Comparison of Hydrological Impacts of Climate Change Simulated by WASMOD and HBV Models in Different Climatic Zones China, Ethiopia, and Norway

Abstract Recent advances in hydrological impact studies points that the response of specific catchments to climate change scenario using a single model approach is questionable. Based on this hypothesis, this study was aimed at investigating the impact of climate change on the hydrological regime of river basins in three different climatic zones (China, Ethiopia and Norway) using WASMOD and HBV hydrological models. Specifically the objectives include (i) examining and comparing the hydrological response of different river basins to climate change scenarios, (ii) testing the sensitivity of WASMOD and HBV models, and (iii) testing the sensitivity of climate change scenarios in different climatic regions. The climate change response of the three basins (Didessa, Dongjiang and Elverum) were evaluated in terms of runoff, actual evapotranspiration and soil moisture storage change for incremental precipitation and temperature change scenarios using HBV and WAMOD models. The parameters of hydrological models were determined in the study catchment using current climatic inputs and observed river flows. The historical time series of climatic data was adjusted according to the climate change scenarios. The hydrological characteristics of the catchments under the adjusted climatic conditions were simulated using the calibrated hydrological model. Finally, comparisons of the model simulations of the current and possible future hydrological characteristics were performed. The calibration and validation results of WASMOD and HBV models show that both models can reproduce the runoff with acceptable accuracy for each basin. The findings of this study demonstrated that high sensitivity was observed for Didessa and Elverum to precipitation and temperature changes, respectively. However, Dongjiang was found less sensitive to both precipitation and temperature changes. In general, the results imply that there is limitation in moisture and temperature for Didessa and Elverum, respectively. The hydrological impact of climate change resulted from synthetic scenario using the two models indicate that the sensitivity of catchments in response to different climate change scenario was different in different climatic regions. Thus, the result demonstrated a concern that hydrological impact of climate change analysis using single hydrological model may lead to unreliable conclusion. In this regard, conducting multi model analysis is one way to reduce such uncertainty. Finally, we recommend further research in this area in order to exhaustively explore hydrological impact of climate change in different regions

Role and Important Properties of a Membrane with Its Recent Advancement in a Microbial Fuel Cell

Microbial fuel cells (MFC) are an emerging technology for wastewater treatment that utilizes the metabolism of microorganisms to generate electricity from the organic matter present in water directly. The principle of MFC is the same as hydrogen fuel cell and has three main components (i.e., anode, cathode, and proton exchange membrane). The membrane separates the anode and cathode chambers and keeps the anaerobic and aerobic conditions in the two chambers, respectively. This review paper describes the state-of-the-art membrane materials particularly suited for MFC and discusses the recent development to obtain robust, sustainable, and cost-effective membranes. Nafion 117, Flemion, and Hyflon are the typical commercially available membranes used in MFC. Use of nonfluorinated polymeric membrane materials such as sulfonated silicon dioxide (S-SiO2) in sulfonated polystyrene ethylene butylene polystyrene (SSEBS), sulfonated polyether ether ketone (SPEEK) and graphene oxide sulfonated polyether ether ketone (GO/SPEEK) membranes showed promising output and proved to be an alternative material to Nafion 117. There are many challenges to selecting a suitable membrane for a scaled-up MFC system so that the technology become technically and economically viable

Monitoring of β-D-galactosidase activity as a surrogate parameter for rapid detection of sewage contamination in urban recreational water

-Abstract: Simple, automated methods are required for rapid detection of wastewater contamination in urban recreational water. The activity of the enzyme b-D-galactosidase (GAL) can rapidly (<2 h) be measured by field instruments, or a fully automated instrument, and was evaluated as a potential surrogate parameter for estimating the level of fecal contamination in urban waters. The GAL-activity in rivers, affected by combined sewer overflows, increased significantly during heavy rainfall, and the increase in GAL-activity correlated well with the increase in fecal indicator bacteria. The GAL activity in human feces (n = 14) was high (mean activity 7 b 107 ppb MU/hour) and stable (1 LOG10 variation), while the numbers of Escherichia coli and intestinal enterococci varied by >5 LOG10. Furthermore, the GAL-activity per gram feces from birds, sheep and cattle was 2–3 LOG10 lower than the activity from human feces, indicating that high GAL-activity in water may reflect human fecal pollution more than the total fecal pollution. The rapid method can only be used to quantify high levels of human fecal pollution, corresponding to about 0.1 mg human feces/liter (or 103 E. coli/100 mL), since below this limit GAL-activity from non-fecal environmental sources may interfere

Multiple linear regression models for estimating microbial load in a drinking water source case from the Glomma river, Norway

