This paper evaluates the effectiveness of generating chlorine dioxide gas using Eka Chemical's method of sodium chlorate/hydrogen peroxide/sulfuric acid technology as it compares to the Rio Linda (Vulcan) chlorine gas/25 percent sodium chlorite system process at the El Paso Water Utilities' 40 mgd Canal (Umbenhauer/ Robertson) Water Plant in El Paso, Texas. With the chlorate-based system, El Paso must depend on the efficiency of the generator to minimize chlorate levels and the ferrous ion to eliminate the excess chlorite after chlorine dioxide reacts with the raw water. The potential impact on lower TTHMs from lower pH water and chlorine free chlorine dioxide solution from Eka Chemical SVP-Pure System should be compared to the existing Rio Linda (Vulcan) Chlorite based system. Chlorate standard concentrations vs. area of peak around 5.6 minutes ( ). Analytical... © 2020 Separation Methods Technologies, Inc. All Rights Reserved. Pfaff, JD. Wirth, MJ, Fatunmbi, HO, “Products Having Multiple-Substituted Polysiloxane Monolayer” U.S. Patent No. The following conclusions can be made with reasonable certainty: Douglas Rittmann, P.E., is water systems division manager for El Paso Water Utilities and a doctoral candidate in the Environmental Science & Engineering program at the University of Texas at El Paso.

The IC analysis was carried out on a Dionex DX500 ion chromatography system with a conductivity/UV detector. Since the Canal Water Plant is actually two 20 mgd facilities located side by side, it was ideal to run comparison plant trials of the two types of technologies in generating chlorine dioxide. “EPA Groundwater & Drinking Water.” hfacts.html (accessed April 3, 2018). Phelan DJ. Further, the oxidation state of chlorine in this ion is -1. This will benefit all consumers in the form of lower costs and increased service. 1. 5,716,705, 1998. All analytes were separated on SMT ionRes A50 column. The molar mass of this anion is 35.5 g/mol. In Table 6, a comparison of chlorite and chlorate levels are presented from samples taken at each plant effluent and within the distribution system that is a blend of both plants effluent. Guidelines for Canadian drinking water quality. Mobley SA et al. Sodium chloride is also known as table salt and is the most common type of salt. The total chlorine dioxide species residual averaged 2.26 mg/l in Plant 1 as compared to 2.03 mg/l in Plant 2. The lower Plant 2 chlorite level was likely due to the slight underfeed of chlorine dioxide causing a slightly higher average settled water turbidity level but with the benefit of the lower chlorite level leaving the plant. In fact, El Paso is currently considering lowering the pH during treatment with acid to increase removal of total organic carbon in order to comply with future Stage 2 disinfection by-products rule of 40 ppb TTHMs as proposed by USEPA. Problems during the first two weeks of setup were easily addressed and posed no concern during operation. With a mind rooted firmly to basic principals of chemistry and passion for ever evolving field of industrial chemistry, she is keenly interested to be a true companion for those who seek knowledge in the subject of chemistry. Due to the high chlorine dioxide demand (480 lbs/day), two units were used. Little is known about the effect of prolonged intake of large amounts of chloride in the diet. To ensure high efficiency, chlorine is slightly overfed in chlorite systems. For an adult human, the oral lethal dose is estimated to be as low as 20 g of sodium chlorate (or 230 mg of chlorate per kg of body weight) [12]. The evaluative cost of generating chlorine dioxide gas from the chlorite suppliers was based on stoichiometric chemistry as presented in Table 1 and the current cost of 25 percent sodium chlorite, $0.357/liquid pound of chlorite solution, multiplied by 5.71 to determine the cost of a pound of chlorine dioxide including chlorine cost. Chlorate is ClO3-. The problems in the first two weeks were related to the trial installation and minor maintenance issues. The objectives of the trial were to compare the effectiveness of the sodium chlorate technology to the sodium chlorite technology in. -20 0 20 40 60 80 100 120 140 160 180 Please visit us at Booth #3355 The intent of the efficiency requirement by the TNRCC regulation is to maximize disinfection capability but with high dosage chlorine dioxide applications in combination with ferrous ion, the main concern by the operator should be the actual chlorine dioxide and chlorite residuals present at the primary effluent (i.e., some excess chlorite from inefficiency by the generator will be eliminated by the ferrous to ferric ion reaction). Most of the compounds containing this anion are highly water soluble. Due to this structure, this anion has multiple resonance structures. During the time of operation, only one machine issue, a loosening of the generator heads, caused a shutdown. Acute Cl– toxicity has actually not been observed in humans except in the special case of impaired sodium chloride metabolism, for instance, in congestive heart failure [9]. Providing reliable and durable machine performance; Producing chlorine dioxide gas at greater than 95 percent efficiency; Minimizing chlorate by-product residuals in the finish water; and. During the time of operation, there were no water complaints or unusual plant performance. “Physiology of the human kidney.” New York, NY, Grune and Stratton, 591, 1969. Chlorite is ClO2-, carrying the same charge as chloride, but with two oxygen atoms bonded to it. According to the electron configuration of a chlorine atom, it has an unpaired electron in its outermost p orbital. 602039). Tables 4 and 5 should be interpreted based on the range of values in each column because the flow, chemical dosages and pH data are 24 hour average readings, while the primary effluent samples for the chlorite, chlorine dioxide and total residuals data is a summary of single daily grab samples' results. Both Plant effluents were able to comply with total oxidant level regulations. 347–360. “Chloride.” Wikipedia, Wikimedia Foundation, 23 July 2018. ... El Paso is able to feed much higher levels of chlorine dioxide because ferrous chloride is used to convert the chlorite to harmless chloride while converting the ferrous ion to a substitute for the primary coagulant in the process. However, this anion is larger than a chlorine atom. McDuffie. At the primary effluent, the ferrous chloride dosage is set at the rate of 3 ppm as (Fe) iron per one ppm of available chlorite/chlorine dioxide leaving the primary effluent.