Chemical & Biological Dynamics

"The remaining bulbs exhibited a surprising degree of variation in the amount of UV emitted; assuming eight hours of exposure per day, the total UV dose (250–400 nm) ranged from 73 to 634 mJ/cm2, while the UVB-only dose (290–320) ranged from 0.01 to 15 mJ/cm2. Under these conditions, it would take between eight days and six months to receive 1 SED, depending on the particular bulb. These results indicate that even within the same class of bulbs, there are sufficient differences between specific models that patients may benefit from using those that have been shown to emit the lowest levels of UVR"

"Remtech was retained by a major water treatment authority to cleanup and determine the cause of a chlorine dioxide explosion which occurred at a raw water pumping station. Shock sensitive sodium chlorite burn residues remained in the building. Forty gallons of burn residues were reacted with 200 pounds of soda ash and 100 pounds of sodium metabisulfite. Heat of reaction energy was dissipated by placing 150 pounds of cubed ice in the reactors. Reactions were conducted in closed poly reactors. Off gasses were collected and passed through two gas scrubbers with a soda ash/sodium metabisulfite solution. Off gasses were monitored to ensure that no chlorine or chlorine dioxide was liberated from the reaction. The temperature of the reaction vessels was monitored to keep temperatures below 120o F. Over two (2) tons of residual sodium chlorite were reacted."

****!!!!****!!!!*** (2015) ***"A methodology is proposed for quantifying the amount of ClO2 gas needed in a package and/or treatment chamber." "The diffusion coefficient was found to be 0.129, 0.145, 0.173 cm2 s−1 at 5, 23, and 40 °C, respectively. Degradation of ClO2 gas under dark, UV-A and fluorescent lamp exposure was found to follow a first-order reaction. Degradation using a 40 W UV-A lamp was approximately four orders of magnitude larger than with a 34 W fluorescent lamp." "ClO2 gas can also be converted to chlorite and then react with oxygen changing their chemical structure, mobility, and properties" "Normally, the antimicrobial activity of gaseous ClO2 increased with a longer treatment time, especially at a low treatment temperature"

"the effect of UV-A and fluorescent lamp on chlorine dioxide gas degradation was observed. The degradation of gas under these conditions followed a first order reaction. In this research, gas degradation using a 40-Watt UV-A lamp was approximately four orders of magnitude larger than with a 34-Watt fluorescent lamp. In dark conditions, less than three percent degradation in gas was observed over a period of six hours.... In the same study, the effect of temperature on the degradation of chlorine dioxide gas was observed at 5° [However, ClO2 is a liquid at 5 degrees??], 23°, and 40°C. In all cases, the effect of temperature was negligible"

The explosion characteristics of chlorine dioxide gas have been studied for the first time in a cylindrical exploder with a shell capacity of 20l. The…

"The purpose of this paper is to present an overview of the properties, preparation methods, and applications of chlorine dioxide. In addition..." "Figure 3. Chlorine dioxide UV/vis spectrum"

The Atlas Accelerated UV testing devices focus on UV specific spectral ranges. They may be used in weathering tests that vary light/dark cycles, temperature, condensing humidity, water sprays, and irradiance control.

"maximum absorbance wavelengths for chlorine dioxide and hypochlorous acid were 360 nm and 292 nm"

(2021) "The disinfection of surfaces in medical facilities is an important element of infection control, including the control of viral infections such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). "

The emergence of severe acute respiratory disease (SARS-CoV-2) variants that cause coronavirus disease is of global concern. Severe acute respiratory disease variants of concern (VOC) exhibiting greater transmissibility, and potentially increased risk ...

We provide here a general view on the interactions of surfactants with viruses, with a particular emphasis on how such interactions can be controlled and employed for inhibiting the infectivity of enveloped viruses, including coronaviruses."

(2021) ****!!!!**** "Cleverin (Taiko Pharmaceutical Co. Ltd, Osaka, Japan) is a mixture of 500 ppm ClO2, 17,900 ppm sodium chlorite, 3300 ppm decaglycerol monolaurate, and 80 ppm silicone"

****!!!!*** "This narrative synthesis aimed to highlight the versatility and suitability of ClO2 in different settings (mostly for waters) and against different viral agents. It may be clear that ClO2 is not a therapeutic product. It cannot be used for healing human or animal tissues, with the exception of skin and mucosa antisepsis." "Bloodborne viruses (HIV-1, HCV, and HBV) may be completely eliminated from medical devices and human fluids after a treatment with 30 mg/L of ClO2 for 30 min."

