Method and apparatus for treating natural gas and oil well drilling waste water

A method of treating contaminated water effluent from a well drilling operation, the contaminated water effluent containing organic contaminants and solid particles, and the method comprising:

• a) infusing a gas containing ozone through the effluent, and causing complete oxidation and decomposition of the organic contaminants to carbon dioxide and water in the effluent;
• b) adding a coagulant into a stream of effluent flowing within a first conduit to increase the particle size of the solid particles contained in the effluent, wherein adding the coagulant is performed under controlled shear conditions caused by flow of the coagulant and stream of effluent flowing within the first conduit at a velocity of the coagulant and stream of effluent between 4 feet and 12 feet per second, the first conduit having a diameter of 1.5 inches and a length of between 20 and 50 feet;
• c) forming pin flocs in the effluent following the adding the coagulant;
• d) adding a flocculant into a stream of effluent containing the pin flocs flowing within a second conduit to increase the particle size of the solid particles contained in the effluent, thereby forming flocs suspended in the effluent, wherein adding the flocculant is performed under the controlled shear conditions caused by flow of the flocculant and stream of effluent flowing within the second conduit at a velocity of the flocculant and stream of effluent between 4 feet and 12 feet per second, the second conduit having a diameter of 1.5 inches and a length of between 20 and 50 feet;
• and
• e) filtering the flocs from the effluent to produce a filtrate and flocculated solids.