Heterogeneous ultrasonic destruction of aqueous organic contaminants

2003 ◽  
Vol 47 (9) ◽  
pp. 137-142 ◽  
Author(s):  
R.P.S. Suri ◽  
A. Kamrajapuram
Keyword(s):  
Reaction Time ◽  
Organic Pollutants ◽  
Organic Contaminants ◽  
Advanced Technology ◽  
Solution Ph ◽  
Cost Of Treatment ◽  
Destruction Rate ◽  
Contaminant Destruction ◽  
The Cost

Sonolysis is emerging as an effective advanced technology for destruction of organic pollutants in wastewater. The focus of this study is to investigate the potential of enhancing the sonochemical destruction of aqueous organics. Increasing the contaminant destruction rate will reduce the reaction time, and possibly reduce the cost of treatment. For this purpose, the effect of H2O2 and/or silica in the presence of ultrasound is examined for destruction of 2-chlorophenol (2-CP). The effect of silica dosage (1, 5, 10, and 20 g/L), peroxide dosage (50, 75, and 100 mg/L), and pH (3,7,and 11) is examined. Low solution pH provided higher destruction of 2-CP. The presence of peroxide or silica enhanced the destruction of 2-CP. The optimum silica dosage was 5 g/L. 100 mg/L of peroxide and 5 g/L of silica present together enhanced 2-CP sonolytic destruction by a factor of approximately 2 as compared to 2-CP destruction with ultrasound only.

Microbiological Detoxification of Hazardous Organic Contaminants: The Crucial Role of Substrate Interactions

1992 ◽  
Vol 25 (11) ◽  
pp. 403-410 ◽  
Author(s):  
B. E. Rittmann
Keyword(s):  
Organic Pollutants ◽  
Information Flow ◽  
Organic Contaminants ◽  
Crucial Role ◽  
Substrate Utilization ◽  
Energy Flows ◽  
Hazardous Pollutants ◽  
Primary Substrate ◽  
Substrate Types

Microbiological detoxification of hazardous organic pollutants is highly promising, but its reliable implementation requires a sophisticated understanding of several different substrate types and how they interact. This paper carefully defines the substrate types and explains how their interactions affect the bacteria's electron and energy flows, information flow, and degradative activity. For example, primary substrates, which are essential for growth and maintenance of the bacteria, also interact with degradation of specific hazardous pollutants by being inducers, inhibitors, and direct or indirect cosubstrates. The target contaminants, which often are secondary substrates, also have the interactive roles of self-inhibitor, inhibitor of primary-substrate utilization, inducer, and a part of an aggregate primary substrate.

scholarly journals Cost of Management of Diabetes Mellitus: A Pan India Study

2021 ◽  
pp. 097275312199849
Author(s):  
Raghuram Nagarathna ◽  
M Madhava ◽  
Suchitra S Patil ◽  
Amit Singh ◽  
K. Perumal ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Urban Areas ◽  
Noncommunicable Disease ◽  
Cost Of Treatment ◽  
Rural And Urban Areas ◽  
Cost Of Disease ◽  
Rural And Urban ◽  
Significant Difference ◽  
The Cost ◽  
Prevalence Of Diabetes Mellitus

Background: Diabetes mellitus is a major noncommunicable disease. While mortality rates are increasing, the costs of managing the disease are also increasing. The all-India average monthly expenditure per person (pppm) is reported to be ₹ 1,098.25, which translates to an annual expenditure of ₹13,179 per person. Purpose: While a number of studies have gone into the aspect of the cost of disease management, we do not find any study which has pan-India reach. We also do not find studies that focus on differences (if any) between rural and urban areas, age or on the basis of gender. We planned to report the cost of illness (COI) in diabetes individuals as compared to others from the data of a pan-India trial. Methods: Government of India commissioned the Indian Yoga Association to study the prevalence of diabetes mellitus in India in 2017. As part of the questionnaire, the cost of treatment was also captured. Data collected from 25 states and union territories were analyzed using the analysis of covriance (ANCOVA) test on SPSS version 21. Results: There was a significant difference ( P < .05) between the average expenses per person per month (pppm) of individuals with self-reported known diabetes (₹1,357.65 pppm) and others (unknown and/or nondiabetes individuals–₹ 999.91 pppm). Similarly, there was a significant difference between rural (₹2,893 pppm) and urban (₹4,162 pppm) participants and between those below (₹1,996 pppm) and above 40 years (₹5,059 pppm) of age. Conclusion: This preliminary report has shown that the COI because of diabetes is significantly higher than others pointing to an urgent need to promote disease-preventive measures.

