Papers by Aleksey Pisarenko
ChemInform Abstract: Two New Methods of Synthesis for the Perbromate Ion: Chemistry and Determination by LC-MS/MS
ChemInform, Oct 27, 2011
ABSTRACT Historically, the synthesis of perbromate ion through conventional oxidation routes has ... more ABSTRACT Historically, the synthesis of perbromate ion through conventional oxidation routes has proven elusive. Herein, we report perbromate ion formation through the reaction of hypobromite and bromate ions in an alkaline sodium hypobromite solution. Formation was established via LC-MS/MS analysis of the bromate and perbromate ions in the reaction solutions over a 13-day period. Furthermore, it was discovered that the perbromate ion was also formed as a result of the electrospray ionization process. Selective reduction of the bromate ion prior to analysis was used to confirm the two formation pathways.
Opflow, Mar 1, 2020
The number of potable reuse projects in the United States has increased the need for operators wh... more The number of potable reuse projects in the United States has increased the need for operators who are knowledgeable about advanced water treatment processes, including membrane treatment technologies.
Ozone-science & Engineering, Feb 3, 2020
Measurement of dissolved ozone (O 3) residual is critical for accurately determining O 3 concentr... more Measurement of dissolved ozone (O 3) residual is critical for accurately determining O 3 concentration-contact time product (CT) in order to establish pathogen removal credit. Higher concentrations of metals and organics in wastewater present more challenging conditions for on-line meters, requiring more frequent calibration and maintenance. This study evaluated the performance, maintenance, and cost of four commercially available over a 1-year period. Individual meter readings were compared to daily grab samples analyzed with an indigo trisulfonate method to determine O 3 residual. Ease of maintenance and reliability of O 3 residual measurements were key parameters in ranking the meters for monitoring ozone CT in a water reuse application.
Talanta, Dec 15, 2009
Gold nanoislands interact with gaseous ozone to produce a surface plasmon resonance shift, simila... more Gold nanoislands interact with gaseous ozone to produce a surface plasmon resonance shift, similarly to the interaction of ozone and gold nanoparticles in water. Gold nanoislands are produced by sputtering, which significantly simplifies the synthesis and produces controlled size for the gold nanoislands. The shift of surface plasmon resonance peak was monitored while gold nanoislands were exposed to variable concentration of gaseous ozone. The shift was then correlated with ozone concentration. Our current results indicate sensing gaseous ozone at concentration of as low as 20 g/L is achievable. Gold nanoislands were reversed to their original wavelength and were able to cycle between the wavelengths as ozone was introduced and removed. Potentially, this system can be useful as a sensor that identifies the presence of ozone at low part-per-billion concentrations of ozone in gaseous media.
Evaluation of Process Control Alternatives for the Inactivation of <i>Escherichia coli</i>, MS2 Bacteriophage, and <i>Bacillus subtilis</i> Spores during Wastewater Ozonation
Ozone-science & Engineering, Oct 1, 2013
ABSTRACT Dissolved ozone concentration integrated over time (CT) is a reliable indicator of disin... more ABSTRACT Dissolved ozone concentration integrated over time (CT) is a reliable indicator of disinfection efficacy in drinking water treatment. However, ozone CT may not be measurable in some wastewater ozone applications. In this study, alternative process control parameters, specifically ozone to total organic carbon (O3:TOC) ratio, differential UV254 absorbance (ΔUV254), and differential total fluorescence (ΔTF), were correlated with the inactivation of Escherichia coli, the bacteriophage MS2, and Bacillus subtilis spores in five secondary wastewater effluents. CT values greater than 9 mg-min/L were generally required for measurable inactivation of B. subtilis spores, and CT values of 1 and 2 mg-min/L consistently achieved greater than 6- and 5-log inactivation of MS2 and E. coli, respectively. The O3:TOC, ΔUV254, and ΔTF correlations for MS2 and B. subtilis were useful for predicting inactivation, while those of E. coli were characterized by greater variability. [Supplementary materials are available for this article. Go to the publisher&amp;#39;s online edition of Ozone: Science &amp;amp; Engineering for the following free supplemental resources: additional figures and data tables.]
