Water and Wastewater Examination Manual

V.Dean Adams

• Publisher: Routledge
• Year: 2017
• Print ISBN:
  9780873711999
• eBook ISBN:
  9781351405072
• Topic: Technology & Engineering
• Subtopic: Environmental Management
• Index: Technology & Engineering

This new manual is an indispensable working lab guide and reference for water/wastewater quality analysis. Based on procedures from "Standard Methods" and "Methods for Chemical Analysis of Water and Waste (EPA)," and other pertinent references the Water and Wastewater Examination Manual is an excellent complement to these references-that you will want to keep at your fingertips. Written especially for use by water quality laboratory technicians and water/wastewater operators, managers and supervisors-who will use this practical manual every day. Procedures are included for parameters frequently used in water quality analysis.

1 Introductory Guidelines for the Use of This Manual

1.1 Safety (Adapted from Standard Methods, 1989)

A General

Safety is a subject of concern for all. In the specific context of laboratories, it is especially important because of the presence and use of hazardous chemicals or equipment, microorganisms that may produce human disease, and radioactive substances. Laboratory management has a vital role to play in ensuring a safe working environment. This role is dictated by federal or state regulations as well as by the appropriate interests of management in the well-being of its employees and the overall productivity of the laboratory. In the final analysis, however, safety is the responsibility of the individual laboratory worker. While management must deal with the work place, the provision of safe procedures, and the training of employees in safe practices, it is the analyst who ultimately makes the laboratory safe or unsafe.

B Laboratory Hazards

Laboratory hazards fall into two major categories: those of universal significance, such as fire, electrical, and mechanical hazards, and those specific to a laboratory, such as chemical or biological hazards. Because this is not intended as a manual of safe practices, general safety problems will not be discussed. However, the use of combustible or explosive reagents and the widespread use of electrical equipment may pose special problems in the laboratory.

BE SURE TO READ A COMPREHENSIVE SAFETY MANUAL BEFORE WORKING IN THE LABORATORY.

From the standpoint of chemical and biological safety, it must be recognized that many reagents require handling with the utmost care either in their original state or in solution, or both. This care is exercised either to protect the health and safety of the analyst or because of environmental hazard or damage, particularly in connection with laboratory waste disposal. A number of reagents specified in this manual may bear labels with the words POISON, DANGER, CAUTION, FLAMMABLE, etc. Handle these with special care.

The safest way to deal with hazardous materials is to avoid their use. Efforts to eliminate such reagents were made in selecting analytical methods for inclusion in the 1989 edition of Standard Methods and in this manual. When avoidance is impossible, hazardous materials are identified, and special precautions against exposure by inhalation, by ingestion, or through the skin are given.

Information on laboratory safety and chemical disposal is available. Reference materials include (see Bibliography): American Water Works Association (1958); Inhorn (1978); Manufacturing Chemists’ Association (1972); Phifer and McTigue (1988); Bennett et al., 1982; Walters (1980); Dux and Stalzer (1988); Safe Storage of Laboratory Chemicals (1984); National Research Council (1981, 1983); Hazards in the Chemical Laboratory (1983); and Safe Handling of Cryogenic Liquids (1987).

C Safety Equipment

Simple safety practices include using mechanical pipettors instead of pipetting by mouth and using safety clothing and fume hoods. Safety glasses or, still better, full face masks offer important protection against explosions or implosions. Additional safety equipment includes fire extinguishers, fire blankets, safety showers, eye wash fountains, and first aid and spill control kits. All laboratory personnel and students working in the lab should know the location of these safety devices and be familiar with their use.

If not sure … ASK!

D Hazardous Materials in this Manual

1. Acids and Alkalies: Concentrated acids and bases may cause chemical burns and are especially hazardous if spilled or splashed into the eyes. Always handle with extreme care to avoid contact. In diluting concentrated acids, always add the acid to water to prevent possible explosion; never add water to the acid.

2. Arsenic: Inorganic arsenic compounds are used to prepare standards and may be present in samples. Arsenic is highly toxic and may cause lung cancer or death: avoid inhalation, ingestion, and skin exposure. Always make dilutions in a hood.

