Abstract: A biofilter irrigation system comprises a cylindrical vessel having a central axis, a media bed positioned within the vessel, a spray head system positioned above the media bed, the spray head system comprising a central hub positioned at the central axis of the vessel, at least one arm extending distally from the central hub toward a wall of the vessel and configured to rotate about the central axis, and a plurality of nozzles connected to the at least one arm. The biofilter irrigation system further comprises a fluid outlet positioned below the media bed.

Abstract: A method of operating an electrochemical device includes periodically discharging a volume of concentrate reject in a timed batch cycle and replacing the concentrate reject with feed water. An electrochemical water treatment system includes a recycle line having a valve controlled by a control module. The control module periodically opens the valve to discharge concentrate reject from the recycle line in a batch timed cycle. The recycle line is fed with feed water to replace the discharged concentrate reject.

Abstract: A filter press includes a plurality of filter plates, a hydraulic cylinder, a follower plate through which the hydraulic cylinder is configured to apply pressure to the plurality of filter plates, and a spacer rod configured to transfer force from the hydraulic cylinder to the follower plate. The spacer rod is coupled to the follower plate by a moveable support that is displaceable between a home position in which the spacer rod is aligned with the hydraulic cylinder and a disengaged position in which the spacer rod is unaligned with the hydraulic cylinder.

Abstract: An electrochemical cell includes a housing having an inlet, an outlet, and a central axis and an anode-cathode pair disposed concentrically within the housing about the central axis and defining an active area between an anode and a cathode of the anode-cathode pair. An active surface area of at least one of the anode and the cathode has a surface area greater than a surface area of an internal surface of the housing. The anode-cathode pair is configured and arranged to direct all fluid passing through the electrochemical cell axially through the active area.

Abstract: A wastewater treatment system including a contact tank, a dissolved air flotation unit, a fermentation unit, and a biological treatment unit is disclosed. A method of retrofitting a wastewater treatment system by arranging the wastewater treatment system such that floated biosolids are fermented in an anerobic environment and fluidly connecting the biological treatment unit to receive at least a portion of the fermented solids is also disclosed. The method optionally includes providing a fermentation unit and fluidly connecting the fermentation unit to a biological treatment unit. A method of treating wastewater including combining the wastewater with activated sludge, floating biosolids from the activated wastewater, fermenting the floated biosolids, and biologically treating the effluent with the fermented solids is also disclosed. A method of facilitating delivery of soluble organic carbon to a biological treatment unit is also disclosed.

Abstract: An ozone generation system which is adaptable for supplying ozone to different medium and small application processes. The system has a source of feed gas, a corona discharge cell receiving the feed gas from the feed gas source and generating ozone for the application process, a flow controller measuring and managing the flow of the feed gas from the feed gas source to the corona discharge cell; and a regulator receiving gas from the corona discharge cell and sending the gas to the application process. The regulator maintains pressure in the corona discharge cell independent of the application process pressure.

Abstract: Systems and methods for removing heavy metals such as selenium from wastewater with zero valent iron media. Air may be introduced directly into a reaction zone of a fluidized bed reactor filled with the media to catalyze treatment.

Abstract: Wastewater treatment systems are disclosed. A wastewater treatment system includes a wastewater conduit disposed in a wastewater treatment vessel, a pump comprising an intake and an outlet connectable to the at least one opening of the wastewater conduit, and an adapter comprising a first end and a second end. The adapter is configured, in a treatment mode, to provide a flow path for wastewater from the wastewater treatment vessel through the adapter and pump to the wastewater conduit. The adapter is further configured to, in a backflush mode, provide a flow path for wastewater through the plurality of nozzles of the wastewater conduit and through the adapter and pump for discharge into the wastewater treatment vessel. Methods of treating wastewater using the system and adapter are disclosed. Methods of retrofitting a wastewater treatment system by providing the adapter are disclosed.

Abstract: A wastewater treatment system including an aeration unit, a contact tank, a dissolved air flotation unit, and a biological treatment unit is disclosed. A method of retrofitting a wastewater treatment system by providing an aeration unit and fluidly connecting the aeration unit to the wastewater treatment system is also disclosed. A method of treating wastewater including aerating wastewater with oxygen, combining the aerated wastewater with activated sludge, floating biosolids from the activated wastewater, and biologically treating the effluent is also disclosed. The method optionally includes combining the floated biosolids with the aerated wastewater and/or activated wastewater. A method of facilitating treatment of high solids content wastewater is also disclosed.

Abstract: The present invention relates to a method and system for controlling disinfection in recirculating water systems and a method for retrofitting a recirculation system.

Abstract: A method of reducing a concentration of hydrogen peroxide from wastewater includes diluting the wastewater with water having a lower concentration of hydrogen peroxide than the wastewater to produce a diluted wastewater, contacting the diluted wastewater with a dissolved iron compound at an acidic pH to form a partially treated wastewater having a lower concentration of hydrogen peroxide than the diluted wastewater, and precipitating iron solids from the partially treated wastewater by raising a pH of the partially treated wastewater to form a neutralized partially treated wastewater.

