Modeling and risk analysis of bromate formation from ozonation of bromide-containing waters

1996 ◽  
Vol 34 (7-8) ◽  
pp. 79-85 ◽  
Author(s):  
Rengao Song ◽  
Roger Minear ◽  
Paul Westerhoff ◽  
Gary Amy
Keyword(s):  
Water Quality ◽  
Risk Analysis ◽  
Ammonia Concentration ◽  
Quality Characteristics ◽  
The Other ◽  
High Ph ◽  
Treatment Processes ◽  
Ozone Dose ◽  
Other Hand

Empirical bromate formation models were developed from batch ozonation data to simulate the effects of important water quality characteristics and treatment processes on bromate formation. Bromate formation was favored at high pH, bromide concentration, alkalinity, and ozone dose. On the other hand, increasing DOC and ammonia concentration decreased bromate formation. Validation of the bromate models demonstrated that the models accurately simulated bromate formation. Risk analysis of bromate formation was performed on 5 utilities in which ozone was used, and it was concluded that under typical ozonation conditions, the associated risk related to bromate formation could be as high as 10−3.

Reproducibility and uncertainty of wastewater turbidity measurements

2008 ◽  
Vol 57 (10) ◽  
pp. 1667-1673 ◽  
Author(s):  
C. Joannis ◽  
G. Ruban ◽  
M.-C. Gromaire ◽  
J.-L. Bertrand-Krajewski ◽  
G. Chebbo
Keyword(s):  
Water Quality ◽  
Calibration Curve ◽  
Field Measurement ◽  
The Other ◽  
Special Focus ◽  
Sewer Systems ◽  
Other Hand ◽  
Main Components ◽  
Standard Solutions

Turbidity monitoring is a valuable tool for operating sewer systems, but it is often considered as a somewhat tricky parameter for assessing water quality, because measured values depend on the model of sensor, and even on the operator. This paper details the main components of the uncertainty in turbidity measurements with a special focus on reproducibility, and provides guidelines for improving the reproducibility of measurements in wastewater relying on proper calibration procedures. Calibration appears to be the main source of uncertainties, and proper procedures must account for uncertainties in standard solutions as well as non linearity of the calibration curve. With such procedures, uncertainty and reproducibility of field measurement can be kept lower than 5% or 25 FAU. On the other hand, reproducibility has no meaning if different measuring principles (attenuation vs. nephelometry) or very different wavelengths are used.

scholarly journals Simulation of optimizing decisions and risk analysis in investment plans

2007 ◽  
pp. 160-164
Author(s):  
Szilvia Katona ◽  
Imre Ertsey
Keyword(s):  
Risk Factors ◽  
Risk Analysis ◽  
The Other ◽  
Simulation Methods ◽  
Prospective Data ◽  
Financing Decisions ◽  
Other Hand ◽  
The Future

Investments always contain risks, as data referring to the future are planned and uncertain. Therefore, besides feasibility analyses we need to perform risk analyses, as well. Through statistic simulation methods, our aim is to examine how uncertain and prospective data as risk factors affect investment-profitability indices. On the other hand, our aim is to find out the optimal innovation – financing decisions by using decision optimizingmethods.

scholarly journals The Effects of pH on the Labellar Sugar Receptor of the Fleshfly

1969 ◽  
Vol 53 (4) ◽  
pp. 450-470 ◽  
Author(s):  
Akio Shiraishi ◽  
Hiromichi Morita
Keyword(s):  
Receptor Site ◽  
Low Ph ◽  
The Other ◽  
High Ph ◽  
Sugar Receptor ◽  
Other Hand ◽  
Wide Range ◽  
Effects Of Ph ◽  
Ionizable Groups ◽  
Inhibition Curve

Reproducible results describing the effects of pH on the response of the labellar sugar receptor of the fleshfly, Boettcherisca peregrina, were obtained. The response to sucrose was independent over a wide range of pH (3.0 to 10.0 for sucrose stimulation), but was inhibited fairly sharply on both sides of this range. Similar results were obtained for monosaccharide stimulation. The receptor was excited on stimulation by water above pH 12.0. The effects of high pH, both inhibitory and excitatory, were affected by the presence of salts. In the presence of 0.5 molar NaCl, for example, the pH-inhibition curve was shifted toward lower pH's by about one pH unit. The effects of low pH, on the other hand, were not affected by salts. Following Dixon's theory, it was concluded that at least five ionizable groups (loosing positive charges above pH 10.5) were located at the receptor site.

