Global Nest Journal最新文献

{"title":"Using an informational entropy-based metric as a diagnostic of flow duration to drive model parameter identification","authors":"I. Pechlivanidis, B. Jackson, H. McMillan, H. Gupta","doi":"10.30955/gnj.000879","DOIUrl":"https://doi.org/10.30955/gnj.000879","url":null,"abstract":"Calibration of rainfall-runoff models is made complicated by uncertainties in data, and by the arbitrary emphasis placed on various magnitudes of the model residuals by most traditional measures of fit. Current research highlights the importance of driving model identification by assimilating information from the data. In this paper, we evaluate the potential use of an entropybased measure as an objective function or as a model diagnostic in hydrological modelling, with particular interest in providing an appropriate quantitative measure of fit to the flow duration curve (FDC). The proposed Conditioned Entropy Difference (CED) metric is capable of characterising the information in the flow frequency distribution and thereby constrain the model calibration to respect this distributional information. Four years of hourly data from the 46.6 km 2 Mahurangi catchment, NZ, are used to calibrate the 6-parameter Probability Distributed Moisture model. Results are analysed using three measures: the proposed entropy-based measure, the Nash-Sutcliffe (NSE), and the recently proposed Kling-Gupta efficiency (KGE). We also examine a conditioned entropy metric that trades-off and reweights different segments of the FDC to drive model calibration in a way that is based on modelling objectives. Overall, the entropy-based measure results in good performance in terms of NSE but poor performance in terms of KGE. This entropy measure is strongly sensitive to the shape of the flow distribution and is, from some viewpoints, the single best descriptor of the FDC. By conditioning entropy to respect multiple segments of the FDC, we can reweight entropy to respect those parts of the flow distribution of most interest to the modelling application. This approach constrains the behavioural parameter space so as to better identify parameters that represent both the “fast” and “slow” runoff processes. Use of this importance-weighted, conditioned entropy metric can constrain high flow predictions equally well as the NSE and KGE, while simultaneously providing wellconstrained low flow predictions that the NSE or KGE are unable to achieve.","PeriodicalId":55087,"journal":{"name":"Global Nest Journal","volume":"14 1","pages":"325-334"},"PeriodicalIF":1.1,"publicationDate":"2012-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69258704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"QUALITY ASSESSMENT OF GROUNDWATER OF ALMADINAH ALMUNAWARAH CITY","authors":"Khalid Obiad Atitallah Al-Muzaini","doi":"10.30955/gnj.000947","DOIUrl":"https://doi.org/10.30955/gnj.000947","url":null,"abstract":"Renewable water resources in Saudi Arabia are limited with groundwater as the major source for water supply. This study was conducted to assess the quality of groundwater in Almadinah Almunawarah, Saudi Arabia. Water samples were collected from 60 wells in 2010. Physical and chemical parameters were examined. The results of colour, turbidity, odour, pH, and nitrite in all samples were below the local drinking water guideline values. The fluoride concentrations in 8% of the samples were higher than the guideline value. The taste in 87% of the samples was unacceptable. Intolerable levels of both total hardness and TDS were found in most of the samples (~ 83%). Nitrate levels were above the guideline value in 65% of sample. Most of the samples (80- 87%) have failed the guidelines for sodium, chloride, and sulfate. On the other hand, none of the samples was found to contain Cr, Ni, Cu, Zn, Cd, Ba, and Pb exceeding the guideline values. However, 5% of the samples have As concentrations over the limit (results 12.0-29.0 μg L-1). Similarly, 5% of the samples have Fe concentrations (320-589 μg L-1) in excess of the guideline value. The level of Mn in only one sample (183 μg L-1) was greater than the guideline value and 10% of the samples have Mg (range 159000-210000 μg L-1) above the limit. Although the water of the investigated wells does not satisfy many of the general drinking water guidelines due to the local environment and climate, most of the samples are in compliance with the guideline values for metals in drinking and irrigation water.","PeriodicalId":55087,"journal":{"name":"Global Nest Journal","volume":"15 1","pages":"374-383"},"PeriodicalIF":1.1,"publicationDate":"2012-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69259332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Perceived benefits of selected wetlands in South-West Nigeria.","authors":"T. Olarewaju, A. Shittu, O. Olubanjo, A. Dipeolu, C. Sodiya","doi":"10.30955/gnj.001005","DOIUrl":"https://doi.org/10.30955/gnj.001005","url":null,"abstract":"Poor appreciation of wetlands has been linked to a massive destruction of wetlands in Nigeria thereby constituting a missed opportunity that would have led to improved income generation, food security and environment sustainability.  