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MANUAL FOR TESTING OF WATER AND …

MANUAL FOR TESTING OF WATERAND wastewater TREATMENTCHEMICALSF inal Reportto theWater Research CommissionbyS. D. Freese, D L Trollip and D J NozaicUmgeni WaterP O Box 9 PIETERMARITZBURG3200 WRC Report No. K5/1184 ISBNA pril 2003 Executive SummaryA large number of chemicals are used in the production of potable WATER and in thetreatment of wastewater effluents. In potable WATER treatment chemicals such asinorganic salts and polymeric organic coagulants are used for primary coagulation, ascoagulant aids and for sludge dewatering; lime and soda ash allow for pH correctionand WATER stabilisation; caustic soda is used for pH adjustment; powdered activatedcarbon (PAC) can remove taste and odour compounds and micropollutants such asatrazine; bentonite aids coagulation; and ammonium hydroxide is used treatment is generally performed using a predominantly biologicalprocess in South Africa, but here too chemicals are often used, such as coagulantsfor sludge conditioning, lime for pH adjustment and to increase the alkalinity content,and aluminium and iron salts for phosphate , standardised TESTING procedures for assessing these process chemicals areseriously la

MANUAL FOR TESTING OF WATER AND WASTEWATER TREATMENT CHEMICALS Final Report to the Water Research Commission by S. …

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Transcription of MANUAL FOR TESTING OF WATER AND …

1 MANUAL FOR TESTING OF WATERAND wastewater TREATMENTCHEMICALSF inal Reportto theWater Research CommissionbyS. D. Freese, D L Trollip and D J NozaicUmgeni WaterP O Box 9 PIETERMARITZBURG3200 WRC Report No. K5/1184 ISBNA pril 2003 Executive SummaryA large number of chemicals are used in the production of potable WATER and in thetreatment of wastewater effluents. In potable WATER treatment chemicals such asinorganic salts and polymeric organic coagulants are used for primary coagulation, ascoagulant aids and for sludge dewatering; lime and soda ash allow for pH correctionand WATER stabilisation; caustic soda is used for pH adjustment; powdered activatedcarbon (PAC) can remove taste and odour compounds and micropollutants such asatrazine; bentonite aids coagulation; and ammonium hydroxide is used treatment is generally performed using a predominantly biologicalprocess in South Africa, but here too chemicals are often used, such as coagulantsfor sludge conditioning, lime for pH adjustment and to increase the alkalinity content,and aluminium and iron salts for phosphate , standardised TESTING procedures for assessing these process chemicals areseriously lacking in this country.

2 There are some recommended tests available for theassessment of some of these chemicals, such as the South African Bureau ofStandards 459-1955 Standard Specification for Lime for Metallurgical Purposes, butthe tests described in this specification are for the most part outdated gravimetricprocedures which are time the case of polyelectrolytes used for primary coagulation in potable watertreatment, there is currently no legislation or regulation system present in this countryfor the control of these chemicals and no standard tests are available to measure theeffectiveness of these chemicals for coagulation. Prior to 1994 all suppliers needed tosupply Department of Health certification before their products would be consideredfor use by UW, but this certification appears to have been issued on an ad hoc basis,subject to the supplier being able to supply approval or certification for his product orthe monomer/s from a recognised world health body such as the World HealthOrganisation (WHO), the United States Environmental Protection Agency (USEPA)and the European Economic Community (EEC).

3 After 1994 the issuing of suchcertification by the Department of Health fell away altogether. WATER utilities such asUmgeni WATER insist that recognised certification is supplied by the polyelectrolytesupplier before using his product, but this system is considered inadequate since itlacks uniformity. The Department of Health is presently in the process ofimplementing a regulatory system for polyelectrolyte control, but this is not expectedto be functional for some time problems are experienced with sludge treatment coagulants, since testsavailable for the assessment of these polyelectrolytes don't necessarily adequatelydescribe the performance of these chemicals for dewatering. At present, no nationalstandard for TESTING these chemicals also arise in assessing powdered activated carbon (PAC).

4 A number oftests are available to measure various parameters such as iodine number, methyleneblue number, phenol number and molasses number. Bodies such as the AmericanWater Works Association (AWWA), the American Society for TESTING and Materials(ASTM) and the Council of chemical Manufacturers' Federations (CEFIC) havestandard procedures for conducting such tests, but at present there is no uniformity inSouth Africa regarding the test procedures used. For example there are threedifferent phenol tests available (Chemviron Carbon, 1998), the most commonly usedbeing the German Standard DIN19603 (1969). There are also two AWWA methods,one for PAC and another for granular activated carbon (GAC). The same is true foriodine number and methylene blue number, at least two or three standard tests beingavailable in each addition to this, these parameters, although useful for production quality control,are not particularly effective for assessing the operating performance of the carbon interms of micropollutant removal (Chemviron Carbon, 1998).

