AWWA-B408-2003.pdf

ANSI/AWWA 8408-03 (Revision of ANSI/AWWA 6408-98) ' American Water Works Association The Authoritative Resource for Safe Drinking WaterSM A WA Standard Liquid Polyaluminum Chloride Ilr, -imn American National Standards Institute Effective date: Jan. 1 , 2004. First edition approved by AWWA Board of Directors Jan. 31, 1993. This edition approved June 19, 2003. Approved by American National Standards Institute Oct. 28, 2003. 6666 West Quincy Avenue Denver, CO 80235-3098 www.awwa.org 1 T 800.926.7337 Advocacy Cornrn mica tions Conferences Education and Training b Science and Technology Sections AWWA Standard This document is an American Water Works Association (AWWA) standard. It is -not a specification. AWWA standards describe minimum requirements and do not contain all of the engineering and administrative information normally contained in specifications. The AWWA standards usually contain options that must be evaluated by the user of the standard. Until each optional feature is specified by the user, the product or service is not fully defined. AWWA publication of a standard does not constitute endorsement of any product or product type, nor does AWWA test, certify, or approve any product. The use of AWWA standards is entirely voluntary. AWWA standards are intended to represent a consensus of the water supply industry that the product described will provide satisfactory service. When AWWA revises or withdraws this standard, an official notice of action will be placed on the first page of the classified advertising section of Journal AWWA. The action becomes effective on the first day of the month following the month of Journal AWWA publication of the official notice. American National Standard An American National Standard implies a consensus of those substantially concerned with its scope and provisions. An American National Standard is intended as a guide to aid the manufacturer, the consumer, and the general public. The existence of an American National Standard does not in any respect preclude anyone, whether that person has approved the standard or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not conforming to the standard. American National Standards are subject to periodic review, and users are cautioned to obtain the latest editions. Producers of goods made in conformity with an American National Standard are encouraged to state on their own responsibility in advertising and promotional materials or on tags or labels that the goods are produced in conformity with particular American National Standards. CAUTION NOTICE: The American National Standards Institute (ANSI) approval date on the front cover of this standard indicates completion of the ANSI approval process. This American National Standard may be revised or withdrawn at any time. ANSI procedures require that action be taken to reaffirm, revise, or withdraw this standard no later than five years from the date of publication. Purchasers of American National Standards may receive current information on all standards by calling or writing the American National Standards Institute, 25 W. 43rd St., Fourth Floor, New York, NY 10036; (212) 642-4900. AWWA unites the drinking water community by developing and distributing authoritative scientific and technological knowledge. Through its members, AWWA develops industry standards for products and processes that advance public health and safety. AWWA also provides quality improvement programs for water and wastewater utilities. All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopy, recording, or any information or retrieval system, except in the form of brief excerpts or quotations for review purposes, without the written permission of the publisher. Copyright O 2004 by American Water Works Association Printed in USA II -,-,- Committee Personnel The A W A Standards Committee on Iron Salts, Aluminum Salts, and Related Coagulant Aids, which reviewed and approved this standard, had the following personnel at the time of approval: Consumer Members B.S. Aptowicz, Philadelphia Water Department, Philadelphia, Pa. T.A. Barber Jr., Coca-Cola Company, Atlanta, Ga. J.I? Corless Jr., Rockville, Md. C.A. Owen, Tampa Bay Water Department, Clearwater, Fla. R.S. Schultz, Bloomington, Ill. J.S. Trotter, City of Bloomington Utilities, Bloomington, Ind. D.I? Wolz, Clean Water Plant, Wyoming, Mich. General Interest Members M.B. Alvarez, CH2M Hill Inc., Orlando, Fla. K.K. Au, Greeley spillage may cause a fire or liberate dangerous gases. 12 AWWA 6408-03 3. Sodium chloride solution, standard, 0.05N. Dry approximately 3.1 g of sodium chloride'in a weighing dish in an oven at 105“ to 110°C for 2 hr. Cool the crystals to room temperature in a desiccator. Weigh 2.9221 g of the dried sodium chloride to the nearest 0.0001 g in a tared weighing bottle. Using a water-wash bottle, quantitatively transfer the crystals through a powder funnel into a 1,000-mL volumetric flask. Add about 150 mL of deionized water and swirl to dissolve the crystals. Dilute to the mark at 20°C with deionized water and mix thoroughly. Store the solution in a polyethylene bottle. 