Method for removing drugs from waste water using neutralized bauxite residue
The instant disclosure relates to methods, systems, and apparatus for polishing wastewater (i.e. non-potable water) using filtration media. More particularly, the instant disclosure relates to wastewater polishing using a bed of mixed metal oxides under certain operating conditions to remove a plurality of contaminants from a wastewater stream.
1. A method comprising:
(a) dissolving at least 5 ppm oxygen into a wastewater stream, wherein the wastewater stream comprises a contaminant profile including at least one drug at an initial drug concentration, wherein said at least one drug is selected from the group consisting of gemfibrozil, hydrochlorothiazide, 2-hydroxy-ibuprofen, ibuprofen, naproxen, triclocarban, triclosan, acetaminophen, azithromycin, caffeine, ciprofloxacin, clarithromycin, cloxacillin, diphenhydramine, diltiazem, erythromycin-H 2 O, fluoxetine, miconazole, norfloxacin, ofloxacin, penicillin V, sulfadiazine, sulfamethoxazole, thiabendazole, trimethoprim, 1,7-dimethlxanthine, cholesterol, and combinations thereof;
(b) flowing the wastewater stream having at least about 5 ppm oxygen dissolved therein into a particulate bed comprising neutralized bauxite residue particles, the bauxite residue particles having an average particle size of less than about 2 inches;
(d) removing at least some of said at least one drug from the wastewater stream to produce a cleaned water stream, wherein the cleaned water stream comprises a final drug concentration less than the initial drug concentration.
2. The method of claim 1 , wherein the removing step comprises removing at least about 40% of said at least one drug from the initial contaminant concentration.
3. The method of claim 1 , further comprising maintaining the pH of the wastewater stream within the range of from about 3 to about 9.
4. The method of claim 1 , wherein the bed comprises a hydraulic loading rate of the wastewater stream onto the bed of not greater than about 0.5 gal/min/ft.
5. The system of claim 1 , wherein the bed comprises a hydraulic conductivity of the wastewater stream through the bed of not greater than about 0.19 cm/s.
6. The method of claim 1 , wherein the particulate bed of neutralized bauxite residue comprises a hydraulic residence time of the wastewater stream in the particulate bed of neutralized bauxite residue of not less than about 33 minutes.
7. The method of claim 1 , wherein the particulate bed of neutralized bauxite residue comprises a field capacity of at least about 50%.