Chemical Treatment Biocide

Chemicals that are used to kill microorganisms and macroorganisms are called biocides (literally meaning killer of the living ). 

Circumferential MFL is best at finding/sizing anomalies in this region 

FIGURE 4.41 Zones of effectiveness of circumferential and axial MFL. (From Bubenik T., Magnetic flux leakage. In the Proceedings of the In-line Inspection Symposium, California Public Utilities Commission, June 24, 2011. With permission.) 

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Environment 100-200°F (38-93°C) heavily fouled with grease and oil, no chemical treatment other than chlorine-bromine biocide may blow out lines when completely plugged with grease, oil, and iron... 

Chemical treatments for bacteria control represent significant cost and environmental liability. Because the regulatory pressure on the use of toxic biocides is increasing, more environmentally acceptable control measures are being developed. 

In the United States, the European Union, and many other countries, as has been mentioned earlier, there are regulations that control the use of biocides and other types of chemicals in industrial situations. Successful efforts to clean up rivers, improve working environments, and remove pollutants from being discharged cannot just be ignored or overridden. The cooling system operator often has a duty to review all water treatment chemicals, including biocides, prior to their potential use on-site. The owner may have rules in place over what biocides are or are not acceptable in the workplace. 

New EU directives may limit the development and application of new biocides and for this reason, and concerns on toxicity or pollution, there is interest in alternative water treatment techniques such as ultrasound, high-pressure vortexing and electro-coagulation. These may also be used where chemical treatment is not appropriate. ATP measurements are likely to prove useful to monitor the effectiveness of these types of treatment but as with chemical biocidal treatment the nature of the ATP results may depend on the mode of action. One type of electrochemical treatment has been evaluated in our laboratory. The results indicate that as with chemical biocide treatment the use of both Total and Free ATP measurements can be of value in the interpretation of the results, monitoring the process efficacy and in optimisation of this method of water treatment. 

If materials selection depends on corrosion control by process-related measures (such as chemical treatment), these should be indicated on the MSD. Indicate the intended injection points and the type of chemical to be injected. Examples include corrosion inhibitors, scale inhibitors, biocides, pH control chemicals, wash water, etc. Also indicate the location of proposed corrosion monitoring and sampling sites. If anodic or cathodic protection is to be part of the corrosion control design, the MSD or its Notes section should indicate the piping and/or equipment to be protected. 

The desired biological action of biocides against unwanted growths on stone, of course, also means that these chemicals pose a threat to the natural environment if they cannot be restricted to the stone substratum. Thus the chemical and physical behaviour, especially their solubility in water and capacity to react with stone components, has an important effect on whether there is a risk of environmental pollution. The interactions with the stone, or indeed previous chemical treatments, could also lead to colour changes or even mechanical damage through crystallisation. 

Treatment programmes to deal with scale formation and crystallisation generally include mixtures of additives so that a wide spectrum of activity is accomplished and may additionally include corrosion control chemicals and biocides. Each system will have unique characteristics and will involve the need "to tailor" the programme to meet the specific needs of that system. 

In Chapter 14 the use of additives to combat potential fouling was discussed. In the use of chemical treatment for cooling water there has to be an emphasis on effective and rapid dispersion since the concentration of the additives employed must be low, i.e. a few mg/l where possible, to minimise cost and to reduce potential pollution problems. In general the additive formulation will be based on the need to limit corrosion (i.e. the use of corrosion inhibitors), scale formation (i.e. the use of crystal modifiers, dispersants or threshold chemicals or a combination) and biofouling (i.e. the use of biocides and dispersants). In many installations additives are injected on the suction side of the main pump so that turbulence within the pump will provide rapid mixing. In very large cooling systems multiple injection nozzles will be required to enhance distribution. 

Physical and chemical treatment techniques to control MIC have become very common in industry. Both of these techniques have been commercialized, and therefore, engineers more than microbiologists are involved in the practice of pigging and application of biocides. 

Chemical treatment (use of biocides) not only must consider cost effectiveness and broad-spectrum features, but also it must be compatible with environmental rules and regulations. This means that the operators are not allowed to use any concentration of any type of biocide they wish. It must also be noted that as intelligent biocides have not (yet) been invented, the biocide cannot differentiate between corrosion-enhancing bacteria and other types of microorganisms and macroorganisms. This will limit application of biocides in industries such as offshore platforms. 

While this method can be quite promising, it still needs to be tested on the field more often. But if this method proves to be a really feasible method to treat MIC, especially in comparison with chemical treatment of MIC by biocides, magnetic treatment of MIC method will have a bright future. In our opinion, water treatment industry will warmly welcome such environmentally friendly treatment methods. 

HjS. This change may result in potential SSC and other cracking mechanisms. Sulfate-reducing bacteria (SRB) activity in the water phase is the primary cause of the H2S increase. As a result, chemical treatment with a biocide may be required. 

In order to cope with water scarcity and pollution of the hydrosphere, two main strategies of water treatment are applied (1) chemical treatment of polluted drinking water, surface water, groundwater and (2) chemical treatment of waste-waters containing biocidal or non-biodegradable components. 

There are efforts underway in the oilfield to find chemicals or treatment regimens that can serve as alternatives to biocides in an effort to control souring, or the effects of souring. Several of these methods are chemical treatments, while the others are physical treatments. 

Wrong hydrotest Untreated water has been used for the test. The untreated water is water for which no chemical treatment (mainly by biocides) to remove corrosion-enhancing bacteria has been done. 

In their review [32], Ribas Silva and Pinheiro quote from the work done by Salvador with regard to the inpact of some biocides on several inorganic materials including concrete. This impact is tabulated in Table 8.2. In addition to chemical treatment of concrete with biocides, other techniques of dealing with concrete such as mechanical and biological measurements were reviewed [32]. 

This chapter explains some physical-mechanical treatments (such as UV and pigging), chemical treatments (use of biocides, the advantages and disadvantages of some biocides, and treatment regimes such as dual biocide treatment,) electrochemical treatments (use of cathodic protection and coatings), and some biological treatments that are currently being researched and applied. 

In the literature of chemical treatment of MIC by biocides, a very commonly used term for a biocide is broad-spectrum . That means that the broad-spectrum... 

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