Abstract: A system for treating metal-contaminated wastewater includes a primary treatment sub-system, a secondary treatment sub-system, and a tertiary treatment sub-system. The tertiary treatment sub-system includes a reactor tank, a source of ballast material, a source of coagulant, a solids-liquid separator, and a controller configured to recycle ballasted solids from the solids-liquid separator to the reactor tank an amount sufficient to generate metal hydroxide floc in the reactor tank to reduce a concentration of dissolved metal in the reactor tank.

Abstract: A method of operating an electrochemical device includes periodically discharging a volume of concentrate reject in a timed batch cycle and replacing the concentrate reject with feed water. An electrochemical water treatment system includes a recycle line having a valve controlled by a control module. The control module periodically opens the valve to discharge concentrate reject from the recycle line in a batch timed cycle. The recycle line is fed with feed water to replace the discharged concentrate reject.

Abstract: A wastewater treatment system including a contact tank, a dissolved air flotation unit, a fermentation unit, and a biological treatment unit is disclosed. A method of retrofitting a wastewater treatment system by arranging the wastewater treatment system such that floated biosolids are fermented in an anerobic environment and fluidly connecting the biological treatment unit to receive at least a portion of the fermented solids is also disclosed. The method optionally includes providing a fermentation unit and fluidly connecting the fermentation unit to a biological treatment unit. A method of treating wastewater including combining the wastewater with activated sludge, floating biosolids from the activated wastewater, fermenting the floated biosolids, and biologically treating the effluent with the fermented solids is also disclosed. A method of facilitating delivery of soluble organic carbon to a biological treatment unit is also disclosed.

Abstract: Methods for processing pretreated phosphogypsum wastewater are disclosed. The pretreated wastewater may be subjected to electrodialysis involving at least one monovalent cation selective membrane. Further downstream membrane treatment may be applied. Upstream precipitation and air-stripping techniques may optionally also be employed. Related systems are also disclosed.

Abstract: A system and method for backwashing a sand filter in a wastewater treatment system. In one aspect, the invention can be a system for backwashing a sand filter comprising: a sand filter configured to remove solids from an untreated wastewater; a container storing chlorine fluidly coupled to the sand filter by a chlorine supply manifold; a flow control mechanism positioned on the chlorine supply manifold between the container and the sand filter, the flow control mechanism alterable between a first position whereby chlorine cannot flow from the container to the sand filter and a second position whereby chlorine flows from the container to the sand filter, the flow control mechanism being biased into the first position; and a processor operably coupled to the flow control mechanism and configured to automatically actuate the flow control mechanism into the second position upon detecting that the sand filter is being backwashed.

Abstract: A method and system for treating wastewater is disclosed. In one example the method comprises activating a mixing system that imparts a motive force on wastewater in a vessel, measuring at least one property of a first portion of the wastewater at a first time, measuring the at least one property of a second portion of the wastewater at a second time subsequent to the first time, calculating a difference between the at least one property measured at the first time and the at least one property measured at the second time, performing a determination of whether the difference is within a predetermined allowable range of differences, and responsive to a result of the determination, controlling a component of the mixing system.

Abstract: An electrical discharge ozone generation cell has first and second electrode base plates which are separated by a nonconductive flat spacer plate. Within a central opening in the spacer plate is fitted an electrode plate in close contact with the first electrode base plate. A dielectric plate in close contact with the second electrode base plate and with the spacer plate helps define a gas discharge chamber with the interior edges of the spacer plate and the electrode plate. Gaskets on the two sides of the spacer plate around the central opening displaced away from the interior edges of the spacer plate ensure a gas seal for the electrical discharge chamber.

Abstract: The present invention generally includes an ozone generation system with a power supply that measures the rate of energy delivered to the ozone generation cell. While changing voltage, frequency or current will likely affect the rate of energy delivery, current, frequency and voltage provide a very poor and unreliable control for an ozone generation cell. It is only through control of the rate of energy delivery that consistent, reliable ozone generation is possible. Based upon the measurements of the rate of energy delivery as measured at the ozone generation cell, compared to the rate of energy delivery supplied, the rate of energy delivery supplied can be adjusted to improve ozone production and control.

Abstract: A system for treating metal-contaminated wastewater includes a primary treatment sub-system, a secondary treatment sub-system, and a tertiary treatment sub-system. The tertiary treatment sub-system includes a reactor tank, a source of ballast material, a source of coagulant, a solids-liquid separator, and a controller configured to recycle ballasted solids from the solids-liquid separator to the reactor tank an amount sufficient to generate metal hydroxide floc in the reactor tank to reduce a concentration of dissolved metal in the reactor tank.