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to an AnMBR, withdrawing at least a fraction of the biogas from the AnMBR, directing a pre-determined amount of the withdrawn biogas to a scrubber, directing a remainder of the withdrawn biogas to a gas distributor, and directing the scrubbed biogas to the AnMBR.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.

The purpose of the present invention is to effectively reduce the corrosion fatigue of an evaporating tube in a boiler which occurs in association with a corrosive environment or repeated application of stress due to the presence of scales. A method for reducing the corrosion fatigue of an evaporating tube in a boiler, in which each of the concentration of chloride ions and the concentration of sulfate ions in the boiler water is managed at 10 mg/L or less. It is preferred to manage each of the concentration of chloride ions and the concentration of sulfate ions in boiler water by subjecting boiler feed water to a desalination treatment with an ion exchange device, a reverse osmosis membrane device or an electrodeionization device or by increasing the collection rate of boiler condensed water.

A system separates and in-situ analyzes a discrete sample of multiphase fluid. The system includes a separation vessel having a first inner chamber for separating a discrete sample of multiphase fluid into liquid phases including an aqueous liquid phase and a nonporous liquid phase, and a built-in water analysis unit. The built-in water analysis unit includes an analytical cell disposed inside the first inner chamber of the separation vessel, the analytical cell having a second inner chamber, and at least one probe having a sensing area disposed in the second inner chamber for in-situ analysis of a sample of the aqueous liquid phase that is separated from the discrete sample of multiphase fluid in the first inner chamber and that is channeled to the second inner chamber from the first inner chamber for the in-situ analysis. The second inner chamber is defined inside the first inner chamber.

The present invention relates to a process and plant for treating feed water containing nitrate. The process includes, sorbing nitrate from the feed water onto an ion exchange resin to form a loaded resin and produce a treated water stream depleted in nitrate, regenerating the loaded resin so that the resin can be reused and produce a brine stream high in nitrate; and converting nitrate in the brine stream into molecular nitrogen gas with the assistance of a bioactive agent.

A method of reducing activity of sulfur and/or nitrogen metabolizing bacteria is provided. The method includes adding a composition of an alkali metal salt of chlorite and/or an alkali metal salt of chlorate and hydrogen peroxide to process water of a cooling tower and increasing a concentration of the composition from about 0 ppm to about 300 ppm in about 1 to about 100 minutes. The method results in significant savings of caustic and reduces sulfur and/or nitrogen metabolizing bacteria in the process water.

The amount of sulfite in water can be determined using fluorescence by adding to the water a fluorophore compound, measuring a fluorescence signal of the water, and determining the amount of the sulfite in the water based on the measured fluorescence signal. This method can be used in a water treatment system in which a sulfite solution is added to treat the water, and the amount of sulfite that is added can be controlled based on the measured fluorescence of the water.

Embodiments of modelling a fluid treatment system are provided herein. One embodiment comprises obtaining synthetic data for a fluid treatment system from a data store. The fluid treatment system comprises a membrane and the fluid treatment system is configured to receive a stream of fluid for treatment. The embodiment further comprises training a performance indicator model using the synthetic data to predict a performance indicator for the fluid treatment system. The performance indicator comprises a permeate sulfate performance indicator and the performance indicator model predicts a sulfate content value in a permeate stream.

This specification describes systems and methods for treating wastewater, for example digestate. The wastewater is separated into a liquid fraction and a solid fraction. The solid fraction of the wastewater is composted. The liquid fraction of the wastewater can be treated, which may result in further by-products. Optionally, at least some of the liquid fraction may be reused in the process. The by-products produced in treating the liquid fraction and/or additional organic solid waste, for example green waste, brought into the treatment facility can be added to the compost. The compost breaks down through aerobic and/or anaerobic digestion processes. Thermophilic conditions may develop in composting piles and increase the rate of evaporation of excess water. When sufficiently dry, the compost may be used as a fertilizer or soil enhancement product.

Methods and systems for removal of ions from aqueous fluids are provided. In certain embodiments, the present disclosure provides a method of removing one or more oxyanions from an aqueous fluid, including the steps of contacting an aqueous fluid containing oxyanions with an aluminum metal whereby aluminum ions are released from the aluminum metal into the aqueous fluid, wherein the one or more oxyanions in the aqueous fluid react with the aluminum ions to form one or more ettringites; controlling a rate of release of the aluminum ions from the aluminum metal; and removing at least a portion of precipitated ettringites from the aqueous fluid.

A method and system of providing seawater into a subterranean formation, including adding chloride salt having a metal cation to the seawater (having sulfate), precipitating sulfate salt (of the metal cation and sulfate), removing the sulfate salt as precipitated to give treated seawater having less sulfate than the seawater, and injecting the treated seawater into the subterranean formation.