scholarly journals Comparative analysis of indicators for assessing the state of activated sludge in the water treatment process

2020 ◽  
Vol 61 (1) ◽  
pp. 96-103
Author(s):  
Yelena S. Balymova ◽  
◽  
Yulia M. Safiullina ◽  
Farida Yu. Akhmadullina ◽  
Rustem K. Zakirov ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Water Treatment ◽  
Activated Sludge ◽  
Evaluation System ◽  
Shannon Index ◽  
The State ◽  
Treated Wastewater ◽  
Control Factor ◽  
Wide Range ◽  
The Impact

This article presents the results of biodiagnostics of activated sludge formed in the wastewater of organic synthesis plants. They are characterized by changes in the concentrations of control pollutants (phenol, non-ionic synthetic surfactants, glycols), as well as chemical oxygen demand in a fairly wide range, which negatively affects at the activated sludge state and does not allow to achieve the regulatory requirements for the quality of treated wastewater. In this paper, the state of active biomass in the process of biological wastewater treatment was evaluated using three quantitative assessment systems: a five-point scale, hydrobiological indices of biodiversity Shannon and Cuba. The paper presents a comparative analysis of systems for quantifying the state of activated sludge, that are recommended for use in water treatment practice, both for simple systems, in which only one control factor affects the state of activated sludge, and for complex systems, that include the impact of a large number of control ecotoxicants on the activated sludge ecosystem. It is shown that in quantitative terms, the established regularities of the influence of control pollutants on the state of activated sludge differ: the five-point evaluation system, in comparison with the Shannon index, reflects deeper changes in the state of the biocenosis, because it evaluates not only the number of hydrobionts, but also their state, as well as the state of activated sludge flakes and the liquid above it. However, the assessment of the activated sludge state by the Cube index revealed a quantitative discrepancy in the change of this index compared to the aforementioned, which suggests that it is not appropriate to use it to describe the dynamics of changes in the state of the bioagent in the process of water treatment.

scholarly journals Combined assimilation of streamflow and snow water equivalent for mid-term ensemble streamflow forecasts in snow-dominated regions

2016 ◽  
Author(s):  
Jean M. Bergeron ◽  
Mélanie Trudel ◽  
Robert Leconte
Keyword(s):  
Data Assimilation ◽  
State Vector ◽  
Snow Water Equivalent ◽  
Synthetic Data ◽  
Hydrologic Model ◽  
Open Loop ◽  
The State ◽  
Wide Range ◽  
Snow Water ◽  
The Impact

Abstract. The potential of data assimilation for hydrologic predictions has been demonstrated in many research studies. Watersheds over which multiple observation types are available can potentially further benefit from data assimilation by having multiple updated states from which hydrologic predictions can be generated. However, the magnitude and time span of the impact of the assimilation of an observation varies according not only to its type, but also to the variables included in the state vector. This study examines the impact of multivariate synthetic data assimilation using the Ensemble Kalman Filter (EnKF) into the spatially distributed hydrologic model CEQUEAU for the mountainous Nechako River located in British-Columbia, Canada. Synthetic data includes daily snow cover area (SCA), daily measurements of snow water equivalent (SWE) at three different locations and daily streamflow data at the watershed outlet. Results show a large variability of the continuous rank probability skill score over a wide range of prediction horizons (days to weeks) depending on the state vector configuration and the type of observations assimilated. Overall, the variables most closely linearly linked to the observations are the ones worth considering adding to the state vector. The performance of the assimilation of basin-wide SCA, which does not have a decent proxy among potential state variables, does not surpass the open loop for any of the simulated variables. However, the assimilation of streamflow offers major improvements steadily throughout the year, but mainly over the short-term (up to 5 days) forecast horizons, while the impact of the assimilation of SWE gains more importance during the snowmelt period over the mid-term (up to 50 days) forecast horizon compared with open loop. The combined assimilation of streamflow and SWE performs better than its individual counterparts, offering improvements over all forecast horizons considered and throughout the whole year, including the critical period of snowmelt. This highlights the potential benefit of using multivariate data assimilation for streamflow predictions in snow-dominated regions.

