Treatment of Diphenhydramine with diferent AOPs including photo-Fenton at circumneutral pH.

The degradation of diphenhydramine hydrochloride (DPH), via UV-vis/H2O2, Fenton, photo-Fenton and photocatalysis processes, was studied under different radiation sources. In addition, the Fenton and photo-Fenton processes at acid pH and circumneutral pH have been compared. The importance of the source of irradiation, UV-C (λ = 254 nm), black blue lamps (BLB, λ = 365 nm) and simulated solar radiation (SB, SolarBox), was investigated at lab-scale. Moreover, compound parabolic collectors (CPC), at pilot plant scale with sunlight, have been also applied in photocatalytic treatments. Photo-Fenton process employing black blue lamps gave the best DPH abatement (100% of DPH conversion at 10 min for acid pH and 20 min for circumneutral pH), using the highest Fe2+ (5 mg/L) and H2O2 (150 mg/L) concentrations at 50 mg/L of initial DPH concentration. Using Fenton, 100% of DPH conversion was reached at 30 min for both pHs tested. In the case of UV-C/H2O2, 100% of DPH elimination was achieved in 20 min using 150 mg/L of H2O2. In the photocatalytic process, using 0.4 g TiO2/L, after 60 min of irradiation, only 35.7% and 8.7% of DPH conversion have been obtained in SB and CPC, respectively. The DPH degradation in the photocatalytic process was greatly enhanced adding H2O2. In all the cases, increasing the H2O2 dose enhances the reaction rate due to higher OH[rad] production. However, not significant mineralization was obtained. The highest DPH mineralization was 36.8% and 38.5% of TOC reduction with photo-Fenton in BLB lamps using 150 mg/L of H2O2 and 2.5 mg/L of Fe2+, for acid pH and circumneutral pH, respectively. The major reaction intermediates these processes were identified by ionization/mass spectrometry and a DPH photo-degradation structures was proposed

A comprehensive approach to simulation of cartridge filtration using CFD

Household water treatment (HWT) systems are widely used for the provision of potable water in many countries with their low-cost key to attaining universal and equitable access to safe and affordable drinking water, Sustainable Development Goal 6.1. Removal of suspended particles (turbidity) from water sources via cartridge filters is often the first step of a HWT system, with the primary treatment increasing the efficiency of a subsequent disinfection step. Whilst the performance of cartridge filters (removal efficiency and pressure drop) can be determined experimentally in long experiments with high volumes of water, numerical simulation adds fundamental insight to the influence of fluid dynamics on particle deposition and vice versa. In this study, a novel computational fluid dynamic (CFD) model was developed to simulate the fundamental mechanisms underpinning the removal of particles within the widely used 10 in. cartridge filter, informed by and complemented with laboratory validation. The Eulerian approach was used to simulate fluid flow with the Lagrangian approach adopted for particle tracking. Rosin-Rammler distribution was implemented with respect to the particle size distribution of the diatomaceous earth particles used in the experiments. Given particles were non-spherical (disk shape), Wadell's sphericity was included to account for the effect of particle shape on drag force. A porous domain was implemented to simulate the filter element through addition of a source term to the momentum equations, with the likelihood of particle deposition, detachment and rebound also considered. Laboratory based validation studies confirmed the novel CFD model to accurately model removal of turbidity and predict the pressure drop across the filter with Root Mean Square Percentage Error (RMSPE) of less than 3%. The simulated location of particle deposition on the filter elements closely matched images taken at several stages during filtration experiments with the model aiding understanding of pattern of particle removal along and within the porous filter structure. This novel and comprehensive modelling methodology can be utilized to simulate the filtration process at the macro-scale, permitting evaluation of new filter designs and materials for advanced filtration systems; ultimately improving HWT system performance and reducing costs to users.</p

Efficacy of single pass UVC air treatment for the inactivation of coronavirus, MS2 coliphage and Staphylococcus aureus bioaerosols

