Conductivity Total Dissolved Solids WQT 134 Aquatic Chemistry II Standard Methods 20 th ed #2510 Conductivity

Week Objectives 1.Understand the role and function of conductivity in water treatment. 2.Understand how to measure conductivity (SM #2510) Relate conductivity to total dissolved solids 1.Understand the role and function of conductivity in water treatment. 2.Understand how to measure conductivity (SM #2510) Relate conductivity to total dissolved solids Reading assignment: American Public Health Association (APHA), American Water Works Association (AWWA) & Water Environment Federation (WEF) Standard Methods for the Examination of Water and Wastewater, 20 th edition Reading assignment: American Public Health Association (APHA), American Water Works Association (AWWA) & Water Environment Federation (WEF) Standard Methods for the Examination of Water and Wastewater, 20 th edition

The conductivity of the source water indicates the quantity of dissolved material present. 1.True 2.False 1.True 2.False

Conductivity #2510 What is conductivity? This test is designed to determine if the sample can carry an electrical current via the movement of ions. This ability depends on the presence of ions; on their total concentration, mobility, and valence; and on the temperature of measurement. Conductivity is an indication of the quantity of ions contained in a solution Why do we care? Dissolved ions/substances/electrolytes in water Determine the presence of salt water intrusion Used for WQ in pipelines, channels, flowing streams, and lakes What is conductivity? This test is designed to determine if the sample can carry an electrical current via the movement of ions. This ability depends on the presence of ions; on their total concentration, mobility, and valence; and on the temperature of measurement. Conductivity is an indication of the quantity of ions contained in a solution Why do we care? Dissolved ions/substances/electrolytes in water Determine the presence of salt water intrusion Used for WQ in pipelines, channels, flowing streams, and lakes

Conductivity #2510 What are the units and conversions? Conductivity is customarily reported in micromhos per centimeter (μmho/cm). The electrical measurement of conductivity is the inverse (reciprocal) of ohms (1/ohms) or mhos. In the International System of Units (SI) the reciprocal of the ohm is the siemens (S) and conductivity is reported as millisiemens per meter (mS/m) 1/ohm = 1 mho = 1 Siemen 1000 micromhos/cm = 1000microSiemens/cm(μS/cm) What are the units and conversions? Conductivity is customarily reported in micromhos per centimeter (μmho/cm). The electrical measurement of conductivity is the inverse (reciprocal) of ohms (1/ohms) or mhos. In the International System of Units (SI) the reciprocal of the ohm is the siemens (S) and conductivity is reported as millisiemens per meter (mS/m) 1/ohm = 1 mho = 1 Siemen 1000 micromhos/cm = 1000microSiemens/cm(μS/cm)

Conductivity #2510 What are disadvantages of the procedure?  Conductivities greater than 10,000 to 50,000 μmho/cm or less than about 10 μmho/cm may be difficult to measure with usual measurement electronics and cell capacitance. What are disadvantages of the procedure?  Conductivities greater than 10,000 to 50,000 μmho/cm or less than about 10 μmho/cm may be difficult to measure with usual measurement electronics and cell capacitance.

Conductivity #2510 What are typical values in nature? Range  Pure Water 0.05 μS/cm  Demineralized Water 0.1 to 1.0 μS/cm  Distilled water 1 to 10 μS/cm  Tap Water 100 to 1000 μS/cm  Potable water 50 to 1500 μmhos/cm.  Industrial wastes 1000 to 10,000 μS/cm Seawater 30,000 to 50,000 μS/cm 5% Sodium Chloride Solution 70,000 μS/cm 10% Sulfuric Acid Solution 140,000μS/cm What are typical values in nature? Range  Pure Water 0.05 μS/cm  Demineralized Water 0.1 to 1.0 μS/cm  Distilled water 1 to 10 μS/cm  Tap Water 100 to 1000 μS/cm  Potable water 50 to 1500 μmhos/cm.  Industrial wastes 1000 to 10,000 μS/cm Seawater 30,000 to 50,000 μS/cm 5% Sodium Chloride Solution 70,000 μS/cm 10% Sulfuric Acid Solution 140,000μS/cm

Conductivity and Total Dissolved Solids #2510 TDS (Total Dissolved Solids): is the amount of solids dissolved in a water sample. SS (Suspended Solids): is the amount of solids that have not dissolved into a water sample, or solids that are insoluble in water. TS (Total Solids) = TDS + SS. TDS (Total Dissolved Solids): is the amount of solids dissolved in a water sample. SS (Suspended Solids): is the amount of solids that have not dissolved into a water sample, or solids that are insoluble in water. TS (Total Solids) = TDS + SS.

What does TDS stand for? 1.Total dissolved solids 2.Temporarily dissolved solids 3.Total disaggregated solids 4.Total dissolved salts 1.Total dissolved solids 2.Temporarily dissolved solids 3.Total disaggregated solids 4.Total dissolved salts

Total solids can be divided into suspended solids and ________ solids. 1.Colloidal 2.Dissolved 3.Settleable 4.Filterable 1.Colloidal 2.Dissolved 3.Settleable 4.Filterable

The total solids in water would be a combination of: 1.Fixed solids and settleable solids 2.Dissolved solids and volatile solids 3.Dissolved solids and suspended solids 4.Suspended solids and fixed solids 5.Fixed solids and dissolved solids 1.Fixed solids and settleable solids 2.Dissolved solids and volatile solids 3.Dissolved solids and suspended solids 4.Suspended solids and fixed solids 5.Fixed solids and dissolved solids

Conductivity and Total Dissolved Solids #2510 Estimate total dissolved solids (mg/L) in a sample by multiplying conductivity (in micromhos per centimeter) by an empirical factor (Conversion done on Hach Probe). This factor may vary from 0.55 to 0.9, depending on the soluble components of the water and on the temperature of measurement. Linear in dilute systems Estimate total dissolved solids (mg/L) in a sample by multiplying conductivity (in micromhos per centimeter) by an empirical factor (Conversion done on Hach Probe). This factor may vary from 0.55 to 0.9, depending on the soluble components of the water and on the temperature of measurement. Linear in dilute systems

Suspended solids, also referred to as filterable residue, represent the weight of solids remaining on a glass fiber filter following filtration and drying at ___ degrees C

___________ solids remain in liquid solution and are defined as the solids that will pass through a 0.45um membrane filter. 1.Suspended 2.Colloidal 3.Dissolved 4.Settleable 1.Suspended 2.Colloidal 3.Dissolved 4.Settleable

__________ solids, extremely fine particles, will not settle from the liquid portion, but can usually be filtered from the liquid with a 0.45-um membrane filter. 1.Dissolved 2.Colloidal 3.Suspended 4.Settleable 1.Dissolved 2.Colloidal 3.Suspended 4.Settleable

If the residue remaining on a filter paper is the suspended solids, these are the solids that pass through the filter. 1.Dissolved (TDS) 2.Volatile 3.Non-volatile 4.Settleable 1.Dissolved (TDS) 2.Volatile 3.Non-volatile 4.Settleable

Conductivity #2510 Summary?  Conductivity not impacted by pH  Conductivity impacted by dissolved solids/sulfate  Conductivity/Resistance increases with increasing temperature. Summary?  Conductivity not impacted by pH  Conductivity impacted by dissolved solids/sulfate  Conductivity/Resistance increases with increasing temperature.