Abstract: A method of treating a wastewater having an ammonia concentration that is toxic to anaerobic bacteria includes introducing the wastewater into an anaerobic biological treatment vessel to produce a digestate, introducing a portion of the digestate into an ammonia removal sub-system to produce an effluent having a lower ammonia concentration than the digestate, diluting the wastewater introduced into the anaerobic biological treatment vessel by introducing a portion of the effluent from the ammonia removal sub-system into the anaerobic biological treatment vessel with the wastewater, and regulating the flow rate of the portion of the effluent from the ammonia removal sub-system to cause the portion of the effluent to be introduced into the anaerobic biological treatment vessel in an amount sufficient to form an anaerobic biological treatment vessel influent having an ammonia concentration lower than an ammonia concentration that is toxic to anaerobic bacteria in the anaerobic biological treatment vessel.

Abstract: A method of treating wastewater from a renewable fuel production comprises anaerobically digesting the wastewater to produce digestate and sludge, aerobically treating the digestate to produce an effluent and a second sludge, separating the effluent into a first filtrate and a first reject, treating the sludge, second sludge, and first reject in a solids-liquid separation apparatus to produce recovered water, directing the recovered water into the mixing tank, filtering the first filtrate in a nanofiltration unit to produce a second filtrate and a second reject, filtering the second filtrate in a first reverse osmosis unit to produce a third filtrate and a third reject, filtering the third reject in a second reverse osmosis unit to produce a fourth filtrate and a fourth reject, combining the third filtrate and fourth filtrate to form a product water, and combining the second reject and the fourth reject into a combined reject for disposal.

Abstract: Methods of controlling hydrogen sulfide concentration of a biogas occupying an anaerobic membrane bioreactor (AnMBR) containing a submerged membrane are disclosed herein. Methods of controlling dissolved sulfide concentration of a mixed liquor within the AnMBR are disclosed. The methods include directing wastewater containing sulfur and a chemical oxygen demand (COD) to an AnMBR, withdrawing at least a fraction of the biogas from the AnMBR, directing a pre-determined amount of the withdrawn biogas to a scrubber, directing a remainder of the withdrawn biogas to a gas distributor, and directing the scrubbed biogas to the AnMBR. Systems for treating wastewater having sulfur and COD are disclosed. The systems include an AnMBR, a scouring gas closed loop, a scrubber, and a control mechanism for directing biogas to the scrubber and to a gas distributor. Methods of retrofitting a system for treating wastewater having sulfur and COD are disclosed.

Abstract: Methods of controlling hydrogen sulfide concentration of a biogas occupying an anaerobic membrane bioreactor (AnMBR) containing a submerged membrane are disclosed herein. Methods of controlling dissolved sulfide concentration of a mixed liquor within the AnMBR are disclosed. The methods include directing wastewater containing sulfur and a chemical oxygen demand (COD) to an AnMBR, withdrawing at least a fraction of the biogas from the AnMBR, directing a pre-determined amount of the withdrawn biogas to a scrubber, directing a remainder of the withdrawn biogas to a gas distributor, and directing the scrubbed biogas to the AnMBR. Systems for treating wastewater having sulfur and COD are disclosed. The systems include an AnMBR, a scouring gas closed loop, a scrubber, and a control mechanism for directing biogas to the scrubber and to a gas distributor. Methods of retrofitting a system for treating wastewater having sulfur and COD are disclosed.