This study assessed people’s perception of selected wetlands benefits in South West, Nigeria. The study was based on primary data obtained in a cross-section survey of 197 individuals that were either resident and/or pursuing livelihood activities in communities around Eleyele, Eriti and Lagos lagoon wetlands  of  Oyo, Ogun and Lagos States, respectively. The study found that majority of respondents  recognised the direct benefits of the Wetlands especially in terms of its role in provision of food, herbs and building materials while only a few recognised its environmental services as it relates to provision of windbreaks, nutrient recycling and microclimate stabilization. The level of appreciation of all Wetland benefits among the respondent was a low Perceived Benefit Index (PBI) value of 0.45 on a scale of one. Tobit regression analysis revealed that age, Wetland share of income, activity type as well as the location of Wetland  are factors that significantly influence people’s perception of Wetlands benefits. It can therefore be concluded that people around Wetlands have a poor appreciation of Wetland benefits especially the environmental services they provide. The study recommends that governments and NGOs should put in place appropriate community based education/awareness campaign to promote better appreciation of Wetlands benefits.","PeriodicalId":55087,"journal":{"name":"Global Nest Journal","volume":"16 1","pages":"169-178"},"PeriodicalIF":1.1,"publicationDate":"2012-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69259409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"NATURAL ORGANIC MATTER FRACTIONATION ALONG THE TREATMENT OF WATER FOR HUMAN CONSUMPTION","authors":"R. F. Vieira, A. Berenguel, M. A. S. Silva, J. Vilaça, V. Domingues, S. Figueiredo","doi":"10.30955/gnj.000828","DOIUrl":"https://doi.org/10.30955/gnj.000828","url":null,"abstract":"The main objective of this study was to characterize the organic matter present in raw water and along the treatment process, as well as itsseasonal variation.A natural organic matter fractionation approach has been applied to Lever water treatment plant located in Douro River, in Oporto (Portugal). The process used was based on the sorption of dissolved organic matter in different types of ion exchange resins, DAX-8, DAX-4 and IRA-958, allowing its separation into four fractions: very hydrophobic acids (VHA), slightly hydrophobic acids (SHA), charged hydrophilic (CHA) and hydrophilic neutral (NEU). The dissolved organic carbon (DOC) determi nation was used to quantify dissolved organic matter. Samples werecollected monthly, during approximately one year, from raw water captured at the surface and under the bed of the river, and after each step of the treatment: pre-filtration in sand/anthrac ite filters, ozonation, coagulation/flocculation, counter current dissolved air flotation and filtration (CoCoDAFF) and chlorination. The NEU fraction showed a seasonal variation, with maximum values in autumn for the sampling points corresponding toraw water captured at the surface and under the bed of the river . It was usually the predominating fraction and did not show a significant decreasethroughout the treatment. Nevertheless their low concentration, the same occurred for the CHA and VHA fractions.There was an overalldecrease in the SHA fraction throughout the water treatment (especiallyafterCoCoDAFF and ozonation)as well as in theDOC . The TSUVA 254 values obtainedfor raw watergenerally variedbetween 2.0 and 4.0LmgC -1 m -1 and between 0.75and 1.78 LmgC -1 m -1 for treated water. It wa s observed a decrease of TSUVA values along the treatment,especially after ozonation. These results may contribute to a further optimization in the process of treating water for human consumption.","PeriodicalId":55087,"journal":{"name":"Global Nest Journal","volume":"11 1","pages":"399-406"},"PeriodicalIF":1.1,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69259017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Anaerobic treatment of glycerol for methane and hydrogen production.","authors":"T. Vlassis, G. Antonopoulou, K. Stamatelatou, G. Lyberatos, G. S. Miguel, S. Rincón, D. Vagiona","doi":"10.30955/gnj.000864","DOIUrl":"https://doi.org/10.30955/gnj.000864","url":null,"abstract":"This work focused on glycerol exploitation for biogas and hydrogen production. Anaerobic digestion of pure glycerol was studied in a continuous stirred tank reactor (CSTR), operated under mesophilic conditions (35 o C) at various organic loading rates. The overall operation of the reactor showed that it could not withstand organic loading rates above 0.25 g COD L -1 d -1 , where the maximum biogas (0.42 ± 0.05 L (g COD) -1 ) and methane (0.30 ± 0.04 L (g COD) -1 ) production were achieved. Fermentative hydrogen production was carried out in