Total Solids (TS) Testing

All natural waters contain solids. Such substances include suspended solids and dissolved solids, which are collectively referred to as total solids (TS). Suspended solids generally refer to organic or inorganic particles that can be seen suspended in water. Total solids is the total amount of residue left after water has been evaporated without any filtration. If the water sample is filtered, the dried residue left on the membrane filter is referred to as total suspended solids (TSS), while the particles obtained from the evaporated filtrate are referred to as total dissolved solids (TDS). These three solids tests can be related with Equation: TS = TDS + TSS.

At BOC Sciences, we can perform a range of solids determinations including total solids, total suspended solids and total dissolved solids using our professional wet chemistry knowledge.

• What is Total Dissolved Solids?

TDS in drinking water are mainly inorganic salts, including calcium, magnesium, potassium, sodium, bicarbonate, chloride and sulfate, as well as some small amounts of organic matter dissolved in the water. Elevated TDS is due to natural environmental features such as mineral springs, carbonate deposits, salt deposits and sea water intrusion, but other sources may include: salts used to de-ice roads, anti-skid materials, drinking water treatment chemicals, rainwater and agricultural runoff, and wastewater discharges. In general, the TDS concentration is the sum of cations (positively charged) and anions (negatively charged) ions in water. Therefore, the TDS testing provides a qualitative measurement of the number of dissolved ions and is often used as an indicator test to determine the general quality of water.

Figure 1. Analysis for Total Solids

• Potential Risks for Total Dissolved Solids
• If the TDS are too low, the water may be corrosive to metal pipes and fixtures, creating a bitter or off-taste
• Elevated TDS indicates that many ions exceed primary or secondary drinking water standards, such as elevated levels of nitrates, arsenic, aluminum, copper, lead, etc., posing health risks or threats to humans

Figure 2. Water Quality Parameters and Measurements (Xerxes, O. 2019)

• Definition of Total Suspended Solids

Suspended matter is generally defined as organic or inorganic particles that can be seen suspended in water. Industrial wastewater is one of the main sources of pollution in surface water because of its large volume and complexity of pollutants. Therefore, TSS testing is an important test for wastewater quality analysis and can be used as an indicator of the degree of pollution.

• Total Suspended Solids Hazard

When the concentration of suspended solids in water is too high, it can lead to low concentrations of oxidized alkenes and the death of aquatic organisms.

Our TS Testing Services

At BOC Sciences, we apply the gravimetric method to determine the total solids, total suspended solids and total dissolved solids.

TS Determination

The TS content of the sample is the remaining solid mass of the sample after being dried in a 100℃ oven for 24 hours, divided by the original mass of the sample. The TS content of thick slurry is reported on a mass percentage (%) basis. For dilute slurries and liquids, TS is usually expressed as mass per volume, most commonly mg/l. As the TS concentration increases, the mud begins to become semi-solid and the representation of the solid/liquid relationship of the mixture switches from solid content to moisture content. Moisture content is defined as the mass of water in a semisolid substance divided by the wet mass of that substance.

Figure 3. Determine Total Solids Level

TSS Determination

TSS is the portion of the TS that is retained on ashless glass fibers.

• First, a measured volume of wastewater is passed through a filter
• Then, the filter containing the residue is dried in an oven at 103 to 105°C for one hour
• Finally, the sample is cooled and weighed
• The difference in weight between of the dry filter before and after solids are passed through is the TSS milligrams (mg) of suspended solids per liter (l) of wastewater filtered

Figure 4. Laboratory procedures to determine total suspended solids (TSS). (Shah, S. M. H.; et al. 2014)

TDS Determination

TDS is the amount of solids in the filtrate during the TSS test.

• First, the liquid passing through the TSS filter is collected in a weighed dish and evaporated at 180°C ± 2°C for one hour
• Then, the dish is re-weighed, and the TDS is equal to the difference between the weight before and after filling with filtrate and drying, in mg per liter of filtrate.

Application of Our TS Testing Services

• Waste Water Treatment
• Provide stability and continuity of the treatment process
• Improve the efficiency of wastewater treatment
• Continuous on-line monitoring reduces the need for time-consuming laboratory analysis
• Real-time monitoring provides more precise process control
• Monitor compliance with limitations placed on solids concentration entering and leaving the plant

• Drinking Water Treatment
• Knowing the TSS and TDS flowing into the water helps determine the correct treatment process and procedures to reduce the load on the filter
• Monitor TSS and TDS of raw and treated water helps to maintain consistency of water quality and corrosivity in compliance with relevant regulations
• Optimize the treatment process, extend filter run time, and provide additional energy cost savings

• Energy Industry

The content of suspended matter in water is an important indicator of water quality. Silt, sand, bacteria, spores and chemical sediments all contribute to turbidity. TS monitoring is therefore critical to maintaining acceptable water quality throughout the power plant