Tools

Determination of TS, TDS and TSS in Water

INTRODUCTION

Water contain different types of impurities like suspended, colloidal and dissolved materials in it. Based on its contaminants water can be broadly defined as mixture of different types of solids in a liquid base. Solids may be classified as settleable, suspended, dissolved, volatile and fixed. All these types together called as total solids. The settleable solids are those, which are capable of settling when, placed in a quiescent condition. The suspended solids are those which are not soluble in water and remain in suspension for a long period. These solids impart turbidity to the water. The dissolved solids impart colour and odour to water. The total, settleable, suspended and dissolved solids include volatile and fixed components.

Solids form an important component in treatment processes. The suspended and settleable solids have to be removed in the sedimentation units and the dissolved solids will have to be removed in the filtration and other secondary treatment facilities. The volatile solids play an important role in biological treatment of waste water.

Solids refer to matter suspended or dissolved in the water or wastewater and may affect water or effluent quality in adverse ways. Waters with high dissolved solids have poor palatability and may cause unfavourable physiological reactions in transient consumers. Solids analyses are critical for controlling biological and physical wastewater treatment processes as well as determining compliance with regulatory agency limits.

  • Total Dissolved Solid (TDS) is the amount of combined contents of all inorganic and organic substances contained in a liquid in molecular, ionized or micro-granular (colloidal sol) suspended form. Total dissolved solids are usually discussed only for freshwater systems, as salinity includes some of the ions constituting the definition of TDS.

  • Total Suspended Solids (TSS) are solids that can be trapped using a filter in water. TSS can include a wide variation in material, such as silt, decaying plant and animal matter, industrial wastes, and sewage. High concentrations of suspended solids can cause several problems to stream health and aquatic life.

  • Total Solids (TS) can be found by summation of TSS and TDS.

  • Volatile Suspended Solids (VSS) are the suspended solids associated with volatile fraction.

  • Fixed Suspended Solids (FSS) are the suspended solids associated with the mineral fraction.

    • Relevant Indian Standard for TS, TDS and TSS Test :

    1. IS 3025 (Part 15)- 1984: Method of Sampling and Test (Physical and Chemical) for Water and Wastewater : Total Residue (total Solids, Dissolved and Suspended, First Revision.