Evaluation of phytotoxicity of effluents from activated sludge and constructed wetland system for wastewater reuse

2019 ◽  
Vol 79 (4) ◽  
pp. 656-667 ◽  
Author(s):  
Ana María Leiva ◽  
Adrián Albarrán ◽  
Daniela López ◽  
Gladys Vidal
Keyword(s):  
Activated Sludge ◽  
Wastewater Reuse ◽  
Treated Wastewater ◽  
Positive Effects ◽  
Treated Wastewater Reuse ◽  
Epicotyl Elongation ◽  
Petri Dishes ◽  
The Impact ◽  
Positive Effect ◽  
Seeds Germination

Abstract The aim of this study was to evaluate the phytotoxicity of wastewater treated with horizontal subsurface flow (HSSF) constructed wetlands (CWs) and activated sludge (AS) system using disinfection treatment such chlorination and ultraviolet (UV) system. To assess the impact of the reuse of different effluents (HSSF-Cl, HSSF-UV, AS-Cl and AS-UV), bioassays using seeds of Raphanus sativus (R. sativus) and Triticum aestivum (T. aestivum), were performed on both Petri dishes and soil. Different treated wastewater concentrations were varied (6.25%, 12.5%, 25%, 50% and 100%) and the percentage of germination inhibition (PGI), percentage of epicotyl elongation (PEE) and germination index (GI) were determined. Positive effects (PGI and PEE <0% and GI >80%) of HSSF-Cl, HSSF-UV, AS-Cl and AS-UV effluents on germination and epicotyl elongation of R. sativus and T. aestivum were observed in Petri dishes bioassays. However, toxic effects of HSSF-Cl, HSSF-UV and AS-Cl on seeds germination and epicotyl elongation of both plant species were detected in soil samples (PGI and PEE >0% and GI <80%). Only R. sativus seeds to be irrigated with AS-UV achieved GI values above 86% for all concentrations evaluated. These results indicated that AS-UV effluent had a positive effect on seeds germination and can be recommended for treated wastewater reuse in agricultural irrigation.

scholarly journals Poverty as a Political Choice: a Comparative Analysis of Reports of the UN Rapporteur’s Visits to the UK and Spain

2021 ◽  
Author(s):  
Ian Cummins ◽  
Emilio José Gómez-Ciriano
Keyword(s):  
Human Rights ◽  
Civil Society ◽  
Comparative Analysis ◽  
Social Workers ◽  
The State ◽  
The Other ◽  
Role Of The State ◽  
The Uk ◽  
The Impact

AbstractThis paper presents a comparative analysis of two reports by the UN Rapporteur on Extreme Poverty and Human Rights, one for Spain and one for the UK. In both countries, austerity policies were introduced following the banking crisis of 2008. The UN Rapporteur reports highlight the damage that was done by welfare retrenchment. In particular, the reports document the impact of austerity on the most vulnerable individuals and communities. The paper uses Somers' (2008) conceptual model of citizenship as the basis for a comparative analysis of two reports. Somers' (2008) model of citizenship is a triadic one which sees the state, market and civil society as competing elements. Each one can serve to regulate and limit the influence or excesses of the other two. Somers argues that neoliberalism has seen the dominance of the market at the expense of the role of the state and the institutions of civil society. Austerity policies saw the market dominating. Having examined the context of the two reports and their conclusions, the paper discussed the implications for individual social workers’ practice and the role of social work as a profession in tackling poverty and marginalisation.

scholarly journals Combined assimilation of streamflow and snow water equivalent for mid-term ensemble streamflow forecasts in snow-dominated regions

2016 ◽  
Vol 20 (10) ◽  
pp. 4375-4389 ◽  
Author(s):  
Jean M. Bergeron ◽  
Mélanie Trudel ◽  
Robert Leconte
Keyword(s):  
Data Assimilation ◽  
State Vector ◽  
Snow Water Equivalent ◽  
Synthetic Data ◽  
Hydrologic Model ◽  
Open Loop ◽  
The State ◽  
Wide Range ◽  
Snow Water ◽  
The Impact

