A method of removing organic pollutants in water by zero-valent iron enhanced hypochlorite includes the steps of: adjusting a pH of raw water containing organic pollutants to 4.0˜9.0; adding zero-valent iron solid and hypochlorite to the raw water in a mixer; and turning on the mixer to carry out stirring reaction. The method constructs a Fenton-like system through the redox reaction in the heterogeneous micro-interface region that occurs between zero-valent iron and hypochlorite which produces a variety of active oxidizing species with high occurrence, improves the shortcomings of the traditional Fenton method, broadens the applicable range of pH, and increases the removal efficiency of pollutants in water by 35˜95%.

In some embodiments, a method may include reducing the microbial load in contaminated water of water recycle loops. These water recycling loops may include pulp and paper mills, cooling towers and water loops, evaporation ponds, feedstock processing systems and/or non-potable water systems. The methods may include providing a peracetate oxidant solution. The peracetate solution may include peracetate anions and a peracid. In some embodiments, the peracetate solution may include a pH from about pH 10 to about pH 12. In some embodiments, the peracetate solution has a molar ratio of peracetate anions to peracid ranging from about 60:1 to about 6000:1. In some embodiments, the peracetate solution has a molar ratio of peracetate to hydrogen peroxide of greater than about 16:1. The peracetate solution may provide bleaching, sanitizing and/or disinfection of contaminated water and surfaces. The peracetate oxidant solution may provide enhanced separation of microbes from contaminated water.

Provided are methods of inhibiting microbial fouling and improving efficiency in biocide dosing in an industrial process containing an aqueous liquid having a biocide demand. In exemplary embodiments, the methods comprise treating an aqueous liquid having a biocide demand with a biocide, monitoring the biocide demand of the aqueous liquid, and filtering a stream of the aqueous liquid. The filtering may be performed in a full-flow or side stream manner.

A water treatment system that can effectively remove persistent organic materials is provided. Water treatment system has: means for adding halogen oxoacid that adds halogen oxoacid to water to be treated that contains organic materials; and ion exchanger loaded apparatus that is positioned downstream of means for adding halogen oxoacid, wherein at least anion exchangers are loaded in ion exchanger loaded apparatus. The water to be treated to which the halogen oxoacid has been added is supplied to ion exchanger loaded apparatus.

A method for treating water in a spa or a hot tub includes, for example, suspending a water treatment dispenser from an upper end of a filter cartridge disposed in a skimmer of the spa or the hot tub. The dispenser includes a water treatment material. A supply of water is passed from the spa or the hot tub into the skimmer and through the filter cartridge so that the dispenser suspended in the filtered water in the filter cartridge is operable to dispense the water treatment material from the dispenser, and a supply of treated filtered water from the filter cartridge is returned to the spa or the hot tub. A cover, for example, may be employed when the dispenser is not used.

Provided is a water recovery system and a water recovery method whereby, in water recovery using a reverse osmosis membrane from water to be treated containing organic matter, it is possible to also suppress slime contamination on the secondary side of the reverse osmosis membrane. A water recovery system includes: a reverse osmosis membrane treatment device which separates water to be treated containing organic matter into permeated water and concentrated water with a reverse osmosis membrane; iodine-based oxidizing agent adding piping which adds an iodine-based oxidizing agent to the water to be treated; and permeated water piping as a supply means for supplying the permeated water as water to be treated in a water utilization system.

Biocide can be controllably added to a feed stream for a membrane. The membrane can separate the feed stream into a purified permeate stream and a concentrate stream containing contaminants from the feed stream. In some examples, a charge neutral biocide is introduced into the feed stream at a first addition rate. The concentration of the charge neutral biocide in the permeate stream is measured to provide a measured concentration of the charge neutral biocide in the permeate stream. The addition rate of the charge neutral biocide can be adjusted based on the measured concentration of the charge neutral biocide in the permeate stream to introduce charge neutral biocide into the feed stream at a second addition rate different than the first addition rate.

In some embodiments, a method may include treating pulp in pulp and paper mills. The methods may include providing a peracetate oxidant solution and generating a reactive oxygen species. The peracetate solution may include peracetate anions and a peracid. In some embodiments, the peracetate solution may include a pH from about pH 10 to about pH 12. In some embodiments, the peracetate solution has a molar ratio of peracetate anions to peracid ranging from about 60:1 to about 6000:1. In some embodiments, the peracetate solution has a molar ratio of peracetate to hydrogen peroxide of greater than about 16:1. The peracetate oxidant solution may provide enhanced treatment methods of bleaching, brightening, and delignifying pulp fibers involving the use of peracetate oxidant solutions.

A water treatment dispensing apparatus has a container for holding water from a water supply and a water disinfectant cartridge located within the container. A housing attached to the container and connected to the cartridge directs water from the cartridge to a remote location, such as a dental instrument. An air pressure device supplies water under pressure to the container to force water to flow through the cartridge and to the remote location.

A method of determining a disinfectant composition of a municipal water supply from a water sample that includes: (a) obtaining a water sample from a water source at a sampling location; (b) adding a chlorine-containing material to the water sample in the presence of an oxidation reduction potential (ORP) measurement device; (c) generating a plurality of ORP measurements during addition of the chlorine-containing material to the water sample; (d) estimating a concentration of one or more of free ammonia, fully combined ammonia, monochloramine, or a mixture of dichloroamine and trichloroamine in the water sample in which the estimation is derived from the relationship between the added chlorine material and the plurality of ORP measurements; and (e) determining a disinfectant composition of the water source at the water sampling location from the concentration calculation. A method of determining free ammonia composition is also included.