Solids In the characterization of wastewater. coarse materials are usually removed before the sample is analyzed for solids Tab 2-3 Definitions ofsolids found in wastewater Fig. 2-1 Interrelationships of solids found in water and wastewater. In much ofthe water quality literature, the solids passing through the filterare called dissolved solids A filtration step is used to separate the total suspended solids tss from the total dissolved solids (tds). Filters with nominal pore sizes varying from 0. 45 um to about 2.0 um have been used for the tss test Fig 2-2 Size ranges of organic contaminants in wastewater and size separation and measurement techniques used for their quantificationSolids In the characterization of wastewater, coarse materials are usually removed before the sample is analyzed for solids. Tab 2-3 Definitions of solidsfound in wastewater Fig. 2-1 Interrelationships of solids found in water and wastewater. In much of the water quality literature, the solids passing through the filter are called dissolved solids. A filtration step is used to separate the total suspended solids (TSS) from the total dissolved solids (TDS). Filters with nominal pore sizes varying from 0.45 µm to about 2.0 µm have been used for the TSS test. Fig. 2-2 Size ranges of organic contaminants in wastewater and size separation and measurementtechniquesused for their quantification