Hydrazine , iron analysis - water treatment plant

Analysis of co2 in degaser

N/50 NaOH:

• 20 cc of N/1 NaOH is diluted to 1000 cc with demineralised water.
• Standarise it against N.50 H2SO4. 10 cc of N/50 NAoH should consume 10 cc of N/50 H2SO4 using phelophthalein indicator.
•  Prepare Phenolphthelin and Methyl orange indicators. as per 7.13 and 7.14 of the work instruction No. SSC/I&T/007/001 for the determination of P and M alkalinity.
• In two 250 ml conical flasks take 100 cc of the water sample to be tested separately.
• In the first flask add three drops of phenolphthelein indicator and titrate against N/.50 NaOH note the reading (A).
• In the 2nd flask add 3 drops of methyle orange indicator and titrate against N/50 NaOH and note the reading (B).

Calculation :

 (B - A) x 8.8 = CO2 presents in ppm (parts per million) in the sample.

ANALYSIS OF HYDRAZINE IN WATER 

Dissolve 0.328 gm of Hydrazine dihydrochloride (N2H4 2HCl) in 100 ml of D.M. water (demineralised water) add 10 ml of HCl (SP Gr 1.19) and dilute to 1 litre in a flask and mix well by shaking to get 1 mg/ml of hydrazine.

Standard hydrazine solution (1ml = .001 mg) : 

• Pipette out of 1 ml of stock soution, prepared in 14.1 into a 100 ml measuring flask and dilute with D.M. water up to the mark and mix well.
• Dissolve 2 gm Para Dimethylamino benzaldehyde in 100 ml of Menthanol (Methyl alcohol ) and add 10 ml conc. HCl (SP gr 1.19) . Mix well and keep in a brown colour bottle away from light.

Colour Develpopment :

• Take 50 cc of water sample in a 100 cc beaker.
• Add 2.5 ml of para - dimethylamino benzaldehyde solution into a beaker and mix well.
• Allow 15 minutes to complete colour development.
• Develop the colour with a known standard hydrazine solution (14.2) in the same manner.

Measurement by spectronic 20D

• Select 458 mm of wave length by wave length control knob.
• Set the mode to Transmittance by pressing mode select control until transmittance LED is lit.
• With sample compartment empty and cover glanes adjust zero control so that the meter reads 0.000 T.
• Set the mode to Absorbance by pressing mode select control until absorbance LED is lit. Insert the test tube filled with Demineralised water and close the cover. Adjust absorbance control to 0.000 A.
• Set the mode to concentration by pressing the mode select control until concentration LED is lit. Insert test tube filled with known value of standard solution (prepared as in No. 14.3) and use the increase or decrease keys to set known value of standard in meter display.
• Rinse the test tube with the sample solution (14.3) and then fill the test tube with the sample solution (14.3 ) and insert in the sample compartment. Close the cover and read the value in the meter display directly.

Report

Report the meter reading display directly as value of Hydrazine in the sample.

ANALYSIS OF IRON IN WATER

Preparation of standard solution:

• Mix equal volumes of conc. HCl and distilled water to get 1:1 HCl solution.
• Dissolve 20 gms of Hydroxylamine Hydrochloride in 100 cc. of distilled water to prepare a 20% W/V Hydroxylamine hydrocloride solution.
• Dissolve 35 gms of sodium Acetate in 100 cc. of distilled water to prepare 35% Sodium Acetate solution.
• Dissolve 1gm of O-Phenanthrolein in 10 ml of methanol and make the volume to 100 cc. with distilled water.

Analysis of Iron in water:

• Take 50 cc of the water sample in a 100 cc. clean beaker. Add 1 cc. of 1:1 HCl followed by 1 cc of 20% hydroxylamine  hydrocloride solution and boil it till the volume reduces to half its initial volume.
• Cool the solution and add 4 ml. of  35% Sodium Acetate soln. to make the pH in between 2.9 and 3.3.
• Add 1cc. of O-phenanthralein soln. and wait for 10 minutes to complete the development of orange red colour and make the volume to 50 cc. with distilled water.
• In the same way develop a standard iron solution and measure the concentration of iron in the water sample against the standard in a 20D spectrometer at 510 nm.

ANALYSIS OF ZINC IN WATER

2N Sodium Acetate Solution :

• Dissolve 68 gm of sodium Acetate in 250 cc of demineralised water.
• 1:7 Acetic Acid Solution : Mix 10 ml acetic acid with 70 ml of demineralised water.

Acetate Buffer

Mix equal volumes of 2N Sodium Acetate and 1:7 Acetic Acid.

Sodium Thiosuphate 

• Dissolve 25 gms of sodium thiosulphate in 100 ml of Demineralised water.
• 16.5 Dithiozone
• Dissolve 25 mg of Dithiozone in 250 ml of carbon tetrachloride.
• Take 10 cc of water sample in a separating funnel. Add 1 cc of sodium thiosulphate and 5 cc of sodium Acetate buffer. Then add 1 cc of Dithizone and 9 cc of carbon tetrachloride and shake vigorously. Compare the colour developed in carbontetracholride layer with the colour of a standard zine solution in the same way either visually or photometrically.

ANALYSIS OF COPPER IN WATER

Preparation of standard solution 

• Mix equal volumes of cocn. HCl and conc. HNO3 to prepare a standard 1:1 solution of HCl and HNO3 .
• Dissolve 20 gms of Hydroxylamine Hydrochloride in 100 cc of distilled water to prepare a 20% W/V Hydroxylamine hydrochloride solution.
• Dissolve 35 gms of Sodium Acetate in 100 cc. of distilled water.
• Dissolve. 1 gm of Neopcuprine in 10 ml. of isopropyl alcohol and make it up to 100 cc. with distilled water to prepare the standard neocuprine solution.

Analysis of copper in water :

• Take 50 cc. of the water sample in a 100 cc. clean beaker. Add 1 cc. of 1 : 1 HCl & HNO3 followed by 2 cc of 20% hydroxylamine hydrochloride solution and boil it till the volume reduces to half its initial volume.
• Cool and add 12 cc. of 35% Sodium Acetate soln. to make the pH in between 4 & 6.
• Add 2 cc. of Neocuprine soln. and wait for 15 minutes to complete the development of yellow colour and make up to 50 cc. with distilled water.
• In the same way develop a standard copper solution and measure the concentration of copper in the water sample against the standard in a 20D sopectrometer at 457 nm.