Disclosed is a modified activated sludge-based two-compartment treatment method for processing nitrate-contaminated drinking water. Raw water is firstly sent to a first TiO.sub.2-modified denitrifying activated sludge bioreactor (2), wherein organic carbon source is added in a controlled amount, and nitrate is partly reduced with nitrite being accumulated. Then, the effluent from the first bioreactor is sent to a second TiO.sub.2-modified denitrifying activated sludge bioreactor (3), wherein organic carbon source and hydrogen gas are supplemented, and remaining nitrate and accumulated nitrite are reduced to nitrogen gas. The denitrified effluent from the second bioreactor is sent to a settling tank (4), and TiO.sub.2-containing precipitates collected from the settling tank receive sequential alkaline and acidic treatment before being injected into the first bioreactor (2) for TiO.sub.2 recycling. The effluent from the settling tank (4), after having been subjected to ozone disinfection and activated carbon filtration, has suitable pH and bicarbonate alkalinity, and the concentrations of nitrate, nitrite and water soluble organics meet the safety standard for drinking water. Also disclosed is a modified activated sludge-based two-compartment treatment device for processing nitrate-contaminated drinking water.

A method of increasing operational efficiency of a power plant includes determining an average rate of accumulation of scale-forming compounds in a cooling water source, directing water from the cooling water source having a first concentration of scale forming compounds through a treatment system to produce a treated water having a lower concentration of scale-forming components than the first concentration by operating the treatment system with operating parameters selected such that a rate of removal of the scale-forming components from the water in the treatment system is greater than the average rate of accumulation of the scale-forming components, directing the treated water back into the cooling water source, and circulating water including the treated water from the cooling water source through a cooling system of the power plant.

A cartridge for use in a water purification apparatus and a water purification method for maintaining a water quality supply are provided. The cartridge comprises an elongated tubular body having first and second ends comprising a fluid inlet and a fluid outlet, and an internal chamber extending between the first and second end. The first end includes an end cap having a first opening in fluid communication with the body. A disinfectant material is disposed in the internal chamber of the body. Filters are disposed in the elongated tubular body adjacent to the first opening and adjacent the second end of the elongated tubular body and are in fluid communication with the internal chamber and the fluid outlet. The second end of the elongated tubular body comprising an exterior surface having a tapered portion and a linear portion adjacent to the tapered portion.

A cartridge for use in a water purification apparatus and a water purification method for maintaining a water quality supply are provided. The cartridge comprises an elongated tubular body having first and second ends comprising a fluid inlet and a fluid outlet, and an internal chamber extending between the first and second end. The first end includes an end cap having a first opening in fluid communication with the body. A disinfectant material is disposed in the internal chamber of the body. Filters are disposed in the elongated tubular body adjacent to the first opening and adjacent the second end of the elongated tubular body and are in fluid communication with the internal chamber and the fluid outlet. The second end of the elongated tubular body comprising an exterior surface having a tapered portion and a linear portion adjacent to the tapered portion.

A system and method for delivering silver ion biocide is described herein. The systems described relate to passing water from a water system through a silver ion release module and optional high-concentration silver ion release module. The system includes an analyzer, detector, and/or controller for monitoring the concentration of silver ion and adjusting the flow path, flow rate, temperature and/or pH of the water in order to obtain the desired concentration of silver ion. The system optionally includes other metal ions released into a water system, the concentration of which may be used to automatically calibrate the described system and/or cause the system to take actions based on the measured concentration of silver ion or of the second metal ion.

The present invention relates to water treatment. In one example, there is provided a method of treating an aqueous system to inhibit growth of one or more micro-organisms therein and/or to reduce the number of live micro-organisms therein. The method includes adding treatment agents to an aqueous system wherein said treatment agents include: (a) a phosphonium compound; and (b) a compound having formula:

M(XO.sub.2).sub.n wherein: M is a Group I or Group II metal; X is a halogen; and n is 1 or 2.

The present invention relates to water treatment. In one example, there is provided a method of treating an aqueous system to inhibit growth of one or more micro-organisms therein and/or to reduce the number of live micro-organisms therein. The method includes adding treatment agents to an aqueous system wherein said treatment agents include: (a) a phosphonium compound; and (b) a compound having formula:

M(XO.sub.2).sub.n wherein: M is a Group I or Group II metal; X is a halogen; and n is 1 or 2.

The present invention relates to microorganism control field in process for treatment of pulp and/or water in paper-making process. More specifically, the present invention provides a microorganism control system, which comprises a first component and a second component which are separately provided, the first component comprises a stabilized halogen-containing bactericidal agent (e.g., a stabilized hypochlorite), and the second component comprises an aminosulfonic acid reagent (e.g., aminosulfonic acid). The present invention further provides a method for controlling microorganism in process for treatment of pulp and/or water in papermaking process, which comprises using the microorganism control system of the present invention.

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.

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.