Abstract. The potential of data assimilation for hydrologic predictions has been demonstrated in many research studies. Watersheds over which multiple observation types are available can potentially further benefit from data assimilation by having multiple updated states from which hydrologic predictions can be generated. However, the magnitude and time span of the impact of the assimilation of an observation varies according not only to its type, but also to the variables included in the state vector. This study examines the impact of multivariate synthetic data assimilation using the ensemble Kalman filter (EnKF) into the spatially distributed hydrologic model CEQUEAU for the mountainous Nechako River located in British Columbia, Canada. Synthetic data include daily snow cover area (SCA), daily measurements of snow water equivalent (SWE) at three different locations and daily streamflow data at the watershed outlet. Results show a large variability of the continuous rank probability skill score over a wide range of prediction horizons (days to weeks) depending on the state vector configuration and the type of observations assimilated. Overall, the variables most closely linearly linked to the observations are the ones worth considering adding to the state vector due to the limitations imposed by the EnKF. The performance of the assimilation of basin-wide SCA, which does not have a decent proxy among potential state variables, does not surpass the open loop for any of the simulated variables. However, the assimilation of streamflow offers major improvements steadily throughout the year, but mainly over the short-term (up to 5 days) forecast horizons, while the impact of the assimilation of SWE gains more importance during the snowmelt period over the mid-term (up to 50 days) forecast horizon compared with open loop. The combined assimilation of streamflow and SWE performs better than their individual counterparts, offering improvements over all forecast horizons considered and throughout the whole year, including the critical period of snowmelt. This highlights the potential benefit of using multivariate data assimilation for streamflow predictions in snow-dominated regions.

Glutton: large-scale integration of non-model organism transcriptome data for comparative analysis

2016 ◽  
Author(s):  
Alan Medlar ◽  
Laura Laakso ◽  
Andreia Miraldo ◽  
Ari Löytynoja
Keyword(s):  
Comparative Analysis ◽  
Large Scale ◽  
De Novo ◽  
Sequence Data ◽  
Model Organism ◽  
Model Organisms ◽  
Rna Seq ◽  
Reference Species ◽  
Wide Range ◽  
The Impact

AbstractHigh-throughput RNA-seq data has become ubiquitous in the study of non-model organisms, but its use in comparative analysis remains a challenge. Without a reference genome for mapping, sequence data has to be de novo assembled, producing large numbers of short, highly redundant contigs. Preparing these assemblies for comparative analyses requires the removal of redundant isoforms, assignment of orthologs and converting fragmented transcripts into gene alignments. In this article we present Glutton, a novel tool to process transcriptome assemblies for downstream evolutionary analyses. Glutton takes as input a set of fragmented, possibly erroneous transcriptome assemblies. Utilising phylogeny-aware alignment and reference data from a closely related species, it reconstructs one transcript per gene, finds orthologous sequences and produces accurate multiple alignments of coding sequences. We present a comprehensive analysis of Glutton’s performance across a wide range of divergence times between study and reference species. We demonstrate the impact choice of assembler has on both the number of alignments and the correctness of ortholog assignment and show substantial improvements over heuristic methods, without sacrificing correctness. Finally, using inference of Darwinian selection as an example of downstream analysis, we show that Glutton-processed RNA-seq data give results comparable to those obtained from full length gene sequences even with distantly related reference species. Glutton is available from http://wasabiapp.org/software/glutton/ and is licensed under the GPLv3.

Nutrient minimisation in the pulp and paper industry: an overview

2004 ◽  
Vol 50 (3) ◽  
pp. 111-122 ◽  
Author(s):  
A.H. Slade ◽  
R.J. Ellis ◽  
M. van den Heuvel ◽  
T.R. Stuthridge
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Paper Industry ◽  
Pulp And Paper Industry ◽  
Pulp And Paper ◽  
Treated Wastewater ◽  
Nitrogen And Phosphorus ◽  
Treatment Technology ◽  
Solids Separation ◽  
The Impact

