Bacterial control

Corrosion inhibitor 1 Bacterial control J Cooling-water system Consumption depends on make-up Chemicals are used to provide adequate reserve... 

Because of their surfactant and filming properties fatty amines such as coco-alkylamine acetate (and more especially diamines, such as tallow propylenediamine) are also occasionally employed in other types of water treatment programs. For example, they may be used as corrosion inhibitors for steel cooling systems, especially those smaller units where minimal operational control is provided. The amines must be continuously dosed to ensure good film formation (and thus corrosion protection), typically at 5 to 10 ppm active amine. They also tend to have good biostatic control properties, which provide a benefit of algal and bacterial control at no extra cost. 

Combined Chlorine-Aldehyde Treatment A combined chlorine-aldehyde treatment that has two stages, that is, chlorination and subsequent biocide application, has been suggested. Short-residence-time shock doses of glutaraldehyde have been applied after chlorination [1180]. It has been established that a primary chlorination in overall bacterial control is useful. 

Offshore oil production is one area in which environmental pollution has been highlighted as an issue, particularly in the use of biocides in production waters. Tetrakis-hydroxymethyl phosphonium salts exhibit acceptable environmental profiles [1120], and they are regarded as the preferred products for bacterial control within the oil production industry. 

Weinberger F, Beltran J, Correa JA, Lion U, Pohnert G, Kumar N, Steinberg P, Kloareg B, Potin P (2007) Spore release in Acrochaetium sp. (Rhodophyta) is bacterially controlled. J Phycol 43 235-241... 

This comprehensive definition makes it elear that a wide number of substances may be eonsidered to be pestieides, and that the eommonality among all pestieides is their ability to provide eontrol over pests. A variety of classifications for pesticides have been developed that are specific for the type of pest controlled. Insecticides, for example, are pesticides that control insects, while herbicides control weeds and fungicides control plant diseases (molds). In addition to these major classifications of pesticides, there are many other classifications. These include nematicides (for nematode control), acaracides (mite control), rodenticides (rodent control), molluscicide (snail and slug control), algacides (algal control), bacteriocides (bacterial control), and defoliants (leaf control). 

In summary, we have demonstrated the successful operation of a "Permasep" RO pleint on biologically active feed waters by using the intermittent injection of iodine as a bacterial control measure. The use of this shock procedure allowed for steady, continuous performcince of the plant euid is expected to have significant impact on future applications of PA membranes to biological action as well as waste waters. 

The source of water samples was a 4-m3/h pilot plant on the Seine River located upstream from Paris, France. The background organic concentration ranged from 2 to 3 mg/L. The process, shown in Figure 1, included an upflow solids contact clarifier (Pulsator, Degremont, Rueil Malmaison, France) followed by rapid sand filtration (RSF). The effluent of the RSF was then split into four lines, which received various levels of ozonation followed by granular activated carbon (GAC) adsorption. Postchlorination (0.2 mg/L residual after 1 h) was used for bacterial control. 

Benzoic acid is generally considered to exhibit an inhibitory effect on microbial growth, although it is of little use for bacterial control, where the greatest problem will occur at pH values above 4, outside the effective limit mentioned above. Improved results are obtained when it is used in conjunction with other preservatives, for example, S02 or sorbic acid, due to synergistic effects. It is interesting to note that the current European Directive, which sets individual limits of 300 rng/1 for sorbic acid and 150 mg/1 for benzoic acid in non-alcoholic flavoured drinks, nevertheless permits a joint preservative use of up to 250 mg/1 sorbic acid with 150 mg/1 benzoic acid. 

Algae and bacterial slime Algae and bacterial control Solubility control... 

Bidle, K.D., and Azam, F. (2001) Bacterial control of silicon regeneration from diatom detritus significance of bacterial ectohydrolases and species identity. Limnol. Oceanogr. 46, 1606-1623. 

Ellwood, B.B., Chrzanowski, T.H., Hrouda, F., Long, GJ. and Buhl, M.L., 1988. Siderite formation in anoxic deep-sea sediments A synergetic bacterially controlled process with important implications in paleomagnetism. Geology, 16 980-982... 

Veliger mussel larvae growth, as in most bivalve larvae, is dependent on temperature, salinity and phytoplankton availability and species composition. Other considerations include larval density, concentration of food and size, bacterial control and shape of the rearing vessels. Loosanoff and Davis (1963) described the basic methodologies for handling and rearing the larvae of bivalves. This technology is well known and has been in commercial use for several decades. 

Bacterial Control Methods Prevention of Bacterial Infection and Food Poisoning... 

Physical methods. Physical means comprise another category of bacterial control. Heat, of course, is the chief physical control method. Freezing retards proliferation. Also, the preservation of food by radiation has received much study, the goal being to sterilize foods and preserve them indefinitely. 

Also see BACTERIA IN FOOD, section headed "Bacterial Control Methods.")... 

PPM FORMALDEHyOE FOR BACTERIAL CONTROL SO PPM CITRIC ACID FOR IRON CONTROL QUADRANT AND OVERALL TRACERS... 

To evaluate the effectiveness of H2S as a biocide in the Tensleep reservoir, 11,200 bbl [1.78X 10 m3] of polymer solution was injected into Well 74. Measurable but not serious plugging was observed on the fracture face. Every precaution was taken to eliminate oxygen from the injection plant facilities (oxygen levels just upstream of the wellhead were always < 10 ppb). Because tritium was used as a tracer in the second test, cobalt-57 was used as the tracer in this test. After the 2-week well shut-in period, polymer levels in the produced fluids were only about one-half of what was expected from the tracer results (Fig. 18). All of the available evidence led to the conclusion that the H2S in FIB did not prevent bacterial degradation of the polymer. This conclusion was supported by the fact that high levels of aerobic, general facultative-aerobic, and sulfate-reducing bacteria were found in the produced solutions. It was not apparent why bacterial control was successful in the laboratory and not in the field. 

Bacterial control in polysaccharide polymer solutions appeared attainable according to laboratory results but could not be sustained in the field. Three single-well pump-back tests showed very severe near-wellbore polymer degradation after a 2-week shut-in period. 

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