Water reused, chlorination

Baird R, Gute J, Jacks C, et al. 1980. Health effects of water reuse A combination of toxicological and chemical methods for assessment. Water Chlorination Environmental Impact and Health Effects 3 925-935. 

UV can also be used in water reclamation and reuse. An example is the reclamation of swimming pool water. Usually, the swimming pool water reuse process includes coagulation, filtration, clarifier, disinfection, and pH adjustment. The conventional swimming pool disinfection chemical is chlorine however, high concentrations of residual chlorine can be harmful to human health. The UV technology can be placed between the filters and chlorine disinfection unit as a pre-disinfection unit and remove pathogens. Hence, much less amount of chlorine (compared with the process without UV unit) is needed for residue disinfectant level. 

For some water reuse applications, activated carbon may be employed to adsorb 90 to 98% of any residual degradation-resistant organics when necessary. The resultant effluent quality is adequate for many industrial coolant or irrigation applications. After minimal further treatment, such as by reaeration and chlorination, it could even be reused for potable purposes in an emergency [55]. However, not enough is known about the potential for accumulation of trace toxins to recommend this procedure for long-term potable water use. 

The CleanSoil process is an ex situ treatment technology that uses steam to remove hydrocarbons and chlorinated solvents from contaminated soils. The steam vaporizes the contaminants from the soil and carries them to a condenser for recovery. The water is converted back into steam and reused in the system. The remaining vapors pass through an activated carbon filter and are released into the atmosphere. The technology has been applied full-scale at multiple sites and is commercially available. 

Remove cap from the reservoir, and sluice away the medium. Wash the bottle and the tubes several times. Leave the reservoir full of water (change frequently) with the fittings in place to remove the chlorine, which may be absorbed by the Marprene. The fittings may have to be replaced. Rinse with deionized water, set up for autoclaving, and reuse... 

To manufacture chlorinated rubber (CR) natural or synthetic rubber such as polyethylene, polypropylene or polyisoprene is degraded to low molecular mass compounds by mastication or addition of radical formers and dissolved in carbon tetrachloride (CTC). Chlorine contents are typically 64-68 wt%. Chlorine gas is introduced into this solution and reacts with the raw material to form CR. The solution is then introduced into boiling water. The CR is precipitated, and the solvent vaporizes. The CR is separated from water, rinsed, dried and ground to form a white powder which is the saleable product. After removal of the water, chlorine, hydrochloric acid and other impurities the solvent is reused. 

The ability of the membrane to concentrate solvents in the permeate varies. Sparingly soluble, volatile solvents such as chlorinated hydrocarbons, benzene and heptane are concentrated up to 100-fold and can be made fit for reuse without any additional treatment other than phase separation. More importantly, in the clean up of contaminated water, the water stream leaving the plant can be reduced to a solvent content of 10 ppm or even less, at which it may be possible to discharge it or polish it at low cost with AC. 

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