Fouling influencing factors

Many factors influence acid corrosion. Metallurgy, temperature, water turbulence, surface geometry, dissolved oxygen concentration, metal-ion concentration, surface fouling, corrosion-product formation, chemical treatment, and, of course, the kind of acid (oxidizing or nonoxidizing, strong or weak) may markedly alter corrosion. 

A fouled condenser can be identified by an increase in vapor condensing temperature, whereas a fouled general cooler will not provide the anticipated hot water return temperature. Fouling is the primary factor in heat-transfer coefficient with which we are most concerned, and one which we can directly influence with a good water treatment program. 

To achieve a high membrane rejection towards the substrate it is important that the pore size of the membrane is smaller than the size of the molecules to be retained. Nevertheless, other factors influence the separation properties of a membrane, such as the shape and flexibility of the substrate and its acid-base properties, as well as the concentration-polarization phenomenon and the membrane fouling. 

The fouling factor influences the heat-transfer coefficient on the inside of the pipe. We have... 

The various influences on the efficacy of UV disinfection are compiled in Fig. 9-1 (cf Malley Jr, 2000). Primarily, the efficacy of UV disinfection depends on the germicidal fluence Ho=EoXt which is the product of fluence rate Eq and the duration time t of the irradiation (often called UV dose , Chapter 2.1) (see Sommer et al., 1998). Other key factors include the hydraulics and hydrodynamics of the UV reactor (Kreft et al., 1986), its geometry (FIGAWA, 1998, Hoyer, 1996), the number and type of UV lamps required (Loge et al., 1996), their temperature profiles with respect to a maximum fluence rate Eq (in the case of LP Hg lamps, cf Fig. 4-8), the water quality and its variability such as UV absorbance/transmittance (Bolton et al., 2001, Sommer et al., 1997), the water matrix, e.g. nitrate concentration, its potential for quartz fouling by inorganic constituents particularly iron ions and hardness (cf Chapter 8-2), the turbidity, the particle content (total sus-... 

Lamminen MO, Walker FIW, and Weavers LK. Mechanisms and factors influencing the ultrasonic cleaning of particle-fouled ceramic membranes. J. Membr. Sci. 2004 237 213-223. 

Co-contaminants, including BTEXs and inorganic compounds such as ammonium or iron may influence the degradation rates of MTBE in reactors due to different mechanisms. This may be due to three factors 1) competitive or non-competitive inhibition by BTEX compounds 2) microbial competition in reactors for occupancy, oxygen and nutrients and 3) fouling of reactor and biological floes due to iron precipitation. 

Of particular interest in this study is the fouling of membrane processes by natural organics. Fouling depends on the characteristics of the natural organics. A detailed review of the characteristics of interest is required to highlight the factors that may influence membrane fouling. Membrane filtration... 

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