Biodegradation of oil sludge

Procedure for preparing a bacteria-laden inoculum, which is suitable for treating water contaminated with oily hydrocarbon materials:

• selecting an environment in which oily organic materials are present, with water, and air, and where the environment contains viable aerobic bacteria of a kind that degrade the oily material;
• extracting a mass IH0 kg of the said oily organic materials from the said environment;
• providing an incubator-vessel, and placing the mass IH0 in the incubator-vessel, together with a mass IW0 kg of water, to form an inoculum-mixture of mass IT0 kg in the incubator-vessel;
• assessing the magnitude of the mass IH0 kgs, and the mass IT0;
• responsively to the mass IH0 being more than two percent of the mass IT0, diluting the inoculum-mixture with water;
• supplying a mix of nutrients, and adding same to the inoculum-mixture in the incubator-vessel, where the mix of nutrients includes, per kg of the mass T0:
• nitrogen, at least 150 milligrams;
• phosphorus, between 50 mg and 1000 mg;
• potassium, between 25 mg and 500 mg;
• magnesium, sulphur, calcium, at least 5 mg of each;
• manganese, at least one mg;
• iron, at least 0.5 mg;
• copper, at least 0.25 mg;
• and cobalt, zinc, boron, molybdenum, at least 0.001 mg of each;
• supplying air to the incubator-vessel, and blowing the air into the inoculum-mixture in such manner as to agitate and aerate the inoculum-mixture, with such overall flowrate and vigour as to cause all portions of the inoculum-mixture in the incubator-vessel to be mechanically mixed and stirred and thoroughly aerated;
• maintaining the temperature of the inoculum-mixture within the range 25-35 deg C;
• maintaining the pH of the inoculum-mixture within the range 6.4 to 7.6;
• assessing the magnitude of the mass IH kg of the oily organic material, from time to time, as that mass diminishes;
• as preparation of the inoculum progresses;
• responsively to the mass IH being diminished from the mass IH0 by enough of an increment to demonstrate that bacteria effective to degrade the oily organic materials are present and viable in the incubator-mixture, whereupon the inoculum-mixture is now termed the prepared-inoculum, transferring the prepared-inoculum to the reaction-vessel.

Procedure for treating water contaminated with oily hydrocarbon material, by promoting rapid bio-degradation of the oily hydrocarbon material;

• where the oily hydrocarbon material is present as a component of a reaction-mixture, with the water to be treated, and non-bio-degradable solids, in a reaction-vessel;
• where, at time t, the magnitude of the mass of the water in the reaction-mixture is Wt tonnes, the mass of the oily hydrocarbon material is Ht tonnes, and the mass of the non-bio-degradable solids is St tonnes, and the total mass of the reaction-mixture, being Wt+Ht+St, is Tt tonnes;
• the procedure includes:
• assessing Ht/Tt, being the fractional mass, in tonnes, of the oily hydrocarbon material per tonne of the reaction-mixture;
• assessing the magnitude of Ht/Tt from time to time, and assessing the rate of fall thereof, being Ht/Tt per day;
• responsively to the rate of fall Ht/Tt per day being slower than a threshold rate, assessing whether the following parameters of the reaction-mixture meet the following conditions:
• that Ht/Tt is less than 0.15 tonnes Ht per tonne Tt;
• that the temperature of the reaction-mixture is within the range 20-37 deg C;
• that the pH of the reaction mixture is within the range 6.5 to 7.5;
• that the vigour and amount of air blown into the reaction-mixture are enough to cause the whole of the reaction-mixture in the reaction-vessel to be mechanically mixed and stirred thoroughly;
• and, responsively to the parameters being outside these conditions, adjusting the parameters accordingly;
• where the threshold rate is 0.005 tonnes Ht per tonne Tt per day;
• again assessing the fraction Ht/Tt, and, responsively to the fraction Ht/Tt 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.
• re-energising a sluggish degradation