The application of integrated study of water quality and statistics for environmental modelling is considered as a powerful analytical tool that has been thrived significantly during recent years. The present study was conducted to identify the significant physico-chemical factors that affects the raw water quality, and to study statistical interrelationships amongst them. Multiple linear regression models were developed to estimate microbial load in the raw water source, using data from the NRV drinking water treatment plant published from 1999 to 2012 and also from Norwegian school of veterinary science through VISK project. The study was conducted based on indicator microbial load which contain Total viable count "Kimtall", Coliform bacteria, Escherichia coli, Clostridium perfringens, and Intestinal Enterococci. In addition, microbial pathogen load of Noro virus, and Adeno virus were also incorporated. The explanatory variables examined for regression analysis were monitored properties of raw water and hyro-climatic data from the catchment which include; river discharge, raw water temperature, rainfall, pH, turbidity, conductivity, colour, and total organic carbon. Each indicator and pathogenic microbial loads have its own unique set of selected explanatory variables. The statistical significance tests were applied to the coefficients of the multiple linear regression models, and they are found to be significant. The regression equations were evaluated using measures of variability, including adjusted R2, which ranges from 38.0 % for Adeno virus concentration to 50.0 % for Ecoli concentration. The results revealed that the regression analysis provide useful mean for rapid monitoring of microbial raw water quality based on the physico-chemical parameters

Kvantitativ mikrobiell risikoanalyse og modellering av vannkvalitet : for drikkevannskilder, badevann og vann til gjenbruk

Despite various efforts to improve water quality in all pathways, waterborne diseases are still a major public health concern in both developing and developed countries. To address the threat of waterborne diseases through different measures, understanding the level of risk is very important. In this regard, quantitative microbial risk assessment (QMRA) is an emerging modelling approach, used to estimate the risk of infection and illness from an exposure to disease causing microorganisms, and is currently promoted by the World Health Organization (WHO) to be used for setting water safety criteria and regulations. While QMRA has been useful in estimating health risk levels, and therefore highlighting risk based management options, there are various challenges to apply this method under different conditions. One of the major challenges is the shortage of quantitative data on the concentration of microbial pathogens and inconsistency in water-related pathways. Therefore, monitoring of microbial pathogens is the preferred form of information for QMRA. Currently, the potential for the integration and use of microbial water quality monitoring and modelling as an input for the QMRA framework is an important issue. This study will enrich the QMRA approach through microbial water quality modelling. The trend, extreme microbial loads, transport, and spreading of microbial pollutants in the identified pathways of interest (drinking water source and recreational coastal water) were investigated using statistically (Paper I), and deterministically (Paper II) based water quality modelling techniques, and then coupled with the QMRA framework (Paper III). There is also a microbial decay rate study in seawater, which could be an input for microbial fate and transport modelling (Paper IV). Furthermore, this study addressed the health risk issues associated with treated greywater reuse (Paper V), and microbial pollutant and nutrient removal efficiency of treated greywater disposal systems (Paper VI). Unsaturated and saturated flow studies provided valuable insights about the removal of microbial pathogens by on-site wastewater treatment systems that could be relevant in some QMRA settings.På tross av bred innsats for å forbedre vannkvaliteten langs alle smitteveier, er vannbåren sykdom fortsatt et folkehelseproblem i både utviklingsland og utviklede land. For å møte trusselen fra vannbårne sykdommer med tilpassede tiltak, er det viktig med en forståelse av risikonivået. I denne sammenhengen er kvantitativ mikrobiell risikoanalyse (QMRA) en modelleringstilnærming som får økt oppmerksomhet, og blir nå anbefalt av Verdens helseorganisasjon (WHO) for å fastsette kriterier og forskrifter for trygt vann. QMRA har vært nyttig for å estimere helserisikonivåer og derigjennom rette fokus mot risikobaserte tiltak, men det er fortsatt diverse utfordringer ved å anvende QMRA under varierte betingelser. En av de største utfordringene er mangelen på kvantitativ informasjon om konsentrasjonene av smittestoffer, og variasjonene i disse gjennom vannets transportveier. Derfor er data fra overvåkning av smittestoffer kjærkommen informasjon for QMRA. Mulighetene for å integrere og bruke data fra overvåkning og modellering av mikrobiell vannkvalitet i QMRA-rammeverket er for tiden en sentral problemstilling. Denne avhandlingen vil styrke QMRA-tilnærmingen gjennom modellering av mikrobiell vannkvalitet. Trender, ekstreme konsentrasjoner, transport og spredning av smittestoffer i en drikkevannskilde og badevann ved kysten ble studert med statistiske (Artikkel I) og deterministiske (Artikkel II) metoder for modellering av vannkvalitet, og deretter knyttet til QMRA-rammeverket (Artikkel III). Det er også en studie av inaktivering av smittestoffer i sjøvann, som kan være inngangsdata for modellering av mikrobiell overlevelse og transport (Artikkel IV). Dessuten har avhandlingen sett på helserisiko knyttet til gjenbruk av behandlet gråvann (Artikkel V), samt fjerning av mikroorganismer og næringsstoffer i systemer for etterbehandling og utslipp av forbehandlet gråvann (Artikkel VI). Studier av umettet og mettet strømning gav verdifull innsikt i fjerningen av smittestoffer i desentraliserte systemer for avløpsbehandling, og kan i noen sammenhenger være relevant for QMRA

