TDS- Total Dissolved Solid
Standard Operating Procedure (SOP) for TDS Testing in Wastewater (APHA Method 2540C) 1. Purpose: To determine the concentration of total dissolved solids (TDS) in wastewater samples using the gravimetric method as specified in APHA Standard Method 2540C. TDS measures the mass of organic and inorganic substances dissolved in water that pass through a filter, typically after evaporation at 180°C. 2. Scope: This SOP applies to the analysis of wastewater samples (industrial, municipal, or environmental) to quantify TDS for regulatory compliance, treatment efficiency, or environmental monitoring. 3. References APHA, AWWA, WEF. Standard Methods for the Examination of Water and Wastewater 24th Edition, Method 2540C: Total Dissolved Solids Dried at 180°C. 4. Definitions TDS: Total Dissolved Solids, the residual mass of dissolved inorganic and organic substances in water passing through a filter (typically 1–2 µm) after evaporation at 180°C. Gravimetric Method: A technique measuring the dry wei...