(2021) {Note: More in-depth evaluation addressing cellular structure of specific areas of body contact, chemistry of surrounding body fluids, etc. would also need to be evaluated if in vitro exposures described herein were to be explored for use on or in areas of the body} "ClO2 is a small molecule with a molecular weight of 67.46, and it forms a stable radical.12 ClO2 is an oxidizer, which is reduced to chlorite ion (ClO2 -) by capturing an electron (ClO2 + e- → ClO2 -). The redox potential (Eº) is relatively high as 0.95 V, therefore does not harm the human microbiome."

"demonstration of the removal of uranium compounds from gaseous diffusion substrates." "...indicate that ClO2 will not exist in the presence of fluorinating agents..."

The sulfonamide antibiotic sulfamethoxazole (SMX) is a widely detected micropollutant in surface and groundwaters. Oxidative treatment with e.g. ozone or chlorine dioxide is regularly applied for disinfection purposes at the same time exhibiting a high potential for removal of micropollutants. Espec …

Xylanase pretreatment was used to improve the chlorine dioxide bleaching of bagasse pulp. The pulp was pretreated with xylanase, which was followed by a chlorine dioxide bleaching stage. The HexA content of the pulp and the AOX content of the bleaching effluent were measured using UV-Vis and GC-MS methods, respectively. The results showed that a good correlation occurred between HexA and kappa number. HexA content of the pulp decreased significantly after the xylanase pretreatment. The AOX content of the bleaching effluent decreased as HexA was removed from the pulp. It was found that AOX could be reduced by up to 29.8%, comparing XD0 with a D0 stage. Fourier transform infrared spectroscopy (FTIR) was employed to determine the breakage of chemical bonds in the pulp. It revealed that some lignin and hemicellulose were removed after xylanase treatment. The GC-MS results showed that some toxic chloride such as 2,4,6-trichlorophenol could be completely removed after xylanase pretreatment.

It is well known that pH is an important parameter for controlling the eucalyptus pulp bleaching...

Diclofenac (DCF), a synthetic non-steroidal anti-inflammatory drug, is one of the most frequently detected pharmaceuticals in the aquatic environment."

An investigation of the kinetics and mechanism for epoxidation of styrene and para-substituted styrenes by chlorite at 25 °C in the pH range of 5-6 is described. The proposed mechanism in water and water/acetonitrile includes seven oxidation states of chlorine (-I, 0, I, II, III, IV, and V) to accou …

Abstract A basic reaction scheme for the integral process of chlorine dioxide (OClO) photolysis at 366 nm in N2-saturated aqueous solution is proposed. The mechanism is supported by the initial quantum yield Φ°366 nm determined experimentally from OClO decay rates measured by electron spin resonance (ESR), chemical analysis of the stable products in solution and numerical simulation of the OClO profiles. In the concentration range 0.5 mM ≤ [OClO] ≤ 20 mM, Φ°366 nm = 0.52 with a 95% confidence interval of 0.50–0.55. Product concentrations determined after complete photobleaching were proportional to OClO initial concentration: [H+] = 0.856 [OClO]0; [HClO] = (0.141 ± 0.010) [OClO]0; [ Cl O 3 − ] = ( 0.551 ± 0.014 ) [OClO]0 and [Cl−] = (0.251 ± 0.015) [OClO]0. In the range of homogeneous light absorption, i.e. [OClO]0 ≤ 1.5 mM, OClO profiles and concentrations of the stable products in solution are well reproduced from numerical integration of the proposed mechanism. The reaction scheme requires the participation of dichlorine pentoxide (Cl2O5), which till now remains no isolated. However, reactions involving formation and hydrolysis of Cl2O5 are critical to reproduce the experimental profiles and explain the identity of the final products.

Insolation of carbon tetrachloride solutions of chlorine dioxide initiates a thermal decomposition, the magnitude of which may exceed that for the photoreaction with low light intensity. This thermal decomposition is inhibited by keeping the solutions at 3 °C. or by adding water.In contradiction to the findings of other investigators, it is found that chlorine and oxygen are not the only products of photodecomposition. As products of the photodecomposition of chlorine dioxide at the wave-lengths 3650 and 4360 Å, the oxides Cl2O, Cl2O6, and Cl2O7 as well as chlorine and oxygen appear. The quantum efficiency at λ 3650 Å is 2, and at 4360 Å, 1.In the unsensitized decomposition, concentration effects are observed which are greatly decreased when the solutions are stirred.In the bromine sensitized decomposition with 5460 Å, there is less chlorine monoxide but relatively as much Cl2O6 and Cl2O7 formed as in the unsensitized reaction.In the sensitized decomposition the quantum yield is independent of the concentration of chlorine dioxide, but depends on the light intensity."

(1932)