Publication history: Accepted - 20 April 2022; Published online - 26 April 2022There is strong evidence that SARS-CoV-2 is spread predominantly by airborne transmission, with high viral loads released into the air as respiratory droplets and aerosols from the infected subject. The spread and persistence of SARS-CoV-2 in diverse indoor environments reinforces the urgent need to supplement distancing and PPE based approaches with effective engineering measures for microbial decontamination – thereby addressing the significant risk posed by aerosols. We hypothesized that a portable, single-pass UVC air treatment device (air flow 1254 L/min) could effectively inactivate bioaerosols containing bacterial and viral indicator organisms, and coronavirus without reliance on filtration technology, at reasonable scale. Robust experiments demonstrated UVC dose dependent inactivation of Staphylococcus aureus (UV rate constant (k) = 0.098 m2/J) and bacteriophage MS2, with up to 6-log MS2 reduction achieved in a single pass through the system (k = 0.119 m2/J). The inclusion of a PTFE diffuse reflector increased the effective UVC dose by up to 34% in comparison to a standard Al foil reflector (with identical lamp output), resulting in significant additional pathogen inactivation (1-log S. aureus and MS2, p < 0.001). Complete inactivation of bovine coronavirus bioaerosols was demonstrated through tissue culture infectivity (2.4-log reduction) and RT-qPCR analysis – confirming single pass UVC treatment to effectively deactivate coronavirus to the limit of detection of the culture-based method. Scenario-based modelling was used to investigate the reduction in risk of airborne person-to-person transmission based upon a single infected subject within the small room. Use of the system providing 5 air changes per hour was shown to significantly reduce airborne viral load and maintain low numbers of RNA copies when the infected subject remained in the room, reducing the risk of airborne pathogen transmission to other room users. We conclude that the application of single-pass UVC systems (without reliance on HEPA filtration) could play a critical role in reducing the risk of airborne pathogen transfer, including SARS-CoV2, in locations where adequate fresh air ventilation cannot be implemented.This research was partly funded through the Invest Northern Ireland Innovation Voucher Programme (IV130218200 and IV130232906). We are grateful to the Global Challenges Research Fund (GCRF) UK Research and Innovation (SAFEWATER; EPSRC Grant Reference EP/P032427/1) for supporting Mr Arsalan Afkhami, Dr William J Snelling and Dr Jeremy W.J. Hamilton. Research at AFBI is funded by US-Ireland Research and Development Partnership in Agriculture grants BRDC-Seq and BRDC-URTMVP. We wish to thank Jonathan McMaw at AFBI for acquisition of images

Efficacy of single pass UVC air treatment for the inactivation of coronavirus, MS2 coliphage and Staphylococcus aureus bioaerosols

Publication history: Accepted - 20 April 2022; Published online - 26 April 2022There is strong evidence that SARS-CoV-2 is spread predominantly by airborne transmission, with high viral loads released into the air as respiratory droplets and aerosols from the infected subject. The spread and persistence of SARS-CoV-2 in diverse indoor environments reinforces the urgent need to supplement distancing and PPE based approaches with effective engineering measures for microbial decontamination – thereby addressing the significant risk posed by aerosols. We hypothesized that a portable, single-pass UVC air treatment device (air flow 1254 L/min) could effectively inactivate bioaerosols containing bacterial and viral indicator organisms, and coronavirus without reliance on filtration technology, at reasonable scale. Robust experiments demonstrated UVC dose dependent inactivation of Staphylococcus aureus (UV rate constant (k) = 0.098 m2/J) and bacteriophage MS2, with up to 6-log MS2 reduction achieved in a single pass through the system (k = 0.119 m2/J). The inclusion of a PTFE diffuse reflector increased the effective UVC dose by up to 34% in comparison to a standard Al foil reflector (with identical lamp output), resulting in significant additional pathogen inactivation (1-log S. aureus and MS2, p < 0.001). Complete inactivation of bovine coronavirus bioaerosols was demonstrated through tissue culture infectivity (2.4-log reduction) and RT-qPCR analysis – confirming single pass UVC treatment to effectively deactivate coronavirus to the limit of detection of the culture-based method. Scenario-based modelling was used to investigate the reduction in risk of airborne person-to-person transmission based upon a single infected subject within the small room. Use of the system providing 5 air changes per hour was shown to significantly reduce airborne viral load and maintain low numbers of RNA copies when the infected subject remained in the room, reducing the risk of airborne pathogen transmission to other room users. We conclude that the application of single-pass UVC systems (without reliance on HEPA filtration) could play a critical role in reducing the risk of airborne pathogen transfer, including SARS-CoV2, in locations where adequate fresh air ventilation cannot be implemented.This research was partly funded through the Invest Northern Ireland Innovation Voucher Programme (IV130218200 and IV130232906). We are grateful to the Global Challenges Research Fund (GCRF) UK Research and Innovation (SAFEWATER; EPSRC Grant Reference EP/P032427/1) for supporting Mr Arsalan Afkhami, Dr William J Snelling and Dr Jeremy W.J. Hamilton. Research at AFBI is funded by US-Ireland Research and Development Partnership in Agriculture grants BRDC-Seq and BRDC-URTMVP. We wish to thank Jonathan McMaw at AFBI for acquisition of images

