Measurement of Suspended Solids

The measurement of suspended sohds should be carried out where necessary as part of a water quality assessment. In oil-field water injection systems for example, where plugging of a tight formation could result, suspended solids must be kept to a minimum. The measurement may also be used as an indication of deteriorating water quality due to bacterial action and/or corrosion in the system. 

The measurement of suspended solids may be undertaken by filter analysis, turbidity meter, or other instruments measuring size and density of particles. Membrane filters are the most suitable for carrying out suspended solids determinations on water that is allowed to flow directly from the process stream. 

Methods of determining oil-field water injection quality are described in NACE Standard TM0173. 

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Another measure of suspended solids is particle size distribution. However, there are no recommendations on particle size distribution in RO feed water that have been established. 

Another measure of suspended solids is particle size distribution. However, there are no recommendations on particle size distribution in RO feed water that have been established. In general, particle size distributions have a lower limit of 0.5 im, while the particles of importance with respect to membrane following may be much smaller in size. 

Sludge age A measure of the length of time a particle of suspended solids has been retained in the activated sludge process. 

Densities of solids are determined by determining the volume of the solid, either by measurement of the solid s dimensions or by displacement of a liquid and then determining the mass on a laboratory balance. The density can also be determined by weighing the object and then weighing it again when suspended in a liquid of known density. 

A3 It is well-known that, if an advanced sensor is available and capable to measure a chemical component within the medium, it is easier to implement the sensor at the output of the process rater than at the input. This fact is justified by several causes such that i) the measuring range of the sensor, the presence of suspended solids and the sensor cost [3]. Then, the total concentration of organic substrate in the influent ST,in is assumed to be unknown, piecewise constant and bounded (i.e., < ST,in < Sipf ). 

Fig. 8.40 Retention (R, defined as deposited solids per unit length of section/total added suspended solids, mm 0 of suspended solids in the soil subsurface (a) distribution of deposited solids in coarse sand and silt loam, (b) relative deposition (defined as -ln(a/a), where a denotes initial amount of applied suspended solids and a. denotes measured amount of deposited solid mass per unit length of section at each depth) of suspended solids in silt loam and coarse sand leached by filtered and unfiltered effluents. (Vinten et al. 1983)...

Shirato, Gotoh, Osasa, and Usami [J. Chem. Eng Japan, 1, 164-167 (January 1968)] present a method for determining the mass flow rate of suspended solids in a liquid stream wherein the liquid velocity is measured by an electromagnetic flowmeter and the flow of solids is calculated from the pressure drops across each of two vertical sections of pipe of different diameter through which the suspension flows in series. 

BS W Bottoms, Sediment, and Water. This centrifuge method is used to measure the approximate amount of suspended solids and water in crude oil and petroleum products. 

Turbidity as a measure of the relative clarity of a sample is a qualitative characteristic which is imparted by solids obstructing the transmittance of light through the sample. Thus, it is not a direct measure of suspended particles in a sample but, instead, a measure of the scattering effect such particles have on light. 

A number of composition analyzers used for process monitoring and control require chemical conversion of one or more sample components preceding quantitative measurement. These reactions include formation of suspended solids for turbidimetric measurement, formation of colored materials for colorimetric detection, selective oxidation or reduction for electrochemical measurement, and formation of electrolytes for measurement by electrical conductance. Some nonvolatile materials may be separated and measured by gas chromatography after conversion to volatile derivatives. 

The maximum turbidity permitted in drinking water is 1 TU. In industrial waters, turbidity is measured in milligrams per liter of suspended solids. For example, in the case of mining sedimentation ponds, the law permits a monthly average concentration of 35 mg L-1, with a maximum of 70 mg L"1. High concentrations of suspended solids are known to inhibit aquatic life. Also, colloidal matter is known to carry various inorganic and organic pollutants. 

Tetryl may be released to the air, water, and soil when old stores of the explosive ate destroyed by exploding or burning. However, tetryl has not been measured in air during any of these activities. Tetryl that was manufactured or stored at military installations, like Army ammunition plants, may still be present in the soil and water at or around these sites. Tetryl is not likely to evaporate into air from water or soil surfaces. However, tetryl may be present in air associated with dust from these sites. Tetryl appears to break-down rapidly in some soils. Picric acid, is one of the break down products of tetryl in soil. Tetryl probably does not easily travel from soil to groundwater. Erosion of soil from contaminated sites may release tetryl to nearby surface water. Once it is in the water, tetryl may dissolve or associate with small particles of suspended solids, sediments, or organic debris. Some of these particles will settle to the bottom. Tetryl breaks down rapidly in sunlit rivers and lakes but much more slowly in groundwater. It is not known whether tetryl will build up in fish, plants, or land animals. See Chapters 4 and 5 for more information on tetryl in the environment. 

Scenario The Getcher Fish Company wants to offer a small hand-held turbidimeter that measures the amount of suspended solids in water. This new product will help sports fishermen detect high fish activity (indicated by low turbidity). A Variable MSA measures the accuracy and stability of the turbidimeter. 

Pen Kem System 7000 Acoustopheretic Titrator Pendse and co-workers used discrete frequencies in the development of the Acoustophoretic titrator. This instrument is based on the measurement of colloidal vibration potential arising from the motion of suspended solids relative to the suspending medium when subjected to a sound field, was the first commercial instrument capable of monitoring zeta potential of concentrated solids. 

Foams are dispersions of gas in a relatively small amount of liquid. When they are still on the surface of the which they were formed, they also are called froths. Bubbles range in size from about 50 fim to several mm. The data of Table 20.1 show densities of water/air foams to range from 0.8 to 24g/L. Some dissolved or finely divided substances may concentrate on the bubble surfaces. Beer froth, for instance, has been found to contain 73% protein and 10% water. Surface active substances attach themselves to dissolved materials and accumulate in the bubbles whose formation they facilitate and stabilize. Foam separation is most effective for removal of small contents of dissolved impurities. In the treatment of waste waters for instance, impurities may be reduced from a content measured in parts per million to one measured in parts per billion. High contents of suspended solids or liquids are removed selectively from suspension by a process of froth flotation. 

Table 9. Application of optical measurement for the estimation of suspended solids...

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