Organic deposit removal

Crude oil displacement/organic deposit removal 10-75gfo tt... 

Wax and asphaltene deposition are formation damage types that should not be treated with add. If acid treatment is necessary, as a means to address other damage types, then a proper organic deposit removal pretreatment must be employed. If organic deposition is found to be the primary or only damage contributor, acidizing can be avoided, which is always desirable. 

Clean-in-place (CIP) units for periodic membrane washing and removal of organic deposits, inorganic scales, and biofouling... 

The origin of the small Sy content of all commercial sulfur samples is the following. Elemental sulfur is produced either by the Frasch process (mining of sulfur deposits) or by the Claus process (partial oxidation of HyS) [62]. In each case liquid sulfur is produced (at ca. 140 °C) which at this temperature consists of 95% Ss and ca. 5% other sulfur homocycles of which Sy is the main component. On slow cooling and crystalhzation most of the non-Ss species convert to the more stable Ss and to polymeric sulfur but traces of Sy are built into the crystal lattice of Ss as sohd state defects. In some commercial samples traces of Ss or Sg were detected in addition. The Sy defects survive for years if not forever at 20 °C. The composition of the commercial samples depends mainly on the coohng rate and on other experimental conditions. Only recrystalhzation from organic solvents removes Sy and, of course, the insoluble polymeric sulfur and produces pure a-Ss [59]. 

Pacification—Treatment of a column-bridged HPLC system with 20% (6 N) nitric acid to remove buffer and organic deposits and protect metal surfaces from corrosion. The column must be removed before acid treatment. Overnight water wash is needed to remove the last traces of acid. 

Organic deposits are formed in several different ways. Before discussing the various means of removing or negating the problems, it is necessary to review how deposits are formed and what determines the rate of deposit formation. 

Various techniques can be used to reduce the loading of suspended solids, organics and microbes in feed water. These include physical processes such as media filtration, cartridge microfiltration and chemical treatments. Chemical addition enhances the filter-ability of the solids such as the addition of coagulants (Table 2.2). Foulants and their control strategies are addressed in Table 2.8. Since any traces of soHds and organics get removed in the first membrane modules in RO and NF systems, these materials typically foul the first stages of an RO/NF system (Table 2.9). Once deposited on the membranes. 

As biogenic amorphous silica by mechanisms still unknown, living organisms can remove silica from extremely dilute solutions and deposit solid silica within themselves in precisely controlled structures of intricate design, perfect almost to molecular dimensions (see Chapter 7). 

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