Introduction to alkalinity test and standard solutions
Download
1 / 9

introduction to alkalinity test and standard solutions - PowerPoint PPT Presentation


  • 311 Views
  • Uploaded on

Introduction to Alkalinity Test and Standard Solutions. By Douglas Rittmann, Ph.D., P.E. Water/Wastewater Consultant Presented to CE 4153 On February 7, 2006. General Considerations. 1. Its capacity to neutralize acids or its buffering capacity. 2. 3 major classes of materials.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' introduction to alkalinity test and standard solutions ' - daniel_millan


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Introduction to alkalinity test and standard solutions
Introduction to Alkalinity Testand Standard Solutions

By

Douglas Rittmann, Ph.D., P.E.

Water/Wastewater Consultant

Presented to

CE 4153

On

February 7, 2006


General considerations

General Considerations

1. Its capacity to neutralize acids or its buffering capacity.

2. 3 major classes of materials

A. Bicarbonates, HCO3- - ≤ pH 8.3

B. Carbonates, CO3- - >pH 8.3 < pH 10

C. Hydroxide, OH- - > pH 10.0


Sanitary significance
Sanitary Significance

1. Lime/Soda Ash Softening

2. Effects on Coagulant Dosing

3. Total Dissolved Solids compliance

4. Industrial Wastes Discharges

5. Calcium Carbonate Stability


Method of analysis
Method of Analysis

1. Phenolphthalein Alkalinity

A. Phenolphthalein indicator

B. pH 8.3 endpoint of titration

C. Measures Carbonates and Hydroxide ions

2. Total Alkalinity

A. Bromcresol green or Methyl Orange indicator

B. pH 4.5 endpoint of titration

C. Measures Bicarbonates


Methods of expressing
Methods of Expressing

1. Phenolphthalein Alkalinity as CaCO3

P. Alk. = ml 0.02N sulfuric acid (1000/ml sample) = mg/L as CaCO3

2. Total Alkalinity as CaCO3

T. Alk. = ml 0.02N sulfuric acid X (1000/ml sample) = mg/L as CaCO3

3. Hydroxide, Carbonate, and Bicarbonate Alkalinity as CaCO3



Standard solutions
Standard Solutions

  • General Considerations

    1. Saves Time in calculating results

    2. Selection of Proper Normality is convenient

    * 1 mg/ml or 1000mg solution

    * 1/eq.wt., example: Alkalinity as CaCO3 = 0.02 N

    3. Preparation of Solution of Proper Normality

    * Material of Known purity is weighed & transferred to volumetric flask

    * Purchase Solutions of known Normality


Preparation of 1n acid solution
Preparation of 1N Acid Solution

* Sulfuric acid used for Alkalinity Test

1 GMW = 98 g pure H2SO4 = 2.016 g H+

1 GMW/2 = 49 g pure H2SO4 = 1.008 g H+

Acid is 96% pure, then 49/0.96 = 51 g = 1.008 g H+

Make 5% stronger = 51 X 1.05 = 53.5 g

Procedure: Weigh about 53g of conc. acid into a small beaker on

Trip balance. Place 500 ml of distilled water in 1-liter graduated cylinder

And add the acid to it. Rinse the contents of the beaker into the cylinder

With distilled water, and add water to the 1-liter mark. Mix by pouring

Back and forth from the cylinder into a large beaker. Cool to room temp.


Primary standard
Primary Standard

* Sodium Carbonate is a convenient primary standard

MW = 106 of Na2CO3

1EW or 1N = 53g/L when reacting with H2SO4 to pH 4.5, T. Alk endpoint

Preparation of 0.02 N Acid or N/50 can be made from 1N based on

ml X N = ml X N

Example: ml X 1.0 = 1000 X 0.02

ml = 20


ad