Visibility turbidity effect

Silica suspended in water can interfere with certain dyeing operations and can cause visible turbidity, as discussed in the introduction to this chapter. Various forms of silica can be determined by any one of several methods as described in Standard Method 4500-Si. For textile use, total silica is the most important. This may be determined gravimetrically by Standard Method 4500-Si-C or by atomic absorption spectrometry by Standard Method 311 ID (Standard Methods, 1998). For information of atomic absorption methods, see the Metals section below. Also, since the detrimental effects in textiles are related primarily to fdtering of the silica on beam and package machines, it often suffices to measure the total suspended solids (TSS) in the water supply. TSS testing is described later in this chapter and is simpler than silica testing. 

The influence of the discharge is visible up to 30 m, mainly because of the presence of relatively high residual organic matter in treated wastewater (COD around 100 mg/L), due to the physico-chemical process of the treatment plant. The TSS concentration (around 30 mg/L) contributes to the turbidity effect in the mixture. The treatment plant extension that should include a biological process would lead to the reduction of wastewater impact in this sea area. 

Time effects have also been observed for bovine plasma albumin, horse serum albumin and rabbit y-globulin (Beaven and Holiday, 1950). The behavior of bovine plasma albumin was most striking the intensity of the absorption in 0.1 N alkali increased steadily over a period of ca. 3 hours at room temperature the light-scattering properties of the solution, as shown by its apparent absorption on the long-wave side of the absorption band proper, also increased. Of the few proteins which were examined, only lysozyme showed no time effect. With trypsin the change in absorption was small and complete in a few minutes at pH 13, but the solution then became visibly turbid. 

The choice of detection device is also quite important since the resolution of size separation for a given column can be markedly affected by the signal characteristics of the detector. The most commonly employed detection is optical turbidity. As will be shown, for a given latex, the effect of detection wavelength can be critical. Thus the optimal set-up employs a variable wavelength UV-visible detector and a standard strip-chart output. 

Turbidimetric analysis is a valuable technique for determining the temperature dependence of the conformational transition of the microgel dispersions and is performed using UV-visible spectroscopy [51, 52]. It is also used to monitor the effect of pH, concentration, hydrophobic and hydrophilic content of the microgel on the turbidity of the dispersion [ 53 ]. 

Schrade et al. (1959) found that the injection of 750 mg of the preparation results within hours in effects similar to those obtained during the course of weeks with administration of polyunsaturated fatty acids by mouth. There was a fall in total serum lipids of as much as 500 mg per 100 ml within a few hours, accompanied by a visible decrease in turbidity. The best response was observed with high initial lipid concentrations. Blood ketones were elevated during this period of time. Juchems et al. (1965) reported similar results. We were unable to produce significant clearing with this material. Further studies will be necessary in the different hyperlipemic syndromes. 

Turbidity. The contribution of turbidity to total absorption is obvious when the solution is visibly cloudy, but can be a subtle source of minor error when merely a pronounced Tyndall effect is observed. 

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