Scales, produced water treatment

In Hydrocyclones A Solution to Produced Water Treatment, Meldrum presents the basic design principle of a dc-oilmg hydrocy leone. System design, early operational experiences, and test results on a full-scale application in the North Sea are discussed. Oil-removal efficiency was seen to rise with increasing reject ratio up to around 1%, producing acceptable outlet concentrations Early field test results on a tension leg platform in the North Sea are discussed. Preliminary data on a pumped system are also given. 

Kwon, S. BCinney, K. - Pilot scale test of a produced water treatment system for initial... 

Techniques for produced water treatment for toxicity reduction are still under development. Novel treatment technologies may yet be applied, but good water management of existing facilities will certainly contribute to the overall control of toxicity. Water treatment chemicals, which reduce the dispersed oil content in the effluent water, can also contribute to the toxicity of such effluent. Other chemicals used to control scale, bio-fouling, and corrosion can also contribute to effluent water toxicity, but are commonly required to reduce equipment maintenance costs. As a result, optimization of the chemicals application program can help control effluent toxicity as well as reduce the overall chemical usage costs. 

In addition to the requirement to conform to steam purity needs, there are concerns that the boiler water not corrode the boiler tubes nor produce deposits, known as scale, on these tubes. Three important components of boiler tube scale are iron oxides, copper oxides, and calcium salts, particularly calcium carbonate [471-34-1]. Calcium carbonate in the feedwater tends to produce a hard, tenacious deposit. Sodium phosphate is often added to the water of recirculating boilers to change the precipitate from calcium carbonate to calcium phosphate (see also Water, industrial water treatment). 

Color can be removed effectively and economically with either alum or ferric sulfate at pH values of 5—6 and 3—4, respectively. The reaction is stoichiometric and is a specific reaction of the coagulant with the color to form an insoluble compound (17). The dosage required may be as high as 100—150 mg/L (380—570 mg/gal). Raw-water colors may be as high as 450—500 units on the APHA color scale. The secondary MCL (maximum contaminant level) for color in the finished water is 15 units, although most municipal treatment plants produce water that seldom exceeds 5 units. 

The title compound is produced by treatment of 2-iodylbenzoic acid with acetic anhydride in acetic acid, and has found wide application as a mild oxidant ( Dess-Martin periodinane ) for ly and 2y alcohols. Although it appears not to be sensitive to impact, unlike the precursor acid, both explode violently when heated under confinement. The oxidant, on treatment with water is hydrolysed back to the explosive 2-iodylbenzoic acid. Forethought and caution are advised before using these explosive materials on any scale of working. 

Much experimental work has been carried out on ozonation in drinking, waste and process water treatment. And since there is still much to be learned about the mechanisms of ozonation, and many possibilities of utilizing its oxidizing potential many experiments will be carried out in the future. Not only researchers but also designers, manufacturers and users of ozonation systems will continue to do bench-scale testing because ozonation is so system dependent. Most full-scale applications have to be tried out bench-scale for each system considered. That means that there is a need for not only fundamental information about the mechanisms of ozonation, but also information on how to set-up experiments so that they produce results that can be interpreted and extrapolated. 

CANMET has a pilot-scaled emulsion-treatment plant (Figure B.l) available to industry for pilot-scaled investigation of heavy-oil-bitumen separation from oil-field-produced waters. This facility is designed to process emulsions at a throughput between 130 L/h (20 barrels per day) and 460 L/h (70 barrels per day) for raw bitumen-oil of API gravity between 8 and 15 (i.e., density between 1014 and 966 kg/m, respectively). 

During the winter months, a water treatment plant produced 350,000 gal of water in one day. The plant operator prepares a sodium fluoride solution by dissolving 9 lb of 98% NaF in 50 gal of water. The solution tank is mounted on a scale. After one day of operation, the scale indicates that 300 lb of solution was fed. What is the theoretical fluoride level in the treated water ... 

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