Abstract: An improved method and apparatus is provided for maintaining a constant gas-to-solids ratio in the effluent from a long vertical shaft waste treatment bioreactor. In a vertical bioreactor wherein waste is circulated under air-injected oxidation conditions around a loop comprising adjacent downcomer and riser chambers connected at their terminals and operatively connected to a separation apparatus, the improvement comprises withdrawing treated effluent from the riser chamber into a cylindrical vessel from whence the effluent is directed either to the separation chamber or into the influent stream depending on the total level of fluid in the bioreactor. Removal of large air bubbles from the effluent is also effected in the cylindrical vessel. The method provides improved gas-to-solids ratio in the effluent and improves sludge flotation in the separation apparatus.

Abstract: A biological waste water treatment carried out in a single tank. The conditions in the tank are controlled to provide a biological reaction zone containing waste water and biodegrading organisms and an overlying clarification zone from which an effluent of treated waste water flows. The recycle stream is continuously withdrawn from the biological reaction zone, supplemented with influent waste water, passed through an oxygen-dissolving device, and the supplemented stream returned to the reaction zone. The oxygen is monitored and supplied to satisfy the demands of the organisms and, at the same time, to keep the oxygen in solution. According to the invention, the supplemented recycle stream is continuously injected along the bottom of the biological reaction zone in a horizontal shallow inflow having a width substantially greater than its depth and a flow considerably greater than that of the influent.

Abstract: Process and apparatus for treating waste water by circulating it, together with oxygen-containing gas, through communicating downflow and upflow pipes enclosed in a treatment chamber, the pipes being open at their bottom ends, and controlling the flow of waste water/gas mixture from the downflow pipe to cause gas bubbles to escape downwardly, or part downwardly and part upwardly, in the treatment chamber.

Abstract: A method for removing biodegradable compounds selected from the group comprising: phenolics, free and fixed ammonia compounds, thiosulfates, cyanides, thiocyanates, sulfides and the like from a feed wastewater. The method comprises the steps of treating the feed wastewater by adding soda ash thereto; and further treating the wastewater by means of an activated sludge treatment in a sludge reactor to reduce the level of biodegradable compounds in the wastewater.A method for removing biodegradable compounds selected from the group comprising phenolics, free and fixed ammonia compounds, thiosulfates, cyanides, thiocyanates, sulfides and mixtures thereof from a feed wastewater comprising the steps of: treating the feed wastewater with an inorganic carbon source; and further treating the wastewater by means of a single-stage activated sludge treatment in a sludge reactor to reduce the level of said biodegradable compounds in the wastewater.

Abstract: A waste treatment apparatus provides a cylindrical vessel adapted to receive a waste water flow therethrough to be treated. The vessel provides an aeration chamber at the outer peripheral portion thereof, with a desirable generally helical flow being generated by aeration bubbles striking angularly deposed baffle plates. A clarifier is provided at the central portion of the cylindrical vessel for clarifying a liquid which enters the clarifier from the aeration chamber. The clarifier comprises a first settling chamber and a second decant chamber through which clear water is collected and transmitted to a chlorination chamber for subsequent discharge. The angularly deposed baffle plates are mounted in the upper portion of the aeration chamber and aid in spinning waste water in a circular or curved path. Likewise, a pair of aeration diffusers mounted in the lower portion of the aeration chamber near the center of the cylindrical vessel move waste water to be treated upwardly and outwardly in a circular path.

Abstract: Wastewater is directed into an aerobic treatment tank which is divided by a partition into an aeration chamber and a settling chamber. The waste material is aerated in the aeration chamber and then directed into the settling chamber. Any solids in the settling chamber settle out and are pumped back into the aeration chamber through a sludge return conduit wherein the returning sludge is saturated with air. The treated liquid is discharged to a drainage area in a colorless, odorless form. The pipes which direct the liquid through the tank are oriented to impede the passage of solids through the system, thereby keeping the solid wastes in the aeration chamber.