scholarly journals Influence of Water Quality Index (WQI) on Biotic Indices of Benthic Macroinvertebrate at Highland Rivers in Kelantan and Pahang

2015 ◽  
Vol 72 (5) ◽  
Author(s):  
Aweng, E. R. ◽  
Sharifah Aisyah, S. O. ◽  
Ahmad Abas, K. ◽  
Ahmad Fadli, A. S. ◽  
Azrinaaini, M. Y. ◽  
...  
Keyword(s):  
Water Quality ◽  
Benthic Macroinvertebrates ◽  
Water Quality Index ◽  
Quality Index ◽  
The Other ◽  
Biotic Index ◽  
Class Iii ◽  
Polluted River ◽  
Ecological Index ◽  
Other Hand

A physicochemical survey of water quality and benthic macroinvertebrates at two rivers namely Sungai Dekong and Dawai in Lojing Highland was conducted on 23 and 24, January 2014. Three stations were selected for physicochemical water quality, one station at Sungai Dekong and two other stations at Sungai Dawai. On the other hand, benthic macroinvertebrates were collected at nine stations, i.e. three stations at Sungai Dekong and the other six stations at Sungai Dawai. Result shows that, Station 1 (Sungai Dekong) recorded Very Poor Biological Monitoring Working Party, BMWP (2.0–12.0), Poor Average Species per Taxon, ASPT (2.0–4.0), Poor Citizen Monitoring Biotic Index, CMBI (2.0–2.3), Fairly Poor Family Biotic Index, FBI (5.3–6.0) and Poor Ephemeroptera, Plecoptera and Trichoptera or EPT Index (0.0). However, the Water Quality Index WQI (70.01) falls into Class III which can be categorized as Slightly Polluted River. On the other hand, Station 2 (Sungai Dawai downstream) recorded better Biotic and Ecological Index but lower Water Quality Index as compared to Station 1. It recorded Moderate BMWP (26.0–84.0), Very Good ASPT (5.3–6.5), Good CMBI (2.7–3.2), Excellent FBI (3.4–4.3) and Moderate EPT Index (2.0–5.0). However, the WQI (54.99) falls into Class III, and can be categorized as Polluted River. Finally, Station 3 (the most upstream station at Sungai Dawai) recorded almost similar Biotic and Ecological Index with Station 2 but in terms of WQI revealed a significant difference. Station 3 recorded Poor BMWP (34.0–46.0), Very Good ASPT (6.5–6.8), Good CMBI (2.9–3.1), Excellent FBI (3.1–3.9) and Moderate EPT Index (3.0–4.0). However, it’s WQI (84.48) falls into Class II which could be categorized as Cleaned River. As a conclusion, physicochemical river water quality was not the only contributing factor to the Biotic Index at the highland rivers as per other factors such as river substrates, river discharge, aquatic plants, river riparian and river canopy. 

scholarly journals BUSINESS RISK ANALYSIS IN ARI WIBOWO'S CENTRAL TILE INDUSTRY IN LOHJINAWI VILLAGE, PRINGSEWU REGENCY IN 2018 - 2020

Riset ◽  
2021 ◽  
Vol 3 (2) ◽  
pp. 550-562
Author(s):  
Wagiyu Wagiyu ◽  
Heri Setiawan
Keyword(s):  
Standard Deviation ◽  
Risk Analysis ◽  
The Other ◽  
Business Risk ◽  
Financial Leverage ◽  
Industrial Environment ◽  
Operating Profit ◽  
Other Hand ◽  
Operating Leverage

