ASTM D4188-17

5.1 Pressure in-line coagulation-flocculation followed by filtration is an effective process to remove suspended and colloidal matter from water and waste water.

5.2 The effectiveness of this process is dependent on the type and concentration of the flocculant or coagulant, or both, the pH, the temperature, the filtration medium(a), and the filtration rate. This practice permits the evaluation of these various parameters.

5.3 This practice can also be used to determine filter backwash and rinse requirements.

5.4 The results obtained from this practice can be used for plant design of large systems.

1.1 This practice covers the procedure used to perform pressure in-line coagulation-flocculation-filtration of water and waste water. It is applicable to water and waste water with relatively low suspended solids (<30 mg/L). The practice is applicable for any size filter greater than 100 mm (4 in.) in diameter.

1.2 This practice for performing pressure in-line coagulation-flocculation-filtration tests in water relies on turbidity measurement to assess the water quality, referring to Test Methods D7315, D6698, or D6855 to perform the turbidity measurement.

1.3 This practice can be used to determine the effectiveness of flocculants or coagulants, or both, and filter medium(a) in removing suspended and colloidal material from water and waste water.

1.4 Interval between filter backwashing, backwash requirements, rinse requirements, and effect of filtration rate on effluent quality can also be obtained with this practice.

1.5 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to inch-pound units that are provided for information only and are not considered standard.

1.6 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.

1.7 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.