This paper reviews nutrient issues within the pulp and paper industry summarising: nitrogen and phosphorus cycles within treatment systems; sources of nutrients within pulping and papermaking processes; minimising nutrient discharge; new approaches to nutrient minimisation; and the impact of nutrients in the environment. Pulp and paper industry wastewaters generally contain insufficient nitrogen and phosphorus to satisfy bacterial growth requirements. Nutrient limitation has been linked to operational problems such as sludge bulking and poor solids separation. Nutrients have been added in conventional wastewater treatment processes to ensure optimum treatment performance. Minimising the discharge of total nitrogen and phosphorus from a nutrient limited wastewater requires both optimised nutrient supplementation and effective removal of suspended solids from the treated wastewater. In an efficiently operated wastewater treatment system, the majority of the discharged nutrients are contained within the biomass. Effective solids separation then becomes the controlling step, and optimisation of secondary clarification is crucial. Conventional practice is being challenged by the regulatory requirement to reduce nitrogen and phosphorus discharge. Two recent developments in pulp and paper wastewater treatment technologies can produce discharges low in nitrogen and phosphorus whilst operating under conventionally nutrient limited conditions: i) the nutrient limited BAS process (Biofilm-Activated Sludge) which combines biofilm and activated sludge technologies under nutrient limited conditions and ii) an activated sludge process based on the use of nitrogen-fixing bacteria. Aerated stabilisation basins often operate without nutrient addition, relying on settled biomass in the benthal zone feeding back soluble nutrients, or the fixation of atmospheric nitrogen. Thus effective nutrient minimisation strategies require a more detailed understanding of nutrient cycling and utilisation. Where it is not possible to meet discharge constraints with biological treatment alone, a tertiary treatment step may be required. In setting nutrient control guidelines, consideration should be given to the nutrient limitations of the receiving environment, including other cumulative nutrient impacts on that environment. Whether an ecosystem is N or P limited should be integrated with wastewater treatment considerations in the further design and development of treatment technology and regulatory guidelines. End-of-pipe legislation alone cannot predict environmental effects related to nutrients and must be supplemented by an effects-based approach.

scholarly journals Strategies and challenges in Kerala’s response to the initial phase of COVID-19 pandemic: a qualitative descriptive study

BMJ Open ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. e051410
Author(s):  
Kannamkottapilly Chandrasekharan Prajitha ◽  
Arya Rahul ◽  
Sujatha Chintha ◽  
Gopakumar Soumya ◽  
Meenu Maheswari Suresh ◽  
...  
Keyword(s):  
Focus Group ◽  
Health System ◽  
Descriptive Study ◽  
The State ◽  
Focus Group Discussions ◽  
Group Discussions ◽  
Wide Range ◽  
Qualitative Descriptive ◽  
The Impact ◽  
Depth Interviews

ObjectiveTo understand the structures and strategies that helped Kerala in fighting the COVID-19 pandemic, the challenges faced by the state and how it was tackled.DesignQualitative descriptive study using focus group discussions and in-depth interviews.SettingState of Kerala, India.Participants29 participants: four focus group discussions and eight in-depth interviews. Participants were chosen purposively based on their involvement in decision-making and implementation of COVID-19 control activities, from the department of health and family welfare, police, revenue, local self-government and community-based organisations. Districts, panchayats (local bodies) and primary health centres (PHCs) were selected based on epidemiological features of the area like the intensity of disease transmission and preventive/containment activities carried out in that particular area to capture the wide range of activities undertaken in the state.ResultsThe study identified five major themes that can inform best practices viz social capital, robust public health system, participation and volunteerism, health system preparedness, and challenges. This study was a real-time exploration of the intricacies of COVID-19 management in a low/middle-income country and the model can serve as an example for other states and nations to emulate or adjust accordingly.ConclusionThe study shows the impact of synergy of these themes towards more effective solutions; however, further research is much needed in examining the relationship between these factors and their relevance in policy decisions.

scholarly journals The Impact of Pre-existing Health Conditions on Cost of Recovery after Workplace Injury: Insight from population-based data linkage in the State of Victoria, Australia

2017 ◽  
Vol 1 (1) ◽  
Author(s):  
Behrooz Hassani-M ◽  
Janneke Berecki-Gisolf ◽  
Alex Collie
Keyword(s):  
Return To Work ◽  
Service Use ◽  
Labour Force ◽  
Length Of Hospital Stay ◽  
The State ◽  
Health Conditions ◽  
Workplace Injury ◽  
Main Challenge ◽  
Wide Range ◽  
The Impact

