WASTE WATER ANALYSIS 2:-MANGANESE, ZINC & SULFIDE-

Test	Parameter	Duration	Method
Wastewater analysis 1	COD	3 hours	Hach 8000
	pH	15 minutes
	Temperature	15 minutes
	SS	15 minutes	Hach 8006
Wastewater analysis 2	Manganese	15 minutes	Hach 8149
	Zinc	15 minutes	Hach 8009
	Sulfide	15 minutes	Hach 8131

EXP 1 : MANGANESE

OBJECTIVE

1. To determine manganese concentration in wastewater sample

INTRODUCTION

The PAN method is a highly sensitive and rapid procedure for detecting low levels of manganese. An ascorbic acid reagent is used initially to reduce all oxidized forms of manganese to Mn2+. An alkaline-cyanide reagent is added to mask any potential interferences. PAN Indicator is then added to combine with the Mn2+ to form an orange-colored complex. Test results are measured at 560 nm.

EQUIPMENT/APPARATUS

Alkaline Cyanide Reagent 12 drops

Ascorbic Acid Powder Pillows 2

PAN Indicator Solution, 0.1% 12 drops

Deionized Water 10 mL

Sample Cells, 1-inch square, 10-mL 2

Stoppers for 18 mm tube 2

PROCEDURES

1. Press STORED PROGRAMS.

2. Select the test.

3. Blank Preparation:

Pour 10.0 mL of deionized water into a square sample cell.

4. Prepared Sample:

Pour 10.0 mL of sample into another square sample cell.

5. Add the contents of one Ascorbic Acid Powder Pillow to each cell. Stopper and invert to dissolve the powder.

6. Add 12 drops of Alkaline-Cyanide Reagent Solution to each cell. Swirl gently to mix. A cloudy solution may form. The turbidity should dissipate after step 7.

7. Add 12 drops of PAN Indicator Solution, 0.1%, to each sample cell. Swirl gently to mix. An orange color will develop in the sample if manganese is present.

8. Press TIMER>OK. A two-minute reaction period will begin.

9. When the timer expires, wipe the blank and insert it into the cell holder with the fill line facing right.

10. Press ZERO. The display will show: 0.000 mg/L Mn

11. Wipe the prepared sample and insert it into the cell holder with the fill line facing right.

12. Press READ. Results are in mg/L Mn.

DISCUSSION

Compare the manganese concentration with Environmental Quality Act 1974

REFFERENCE

DR 2800 Spectrophotometer Procedures Manual November 2005 Edition 1

EXP 2 : ZINC

OBJECTIVE

To determine zinc concentration in wastewater sample

INTRODUCTION

Zinc and other metals in the sample are complexed with cyanide. Adding cyclohexanone

causes a selective release of zinc. The zinc reacts with 2-carboxy-2'-hydroxy-5'-sulfoformazyl benzene (zincon) indicator to form a blue-colored species. The blue color is masked by the brown color from the excess indicator. The intensity of the blue color is proportional to the amount of zinc present. Test results are measured at 620 nm.

EQUIPMENT/APPARATUS

Zinc Reagent Set:

Cyclohexanone 0.5 mL

ZincoVer 5 Reagent Powder Pillow 1

Cylinder, graduated mixing, 25-mL 1

Sample Cells, 1-inch square glass, 10 mL 2

PROCEDURES

CAUTION

ZincoVer 5 Reagent contains cyanide and is very poisonous if taken internally or if fumes are inhaled. Do not add to an acidic sample (pH <>

1. Press STORED PROGRAMS.

2. Select the test.

3. Fill a 25-mL graduated mixing cylinder with 20 mL of sample.

4. Add the contents of one ZincoVer 5 Reagent Powder Pillow to the cylinder. Stopper.

5. Invert several times to dissolve the powder completely. Inconsistent readings may result for low zinc concentrations if all the particles are not dissolved. The sample should be range. If the sample is brown or blue, either the zinc concentration is too high, or an interfering metal is present. Dilute the sample and repeat the test.

6. Blank Preparation: Pour 10 mL of the solution into a square sample cell.

7. Prepared Sample: Use a plastic dropper to add 0.5 mL of cyclohexanone to the remaining solution in the graduated cylinder.

8. Press TIMER>OK. A 30-second reaction period will begin. During the reaction period, stopper the cylinder and vigorously shake the prepared sample. The sample will be reddish-orange, brown, or blue, depending on the zinc concentration.

9. Press TIMER>OK. A three-minute reaction period will begin. During this reaction period, complete step 10.

10. Pour the prepared sample solution from the cylinder into a second square sample cell.

11. When the timer expires, wipe the blank and insert it into the cell holder with the fill line facing right. Press ZERO. The display will show: 0.00 mg/L Zn

12. Wipe the prepared sample and insert it into the cell holder with the fill line facing right. Press READ. Results are in mg/L Zn.

DISCUSSION

Compare the zinc concentration with Environmental Quality Act 1974

REFERENCE

DR 2800 Spectrophotometer Procedures Manual November 2005 Edition 1

EXP 3 : SULFIDE

OBJECTIVE

To determine sulfide concentration in wastewater sample

INTRODUCTION

Hydrogen sulfide and acid-soluble metal sulfides react with N,N-dimethyl-p-phenylenediamine sulfate to form methylene blue. The intensity of the blue color is proportional to the sulfide concentration. High sulfide levels in oil field waters may be determined after proper dilution. Test results are measured at 665 nm.

EQUIPMENT/APPARATUS

Sulfide 1 Reagent 2 mL

Sulfide 2 Reagent 2 mL

Water, deionized 25 mL

Pipet, serological, 10-mL 1

Pipet Filler, safety bulb 1

Sample Cells, 1-inch square, 10 mL, matched pair 2

Stopper for 18-mm tube 2

PROCEDURES

1. Press STORED PROGRAMS.

2. Select the test.

3. Prepared Sample: Avoiding excess agitation of the sample, use a pipet add 10 mL of sample to a square sample cell.

4. Blank Preparation: Measure 10 mL of deionized water into a second square sample cell.

5. Use the calibrated dropper to add 0.5 mL of Sulfide 1 Reagent to each cell. Swirl to mix.

6. Use the calibrated dropper to add 0.5 mL of Sulfide 2 Reagent to each cell.

7. Cap the cell and immediately invert to mix. A pink color will develop, then the solution will turn blue if sulfide is present.

8. Press TIMER>OK. A five-minute reaction period will begin.

9. When the timer expires, wipe the blank and insert it into the cell holder with the fill line facing right.

10. Press ZERO. The display will show: 0 μg/L S2–

11. Wipe the prepared sample and insert it into the cell holder with the fill line facing right.

12. Press READ. Results are in μg/L S2–.

DISCUSSION

Compare the sulfide concentration with Environmental Quality Act 1974

REFERENCE

DR 2800 Spectrophotometer Procedures Manual November 2005 Edition 1