batch reactors under mesophilic conditions (35 o C), using heat-pretreated anaerobic microbial culture as inoculum. The effects of initial concentration of glycerol and initial pH value on hydrogen production were studied. The highest yield obtained was 22.14 ± 0.46 mL H2 (g COD added) -1 for an initial pH of 6.5 and an initial glycerol concentration of 8.3 g COD L -1 . The main metabolic product was 1.3 propanediol (PDO), while butyric and acetic acids as well as ethanol, at lower concentrations, were also determined.","PeriodicalId":55087,"journal":{"name":"Global Nest Journal","volume":"14 1","pages":"149-156"},"PeriodicalIF":1.1,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69258669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Increase of biogas production through co-digestion of lipids and sewage sludge.","authors":"C. Noutsopoulos, D. Mamais, K. Antoniou, C. Avramides","doi":"10.30955/gnj.000862","DOIUrl":"https://doi.org/10.30955/gnj.000862","url":null,"abstract":"The aim of this study was to assess the feasibility of co-digesting lipids originated from domestic wastewater along with sewage sludge. Three lab-scale single stage mesophilic anaerobic digesters were operated under a constant hydraulic retention time (15 days). One system (C) was fed on a daily basis with sewage sludge and served as the control system and its operation was compared with two experimental systems (E1 and E2). Both experimental systems received mixtures of sludge and lipids with different lipids content (20 % for system E1 and 60 % for system E2 on a VS basis), whereas organic loadings were 2 KgVS m -3 d -1 and 3,5 KgVS m -3 d -1 for systems E1 and E2, respectively. According to the results it can be stated that the addition of lipids to sewage sludge up to 60 % on a VS basis resulted in a significant increase of biogas production without producing any severe effects on the properties of the digested sludge. More specifically biogas production of reactor E1 was 18 % greater than that of reactor C, whereas biogas produced in reactor E2 was even greater (50 % higher than that of reactor C). Finally it is interesting that during start-up a lag phase was recorded at reactor E2 before biogas production initiated, which should be attributed to the time required for growth of acetogenic bacteria capable to degrade LCFA.","PeriodicalId":55087,"journal":{"name":"Global Nest Journal","volume":"14 1","pages":"133-140"},"PeriodicalIF":1.1,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69258653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bioethanol production from thermochemically pre-treated olive mill solid residues using the yeast Pachysolentannophylus.","authors":"S. Senkevich, I. Ntaikou, G. Lyberatos, G. S. Miguel, S. Rincón, D. Vagiona","doi":"10.30955/gnj.000861","DOIUrl":"https://doi.org/10.30955/gnj.000861","url":null,"abstract":"Olive oil mill solid residue (OMSR) is the solid waste generated during olive oil production process in three-phase olive mills. It consists of the remaining pulp of olive processing after the extraction of oil, as well as the cracked seeds of the olive fruits, containing thus mainly lignocellulose and residual oil. The commonly used practice for OMSR management is combustion, after having extracted the residual oil by secondary extraction using organic solvents. Other proposed ways of OMSR management are their exploitation as substrate for edible fungi production and compost, and as feedstock for biofuels generation such as methane and bioethanol. In the latter case, the complex carbohydrates (cellulose and hemicellulose) of the lignocellulose of OMSR have to be degraded towards their simple sugars and further fermented via microorganisms. The purpose of the present study was to investigate the effect of thermochemical pre-treatment of OMSR, on the final ethanol yield from the yeast Pachysolen tannophilus. Nine different types of OMSR-based substrates were tested i.e. raw OMSR, hydrolysates generated from pretreated OMSR with NaOH (0.5 %, 1.5 % w/v) and H2SO4 (0.5 %, 1.5 % v/v), and pretreated OMSR with NaOH (0.5 %, 1.5 % w/v) and H2SO4 (0.5 %, 1.5 % v/v) whole biomass. It was shown that in all cases pretreatment enhanced the consumption of carbohydrates as well as ethanol final yields.","PeriodicalId":55087,"journal":{"name":"Global Nest Journal","volume":"14 1","pages":"118-124"},"PeriodicalIF":1.1,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69259135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Combustion characterization of producer gas from biomass gasification.","authors":"J. J. Hernández, J. Barba, G. Aranda, G. S. Miguel, S. Rincón, D. Vagiona","doi":"10.30955/gnj.000859","DOIUrl":"https://doi.org/10.30955/gnj.000859","url":null,"abstract":"In the present work, premixed flames from the combustion of producer gas have been analyzed. Two different compositions have been tested, corresponding to air and steam gasification processes (the latter leading to a better quality gas due to its higher