5 In the experience of theauthors, a low iodine number generally indicates that the carbon will not be effectivefor taste and odour removal, but a high iodine number gives no indication of the abilityof the carbon to adsorb these micropollutants. Since micropollutant removal is theusual application of activated carbon in WATER treatment , it has been necessary for anumber of Southern African WATER Authorities to devise an alternative method forassessing this lack of any standardised TESTING procedures makes it difficult to assess orcompare these products, or to conduct routine quality control tests on them, whichcould even result in negative health and environmental implications. There are alsono standard procedures available for conducting tender evaluations of thesechemicals.

6 Therefore Umgeni WATER , in conjunction with the WATER ResearchCommission, undertook to collate and evaluate the various test procedures availablefor assessment of the most commonly used chemicals in the WATER and wastewatertreatment industries, resulting in the production of this MANUAL . The MANUAL attemptsto address a number of these inadequacies and contains standard tests, many ofwhich can be conducted using relatively simple equipment, procedures for evaluationof process chemicals, standard worksheets for the various tests as well asspreadsheets for those tests requiring ObjectivesThere were three main objectives of this project:1. Assess the various procedures used in Southern Africa to evaluate thedifferent chemicals used in WATER and wastewater Identify the critical determinands for evaluation of WATER and wastewatertreatment chemicals and recommend standard procedures for TESTING Produce a MANUAL for all Southern African WATER and wastewater authorities touse for evaluation of the chemicals used in WATER and wastewater MANUAL would set out standard procedures for the assessment of waterand wastewater treatment chemicals and wherever possible.

7 Theseprocedures would be simple enough that they could be performed without theneed for sophisticated MethodologyInitially a literature survey was conducted in order to gather all available testprocedures for the following WATER and wastewater treatment chemicals:polyelectrolytes for primary coagulation and as coagulant aidspolyelectrolytes for sludge dewateringbentoniteinorganic coagulants ( aluminium sulphate, ferric chloride)lime (quicklime and slaked lime)soda ashiiicaustic sodaoxidants and disinfectants ( hypochlorite, chlorine dioxide, ozone, hydrogenperoxide, bromine)ammonium hydroxideactivated carbonfluorideOnce this had been done, a number of the main role players in the WATER andwastewater industry in Southern Africa were consulted regarding the test procedureswhich they use.

8 Institutions, WATER authorities and companies which collaborated withthe authors by providing test procedures, information and chemicals are listed below:Rand WaterCity of Cape TownNelson Mandela Metropolitan CouncilBHT-SudchemieZetachemMost of the tests were evaluated in the Research and Development Laboratories,Umgeni WATER to determine their accuracy, repeatability, limit of detection and theease with which each test could be performed and its value in assessing a particularchemical. Emphasis was placed in selecting tests that not only analysed criticalfactors for a treatment chemical , but which were both accurate and simple whereverpossible. Whenever a test required sophisticated instrumentation, attempts havebeen made to provide an alternative that can be conducted using Summary of ManualThis MANUAL is divided into 9 chapters, the first being an introduction and the lastcontaining reference details, while Chapters 2 to 8 deal with test procedures forlogical groupings of WATER and wastewater treatment chemicals, these being:Chapter 2: CoagulantsChapter 3: Coagulant AidsChapter 4: Sludge treatment CoagulantsChapter 5: pH Adjustment and Stabilisation ChemicalsChapter 6: Oxidants and DisinfectantsChapter 7: Activated CarbonChapter 8.

9 Fluoridation ChemicalsWhere relevant worksheets have been included at the end of a section or method toassist the user in entering the necessary data and carrying out methods contained in the MANUAL have been taken from a wide variety ofsources including Standard Methods for the Examination of WATER and wastewater ,the America WATER Works Association (the ANSI/AWWA methods), the AmericanSociety for TESTING and Materials (ASTM), the Council of chemical Manufacturers'Federations (CEFIC), the German Standard DIN Standards as well as tried andtested methods from the Umgeni WATER Laboratories and from the collaboratorsmentioned in Section has resulted in a MANUAL that provides TESTING procedures for most of thechemicals used in WATER and wastewater treatment in Southern Africa, that aregenerally fairly simple to conduct and which are reliable and repeatable.

10 It is hopedthat this MANUAL will offer the first step towards providing standardised procedures forthe evaluation of WATER and wastewater treatment chemicals and assist in providingthe technical background for future legislation governing the use of these MANUAL emanates from a project funded jointly by the WATER ResearchCommission and Umgeni WATER and entitled: MANUAL for TESTING of WATER and wastewater treatment Devey of the Nelson Mandela Metropolitan Council, John Geldenhuis ofRand WATER , Sarel Pieterse of the City of Cape Town, and Tony Reynolds and NevilleLee of Sudchemie-BHT are gratefully acknowledged for their assistance andinvolvement in producing this financing of the project by the WATER Research Commission and the provision oflaboratory and analytical facilities by Umgeni WATER are gratefully involvement and dedication of Mrs.


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