An Implementation of a Decision Support Tool to Assess Treatment of Emerging Contaminants in India

This is the final version. Available on open access from Scientific Research Publishing via the DOI in this recordEmerging contaminants have been increasingly studied over the past decade to improve the understanding of their fate, occurrence and toxicological effects on the environment and human health. Originally wastewater treatment plants were not designed to remove these pollutants of emerging concern. However, research is now focusing on determining which existing treatment unit processes are suited to their removal. This research sets out to determine suitable treatment options for thirty nine emerging contaminants including various Pharmaceuticals and Personal Care products. The treatment options used in this study are taken from a developed decision support tool (WiSDOM) which formulates wastewater trains/packages for treatment of wastewater in India. The tool also evaluates the performance of each optimal solution in terms of removal of conventional pollutants (such as biochemical oxygen demand, chemical oxygen demand, total nitrogen, total phosphorous, faecal coliform etc.), using multi-objective genetic algorithms and multi-criteria decision analysis. An Excel Spreadsheet Program (ESP) was developed as an add-on to the tool, allowing the ESP to take an initial concentration of any of the thirty nine emerging contaminant and pass it through the treatment trains (generated/selected by the WiSDOM tool) to determine the removal efficiency. Three scenarios were developed to analyse the removal of emerging contaminants in India. The scenarios were designed to capture the influence of different socio-economic contexts and wastewater characteristics on the treatment technology selection. The tool generated results suggest that the use of constructed wetlands can remove a large proportion of emerging contaminants, resulting in low energy requirements and operational costs and wildlife habitats. However, the land requirement for this process is not always suited to urban areas in India. Advanced oxidation processes were also efficient at removing emerging contaminants. However, the energy requirements for this process were high. Emerging contaminants have different physical and chemical properties; therefore, future evaluations of each chemical should be monitored separately to generate suitable technologies suited to optimal removal.Engineering and Physical Sciences Research Council (EPSRC)European CommissionNatural Environment Research Council (NERC

Emerging pollutants in developing countries: Optimising sustainable treatment solutions

This is the author accepted manuscriptOver the past decade the research surrounding the occurrence, source, fate and removal of emerging pollutants has been increasing. The aim of this study was to create an add-on program which analyses the removal of emerging pollutants, to an existing decision support tool (WiSDOM). The tool was also used to evaluate the performance of each optimal solution in terms of removal of conventional pollutants using Multi Objective Genetic Algorithms and Multi Criteria Decision Analysis. Information was collated regarding minimum and maximum concentrations of emerging pollutants for surface water, groundwater, untreated wastewater, drinking water and treated wastewater. This information was used to populate an Excel Spreadsheet Program (ESP) which analysed the removal efficiencies of 13 different emerging pollutants for 42 wastewater treatment unit processes. The ESP is incorporated into the WiSDOM tool to allow the tool to calculate the removal of emerging pollutants. Three main scenarios were created to test the application of the tool and ESP. Scenario 1 focussed on the removal of emerging pollutants from from areas effected by tourism at different scales. Scenario 2 looked at the treatment suited for the removal of emerging pollutants from different socio-economic regions. Lastly, Scenario 3 looked at removing emerging pollutants from hospital and industrial wastewater. The scenarios were focused on wastewater treatment in India and investigated the removal of 13 emerging pollutants commonly found in India.Engineering and Physical Sciences Research Council (EPSRC)European CommissionNatural Environment Research Council (NERC

Optimising wastewater treatment solutions for the removal of contaminants of emerging concern (CECs): A case study for application in India

This is the author accepted manuscript. The final version is available from IWA Publishing via the DOI in this record.The aim of this study was to produce optimal wastewater treatment solutions to calculate the removal of different CECs found in developing countries. A new methodology was developed for a decision support tool (WiSDOM), which focuses on producing treatment solutions suited to treating water for reuse to Indian Water Quality Standards. WiSDOM-CEC analyses the removal of CECs through different treatment solutions and was also used to evaluate the performance of each treatment train solution in terms of removal of conventional pollutants using multi-objective optimisation and multi criteria decision analysis. Information was collected on different CECs across different regions of India, and the removal of eighteen different CECs through 42 wastewater treatment unit processes for five different regions of India was analysed. Comparisons between similar categories of CECs, such as non-steroidal anti-inflammatory showed that emerging contaminants all react differently to individual treatment options. For example, the removal of Ibuprofen (IBP) and Naproxen (NPX) varied from >80% and 0%, respectively, for a solution in Karnataka involving sedimentation, submerged aerated filter, ultra-filtration and Nano filtration. In Tamil Nadu results ranged from 36.8% to 72% for Diclofenac, 10.7% to 66.5% for IBP and 0% for NPX.European CommissionNatural Environment Research Council (NERC)Engineering and Physical Sciences Research Council (EPSRC

Mid-term follow-up of patients with Brugada syndrome following a cardioverter defibrillator implantation: A single center experience