scholarly journals Mechanisms and adsorption capacities of biochar for the removal of organic and inorganic pollutants from industrial wastewater

2020 ◽  
Author(s):  
T. G. Ambaye ◽  
M. Vaccari ◽  
E. D. van Hullebusch ◽  
A. Amrane ◽  
S. Rtimi
Keyword(s):  
Organic Contaminants ◽  
Pyrolysis Temperature ◽  
Low Cost ◽  
Industrial Effluents ◽  
Economic Benefits ◽  
Inorganic Pollutants ◽  
Solution Ph ◽  
Adsorption Mechanisms ◽  
Adsorption Capacities ◽  
Temperature Solution

AbstractCurrently, due to the rapid growth of urbanization and industrialization in developing countries, a large volume of wastewater is produced from industries that contain chemicals generating high environmental risks affecting human health and the economy if not treated properly. Consequently, the development of a sustainable low-cost wastewater treatment approach has attracted more attention of policymakers and scientists. The present review highlights the recent applications of biochar in removing organic and inorganic pollutants present in industrial effluents. The recent modes of preparation, physicochemical properties and adsorption mechanisms of biochar in removing organic and inorganic industrial pollutants are also reviewed comprehensively. Biochar showed high adsorption of industrial dyes up to 80%. It also discusses the recent application and mechanism of biochar-supported photocatalytic materials for the degradation of organic contaminants in wastewater. We reviewed also the possible optimizations (such as the pyrolysis temperature, solution pH) allowing the increase of the adsorption capabilities of biochar leading to organic contaminants removal. Besides, increasing the pyrolysis temperature of the biochar was seen to lead to an increase in its surface area, while it decreases their amount of oxygen-containing functional groups, consequently leading to a decrease in the adsorption of metal (loid) ions present in the medium. Finally, the review suggests that more research should be carried out to optimize the main parameters involved in biochar production and its regeneration methods. Future efforts should be also carried out towards process engineering to improve its adsorption capacity to increase the economic benefits of its implementation.

scholarly journals Why Do Some Firms Spend So Much on Medical Care? Accounting for Variation

2000 ◽  
Vol 3 (1) ◽  
Author(s):  
Matthew Eichner ◽  
Mark McClellan ◽  
David A. Wise
Keyword(s):  
Health Care ◽  
Health Care Cost ◽  
Health Care Expenditures ◽  
Cost Of Treatment ◽  
Consistent Method ◽  
The Difference ◽  
The Cost ◽  
Cost Differences ◽  
Average Expenditure

We are engaged in a long-term project to analyze the determinants of health care cost differences across firms. An important first step is to summarize the nature of expenditure differences across plans. The goal of this article is to develop methods for identifying and quantifying those factors that account for the wide differences in health care expenditures observed across plans.We consider eight plans that vary in average expenditure for individuals filing claims, from a low of $1,645 to a high of $2,484. We present a statistically consistent method for decomposing the cost differences across plans into component parts based on demographic characteristics of plan participants, the mix of diagnoses for which participants are treated, and the cost of treatment for particular diagnoses. The goal is to quantify the contribution of each of these components to the difference between average cost and the cost in a given firm. The demographic mix of plan enrollees accounts for wide differnces in cost ($649). Perhaps the most noticeable feature of the results is that, after adjusting for demographic mix, the difference in expenditures accounted for by the treatment costs given diagnosis ($807) is almost as wide as the unadjusted range in expenditures ($838). Differences in cost due to the different illnesses that are treated, after adjusting for demographic mix, also accounts for large differences in cost ($626). These components of cost do not move together; for example, demographic mix may decrease expenditure under a particular plan while the diagnosis mix may increase costs.Our hope is that understanding the reasons for cost differences across plans will direct more focused attention to controlling costs. Indeed, this work is intended as an important first step toward that goal.

