Water Treatment

"Treatment of reclaimed water with ClO2 did not improve irrigation water safety."

"When chlorine dioxide dosage was increased from 0 to 30 mg/L, the genotoxicity of wastewater first decreased rapidly and then tended to be stable, while when the chlorine dosage was increased from 0 to 30 mg/L, the genotoxicity of wastewater changed diversely for different samples. It was then found that ammonia nitrogen did not affect the change of genotoxicity during chlorine dioxide disinfection of wastewater, while it greatly affected the change of genotoxicity during chlorine disinfection of wastewater. When the concentration of ammonia nitrogen was low (< 10–20 mg/L), the genotoxicity of wastewater decreased after chlorine disinfection, and when the concentration of ammonia nitrogen was high (> 10–20 mg/L), the genotoxicity of wastewater increased after chlorine disinfection."

Regulations for Chlorine Dioxide and other disinfectants used for treating water, under SWDA (Safe Water Drinking Act) and FIFRA (Federal Insecticide, Fungicide, and Rodenticide Act)

The use of chlorine dioxide to disinfect drinking water and ameliorate toxic components of wastewater has significant advantages in terms of providing safe water. Nonetheless, significant...

In water treatment dissolved organic matter (DOM) is typically the major sink for chemical oxidants. The resulting changes in DOM, such as its optical properties have been measured to follow...

Chlorine dioxide has been reported as very efficiently removing pesticides and other organic compounds from water matrixes. Due to pesticide toxicity and potential toxicity of their...

"Disinfection with ClO2 produced fewer total trihalomethanes (TTHMs) and haloacetic acids (HAAs) than chlorination but did produce low levels of chlorite. These data indicate that replacing Cl2 with ClO2 would further control microbiological re-growth and minimize TTHM and HAA formation, but may introduce other DBPs. "

The impact of disinfection efficacy in natural waters was evaluated by performing disinfection assays using four untreated surface waters of various qualities and ultra-pure buffered waters as a baseline condition for comparison. Bacillus subtilis spores were spiked in these waters and disinfection …

The effect of inlet pressure and geometrical parameters on disinfection was studied using HC alone and the results showed that increasing inlet pressure and using more and bigger holes of orifice plates can result in a higher disinfection rates. When HC was combined with chemicals, HC can reduce the doses of the chemicals and shorten the time of disinfection.

The effect of chlorine dioxide (ClO2) oxidation on the formation of disinfection by-products (DBPs) during sequential (ClO2 pre-oxidation for 30 min) and simultaneous disinfection processes with free chlorine (FC) or monochloramine (MCA) was investigated. The formation of DBPs from synthetic humic a …

Drinking water utilities may have to consider changing disinfectant to improve water quality and meet more stringent disinfection regulations. The objective of this study was to evaluate the respon...

The discovery of Legionella bacteria (which causes Legionnaire's disease) led to closures at some of the Atlanta-based offices for the Centers for Disease Control and Prevention.

Total Aerobic Bacteria Test for Cooling Water. IMMEDIATE. Rapid Bio Intelligence yields clear results in just 15 minutes. Compare with traditional field-based tests, which require 48 hours or more to complete. ACCURATE. Rapid Bio Intelligence test results (CFU/mL) are delivered by the Nalco Water E-data mobile app for greater consistency and reliability.

{Brief discussion of chlorine dioxide in drinking water}

"chlorine dioxide acted on all layers simultaneously, but spores still persisted in the deepest layer of the biofilm/corrosion matrix after 6 days of disinfection at 15 and 25  mg/L chlorine dioxide."

{Includes contact info}

{Testing done with packets of Avantec chlorine dioxide powder} "7 mg/L chlorine dioxide, a 5-log decrease in fecal coliform concentration was achieved after 20 minutes of contact time (Ct = 140 mg*min/L). The same chlorine dioxide concentration caused a 6-log decrease in coliphage concentration after 20 minutes of contact time. In contrast, the same Ct value for free chlorine resulted in a 5-log decrease in fecal coliform concentration, but only a 1-log decrease in coliphage concentration" "Evaluation of chlorine dioxide in reducing spore formers would provide a measure of effectiveness against stress-resistant microorganisms. F-specific and somatic coliphages are viruses that infect E. coli by two different mechanisms. F-specific coliphages are RNA or DNA viruses that infect via the F-pilus of male strains of E. coli. Somatic coliphages are DNA viruses that infect via the outer cell membrane. These coliphage have been used as surrogate organisms to indicate capacity for transport and survival of enteric viruses from fecal contamination in water"

I'm looking for a good chemical water purification solution. Here are three chlorine-based options (iodine is out, for obvious reasons): -...

"As the coronaviruses are enveloped viruses, it should be considered that a combination of UV and chemical oxidation disinfection is suggested to better inactivate coronaviruses, which can achieve at least 5 log units reduction of the waterborne virus " "For the inactivation of coronaviruses in wastewater, a study to explore the inactivation of SARS virus in municipal wastewater by chlorine and chlorine dioxide showed that the chlorine dosage of 20 mg L-1, a contact time of over 1 min, and free chlorine residual of >0.4 mg L−1 were found to complete coronaviruses inactivation, while chlorine dioxide needs to be using a dose of 40 mg L−1 with a required contact time of >5 min to achieve the same effect [58]. However, the co-existing high concentration of organic compounds and suspended solids in wastewater would interfere with disinfection for the virus."

This research evaluated a chlorine gas–solid sodium chlorite chlorine dioxide (ClO2) generation system at the Roanoke County (Va.) Spring Hollow Water Treatment Facility and monitored concentrations ...

PubMed journal article: Disinfectant efficacy of chlorite and chlorine dioxide in drinking water biofilms. Download Prime PubMed App to iPhone, iPad, or Android

"ossible alternative to Cl and can be most ideal for virus inactivation. ClO2 can be adsorbed into the capsomeres protein of virus and react with RNA. It appears as an effective microbicide under the pH, temperature and turbidity generally prevailing in WTP. In one of the earliest studies by Harakeh et al. (1987), efficacy of ClO2 was investigated against bacteriophage f2, poliovirus 1, echovirus 1, coxsackievirus B5, simian rotavirus (SA11) and human rotavirus. Except a required dose of 17.25 ppm (residual 5 ppm after 1 min) for the most resistant coxsackie virus, all other viruses were inactivated by dose of 15.25 ppm (residual 4 ppm after 1 min) or less. Similarly, more remarkable inactivation effect of ClO2 on viruses such as Coxsackie B3, Poliovirus-1, ECHO-11, Herpes simplex virus 1, Adenovirus-7 and Mumps virus than that of liquid chlorine was reported by Junli et al. (1997). ClO2 was effective under a wider pH range at a dosing of 1.0 mg l−1. Report by White (1999) revealed that ClO2 is even more effective than ozone and chlorine against some particular viruses. "