BACKGROUND: Brugada syndrome is an arrhythmogenic disease characterized by an ECG pattern of ST-segment elevation in the right precordial leads and an increase risk of sudden cardiac death. Risk stratification for the life-threatening arrhythmic events in Brugada syndrome is not yet established. In the present study, we report our experience in patients with Brugada syndrome, following an ICD implantation. METHODS AND RESULTS: A total of 12 patients (11 men, 1 woman) with a mean age of 46.5±11.8 were studied. At diagnosis, 7 patients had syncope of unknown origin, 2 patients were asymptomatic, 2 patients were survivors of cardiac arrest, and 1 had documented clinical VT requiring direct cardioversion for termination. Age was similar between the symptomatic and asymptomatic patients (46.6±13 vs. 46±2.8, respectively). Two patients reported a family history of sudden cardiac death. In 3 patients, spontaneous coved-type ECG was found at baseline. In 9 patients, a class I antiarrhythmic drug administration unmasked the characteristic type I ECG. In 4 patients (2 symptomatic with syncope at presentation and 2 asymptomatic), who underwent PES, sustained polymorphic VT or VF was induced. VF was induced by single extrastimuli in 2 symptomatic patients (1 from RV apex and 1 from RVOT). In 2 asymptomatic patients, VF was induced by two and triple ventricular extrastimli (1 from RV apex and 1 from RVOT). None of them experienced an event during follow-up. No significant difference was found between symptomatic and asymptomatic patients (p=NS). The mean follow-up period for the entire study population was 27.83±11.25 months. During follow-up, 2 patients (one with prior cardiac arrest and another with syncope) had VF. Both of them had a type I ECG after provocation with a class I antiarrhythmic drug. None of them had undergone programmed ventricular stimulation. Five patients (41.7 %) had inappropriate ICD interventions during follow-up. The cause of inappropriate therapy was sinus tachycardia in 2 patients, AF in 2 patients and T wave oversensing in 1 patient. CONCLUSION: Knowledge about Brugada syndrome is steadily progressing but there are still unanswered issues dealing with the risk stratification and the management of patients

Multiple arrhythmogenic substrate for tachycardia in a patient with frequent palpitations

We report a 26-year-old woman with frequent episodes of palpitation and dizziness. Resting electrocardiography showed no evidence of ventricular preexcitation. During electrophysiologic study, a concealed right posteroseptal accessory pathway was detected and orthodromic atrioventricular reentrant tachycardia incorporating this pathway as a retrograde limb was reproducibly induced. After successful ablation of right posteroseptal accessory pathway, another tachycardia was induced using a concealed right posterolateral accessory pathway in tachycardia circuit. After loss of retrograde conduction of second accessory pathway with radiofrequency ablation, dual atrioventricular nodal physiology was detected and typical atrioventricular nodal reentrant tachycardia was repeatedly induced. Slow pathway ablation was done successfully. Finally sustained self-terminating atrial tachycardia was induced under isoproterenol infusion but no attempt was made for ablation. During 8-month follow-up, no recurrence of symptoms attributable to tachycardia was observed

Sustainable Treatment of Emerging Pollutants in the Context of India

This is the author accepted manuscript.Emerging pollutants have been increasingly studied over the past decade to improve our understanding of their fate, occurrence and toxicological effects on the environment and human health. The aim of this research is to develop a model that calculates the removal of emerging pollutants in India using different treatment unit processes. Different wastewater treatment scenarios based in India were defined considering several variables and factors including: influent water quality, intended use of effluents, available resources, operational envelop and treatment efficiency of technologies. WiSDOM Tool was used to find optimal wastewater trains/packages for treatment keeping in view technical, environmental, social and economic aspects. The tool also evaluates the performance of each optimal solution in terms of removal of current pollutants (such as BOD, COD, TN, TP, FC etc.) using multi-objective genetic algorithms and multi-criteria decision analysis. An Excel spreadsheet model was developed, where the treatment trains (generated/selected by the WiSDOM tool) were passed through to determine the removal efficiency of emerging pollutants. Each emerging pollutant has different physical and chemical properties and therefore, each compound should be monitored separately to generate the optimum removal. Further research is required to bridge the knowledge gap regarding emerging pollutants and their removal during treatment.Part of this study describes work being carried out under EC FP7-funded projects: Grant agreement no: 308672 “Saraswati”. The project sponsors had no involvement in the study design, collection, analysis and interpretation of data or in the writing of the manuscript

Coexistence of atrioventricular nodal reentrant tachycardia and idiopathic left ventricular outflow-tract tachycardia