From Punishment to Harm Reduction: Resecularization of Addiction in Contemporary Iran

© Oxford University Press, 2014. This chapter analyzes the issue of addiction. It argues that after the Revolution the treatment of substance abuse began to be seen by the government outside the previously held medical paradigm. In accordance with the government\u27s new standards of morality, which were drawn along the Islamic religious precepts, and in accordance with new ideological rhetoric, stringent antidrug campaigns were launched; elements of these campaigns included the fining of addicts, imprisonment, physical punishment, and even the death penalty for serious offenses. Substance-abuse specialists from the medical community-no longer benefiting from government support-were marginalized and treatment centers were closed. Despite these measures (and in tandem with the Iran- Iraq War, political repression, and a deteriorating economy), the drug problem continued to grow, with the number of addicts increasing rapidly. In the early 1990s, as the more pragmatic Rafsanjani came to power, the government began to take a less doctrinaire approach to substance abuse. The chapter explores the history of this shift in policy, beginning with the early days of treatment policy in the Qajar and Pahlavi periods through the early postrevolutionary governments in Iran, and finally to the current crystallization of the harm-reduction treatment model exemplified by community-sponsored methadone and bupenorphine-addition drug-treatment programs

Treatment of Diphenhydramine with diferent AOPs including photo-Fenton at circumneutral pH.

The degradation of diphenhydramine hydrochloride (DPH), via UV-vis/H2O2, Fenton, photo-Fenton and photocatalysis processes, was studied under different radiation sources. In addition, the Fenton and photo-Fenton processes at acid pH and circumneutral pH have been compared. The importance of the source of irradiation, UV-C (λ = 254 nm), black blue lamps (BLB, λ = 365 nm) and simulated solar radiation (SB, SolarBox), was investigated at lab-scale. Moreover, compound parabolic collectors (CPC), at pilot plant scale with sunlight, have been also applied in photocatalytic treatments. Photo-Fenton process employing black blue lamps gave the best DPH abatement (100% of DPH conversion at 10 min for acid pH and 20 min for circumneutral pH), using the highest Fe2+ (5 mg/L) and H2O2 (150 mg/L) concentrations at 50 mg/L of initial DPH concentration. Using Fenton, 100% of DPH conversion was reached at 30 min for both pHs tested. In the case of UV-C/H2O2, 100% of DPH elimination was achieved in 20 min using 150 mg/L of H2O2. In the photocatalytic process, using 0.4 g TiO2/L, after 60 min of irradiation, only 35.7% and 8.7% of DPH conversion have been obtained in SB and CPC, respectively. The DPH degradation in the photocatalytic process was greatly enhanced adding H2O2. In all the cases, increasing the H2O2 dose enhances the reaction rate due to higher OH[rad] production. However, not significant mineralization was obtained. The highest DPH mineralization was 36.8% and 38.5% of TOC reduction with photo-Fenton in BLB lamps using 150 mg/L of H2O2 and 2.5 mg/L of Fe2+, for acid pH and circumneutral pH, respectively. The major reaction intermediates these processes were identified by ionization/mass spectrometry and a DPH photo-degradation structures was proposed