【国外标准】 Standard Practice for Operating the Severe Wastewater Analysis Testing Apparatus

5.1 Domestic wastewater headspace environments are corrosive due to the presence of sewer gases and sulfuric acid generated during the biogenic sulfide corrosion process.5 This operating procedure provides an accelerated exposure to sewer gases and concentration of sulfuric acid commonly produced by bacteria within these sewer environments.65.2 The results obtained by the use of this practice can be a means for estimating the protective barrier qualities of a protective coating or lining for use in severe sewer conditions.5.3 Some protective coatings or linings may not withstand the exposure temperature specified in this practice but have demonstrated satisfactory performance in actual sewer exposures, which are at lower temperatures.1.1 This practice covers the basic apparatus, procedures, and conditions required to create and maintain the severe wastewater analysis testing apparatus used for testing a protective coating or lining.1.2 This apparatus may simulate the pertinent attributes of a typical domestic severe wastewater headspace (sewer) environment. The testing chamber comprises two phases: (1) a liquid phase containing a prescribed acid and saline solution, and (2) a vapor phase consisting of air, humidity, and concentrated sewer gas (Note 1). The temperature of the test chamber is elevated to create accelerated conditions and reaction rates.NOTE 1: For the purposes of this practice, sewer gas is composed of hydrogen sulfide, carbon dioxide, and methane gas.1.3 Caution—This practice can be extremely hazardous. All necessary precautions need to be taken when working with sewer gas, sulfuric acid, and a glass tank. It is highly recommended that a professional testing laboratory experienced in testing with hydrogen sulfide, carbon dioxide, and methane gases perform this practice.1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Some specific hazards statements are given in Section 8 on Hazards.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.