3. Azides: Sodium azide is used in a number of procedures including the test for dissolved oxygen. It is toxic and reacts with acid to produce the still more toxic hydrazoic acid. When discharged to a drain, it may react with and accumulate on copper or lead plumbing fixtures. The metal azides are explosive and detonate readily. Avoid inhalation, ingestion, and skin exposure. Destroy azides by adding a concentrated solution of sodium nitrite, NaNO₂ (1.5 g NaNO₂/g sodium azide). To remove accumulated metal azides from drainpipes and traps, treat overnight with a 10% solution of sodium hydroxide.

4. Biohazards: Samples may contain pathogenic microorganisms. Exposure to these organisms may be incidental to chemical or biological examination or occur in the specific examination for certain disease-producing organisms. In either case, avoid ingestion particularly in culturing pathogens. Use aseptic techniques and sterilize all discarded cultures.

5. Compressed Gases: Compressed gases are used widely in most laboratories, especially if an atomic absorption spectrophotometer or a gas Chromatograph is used. The gases may be flammable or explosive and require careful handling. Protect the cylinders themselves from freezing, overheating, and mechanical damage. Chain, lock, or otherwise prevent the cylinders from moving or falling over. Use the appropriate pressure-reducing valve for each type of gas cylinder.

6. Cyanides: Cyanides are used as reagents or may be present in samples. Most cyanides are toxic; avoid ingestion. Handle such solutions in a fume hood and avoid inhalation. In acid solution, the toxic gas hydrogen cyanide may be produced; therefore, do not acidify cyanide solutions.

7. Mercury: Mercury and its compounds are used to prepare standards, displace gases, serve as indicator liquid in thermometers, and preserve samples. Liquid mercury is a toxic volatile element. Handle spills expeditiously to prevent inhalation. Keep powdered sulfur on hand to spread immediately on mercury spills to minimize volatilization before cleanup. Disposal of samples containing mercury is environmentally damaging. Store mercury waste solutions in labeled containers. The mercury will be precipitated and collected by filtration for disposal.

8. Perchloric Acid: Perchloric acid is used in digesting organic matter. It can react explosively with organic matter and must be handled with care; predigest samples containing organic matter with nitric acid before adding perchloric acid, and do not add perchloric acid to a hot solution. Like azides in a drain, Perchlorates may accumulate in a hood or air exhaust system. Accumulated Perchlorates may react explosively with organic matter; use special perchloric acid fume hoods and ducting when using perchloric acid digestion procedures.

9. Toxic or Carcinogenic Organic Compounds: Organic solvents and solid organic reagents are used in many determinations. These may be flammable or explosive, and as such require special handling and storage, or they may be toxic or carcinogenic. Handle such solvents as chloroform, carbon tetrachlo- ride, benzene, etc., in a fume hood and avoid inhalation, skin contact, and ingestion.

Note: In general, most waste organic solvents can be repurified by distillation and reused. Store in labeled waste containers. Distill carefully in a distillation apparatus where the temperature is maintained at the boiling point of the solvent in question.

1.2 Quality Control and Quality Assurance

A References

See Standard Methods (1989, pp. 1–1 through 1-30), EPA (1979), Quality Assurance Manual (1979), and Taylor (1987).

B Introduction

A good quality control program at an analytical laboratory involves a number of practices. It goes beyond simply having adequate personnel, facilities, equipment, reagents, and standards. On a routine basis, quality control samples must be analyzed along with unknown samples (see 1.2 C). Many laboratories also undergo routine proficiency testing by analyzing independent reference samples for laboratory evaluation (external quality control). In addition, each laboratory should maintain precision and accuracy data for each analysis (see 1.2 D, 1.3, 1.4, and 1.5).

C Internal Quality Control

Internal quality control samples are g...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Table of Contents
• 1. Introductory Guidelines for the Use of This Manual
• 2. Methods for Determining Physical Properties
• 3. Methods for the Determination of Metals
• 4. Methods for the Determination of Inorganics and Nonmetals
• 5. Methods for the Determination of Organics
• 6. Methods for Biological Determination
• Appendix A, Precision and Accuracy Forms
• Appendix B, Atomic Weights
• Definitions of Abbreviations, Terms, and Units
• Bibliography
• Index