Patent ID: 6652752
Filing Date: 2003-11-25
Classification: C02F,Y02W

Abstract:
A procedure for treating water contaminated with oily hydrocarbon material, by promoting rapid biodegradation of the oily hydrocarbon material, where the oily hydrocarbon material is present as a component of a reaction-mixture, with the water and non-bio-degradable solids, which is present as an initial batch of the reaction-mixture in a reaction-vessel, including:assessing the magnitude of the initial mass of the water in the reaction-mixture, being W0 tonnes, the initial mass of the oily hydrocarbon material, being H0 tonnes, and the initial mass of the non-bio-degradable solids, being S0 tonnes, and noting the combined total W0+H0+S0 as the mass T0 tonnes of the initial batch; where the procedure is carried out on an industrial scale, in that the mass T0 is several tonnes; assessing the fraction H0/T0 and, responsively to the fraction being so large that the reaction mixture contains a substantial mass of undissolved hydrocarbons, carrying out the following micro-biological treatment procedure: supplying a mix of nutrients, and adding same to the reaction-mixture in the reaction-vessel, where the mix of nutrients includes, per tonne of the combined mass T0: nitrogen, at least 150 grams; phosphorus, between 50 grams and 1000 grams; potassium, between 25 grams and 500 grams; magnesium, sulphur, calcium, at least 5 grams of each; manganese, at least one gram; iron, at least 0.5 grams; copper, at least 0.25 grams; and cobalt, zinc, boron, molybdenum, at least 0.001 grams of each; providing a surfactant formulation in such amount that, when the surfactant is thoroughly mixed into the initial batch of reaction-mixture, the mixture forms an oil-in-water emulsion; supplying air to the reaction-vessel, and blowing the air into the reaction-mixture in such manner as to agitate and aerate the reaction-mixture, with such overall flowrate and vigour as to cause all portions of the reaction-mixture in the reaction-vessel to be mechanically mixed and stirred and thoroughly aerated; maintaining the temperature of the reaction-mixture within the range 20-37 degC.; maintaining the pH of the reaction mixture at a pH suitable for bacterial groweth and hydrocarbon degradation; assessing the magnitude of the mass Ht of the oily hydrocarbon material at time t, from time to time, as the mass diminishes, as treatment progresses; responsively to the mass Ht reaching an acceptably safe level, whereby the batch of reaction-mixture now comprises a batch of treated-mixture, discharging the batch of treated-mixture from the reaction-vessel.