Fouling suspended solids effect

Ultrafiltration of heterogenous colloidal suspensions such as citrus juice is complex and many factors other than molecular weight contribute to fouling and permeation. For example, low MW aroma compounds were unevenly distributed in the permeate and retentate in UF in 500 kd MWCO system (10). The authors observed that the 500 kd MWCO UF removed all suspended solids, including pectin and PE. If PE is complexed to pectate in an inactive complex, then it is conceivable that release of PE from pectin with cations will enhance permeation in UF. At optimum salt concentration, less PE activation was observed at lower pH values than at higher pH (15). In juice systems, it is difficult to separate the effect of juice particulates on PE activity. Model studies with PE extracts allows UF in the absence of large or insoluble particulates and control of composition of the ultrafilter. In... 

For UV to be effective, certain water conditions must be met. The water must be free of suspended solids, which can foul quartz sleeves, thereby reducing the amount of radiation reaching the water. Some UV systems include cleaning mechanisms for quartz sleeves. The water should also be free of taste, odor, iron, and manganese. Furthermore, chloride, bicarbonate, and sulfates should be reduced, as these affect the absorption of UV radiation.(9) Thus, some pretreatment is required prior to sending water to a UV system. 

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