The disclosure discloses a production method for full resource recycling of sulphate-process titanium dioxide production wastewater. The method comprises the steps: adding sulphate-process titanium dioxide production wastewater neutralized with lime and treatment wastewater obtained by separating gypsum in a filter press into a recycled sodium carbonate solution to precipitate saturated calcium sulfate in the treatment wastewater, clarifying slurry to separate a calcium carbonate precipitate from a sodium sulfate solution, and performing membrane separation on the separated sodium sulfate solution in a membrane filter; and adding lime into the concentrated phase sodium sulfate solution for causticizing reaction, wherein the filtrate is used as a sodium hydroxide solution, carbonizing using a carbon dioxide-containing tail gas produced in the production process of titanium dioxide to obtain a sodium carbonate solution, and then precipitating saturated calcium sulfate in the treatment wastewater again.

This disclosure provides techniques for treatment of aqueous matrices using electrolysis to produce soluble metals. An aqueous matrix of interest is passed through an electrolysis device with at least one consumable electrode, which dissolves under applied current, transferring a desired reagent to the aqueous matrix of interest. In one embodiment, the electrolysis device is used in a water delivery network to passivate hexavalent chromium (Cr6) and/or convert it to trivalent chromium; the electrode can be made of food-grade metal tin, which is electrolyzed to form a stannous reagent, which then reacts with the Cr6. The disclosed techniques provide for Cr6 passivation without requiring the use of concentrated acids or other harmful substances. Long term reagent generation efficiency can be enhanced through the use of cleaning processes which maintain a fresh electrode surface in contact with the aqueous matrix of interest.

Methods and systems for the controlled production of aqueous halogen solutions with varying compositions are disclosed. According to an embodiment, aqueous solutions of hypochlorite ions are modified through the sequential addition of pH adjusting chemicals, non-chloride halide ions, and halogen stabilizing compounds. Sensors, for measuring physical and chemical properties of the solutions as they change due to the impact of the various chemical reactions, are linked to a control system which, in turn, can control the input of one or more chemicals. The control system facilitates the production of a solution with desired characteristics in terms of pH, specific halogen composition, degree of halogen stabilization, and limiting the production of undesired by products such as bromate ions.

A system and associated method for producing an HOCl solution and an NaOH solution includes a generator operable for producing the HOCl and NaOH solutions utilizing electricity and a mixture of water and brine in an electrolysis cell. The generator includes a mechanical fixed flow restrictor (FFR) operable for controlling at least one of a pH of the HOCl solution and a free available chlorine (FAC) of the HOCl solution. The FFR includes an insert having a longitudinal fluid passageway. The length of the insert and the diameter of the fluid passageway are selected to control the pH of the HOCl solution and/or the FAC of the HOCl solution. The FFR is interchangeable so that the pH of the HOCl solution and/or the FAC of the HOCl solution can be precisely controlled.

A platform for sequestering carbon dioxide using a body of water is described. The platform has a vessel for holding solid metal hydroxide and for exposing the solid metal hydroxide to a flow of water to create a solution of a metal hydroxide having a pH level. The solution containing metal hydroxide is released into the body of water, causing a reaction with the carbon dioxide present in the body of water, thereby producing metal carbonate/bicarbonate, thus sequestering the carbon dioxide. A choice of the metal in the metal hydroxide, a rate of the releasing the solution containing the metal hydroxide into the body of water, and a flow rate of the flow of water so that to substantially maintain the solution containing the metal hydroxide at the pH level that is defined as environmentally safe and not changing chemistry of seawater. A corresponding method is also provided.

A system and method for treatment of wastewater, in which the system includes a blackwater reactor configured to receive a stream of blackwater influent, to contain the blackwater therein during treatment of the blackwater, to facilitate recovery of methane and nutrient precipitates therefrom, and to output partially treated blackwater, and a greywater reactor configured to receive a stream of greywater influent and the partially treated blackwater output from the blackwater reactor, to contain the greywater and the partially treated blackwater therein during greywater treatment, and to output greywater treatment discharge. The process includes inputting a stream of blackwater into the blackwater reactor; treating the blackwater in the blackwater reactor with an anaerobic digestion process; controlling a pH level of the blackwater within the blackwater reactor; recovering nutrient precipitates from the blackwater reactor, optionally independent of chemical additives; and recovering methane from the blackwater reactor.

A total biological count associated with treated water produced by a wastewater treatment system may be monitored online in a decentralized non-potable water system. Preventative and/or corrective action can be taken in response to a deviation from a predetermined threshold level.

A method of providing sustained odor control in an extended sewer line is disclosed. The method includes measuring at least one parameter of the sewer line including average wastewater volume, flow rate, and retention time and administering a blended composition which includes an immediate release compound and an extended release compound into the sewer line to control concentration of an odorous compound therein. A method of facilitating sustained odor control in an extended sewer line is also disclosed. The method includes providing the blended composition including the immediate release compound and the extended release compound and instructing a user to administer the blended composition to the sewer line control concentration of the odorous compound therein. A system for providing sustained odor control in the extended sewer line including sensors to measure sewer line parameters and a controller to instruct administration of the blended composition is also disclosed.

Presented herein is a voltaic cell containing a biofilm for facilitating energy conversion in a bioelectrochemical energy conversion cell where the biofilm includes one or more microbial populations.

The present invention describes an automated, transportable and energy-efficient with a hybrid power capacity wastewater treatment facility that allows for the disinfection of contaminated sanitation wastewater in order to preserve the environment and provide a greater availability of this resource and its reuse. The facility described in the present invention allows to carry out a process for water treatment in five stages based in equalization, oxidation sedimentation, disinfection and filtration. Moreover, it has a photovoltaic feeding system and a night lighting system that allows the operation of the facility in a hybrid way during the day and the night, as well as a structure that allows its easy transportation. Finally, the facility has an automated system comprised by a control panel that allows to manage and monitor every operational condition of it, that integrates and sends all processed programmable information to a programmable logic controller.