pH Neutralization For Pollution Control

Mahesh Parikh Daniel Boone
6710 N. Washetenaw Ave.
Chicago IL 60645
(312) 534-2160

Objectives: 1. Acid and Base Recognition 2. Neutralization of Acid and Base Chemicals for Pollution Control 3. Practical Application For Chemical Industries Materials needed: Vinegar (Acetic acid) Baking Soda Distilled Water Hydrogen peroxide Detergent All purpose cleaner Industrial effluent Caustic lye (NaOH) pHydrion paper Ammonia Lime Beakers, test tubes, stirrers Strategy: Divide whole class into four groups. Each person from respective group takes vinegar solution in beaker about 10mL. Each group should also collect pHydrion paper. Then each group has to dip pHydrion paper into vinegar solution and observe the color. From the color of the pHydrion paper, each group will decide pH numerical value by referring to the color chart. Each group should record the pH value in record data sheet. From pH value, each group will be able to decide whether vinegar solution is acidic or alkaline. Second chemical solution to be given to each group is washing soda. Repeat the same procedure. Third chemical solution to be given to each group is hydrogen peroxide. Repeat the same procedure. Then the teacher demonstrates dilute hydrochloric acid to show its pH value, that is acidic. Next, pH of mild detergent is to be tested, that is almost neutral. Other solutions we tested were all purpose cleaner, ammonia, caustic lye, and industrial effluent. Thereafter ask each group to make a chart. Let them prepare three columns, one for acid, one for base, and one for neutral. Discussed results with students. Have students continue filling results in data chart. After testing industrial effluent class discussed consequences of its disposal to sewer system. Take 20mL of hydrochloric acid in beaker. Add same amount of lime (CaCO3)
into beaker. Stir it and measure its pH value. If mixed solution is not
achieving pH value as 7 then keep on adding lime solution until it achieves pH
value as 7. At this point, titration is said to be completed. Explain to
students that quantity of lime material required for neutralization depends on
concentration of acid.

After this, explain to the students that is why lime is commonly used for
neutralizing industrial effluent. The reasons explained were that lime is a
strong base, economical, and most to use.

Second neutralization process shown to students was caustic lye, and
strong hydrochloric acid.

Application: Use overhead projector to show transparency of standard model of small scale industry pollution treatment plant, explain its operation, and design. Conclusion: During enrichment sessions, we had discussed the importance of neutralization process. Students explained that if industrial effluent is not neutralized then effluent will corrode the sewer pipelines and it will penetrate inside the soil. Seepage of effluent remains as ground water so when a tube well is used, the water will come out polluted. This polluted water is toxic and harmful for domestic purpose.
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