Provided herein are methods of reducing microbial concentrations in water with a peracid disinfectant. The method can include the steps of measuring the quality of the water in real-time and dosing the water with a first dose of a peracid disinfectant; measuring the peracid disinfectant demand; and adding one or more subsequent doses of the peracid disinfectant. The subsequent peracid disinfectant dose can be controlled by a processor-based controller based on peracid disinfectant demand.

A biological reactor system treats concentrated contaminated water with a combination of upflow and downflow bioreactors that are downstream from a reverse osmosis or other concentrator. The system may have a fail safe configuration where flush water may be introduced to the reactors in the event of a power failure or when taking the reactors offline. Many reverse osmosis systems introduce antiscalant treatments upstream so that the reverse osmosis filters do not scale. However, such treatments result in superconcentrated conditions of the antiscalants in the contaminated water processed by the bioreactors. A flushing system may deconcentrate the bioreactors to prevent the antiscalants from precipitating and fouling the bioreactors.

A desalination system (100) having an intake unit (110) providing seawater to a pre-treatment unit (120) connected to a reverse osmosis (RO) desalination unit (130) and a post treatment unit (150). The desalination system (100) is configured to operate without any external addition of chemicals to simplify logistics and regulation concerns. The units of the system are configured to prevent biofouling, scaling and corrosion by mechanical and biological means including high flow speeds, biological flocculation of colloids, and making the water entering the RO units inhospitable to bacteria and other organisms that cause biofouling, hence preventing their settlement and removing them with the brine. Recovery rate is lowered and energy is recovered to increase the energetic efficiency and minerals that are added to the product water are taken from the brine.

A solution for treating a fluid, such as water, is provided. An ultraviolet transparency of a fluid can be determined before or as the fluid enters a disinfection chamber. In the disinfection chamber, the fluid can be irradiated by ultraviolet radiation to harm microorganisms that may be present in the fluid. One or more attributes of the disinfection chamber, fluid flow, and/or ultraviolet radiation can be adjusted based on the transparency to provide more efficient irradiation and/or higher disinfection rates. In addition, various attributes of the disinfection chamber, such as the position of the inlet(s) and outlet(s), the shape of the disinfection chamber, and other attributes of the disinfection chamber can be utilized to create a turbulent flow of the fluid within the disinfection chamber to promote mixing and improve uniform ultraviolet exposure.

Provided are a water treatment apparatus and a water treatment method capable of performing a significant water quality evaluation of treated water before the filtration process, and capable of rapidly responding to a change in water quality of the treated water. A water treatment apparatus of the present invention includes a treated water filtering unit which filters treated water supplied from a treated water line to become filtered water, a filtered water mixing unit which is provided in a treated water extraction line diverging from the treated water line to reduce a turbidity concentration in the treated water of the treated water extraction line to become measured water, and a water quality measuring unit which is provided at a rear stage of the filtered water mixing unit in the treated water extraction line and measures water quality of the measured water to evaluate the water quality of the treated water.

A filtration treatment system of raw water includes a raw water supply line to supply raw water, a filtration device provided on the raw water supply line to filter impurities in the raw water, a separation device provided on a rear side of the filtration device and equipped with a separation membrane to separate filtered raw water into permeated water and concentrated water; an organic substance monitoring device provided on either front or rear or both front and rear of the filtration device to monitor an amount of an organic substance in the raw water, and a control device to execute backwashing of the filtration device with the permeated water as backwashing water in a case in which the amount of the organic substance in the raw water exceeds a reference value as a result of monitoring by the organic substance monitoring device.

A system for disinfecting a fluid, including: a flow cell including one or more inlet ports and one or more outlet ports, wherein the flow cell is configured to communicate a fluid containing a biological contaminant from the one or more inlet ports to the one or more outlet portions through an interior portion thereof; and one or more point radiation sources disposed about the flow cell, wherein the one or more point radiation sources are operable for delivering radiation to the biological contaminant; wherein an interior surface of the flow cell is operable for reflecting the radiation delivered to the biological contaminant by the one or more point radiation sources; and wherein the interior surface of the flow cell is operable for reflecting the radiation delivered to the biological contaminant by the one or more point radiation sources such that a radiation intensity is uniform throughout the interior portion of the flow cell. In one exemplary embodiment, the flow cell is an integrating sphere. Optionally, the system also includes a photocatalyzing material disposed on at least a portion of the interior surface of the flow cell.

The present invention relates to apparatus, methods, and applications for treating wastewater, and more particularly to biological processes for removing pollutants from wastewater. This invention further relates to apparatus and methods for growing microbes on-site at a wastewater treatment facility, and for economically inoculating sufficient microbes to solve various treatment problems rapidly.

A liquid treatment device includes a base with a power source, a UV-LED module for providing UV-B or UV-C light to liquid, an LED for providing visible light, and a processor for selectively powering the UV-LED module and the LED, and having a UV transmissive material above the UV-LED module for allowing the UV-B or UV-C band light from the UV-LED module to be transmitted from the base housing, and a liquid storage housing removably coupled to the base housing with a storage portion configured to hold liquid and having a bottom portion comprising a UV transmissive material for allowing the UV-B or UV-C band light from the UV-LED module to be transmitted into the liquid, and an output coupled for restricting outflow of the liquid from the storage portion.

Disclosed herein are methods and systems for removing carbon dioxide (CO.sub.2) from water and quantifying the carbon so removed, thus facilitating valuation of that carbon for schemes (e.g., Kyoto agreement) that attach financial rewards for capture, sequestration or removal of carbon or CO.sub.2.