Transactions of the Illinois State Academy of Science Volume 8 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1915 Excerpt: ...Agr., Bur. of Chem., Circular No. 99. The results from the samples obtained from the purification plants are given in a table. In all cases the arsenic is recorded as arsenic trioxide, As2O3. Five gram samples of the alum were used, as this amount gave stains best suited for comparison with the standards. Quincy and the Rock Island Arsenal each submitted samples from two different manufacturers, therefore twenty-three samples from twenty-one places were examined. TABLE I. ARSENIC AS As.C-3 IN FILTER ALUMS USED IN ILLINOIS Arsenic as As2OB City Pts. per mil Percent Gallons Cairo 1.6.00016 3213 Carlinville 1.8.00018 2856 Charleston 1.2.00012 4283 Chicago and Rogers Park 1.4.00014 3671 E. St. Louis and Granite City.....8.00008 6425 Decatur 1.4.00014 3671 Elgin 1.6.00016 3213 Ft. Sheridan 1.2.00012 4283 Hamilton 1.4.00014 3671 Kankakee.8.00008 6425 Kenilworth 1.4.00014 3671 Lawrenceville 3.0.00030 1713 Macomb 1.6.00016 3213 Moline 1.0.00010 5140 Mt. Carmel _ 2.0.00020 2570 Mt. Vernon 1.2.00012 4283 Pana 1.2.00012 4283 Quincy 1.0.00010 5140 Quincy 4.0.00040 1285 Rock Island 2.0.00020 2570 Rock Island Arsenal 1.6.00016 3213 Rock Island Arsenal 1.0.00010 5140 Streator 3.4.00034 1512 Gallons of water containing a minimum medicinal dose of 2 mg. when the water Is treated with 6 grains of alum per gallon, provided that all the arsenic remains In solution. The results obtained by analyzing alum used in Illinois clearly show that arsenic in exceedingly small amounts is always present in filter alums. We find a minimum of 0.8 parts per million (.00008 per cent) and a maximum of 4.0 parts per million (.0004 per cent) of arsenic as As2O3 in the alum used by Illinois water purification plants. If a water were treated with alum containing the maximum amount of arsenic found...