Empirical Modeling of Bromate Formation and Chemical Control Strategies at Multiple Water Reuse Facilities Using Ozone
Ozone-science & Engineering, Dec 29, 2022
IDA Journal of Desalination and Water Reuse, Apr 1, 2012
W orldwide interest in reclaiming municipal wastewater has been gaining momentum due to an ever-i... more W orldwide interest in reclaiming municipal wastewater has been gaining momentum due to an ever-increasing demand placed on overtaxed water supplies. Developments in membrane technology during the past decade now allow reclamation to be an appealing technical, financial, and regulatory option to reduce the burden. Combining microfiltration (MF) and reverse osmosis (RO) is an accepted practice for treating secondary effluent to allowable levels for common and advanced reuse applications. Several municipalities in the United States and abroad use this practice on a large scale (Bartels et al, 2010). Integrating MF with an activated sludge treatment using a membrane bioreactor (MBR) is an important innovation in advanced wastewater treatment. An MBR can directly treat primary effluent, thereby reducing a municipal plant's overall footprint and the amount of generated sludge. Combining microfiltration (MF) and reverse osmosis (RO) is an accepted practice for treating secondary effluent to allowable levels for common and advanced reuse applications. Several municipalities in the United States and abroad use this combination on a large scale. This leads to the next innovation in treating wastewater-membrane bioreactors (MBRs), the specialized use of MF integrated with activated sludge treatment followed by RO. The Southern Nevada Water Authority has been conducting an ongoing test of such a configuration at the Las Vegas Water Pollution Control Facility since 2009. The study's goal is to better understand the fouling of RO membranes, which directly treat MBR effluent, and to evaluate technologies to minimize RO fouling. The pilot has had stable operation for more than 4,000 hours and has not required RO cleaning when operated at a flux rate of 14 gpd/ft 2 (23.8 LMH) and higher. The results have confirmed that MBR-RO is a viable wastewater treatment technology.
AWWA water science, Nov 1, 2020
Constituents in the feed of reverse osmosis (RO) processes pass into the product by two mechanism... more Constituents in the feed of reverse osmosis (RO) processes pass into the product by two mechanisms: diffusion through the membrane and advection through defects in the system. While minerals and tracers pass via both mechanisms, pathogens pass only via advection. Using mass and flow balances, a rigorous model is developed to characterize the response of both viruses and tracers in RO systems. The model is used to assess several tracers being considered today. Early virus testing and the commercial requirements of desalination are reviewed, leading to the conclusion that some degree of advection can be expected to be present in RO systems but that commercial incentives can be expected to maintain pathogen removal due to defects somewhat greater than 4.0 log. Model results suggest that the best tracers currently in use can detect defects near this log reduction value but that there is still room for improvement.
Analytical Measurements and Predictions of Perchlorate Ion Concentration in Sodium Hypochlorite Solutions and Drinking Water: Kinetics of Perchlorate Ion Formation and Effects of Associated Contaminants
ANALYTICAL MEASUREMENTS AND PREDICTIONS OF PERCHLORATE ION CONCENTRATION IN SODIUM HYPOCHLORITE S... more ANALYTICAL MEASUREMENTS AND PREDICTIONS OF PERCHLORATE ION CONCENTRATION IN SODIUM HYPOCHLORITE SOLUTIONS AND DRINKING WATER: KINETICS OF PERCHLORATE ION FORMATION AND EFFECTS OF ASSOCIATED CONTAMINANTS by Aleksey N. Pisarenko The dissertation consists of six chapters that summarize the investigation of factors impacting perchlorate ion formation in sodium hypochlorite solutions and the development of a predictive model for perchlorate ion formation. There are also two appendices detailing the synthesis and applications of nanomaterials for designing sensors. Chapter 1 gives a brief history of perchlorate ion as an emerging contaminant. A background on the occurrence, toxicology, and regulatory actions is provided. Chapter 2 focuses on the analytical methods that were developed and validated for analysis of perchlorate, bromate, chlorate, hypochlorite, and chlorite ions in various hypochlorite ion solutions. Comparison of a LC-MS/MS method and an iodometric titration method is provided. The chapter also details sample preparation methods, such as the use of malonic acid to stop formation of perchlorate ion. Chapter 3 details the experimental matrix to identify factors that impact perchlorate ion formation. Effects of different contaminants were investigated at elevated temperatures. Chapter 4 provides a detailed