ABSTRACTObjectiveComorbidity is known to affect length of hospital stay and mortality after trauma but less is known about its impact on recovery beyond the acute care period. A main challenge to study the impact of pre-existing conditions is that information on these conditions is not collected systematically and comprehensively. The aim of this study was to investigate the role of pre-existing health conditions in recovery from workplace injury using linked data. ApproachIn Victoria, Australia, approximately 85% of the labour force is covered by the state workers compensation scheme regulated by WorkSafe Victoria. The scheme provides financial compensation for healthcare and income support to eligible injured workers. . One year of WorkSafe claims for injuries that occurred between 1/07/2008 and 31/06/2009 (N = 49,171) were linked to eight years of pre-injury hospital admission admissions and emergency department presentations, received from the state Department of Health and Human Services. Main outcomes of the study included the total and categorical cost of recovery (e.g. hospital, medical, allied health) measured over short (2-6 months), medium (1-2 years) and long-term (5 years) periods. All models controlled for characteristics of the worker, workplace and injury.ResultsThe preliminary results show that the cost of recovery from workplace injury is significantly associated with history of pre-injury admissions: Workers with pre-injury admissions have higher cost of recovery including longer periods of time off work as well as further cost of health service use during recovery. As this is an ongoing project, further detailed results will be presented at the conference such as the impact of admission under each category of pre-existing conditions according to ICD codes on a wide range of outcomes after workplace injury.Conclusion Our findings are expected to help government injury compensation regulators to better understand the drivers of compensation costs and other key system outcomes such as return to work. The findings will support better allocation of financial resources, better internal management of claims and efficient allocation of physical and human resources and therefore greater client satisfaction leading to ensuring faster recovery, return to work and more effective as well as efficient service provision.

scholarly journals Impact of Short-Term Exogenous Shocks on Taxpayer Behavior and Tax Evasion

2021 ◽  
Vol 20 (2) ◽  
pp. 241-268
Author(s):  
V. A. Molodykh ◽  
Keyword(s):  
Tax Evasion ◽  
Individual Characteristics ◽  
The State ◽  
Short Term ◽  
Modeling Tools ◽  
Agent Based ◽  
Exogenous Shocks ◽  
External Influences ◽  
Wide Range ◽  
The Impact

The evolution of views on tax evasion following the introduction of limited rationality and social and psychological factors into the models of taxpayer behavior has increased the plausibility of the initial assumptions of the models, but it has made it difficult to use classical approaches based on the search for equilibrium states. The variety of behavioral responses of taxpayers due to the many factors that influence their choice has led to the fact that tax evasion has come to be considered as the result of nonlinear and dynamic interactions between the state and taxpayers. In such models, small short-term external influences can act as shocks, which leads to the emergence of a wide range of different long-term trends, the analysis of which within the framework of traditional approaches is difficult. In this regard, the purpose of this review study is to study the evolution of views on the behavior of taxpayers that has led to the emergence of new approaches to modeling tax evasion where the key role is assigned to the analysis of the impact of external shocks of various scales and nature. The research hypothesis is that modern approaches to the study of tax evasion problems make it necessary to consider the interaction of the state and taxpayers within the framework of the theory of non-equilibrium and nonlinear systems in which minor external influences can play the role of shocks, and the most promising direction of their study is the use of agent-based modeling tools. The results of the study confirm that the use of agent-based models is a promising approach for integrating existing approaches in the study of tax evasion processes. The proposed concept of building an agent-based model for analyzing the processes of tax evasion allows us to answer the question of how short-term exogenous shocks will affect the preferences of taxpayers, taking into account their individual characteristics and accepted behavioral patterns in society.

scholarly journals Chlorine As a Disinfectant in Water Treatment

2021 ◽  
Vol 9 (10) ◽  
pp. 172-178
Author(s):  
Rifahat Muntaha
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Sodium Hypochlorite ◽  
Sodium Hypochlorite Solution ◽  
Calcium Hypochlorite ◽  
Elemental Chlorine ◽  
Wide Range ◽  
Water Chlorination ◽  
The One ◽  
The Impact

Abstract: Disinfection of treated water is a necessary process. For this, chlorine and its products are widely used. During the treatment process, chlorine is added to drinking water as elemental chlorine, sodium hypochlorite solution or dry calcium hypochlorite. When applied to water, each of these forms “free chlorine”, which destroys pathogenic organisms. If adequate water treatment is not readily available, the impact on public health can be devastating. Worldwide, about 1.2 billion people lack access to safe drinking water, and about 2.4 billion people lack sanitation. As per WHO, 3.4 million people die from waterrelated diseases. Drinking water chlorination will remain a cornerstone of disinfection. This is because of the wide range of benefits provided by chlorine. However, alternative disinfectants including ozone and UV radiation are available, all disinfection methods have unique benefits, limitations and costs. So, an engineer has to consider all the pros and cons of a disinfectant method properly before deciding the one to adopt. Keywords: Disinfection, Gaseous Chlorination, Sodium Hypochlorite, Calcium Hypochlorite, Ultraviolet, Ozone, Chlorine dioxide

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