The zinc ion stabilization efficacy of synthetic, biodegradable, hybrid, and natural polymers has been studied. The results show that performance of polymers tested strongly depends on the polymer architecture. Based on the data collected, the performance of synthetic polymers may be ranked as follows: ter-> co-> homopolymers. For hybrid polymers the trend is CMI-25 > CMI-15. It has also been found that among carboxyl containing homopolymers synthetic polymers perform better than bio- and natural polymers. The precipitate consisted mainly of zinc oxide which was predominant at the experimental conditions, with plate like crystallites with a wide particle size distribution. The presence of low dosage of acrylic acid homo- and terpolymers did not have any effects on the morphology of the precipitated crystals but showed reduction in zinc oxide particle size.
Fouling of equipment surface by unwanted materials is a well-documented problem in industrial water systems.1 The foulants are generally classified into four categories: a) mineral scales i.e., calcium carbonate, calcium sulfate, calcium phosphate, magnesium hydroxide, etc., b) corrosion products i.e., iron oxide, zinc oxide, copper oxide, etc., c) microbiological mass i.e., bacteria, algae, fungi, and other organisms, and d) deposits i.e., clay, silt, calcium-inhibitor salts, corrosion products, etc. If not properly controlled, these unwanted materials may lead to severe operational and economic problems including loss of heat transfer, plugging of equipment, increased pumping costs, loss production due to downtime, inefficient use of chemicals, premature equipment replacement, and increased operational costs. The industrial water systems plagued by these unwanted materials include boiler, cooling, desalination, geothermal, oil and gas production, semiconductor manufacturing, etc. Mitigation of mineral scales, corrosion, and suspended matter in these systems is done by incorporating different types of additives such as scale inhibitors, corrosion inhibitors, and dispersants in the formulations. Microbiological mass is controlled by biocides which are fed separately.
Corrosion is defined as the deterioration of metal by a chemical or electrochemical reaction with its environment. Numerous factors such as metallurgy, water chemistry, temperature, pH, dissolved gases, and water flow rate, influence corrosion. Since different metals corrode for different reasons, it is therefore important to keep in mind the metallurgy present while developing a treatment program with inhibitors that are effective in controlling all potential corroding surfaces. Foulants resulting from industrial water system corrosion include oxides and hydroxides of iron, copper, and zinc. Corrosion in industrial water systems is controlled by incorporating one or more of four major inhibitors and a variety of supplements in the water treatment formulation. Corrosion inhibitors are generally classified, depending on their mode of action, as anodic i.e., chromate, nitrite, molybdates, phosphates; cathodic, i.e., zinc ions, polyphosphates and phosphonates in conjunction with calcium ions; oxygen-absorbing i.e., sulfites, hydrazine; and organic i.e., benzotriazole, triazole, etc.