investigation of the effects of concentration of hypochlorite and chlorate ions, ionic strength, and temperature. The order of the perchlorate ion formation with respect to hypochlorite and chlorate ions was determined. A thorough investigation of the various effects led to derivation of a simple expression that relates the effects of ionic strength and temperature on the second-order rate constant. Chapter 5 focuses on validation and application of the developed predictive expression on various hypochlorite ion solutions. Bleach 2001 Predictive Model was used to predict the decomposition of hypochlorite ion, and the output was used together with the predictive expression developed in this work to predict formation of perchlorate ion in hypochlorite ion solutions. Potential formation of perchlorate ion in stored hypochlorite ion solutions is discussed, and recommendations to minimize formation of perchlorate ion are provided. Chapter 6 summarizes the findings of this Dissertation and provides conclusions in the context of perchlorate ion contamination of drinking water when hypochlorite ion is used as a disinfectant. ANALYTICAL MEASUREMENTS AND PREDICTIONS OF PERCHLORATE ION CONCENTRATION IN SODIUM HYPOCHLORITE SOLUTIONS AND DRINKING WATER: KINETICS OF PERCHLORATE ION FORMATION AND EFFECTS OF ASSOCIATED CONTAMINANTS
Journal of Materials Science, Jul 20, 2007
Microwave radiation simplifies synthesis methods by reducing reaction times, requiring fewer mate... more Microwave radiation simplifies synthesis methods by reducing reaction times, requiring fewer materials, and also controlling reaction processes. We have successfully synthesized nanoparticles of iron oxide and zinc oxide coated on zeolite A using microwaves. The radiation assisted in displacing either ferrous or zinc ions from the pre-loaded zeolite network and increasing reaction speed with solution at the interface. Products were characterized by TEM, XRD, VSM, ICP-AES, and fluorescence. We demonstrate the ability of using cationexchanged zeolites as microreactors to bias reactions onto the zeolite surface. Efficient structure-directed surface reactions are a potential route to making unique supported nanomaterials for applications such as sensors, environmental remediation, and chemical catalysis.
Preozonation Effects on the Reduction of Reverse Osmosis Membrane Fouling in Water Reuse
Ozone-science & Engineering, Sep 1, 2011
Research suggests that compounds with the N-N-(CH 3) 2 building block will form NDMA. Chloraminat... more Research suggests that compounds with the N-N-(CH 3) 2 building block will form NDMA. Chloramination of dimethylamines N-(CH 3) 2 can form nitrosamines Ozonation of dimethylamines N-(CH 3) 2 forms an aldehyde as the major product
Microbial Water Quality through a Full-Scale Advanced Wastewater Treatment Demonstration Facility
ACS ES&T engineering, Oct 6, 2022
Journal American Water Works Association, Apr 1, 2018
The mechanical reliability of a direct potable reuse (DPR) treatment train-consisting of ozone, b... more The mechanical reliability of a direct potable reuse (DPR) treatment train-consisting of ozone, biological activated carbon, microfiltration/ultrafiltration, reverse osmosis, and ultraviolet light with advanced oxidation-was evaluated using critical component analysis at the Demonstration Pure Water Facility in San Diego, Calif. Operators maintained logs of all mechanical issues that occurred over a yearlong test period; these were used to calculate several reliability metrics for the unit processes. Mechanical issues were also cross-referenced with treatment performance data to determine whether any "critical" failures-i.e., those that impacted pathogen reduction performanceoccurred. The results demonstrated that no critical failures occurred, though the communication systems experienced critical malfunctions. These malfunctions triggered an immediate system shutdown, mitigating the potential risk to public health. While several components experienced failures, malfunctions, and/or maintenance events, the processes maintained a high degree of availability, demonstrating that DPR facilities can be designed with a high degree of mechanical reliability.
Critical Review on Bromate Formation during Ozonation and Control Options for Its Minimization
Critical Review on Bromate Formation during Ozonation and Control Options for Its Minimization
Environmental Science & Technology, Jun 26, 2023
Microbial Water Quality through a Full-Scale Advanced Wastewater Treatment Demonstration Facility
ACS ES&T Engineering
The formation of perchlorate, bromate, and other contaminants in hypochlorite solutions: Implications for water utilities
Measurements and Predictions of Clo4- In Naocl and Drinking Water
Minimize Perchlorate Formation in Hypochlorite Solutions
Opflow, 2009
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Papers by Aleksey Pisarenko