Standard Test Method for In-situ Determination of Turbidity Above 1 Turbidity Unit (TU) in Surface Water

Importancia y uso:

5.1 Turbidity is monitored to help control processes, monitor the health and biology of aquatic environments and to determine the impact of environmental events such as storms, floods, runoff, etc. Turbidity is undesirable in drinking water, plant-effluent waters, water for food and beverage production, and for a large number of other water-dependent manufacturing processes. Turbidity is often reduced by coagulation, sedimentation and water filtration. The measurement of turbidity may indicate the presence of particle-bound contaminants and is vital for monitoring the completion of a particle-waste settling process. Significant uses of turbidity measurements include:

5.1.1 Compliance with permits, water-quality guidelines, and regulations;

5.1.2 Determination of transport and fate of particles and associated contaminants in aquatic systems;

5.1.3 Conservation, protection and restoration of surface waters;

5.1.4 Measure performance of water and land-use management;

5.1.5 Monitor waterside construction, mining, and dredging operations;

5.1.6 Characterization of wastewater and energy-production effluents;

5.1.7 Tracking water-well completion including development and use; and

5.1.8 As a surrogate for other constituents in water including sediment and sediment-associated constituents.

5.2 The calibration range of a turbidimeter shall exceed the expected range of TU values for an application but shall not exceed the measurement range specified by the manufacturer.

5.3 Designs described in this standard detect and respond to a combination of relative absorption, intensity of light scattering, and transmittance. However, they do not measure these absolute physical units as defined in 3.2.15 and 3.2.19.

5.4 Several different turbidimeter designs may be used for this test method and one design may be better suited for a specific type of sample or monitoring application than another. The selection flowchart in Annex A1 provides guidance for the selection of an appropriate turbidimeter design for a specific application.

5.5 Report turbidity in units that reflect the design of the turbidimeter used as recommended in 4.3. See Table 1 and Section 7 for a discussion of the design criteria and derivation of reporting units.

5.6 Table 1 and Section 7 lists the turbidimeter designs currently used for in-situ measurements. Future revisions of the method may include additional designs.

Subcomité:

D19.07

Referida por:

D4410-16, D8298_D8298M-23, D8297_D8297M-23

Volúmen:

11.01

Número ICS:

13.060.60 (Examination of water for physical properties)

Palabras clave:

90° scatter; backscatter; forward scatter; in-situ turbidity; multi-beam meter; turbidimeter; turbidity; turbidity interferences; turbidity standards;