CO and H2 concentration and its lower N2 content). The main objectives of the work have been the determination of the flame stability region (placed between the flashback and the blowoff limits) for each producer gas composition, as well as the study of the OH and CH radicals. The combustion experimental tests have been carried out by using an atmospheric burner and a chemiluminescence camera. The results obtained show that producer gas coming from biomass entrained-flow steam gasification seems to be more adequate to be used in combustion systems, since it provides a larger flame stability region, and its blowoff limit for a given relative producer gas/air ratio is higher (which enable to obtained more power). From the study of CH and OH radicals, it can be deduced that it is possible to reduce the nitrogen oxides emissions up to 18.6 and 15.2 % with producer gas from steam gasification and air gasification respectively by using lean mixtures (while keeping the flame stability).","PeriodicalId":55087,"journal":{"name":"Global Nest Journal","volume":"14 1","pages":"125-132"},"PeriodicalIF":1.1,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69259122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative behaviour of agricultural biomass residues during thermochemical processing.","authors":"S. Rincón, A. Gómez","doi":"10.30955/gnj.000866","DOIUrl":"https://doi.org/10.30955/gnj.000866","url":null,"abstract":"A study of the pyrolysis and gasification of biomass residues such as oil palm shells and fibers, coffee shells, sugarcane bagasse and beech wood is presented. All of them are abundant agroindustrial biomass residues in Latin American countries. The characterization of the raw materials and products includes proximate analysis (water, ash and volatile matter contents) and ultimate analysis. Pyrolysis and gasification experiments are carried out in a thermobalance and in a pilot scale rotary kiln reactor. Both facilities are equipped with evolved gas analysis. Pyrolysis experiments were carried out using nitrogen as carrier gas by heating up to a temperature of 950 °C. Gasification is performed using water vapour as reaction agent in a concentration of 70 % H2O in nitrogen. The gasification temperature is set to 850 °C. All wastes show similar behavior during pyrolysis in the thermobalance with the main mass loss at temperatures below 550 °C. The solid fraction varied from 18 % for sugarcane bagasse to 27 % for oil palm shells and the gas fraction from 18 % for oil palm shells to 22 % for sugarcane bagasse. The main evolved gases are CO2 (9 – 12%), CO (3.5 – 7.5 %) and CH4 (1.6 – 3 %). H2 was also found but in a very small fraction (0.5 – 0.7 %) (all fractions are referred to the initial dry mass). The heating value of the pyrolysis products from the experiments in the thermobalance of the different wastes presented small variations with a mean value of 6.5 MJ kg -1 for the evolved gas, 20 MJ kg -1 for the tar and 19 MJ kg -1 for the solid residual. The presence of secondary reactions in the rotary kiln affects considerably the amount of gas and tar in the products. The higher heating value of the evolved gases varies between 17 and19 MJ kg -1 . The obtained results allow a possible further technological use of these materials as a cheap renewable energy source in countries where these materials can be found.","PeriodicalId":55087,"journal":{"name":"Global Nest Journal","volume":"14 1","pages":"111-117"},"PeriodicalIF":1.1,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69258692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"THE APPLICATION OF FERRATE FOR SEWAGE TREATMENT: PILOT- TO FULL-SCALE TRIALS","authors":"Jia-Qian Jiang, C. Stanford, A. Mollazeinal","doi":"10.30955/gnj.000821","DOIUrl":"https://doi.org/10.30955/gnj.000821","url":null,"abstract":"This paper aims to study a relative new technology, the online generation and application of ferrate(VI), for sewage treatment, from pilot to full scale trials at Hailsham North Wastewater Treatment Plant of Southern Water Ltd of UK. The work presented in this paper has significant impact on the use of ferrate(VI) in water and waste water treatment practice; the online production and application of ferrate(VI) resolves problems of the instability and needs no transportation. The current efficiency of ferrate(VI) generation was up to 70% through the developed system, which is relatively high. For achieving the same phosphorus removal target from the crude sewage, the ferrate dose required was in a very lower range, 0.01 - 0.2 mg Fe 6+ /L in comparison with high doses of ferric sulphate; these will reduce the chemical demand and sludge production and therefore result in a low operating cost and generate substantial cost saving in treating sewage.","PeriodicalId":55087,"journal":{"name":"Global Nest Journal","volume":"14 1","pages":"93-99"},"PeriodicalIF":1.1,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69258933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}