants. Air pollutant 1 Dust (size 5-25 µm) 2 Carbon mon...

The 2.4 ml of raw sewage is diluted to 240 ml. The Dissolved Oxygen (DO) of the diluted sample at the beginning of Biochemical Oxygen Demand (BOD) test was 8 mg/l and it was 6 mg/l...

The average sewage from a city is 90 million litres per day and the average 5-day Biochemical Oxygen Demand (BOD5) is 300 mg/l. Average standard BOD5 of the domestic sewage is 0.08...

The bacteria mainly responsible for crown corrosion in a sewer is ________.

Fecal Coliform (FC) concentration in river water was measured as 10780 cfu/100 ml. The FC concentration after the conventional water treatment, but before chlorination, was measure...

Identify the treatment technology/technologies NOT recommended for highly biodegradable organic solid wastes.

The Surface Overflow Rate (SOR) in a rectangular sedimentation tank is 45 m³/m²/d. Minimum diameters of spherical inorganic and organic particles expected to be completely removed...

A compound has a general formula C_aH_bO_cN_d and molecular weight 187. A 935 mg/l solution of the compound is prepared in distilled deionized water. The Total Organic Carbon (TOC)...

Which one of the following products is NOT obtained in anaerobic decomposition of glucose?

A 2m x 2m tank of 3 m height has inflow, outflow and stirring mechanisms. Initially, the tank was half-filled with fresh water. At t = 0, an inflow of a salt solution of concentrat...

Activated carbon is used to remove a pollutant from wastewater in a mixed batch reactor, which follows first-order reaction kinetics. At a reaction rate of 0.38 /day, the time (in...

An organic waste is represented as C240O200H180N5S. (Atomic weights: S-32, H-1, C-12, O-16, N-14). Assume complete conversion of S to SO2 while burning. SO2 generated (in grams) pe...

Which of the following is/are NOT active disinfectant(s) in water treatment?

For the elevation and temperature data given in the table, the existing lapse rate in the environment is ________ °C/100 m (round off to two decimal places). Elevation from ground...

Match the following air pollutants with the most appropriate adverse health effects: Air pollutant (P) Aromatic hydrocarbons (Q) Carbon monoxide (R) Sulfur oxides (S) Ozone Health...

The theoretical aerobic oxidation of biomass (C5H7O2N) is given below: C5H7O2N + 5O2 → 5CO2 + NH3 + 2H2O The biochemical oxidation of biomass is assumed as a first-order reaction w...

The total hardness in raw water is 500 milligram per liter as CaCO3. The total hardness of this raw water, expressed in milligram equivalent per liter, is (Consider the atomic weig...

A process equipment emits 5 kg/h of volatile organic compounds (VOCs). If a hood placed over the process equipment captures 95% of the VOCs, then the fugitive emission in kg/h is

Henry's law constant for transferring O2 from air into water, at room temperature, is $1.3 \frac{mmol}{liter-atm}$. Given that the partial pressure of O2 in the atmosphere is 0.21...

In a water sample, the concentrations of Ca2+, Mg2+ and HCO3- are 100 mg/L, 36 mg/L and 122 mg/L, respectively. The atomic masses of various elements are: Ca = 40, Mg = 24, H = 1,...

Two discrete spherical particles (P and Q) of equal mass density are independently released in water. Particle P and particle Q have diameters of 0.5 mm and 1.0 mm, respectively. A...

At a municipal waste handling facility, 30 metric ton mixture of food waste, yard waste, and paper waste was available. The moisture content of this mixture was found to be 10%. Th...

A sewage treatment plant receives sewage at a flow rate of 5000 m³/day. The total suspended solids (TSS) concentration in the sewage at the inlet of primary clarifier is 200 mg/L....

A 2% sewage sample (in distilled water) was incubated for 3 days at 27 °C temperature. After incubation, a dissolved oxygen depletion of 10 mg/L was recorded. The biochemical oxyge...

A sample of air analyzed at 25 °C and 1 atm pressure is reported to contain 0.04 ppm of SO2. Atomic mass of S = 32, O = 16. The equivalent SO2 concentration (in µg/m³) will be ____...

A water treatment plant has a sedimentation basin of depth 3 m, width 5 m, and length 40 m. The water inflow rate is 500 m³/h. The removal fraction of particles having a settling v...

A 50 mL sample of industrial wastewater is taken into a silica crucible. The empty weight of the crucible is 54.352 g. The crucible with the sample is dried in a hot air oven at 10...

A water filtration unit is made of uniform-size sand particles of 0.4 mm diameter with a shape factor of 0.84 and specific gravity of 2.55. The depth of the filter bed is 0.70 m an...

A water sample is analyzed for coliform organisms by the multiple-tube fermentation method. The results of confirmed test are as follows: Sample size (mL) 0.01 0.001 0.0001 Number...

A water supply scheme transports 10 MLD (Million Litres per Day) water through a 450 mm diameter pipeline for a distance of 2.5 km. A chlorine dose of 3.50 mg/litre is applied at t...

A gaseous chemical has a concentration of 41.6 µmol/m³ in air at 1 atm pressure and temperature 293 K. The universal gas constant R is 82.05×10⁻⁶ (m³ atm)/(mol K). Assuming that id...

A stream with a flow rate of 5 m³/s is having an ultimate BOD of 30 mg/litre. A wastewater discharge of 0.20 m³/s having BOD₅ of 500 mg/litre joins the stream at a location and ins...

A completely mixed dilute suspension of sand particles having diameters 0.25, 0.35, 0.40, 0.45 and 0.50 mm are filled in a transparent glass column of diameter 10 cm and height 2.5...

A sample of air analysed at 0°C and 1 atm pressure is reported to contain 0.02 ppm (parts per million) of NO2. Assume the gram molecular mass of NO2 as 46 and its volume at 0°C and...

A wastewater is to be disinfected with 35 mg/L of chlorine to obtain 99% kill of micro-organisms. The number of micro-organisms remaining alive (Nt) at time t, is modelled by Nt =...

A city generates 40×10⁶ kg of municipal solid waste (MSW) per year, out of which only 10% is recovered/recycled and the rest goes to landfill. The landfill has a single lift of 3 m...

A flocculation tank contains 1800 m³ of water, which is mixed using paddles at an average velocity gradient G of 100/s. The water temperature and the corresponding dynamic viscosit...

A coal containing 2% sulfur is burned completely to ash in a brick kiln at a rate of 30 kg/min. The sulfur content in the ash was found to be 6% of the initial amount of sulfur pre...

A water sample analysis data is given below. Ion Concentration, mg/L Atomic Weight Ca²⁺ 60 40 Mg²⁺ 30 24.31 HCO₃⁻ 400 61 The carbonate hardness (expressed as mg/L of CaCO₃, up to o...

The equivalent sound power level (in dB) of the four sources with the noise levels of 60 dB, 69 dB, 70 dB and 79 dB is _________

The ultimate BOD (L₀) of a wastewater sample is estimated as 87% of COD. The COD of this wastewater is 300 mg/L. Considering first order BOD reaction rate constant k (use natural l...

1 TCU is equivalent to color produced by

MPN index is measure of one of the following: