A system for agricultural irrigation water oxygenation for enriching soil oxygen level comprises a source of compressed oxygen (and not compressed air) coupled to a water line feeding an irrigation system, such as a drip irrigation system. The coupling system may include a pressure sensor for measuring the pressure in the water line, a solenoid safety valve, a control valve, a flow meter and a controller that controls the flow of oxygen from the source of compressed liquid oxygen to the water line using the components of the coupling system, without using a special cavitation valve and using off-the-shelf components while achieving the same benefits as a system incorporating the special cavitation valve.

Disclosed herein are systems and processes for treating a Waste Stream comprising biosolids, the Waste Stream provided at varying flow rates and solids concentrations so as to achieve an SOUR of 1.5 mg O.sub.2/g/hr or less and an ORP of at least +300 mV. The system includes a biosolids manipulation device to adjust the volume of suspended solids as a percent of the total volume of the Waste Stream to five (5) percent or less; a chemical oxidant feed device to dose the Waste Stream with an oxidant such as chlorine dioxide, ozone, or similar oxidant, and a treatment vessel associated with said chemical oxidant feed device through which said Waste Stream flows, wherein said chemical oxidant feed device and said treatment device are configured so as to achieve a dose rate between 25 and 200 parts per million of the Waste Stream and substantially complete mixing of the oxidant within 30 seconds of dose delivery in the treatment vessel.

The invention relates to a method for controlling a concentration of dissolved oxygen in a volume (V) of water (W), wherein a device (1) for dissolving oxygen in water (W) is submerged in said volume (V) of water, wherein oxygen is injected by the device (1) with an adjustable flow rate into a main water stream (W′) sucked into a housing (100) of the device (1), and wherein the oxygen enriched main water stream (W′) is discharged by the device (1) out of the housing (100) of the device (1) into said volume (V) of water (W), and wherein a current concentration of oxygen dissolved in the sucked main water stream (W′) is measured with an oxygen probe (6) that is integrated into the housing (100) of the device (1), wherein said current concentration of dissolved oxygen is transmitted in a wireless fashion to a hand-held device (9) of an operator, and wherein the flow rate of the injected oxygen is controlled such that the measured current concentration of dissolved oxygen approaches a pre-defined reference value.

Disclosed is a method for treating wastewater containing heavy metal. First, the wastewater containing heavy metal is subjected to a homogenization treatment, such that the water quality of the wastewater containing heavy metal from different processes is homogenized. The homogenized wastewater containing heavy metal is subjected to an anaerobic-aerobic circulating treatment in a membrane bioreactor (2), in which heavy metal ions are reduced by the action of microorganisms in the anaerobic treatment process. The membrane bioreactor (2) is filled with a hollow fiber membrane (3) containing a quinone group, which serves as an electron mediator that can accelerate the enzymatic reduction of heavy metal ions during the anaerobic treatment. During the aerobic treatment, the COD and SS in the wastewater are further removed.

Systems and methods for intensive recirculating aquaculture are provided herein. An example system includes water sourced from a first segment of a saline aquifer, a recirculating aquaculture system receiving the sourced water and producing discharge water, and a water discharge point located within a second segment of the saline aquifer disposed below the first segment of the saline aquifer.

A method of processing waste water to produce a filtrate is provided. The method includes the steps of: introducing untreated wastewater to an inlet zone of a bioreactor; introducing a concentrate of treated waste water with at least 10,000 mg/L of total suspended solids into the inlet zone of the bioreactor to form a biological active mixture; aerating the biological active mixture in an aeration zone of the bioreactor to produce treated waste water; filtering the treated waste water to produce a filtrate and the concentrate, wherein the filtrate created by the filtering has total suspended solids of less than 10 mg/L; transferring at least a portion of the concentrate to the inlet zone of the bioreactor; and transferring the filtrate external to the bioreactor as clean water.

The invention relates to a method and apparatus for treating water. Iron is removed biologically from humus-rich water with the solution according to the invention. In the method, the water being treated is conveyed through a filter, which filter comprises filter material. Before the water is conveyed to the filter, the pH value of the water is lowered with an acidification part that is included in the apparatus.

A stabilized, gas-infused liquids containing ultra high concentrations of infused gas, produced by: generating a gas-infused liquid in a sealed vessel under a high pressure of at least 20 psi; stabilizing the gas-infused liquid by passing the liquid while still under the high pressure through a tubular flow path arrangement which compresses the infused gas into nano bubbles in the liquid; infusing an additional amount of the gas into the stabilized liquid by injecting the same, while still under high pressure, back into the sealed pressure vessel along with more of the gas; and again stabilizing the liquid by again passing liquid, while still under the high pressure, through the tubular flow path arrangement to thereby form the additional amount of infused gas into nano bubbles in the liquid.

A method of controlling a volatile fatty acid in an aqueous industrial system is provided in the present disclosure. The method includes determining a level of dissolved oxygen in process water in the aqueous industrial system and adding an effective amount of a control agent to the process water if the determined level of dissolved oxygen is above a predetermined level. The compositions and methods can lower the amount of VFA present in the aqueous industrial system.

A method, a system and an apparatus for wastewater treatment using a combination of separation of fat, oil and grease (FOG) and biological treatment for reducing the amount of fat, oil and grease (FOG) in wastewater with the aid of a liquid culture of microorganisms is provided. In particular, the technology disclosed relates to a method and process for the separation and treatment of FOG, as well as a container tank and an outlet pipe construction adapted for improving the gravimetric FOG separation process and the breaking down of FOG using microorganisms.