On-site treated wastewater disposal systems – The role of stratified filter medias for reducing the risk of pollution

The transmission of pathogens from partially or fully treated wastewater to different water sources are a pervasive risk to public health. To reduce the risk, the integration of source separation, on-site greywater treatment system, and an efficient disposal scheme are the most critical approaches. This study intended to evaluate the removal of nutrient and microbial suspension in the filtration systems used for effluent disposal. The effluent from an on-site greywater treatment plant was loaded into the columns, and the effluent from the columns was monitored for nutrients, total coliform bacteria, Escherichia coli, and Salmonella typhimurium phage 28B (St28B) for one year. Thus, from the range of infiltration systems tested, column-B (15 cm layer of each, Filtralite, fine sand, and till soil) showed the highest removal of total coliforms and E. coli, 3–4 log10 reduction, while the lowest removal observed in column-C (a layer of 25 cm crushed stone and 50 cm till soil), 2–3 log10 reduction. The virus removal efficiency of the columns reduced from 19% to 70% during the simulation of a rainfall event. Moreover, the rise of St28B concentration after rainfall experiment may probably the sign of detachment enhanced by low ionic strength rainwater.publishedVersio

Treated greywater reuse for hydroponic lettuce production in a green wall system: Quantitative health risk assessment

publishedVersio

Quantitative microbial rsk assessment and water quality modelling : on drinking water sources, recreational and recycled waters

Despite various efforts to improve water quality in all pathways, waterborne diseases are still a major public health concern in both developing and developed countries. To address the threat of waterborne diseases through different measures, understanding the level of risk is very important. In this regard, quantitative microbial risk assessment (QMRA) is an emerging modelling approach, used to estimate the risk of infection and illness from an exposure to disease causing microorganisms, and is currently promoted by the World Health Organization (WHO) to be used for setting water safety criteria and regulations. While QMRA has been useful in estimating health risk levels, and therefore highlighting risk based management options, there are various challenges to apply this method under different conditions. One of the major challenges is the shortage of quantitative data on the concentration of microbial pathogens and inconsistency in water-related pathways. Therefore, monitoring of microbial pathogens is the preferred form of information for QMRA. Currently, the potential for the integration and use of microbial water quality monitoring and modelling as an input for the QMRA framework is an important issue. This study will enrich the QMRA approach through microbial water quality modelling. The trend, extreme microbial loads, transport, and spreading of microbial pollutants in the identified pathways of interest (drinking water source and recreational coastal water) were investigated using statistically (Paper I), and deterministically (Paper II) based water quality modelling techniques, and then coupled with the QMRA framework (Paper III). There is also a microbial decay rate study in seawater, which could be an input for microbial fate and transport modelling (Paper IV). Furthermore, this study addressed the health risk issues associated with treated greywater reuse (Paper V), and microbial pollutant and nutrient removal efficiency of treated greywater disposal systems (Paper VI). Unsaturated and saturated flow studies provided valuable insights about the removal of microbial pathogens by on-site wastewater treatment systems that could be relevant in some QMRA settings

On-site treated wastewater disposal systems – The role of stratified filter medias for reducing the risk of pollution

The transmission of pathogens from partially or fully treated wastewater to different water sources are a pervasive risk to public health. To reduce the risk, the integration of source separation, on-site greywater treatment system, and an efficient disposal scheme are the most critical approaches. This study intended to evaluate the removal of nutrient and microbial suspension in the filtration systems used for effluent disposal. The effluent from an on-site greywater treatment plant was loaded into the columns, and the effluent from the columns was monitored for nutrients, total coliform bacteria, Escherichia coli, and Salmonella typhimurium phage 28B (St28B) for one year. Thus, from the range of infiltration systems tested, column-B (15 cm layer of each, Filtralite, fine sand, and till soil) showed the highest removal of total coliforms and E. coli, 3–4 log10 reduction, while the lowest removal observed in column-C (a layer of 25 cm crushed stone and 50 cm till soil), 2–3 log10 reduction. The virus removal efficiency of the columns reduced from 19% to 70% during the simulation of a rainfall event. Moreover, the rise of St28B concentration after rainfall experiment may probably the sign of detachment enhanced by low ionic strength rainwater