4. Iron indicator solution. To a 1,500-mL beaker add 62 g of ferric ammonium sulfate, FeNHq(S04)2.12H20, and 500 mL of deionized water. Stir until the crystals are dissolved. Add 438 mL of concentrated nitric acid and mix. Store the solution in a polyethylene bottle. 5. Potassium thiocyanate solution, 0.05N. Weigh 4.86 g of potassium thiocyanate to the nearest 0.01 g in a tared weighing bottle. Quantitatively transfer the crystals through a powder funnel into a 1,000-mL volumetric flask. Add about 2 50 mL of deionized water and swirl to dissolve the crystals. Dilute to the mark with deionized water and mix thoroughly. Store the solution in a polyethylene bottle. 6. Benzyl alcohol. Dispense from an amber-glass dropping bottle. Benzyl alcohol vapor is irritating to the eyes, nose, and throat; the liquid can burn skin and eyes and also may be readily absorbed through the skin. It is combustible. Keep the reagent away from heat or flame. 7. Silver nitrate solution, standard 0.05N. Weigh 8.495 g of silver nitrate to the nearest 0.001 g in a tared weighing bottle. Quantitatively transfer the crystals through a powder funnel into a 1,000-mL volumetric flask. Add about 250 mL of deionized water and swirl to dissolve the crystals. Dilute to the mark with deionized water and mix thoroughly. Store the solution in a tightly stoppered amber-glass bottle. Standardize the solution as follows: a. Pipette 25.0 mL of the standard 0.05Nsodium chloride solution into each of three 500-mL glass-stoppered Erlenmeyer flasks. Determine the temperature of the sodium chloride solution and correct the volume pipetted to 20°C (Sec. 5.7.5131, Table 2). Carry each flask through the remaining steps of the procedure. b. Add 100 mL of deionized water and 5 mL of iron indicator solution. Swirl to mix. Using a 50-mL class A burette, add 27.0 mL of the silver nitrate solution being standardized, while swirling vigorously. Record the exact volume of the silver nitrate solution added to the nearest 0.01 mL, determine its temperature, and correct the volume to 20°C (Sec. 5.7.53, Table 1). LIQUID POLYALUMINUM CHLORIDE 13 Table 2 Temperature corrections for volumetric solutions mL Correction per mL Used* Factor + Temperature N/20 or less N110 NI 1 NI20 or less NI10 NI 1 “C solutions solutions solutions solutions solutions solutions 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 +0.0008 +0.0006 +0.0005 +0.0003 +0.0002 0.0000 -0.0002 -0.0004 -0.0006 -0.0008 -0.00 1 o -0.0013 -0.0015 -0.0018 -0.0020 -0.0023 +0.0008 +0.0007 +0.0005 +0.0004 +0.0002 0.0000 -0.0002 -0.0004 -0.0006 -0.0009 -0.001 1 -0.0013 -0.0016 -0.00 19 -0.0021 -0.0024 +0.0011 +0.0009 +0.0007 +0.0005 +0.0003 0.0000 -0.0003 -0.0005 -0.0008 -0.00 1 2 -0.0015 -0.00 18 -0.0022 -0.0025 -0.0029 -0.0033 1 .O008 1 .O006 1.0005 1 .O003 1 .o002 1 .o000 0.9998 0.9996 0.9994 0.9992 0.9990 0.9987 0.9985 0.9982 0.9980 0.9977 1 .O008 1 .O007 1.0005 1.0004 1 .o002 1 .o000 0.9998 0.9996 0.9994 0.9991 0.9989 0.9987 0.9984 0.9981 0.9979 0.9976 1.0011 1 .O009 1.0007 1.0005 1.0003 1 .o000 0.9997 0.9995 0.9992 0.9988 0.9985 0.9982 0.9978 0.9975 0.9971 0.9967 *Apply correction to mL used to obtain corrected volume or +Multiply factor by mL used to obtain corrected volume. c. Add 10 drops of benzyl alcohol, stopper the flask, and shake it vigorously for 30 seconds. Place a 500-mL Erlenmeyer flask beneath a long-stem funnel fitted with Whatman 42 or equivalent filter paper. Transfer the contents from the stoppered flask to the funnel. Rinse this flask with about 5 mL of deionized water, stopper the flask, and thoroughly shake the rinse water around in the flask. Transfer the rinse water to the filter. Repeat the rinsing and the transfer of the rinse water. A complete transfer of the precipitate to the filter is not necessary. Wash the precipitate on the filter twice with cold water and collect the washings with the filtrate. Using a class A burette, slowly and while constantly swirling, titrate the combined filtrate, 14 A W A B408-03 rinse water, and washings with 0 . 0 5 potassium thiocyanate solution until a faint red color persists. - (Eq 7) (mL NaC1 at 2O0C)(0.05O0) (mL AgNO, at 2OOC) (mL KSCN x F2) normality of AgNO, = d. Determine the factor F2 as follows: Add about 9 mL of the silver nitrate solution from the 50-mL burette to a 250-mL Erlenmeyer flask. Add 100 mL of water and 5 mL of iron indicator solution. Swirl to mix. Titrate slowly with the KSCN solution from the 10-mL burette, while swirling constantly, until a faint reddish color persists. e. Average the three results. f. Restandardize monthly. mL AgN03 mL KSCN F2 = g. Repeat the determination and use the average factor rounded off to the nearest 0.001 mL AgN0,lmL KSCN. Determine F2 each time a new KSCN or AgNO, solution is prepared. 