Business risk is the potential deviation of corporate results  and financial results because the company enters a certain business with a typical industrial environment and uses certain technologies. In business there are so many decisions or actions that must be made, it makes more and more risks that may occur as a result. The purpose of this research is to find out how big the Business Risk Central Tile Industry in Lohjinawi Village, Pringsewu Regency,The analysis was carried out descriptively, using standard deviation of ROE; Financial Leverage; Operating Leverage namely the sensitivity of EBIT to changes in the company's sales; as well as Degree of Operation Leverage (DOL). The results of the analysis show that: 1) ROE, has increased due to an increase in Sales and an increase in EAT, and vice versa; 2)The use of debt can increase the Company's ROE; 3) Operating Leverage, where EBIT is very sensitive to changes in company sales; 4)Degree of Operating Leverage (DOL) measures what percentage of EBIT changes if sales; 2018-2019 of 1.50x  which means DOL of 150% that every 100% increase or 1x sales will cause an increase in operating profit of 1.50x otherwise, if sales decrease 1x then operating profit will decrease by 1.50x. While the year 2019-2020 amounted to 2.01x which means a DOL of 201% indicates that every 100% or 1x decrease in sales will cause a 2.01x decrease in operating profit. On the other hand, if sales decrease 1x, operating profit will decrease by 2.01x.

The Importance of Knowledge-Based Risk Processes to Risk Analysis

2021 ◽  
Vol 17 (1) ◽  
pp. 33-51
Author(s):  
Amine Nehari-Talet ◽  
Louay Karadsheh ◽  
Samer Alhawari ◽  
Hana Hunaiti
Keyword(s):  
Information Technology ◽  
Risk Analysis ◽  
The Other ◽  
Research Model ◽  
It Projects ◽  
Knowledge Based ◽  
Other Hand ◽  
It Project ◽  
Risk Processes

Knowledge-based risk processes are suitable key elements within organizations since they can minimize the possibility and impact of an information technology (IT) project. The aim of this paper is to explain how the alignment between knowledge-based risk processes to validate risk analysis. A questionnaire was developed and distributed to a sample of 135 respondents who were actively engaged in IT. The proposed research model explained that 50 to 62% from of the variance in knowledge-based risk processes to risk analysis. The results showed that the two selected factors (identification and sharing) have a partially mediate and significant impact on risk analysis by knowledge-based risk repository. On the other hand, the examination is not mediated and not a significant impact on risk analysis. The findings of this study imply the understanding of knowledge-based risk processes to risk analysis This study will contribute to the field by examining the effects knowledge-based risk on risk analysis for IT projects.

scholarly journals The effects of the flood of October 2008 on the water quality in the M’zab valley, Algeria

2019 ◽  
Vol 40 (1) ◽  
pp. 173-180
Author(s):  
Kheira Bouamer ◽  
Boualem Remini ◽  
Mohamed Habi ◽  
Khaled Rezzag
Keyword(s):  
Water Quality ◽  
Calcium Chloride ◽  
Magnesium Sulphate ◽  
Water Samples ◽  
Alluvial Aquifer ◽  
The Other ◽  
Spectroscopic Methods ◽  
Other Hand ◽  
Volumetric Methods

Abstract With a flow estimated at 1200 m3∙s−1 and a height of 8 m downstream, the flood that occurred on October 10, 2008 spread along the M’zab River over a length of more than 180 km. Material and human damage is visible, but its effects on the quality of the waters of the alluvial layer remain unknown: this is the purpose of this paper. Samples of groundwater were taken during the period 2005–2012 in 4 oases of the valley. Physicochemical analyses were performed using molecular and flame spectroscopic methods and also volumetric methods on water samples. The results obtained were interpreted using histograms and hydrochemical diagrams, such as the Avignon software (L.H.A) (version 4, 2008). Low effect of flood on the water quality of the alluvial aquifer was manifested by concentrations of magnesium sulphate and calcium chloride. On the other hand, there is an accumulation of salts infiltrated by sewage except for the zone of Bouchen. The diagrams show that there is an improvement in water quality in this area.

The effects of the co-existing compounds on the decomposition of micropollutants using the ozone/hydrogen peroxide process

2000 ◽  
Vol 42 (7-8) ◽  
pp. 353-361 ◽  
Author(s):  
K. Kosaka ◽  
H. Yamada ◽  
S. Matsui ◽  
K. Shishida
Keyword(s):  
Hydrogen Peroxide ◽  
Humic Acid ◽  
The Other ◽  
Treatment Efficiency ◽  
Radical Chain ◽  
Chain Reactions ◽  
Ozone Dose ◽  
Other Hand ◽  
Lower Effect ◽  
17Β Estradiol