Double tachycardia is a relatively rare condition. We describe a 21 year old woman with history of frequent palpitations. In one of these episodes, she had wide complex tachycardia with right bundle branch and inferior axis morphology. A typical atrioventricular nodal tachycardia was induced during electrophysiologic study, aimed at induction of clinically documented tachycardia. Initially no ventricular tachycardia was inducible. After successful ablation of slow pathway, a wide complex tachycardia was induced by programmed stimulation from right ventricular outflow tract. Mapping localized the focus of tachycardia in left ventricular outflow tract and successfully ablated via retrograde aortic approach. During 7 month's follow-up, she has been symptom free with no recurrence. This work describes successful ablation of rare combination of typical atrioventricular nodal tachycardia and left ventricular outflow tract tachycardia in the same patient during one session

Latent atriofascicular pathway participating in a wide complex tachycardia: Differentiation from ventricular tachycardia

Accessory pathways with anterograde decremental conduction properties usually are characterized by presence of antegrade preexcitation during atrial pacing. We report a 38-year-old man with frequent episodes of palpitation. No evidence of ventricular preexcitation was seen during sinus rhythm or atrial pacing. All electrophysiologic maneuvers were compatible with an antidromic tachycardia using atriofascicular pathway as the antegrade limb and the atrioventricular nodal pathway as retrograde limb. Radiofrequency ablation at recording site of accessory pathway potential resulted in cure of tachycardia with no recurrence during 3-month follow-up. This report indicated that atriofascicular pathway-mediated tachycardia should be considered in differential diagnosis of all cases of wide complex tachycardia with left bundle branch morphology and left axis. © 2006, The Authors

Optimal side of implant for single-lead VDD pacing: Right-sided versus left-sided implantation

Background: Atrial undersensing occurs in a considerable number of patients with single-lead VDD pacing. This study tried to determine the role of implant side in maintenance of the VDD mode in patients with isolated atrioventricular (AV) block. Methods: Eighty-two patients with isolated AV block (46 females; mean age, 58 ± 17 years) received a single-lead VDD pacemaker (Medtronic Kappa, n = 70 and St. Jude Medical Affinity, n = 12). The patients were randomly assigned to one of two implantation groups (group I: right-sided VDD and group II: left-sided VDD). In each group, the P-wave amplitudes were determined at implantation, predischarge, 2-month, and 6-month follow-up. At each follow-up visit, stored event histograms of pacemaker were also retrieved. The atrial sensing measurements were compared between two groups. Results: Implantation was easier from right side (1.7 ± 1.0 vs 2.8 ± 1.7 attempts, P = 0.001). Implant P-wave was higher in group I compared to group II (4.2 ± 1.7 vs 2.7 ± 1.0 mV, P < 0.0001). During follow-up, higher P-wave amplitudes were obtained in group I both at predischarge (2.6 ± 1.3 vs 1.4 ± 1.1 mV, P < 0.0001), 2-month (2.8 ± 1.8 vs 1.3 ± 1.0 mV, P < 0.0001), and 6-month (2.9 ± 1.7 vs 1.3 ± 0.9 mV, P < 0.0001) evaluations but remained stable throughout the 6 months in both groups. After implantation, VDD function was better maintained in group I than group II (100 vs 90, P = 0.026). Incidence of atrial undersensing was lower in group I than group II (P = 0.026) in last follow-up visit. Conclusions: Implant side has a significant influence on atrial sensing performance in single-lead VDD pacing. Thus, right-side implantation should be the preferred approach for the implantation of VDD single-lead systems

Is the activation potential of Mahaim pathway always a fast potential? Implication for radiofrequency catheter ablation

Introduction: Accessory pathways (AP) exhibiting Mahaim physiology are amenable to radiofrequency (RF) catheter ablation. The recording of an AP potential is an excellent guide for selection of ablation site. The purpose of this study is to determine whether the pathway potential is always a fast potential. Methods: Ten patients (six females, mean age, 30±12 years) with preexcited tachycardias involving a Mahaim pathway underwent electrophysiological study and subsequent attempts at RF ablation. Mahaim potentials (M-potential) recorded at the site of successful ablation were reviewed and classified by at least two reviewers. Results: In all patients, Mahaim pathways were characterized as atriofascicular types. The M-potential was fast in seven patients (group one), and slow in the remaining patients (group two). All group two patients had a history of prior failed ablation. Atrial electrograms were recorded closer to the QRS onset in group one. Atrium to fast M-potential (42±15 ms) was shorter than atrium to slow M-potential (83±12 ms, P=0.03) but M-potentials were recorded with similar distance before local ventricular electrogram (P=NS). Ablation was successful in all patients with mean of 2.9±1.4 RF applications per patient. Ablation data were similar between the two groups (P=NS). No complications occurred. During 12 months of follow-up, no recurrence was observed. Conclusion: Our results illustrated that the activation potential of Mahaim pathways is not always a fast potential. One-third of Mahaim pathways can be mapped and ablated when the slow type of M-potential was used as a target for ablation. We also confirmed high efficacy of catheter ablation of Mahaim pathways guided by activation potentials. © 2005 The European Society of Cardiology. Published by Elsevier Ltd. All rights reserved