5.7.2 Apparatus. 1. 2. Weighing dish. 3. Drying oven. 4. Desiccator. 5. 1,500-mL beaker. 6. 1,000-mL volumetric flask. 7. 8. 50-mL class A burette. 9. 50-mL pipette. Analytical balance accurate to 0.0001 g. 500-mL Erlenmeyer flask with stoppers. 10. 250-mL Erlenmeyer flask. 11. 250-mL beaker. 12. 1OO-mL volumetric flask. 5.7.3 Procedu re. NOTE: Anions, such as bromide, iodide, ferricyanide, ferrocyanide, and thiocyanate, which form silver salts that are less soluble than silver chloride in dilute nitric acid solution, are also titrated and give rise to positive interference. None of these anions is expected to be present in the sample in significant amounts. LIQUID POLYALUMINUM CHLORIDE 15 Bivalent mercury causes negative interference by forming a stable complex with thiocyanate ion. 1. Weigh 4 g of the sample to the nearest 0.001 g in a 250-mL beaker. Dilute to about 50 mL with deionized water. AcidiSl with 5 mL of concentrated nitric acid and boil for 5 min. Cool and transfer the sample to a 100-mL volumetric flask and dilute to volume. Pipette 10.00 mL of this solution to a 500-mL glass- stoppered Erlenmeyer flask and dilute to about 150 mL with deionized water. 2. 3. Add 5 mL iron indicator solution to the flask. Swirl to mix. From a zeroed, 10-mL class A burette add 1.0 mL of 0.05N potassium thiocyanate solution and swirl to mix. Do not rezero this burette; the titration with thiocyanate solution will continue in Sec. 5.7.3(8). 4. Fill and zero a 50-mL class A burette with standard 0.05N silver nitrate solution. Titrate slowly while swirling vigorously until the red color is completely discharged. Add an additional 2 mL of standard 0.05N silver nitrate solution. Record the exact volume of silver nitrate solution to the nearest 0.01 mL. 5. Add 10 drops of benzyl alcohol, stopper the flask, and shake it vigorously for 30 seconds (see note, Sec. 5.5.3). 6. Place a 500-mL Erlenmeyer flask beneath a long-stem funnel fitted with Whatman 42 or equivalent filter paper. 7. Transfer the contents from the stoppered flask to the funnel. Rinse this flask and thoroughly shake the rinse water around in the flask. Transfer the rinse water to the filter. Repeat the rinsing and the transfer of the rinse water. A complete transfer of the precipitate to the filter is not necessary. Wash the precipitate on the filter twice with cold water and collect the washings with the filtrate. 8. Using the 10-mL burette from which KSCN was added in Sec. 5.7.3(3), slowly and with constant swirling, titrate (without rezeroing) the filtrate with 0.05N potassium thiocyanate solution until a faint red color persists (see notes, Sec. 5.7.5). 5.7.4 Calcu lation. Chloride, as percent C1 = (mLAgN03) - (mL KSCN x F,)(N ofAgNO,)(3.545) grams of x 10/100 (Eq 9) 5.7.5 1. Notes and temperature correctionsfor volumetric solutions. Shaking with benzyl alcohol facilitates filtration by coagulating the precipitate. -,-,- 16 AWWA B408-03 2. A back-titration of at least 0.5 mL KSCN solution is necessary to ensure that an adequate excess of silver nitrate solution was present to completely precipitate all the chloride present in the sample. 3. When volumetric solutions are standardized at 2O“C, titrations should be made at this temperature or corrections applied to reduce the volume of the solution used in titrations to 20°C. Table 1 shows corrections for temperatures from 15“ to 30°C. Sec. 5.8 Rejection-Notice of Nonconformance If the liquid PAC1 product delivered to the purchaser does not meet the requirements of this standard, the purchaser shall provide a notice of nonconfor- mance to the supplier within 10 days after receipt of the shipment at the point of destination. The results of the purchaser's tests shall prevail, unless the supplier notifies the purchaser within five days after receipt of the notice of nonconformance that a retest is desired. On receipt of the request for a retest, the purchaser shall forward to the supplier one of the sealed samples taken in accordance with Sec. 5.1 of this standard. In the event that the results obtained by the supplier on retesting do not agree with the test results obtained by the purchaser, forward the other sealed sample, unopened, for analysis to a referee laboratory agreed on by both parties. The results of the referee analysis shall be accepted as final. SECTION 6: DELIVERY* Sec. 6.1 Marking Each shipment of material shall carry with it some means of identification. 6.1.1 Packaged material. Each container of PAC1 shall have marked legibly on it the net weight of the contents, the name of the manufacturer, the lot number, and a brand name, if any, and shall bear such other markings as required by applicable laws. 6.1.2 Bulk material. When shipped in bulk, the information required in Sec. 6.2 for packaged material shall accompany the bill of lading. *G