The effect of co-existing compounds on the decompositions of three target compounds (i.e., 1,2,4-trichlorobenzene (TCB), 1,4-dioxane, and 17β-estradiol) using the ozone/hydrogen peroxide (O3/H2O2) process was investigated. Their reactivities toward HO• are assumed to be of the order of 109 /M · s. The decomposition rate of TCB was much higher during the O3/H2O2 process than during ozonation in the presence of bicarbonate ion, an inhibitor of radical chain reactions. 17β-Estradiol, a highly reactive target compound toward ozone, was decomposed at lower ozone dose than TCB and 1,4-dioxane, lowly reactive target compounds toward ozone, in the presence of humic acid. The reactivities of the co-existing compounds toward HO• were significantly related to the treatment efficiency of TCB when their concentrations as TOC were similar. The effect of humic acid, fulvic acid, and glucose, target compounds highly reactive toward HO•, on the decomposition of TCB was similar regardless of co-existing compounds. On the other hand, significantly lower effect of acetate and oxalate ions, target compounds lowly reactive toward HO•, on the decomposition of TCB was observed. Ozone dose required for the decomposition of TCB was inversely proportional to TCB concentration when HO• generated was greatly scavengedby co-existing compounds. On the other hand, ozone dose required for the decomposition of TCB was less affected by TCB concentration when HO• generated was used effectively for the decomposition of TCB.

scholarly journals Efficiency of Water Quality Index Approach as an Evaluation Tool

2013 ◽  
Vol 20 (2) ◽  
pp. 247-255 ◽  
Author(s):  
Hülya Boyacioğlu ◽  
Vildan Gündoğdu
Keyword(s):  
Water Quality ◽  
Water Quality Index ◽  
Quality Index ◽  
Poor Quality ◽  
High Flow ◽  
The Other ◽  
Low Flow ◽  
Complex Data ◽  
Other Hand ◽  
Index Approach

Abstract This study aimed to demonstrate efficiency of documented index method “universal water quality index-UWQI” to evaluate surface water quality and investigate seasonal and temporal changes, in the case of Gediz River Basin Turkey. UWQI expressed results relative to levels according to criteria specified in European legislation (75-440 EEC). The method produced a unitless number ranging from 1 to 100 and a higher number was indicator of better water quality. Water quality is classified into five classes and index scores between 95-100 represent excellent and lower than 24 represent poor quality. In the study, dissolved oxygen-DO, pH, mercury-Hg, cadmium-Cd, total phosphorus-TP, biochemical oxygen demand- BOD and nitrate nitrogen-NO3-N have been chosen as index determinants. Samples analyzed for these variables were collected from five stations on monthly basis along two years. Based on UWQI classification scheme, water quality at sampling stations had scores below 40 and assigned to “marginal” which is between fair and poor quality class. On the other hand sub-indices of water quality determinants showed seasonal differences for some parameters. Cd concentrations were higher in “high flow” and lower values were observed in “low flow” periods. This was explained by negative impact of urban runoff on water quality. On the other hand DO concentrations were higher in “high flow” period. Under “low flow” conditions water quality at upstream stations (where the industrial density is low) was comparably better than downstream part. The study showed that index approach can be efficient tool to: a) evaluate water quality, b) investigate spatial and seasonal variations and finally, c) extract required information from complex data sets that is understandable by non-technical people.

scholarly journals Reliability and Problems of Wastewater Treatment Processes in the Algerian Sahara

2021 ◽  
Author(s):  
Rachid Zegait ◽  
Saber Kouadri ◽  
Samir Kateb ◽  
Mohamed Azlaoui
Keyword(s):  
Wastewater Treatment ◽  
High Temperature ◽  
Water Resources ◽  
The Other ◽  
Treatment Processes ◽  
Other Hand ◽  
Algerian Sahara ◽  
Urbanized Areas ◽  
Treated Effluents ◽  
The Impact

This modest chapter deals more particularly with the reliability and the problems of the different processes used at the level of several treatment plants installed in the Algerian Sahara with the aim of eliminating the nuisances and the risks of contamination in the urbanized areas, protecting the receiving environment and water resources, the possibility of reusing treated effluents for irrigation. Through an evaluation of the performance of these stations after years of operation which confronted with climates such as the high temperature and evaporation and the impact of the sand winds on the efficiency of the basin, technical and anthropic problems such as the salinity and mismanagement of the waters on the other hand.

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