scholarly journals Municipal Leachate Treatment by Fenton Process: Effect of Some Variable and Kinetics

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Mohammad Ahmadian ◽  
Sohyla Reshadat ◽  
Nader Yousefi ◽  
Seyed Hamed Mirhossieni ◽  
Mohammad Reza Zare ◽  
...  
Keyword(s):  
Reaction Time ◽  
Color Removal ◽  
Molar Ratio ◽  
Order Kinetic ◽  
Fenton Process ◽  
Solution Ph ◽  
Leachate Treatment ◽  
First Order ◽  
Order Kinetic Model ◽  
Better Than

Due to complex composition of leachate, the comprehensive leachate treatment methods have been not demonstrated. Moreover, the improper management of leachate can lead to many environmental problems. The aim of this study was application of Fenton process for decreasing the major pollutants of landfill leachate on Kermanshah city. The leachate was collected from Kermanshah landfill site and treated by Fenton process. The effect of various parameters including solution pH, Fe2+and H2O2dosage, Fe2+/H2O2molar ratio, and reaction time was investigated. The result showed that with increasing Fe2+and H2O2dosage, Fe2+/H2O2molar ratio, and reaction time, the COD, TOC, TSS, and color removal increased. The maximum COD, TOC, TSS, and color removal were obtained at low pH (pH: 3). The kinetic data were analyzed in term of zero-order, first-order, and second-order expressions. First-order kinetic model described the removal of COD, TOC, TSS, and color from leachate better than two other kinetic models. In spite of extremely difficulty of leachate treatment, the previous results seem rather encouraging on the application of Fenton’s oxidation.

Expectations and Recent Experience for Gas Turbine Reliability, Availability, and Maintainability (RAM)

2007 ◽  
Author(s):  
Robert F. Steele ◽  
Dale C. Paul ◽  
Torgeir Rui
Keyword(s):  
Power Systems ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Advanced Technology ◽  
Recent Experience ◽  
Reliability Growth ◽  
Market Place ◽  
New Product Introductions ◽  
Low Emission ◽  
The Cost

Since the early 1990’s there have been significant changes in the gas turbine, and power generation market place. The ‘F-Class’ Gas Turbines, with higher firing temperatures, single crystal materials, increased compressor pressure ratios and low emission combustion systems that were introduced in the early 1990’s have gained significant field experience. Many of the issues experienced by these new product introductions have been addressed. The actual reliability growth and current performance of these advanced technology machines will be examined. Additionally, the operating profiles anticipated for many of the units installed during this period has been impacted by both changes in the anticipated demand and increases in fuel costs, especially the cost of natural gas. This paper will review how these changes have impacted the Reliability, Availability, and Maintainability performance of gas turbines. Data from the ORAP® System, maintained by Strategic Power Systems, Inc, will be utilized to examine the actual RAM performance over the past 10 to 15 years in relation to goals and expectations. Specifically, this paper will examine the reliability growth of the F-Class turbines since the 1990’s and examine the reliability impact of duty cycle on RAM performance.

scholarly journals Investigations on Efficiently Interfaced Steel Concrete Composite Deck Slabs

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
K. N. Lakshmikandhan ◽  
P. Sivakumar ◽  
R. Ravichandran ◽  
S. Arul Jayachandran
Keyword(s):  
Longitudinal Shear ◽  
Advanced Technology ◽  
Shear Connector ◽  
Premature Failure ◽  
Shear Connectors ◽  
Reinforced Concrete Slabs ◽  
Composite Slabs ◽  
Strength And Stiffness ◽  
The Cost ◽  
Deck Slab

The strength of the composite deck slab depends mainly on the longitudinal shear transfer mechanism at the interface between steel and concrete. The bond strength developed by the cement paste is weak and causes premature failure of composite deck slab. This deficiency is effectively overcame by a shear transferring mechanism in the form of mechanical interlock through indentations, embossments, or fastening studs. Development of embossment patterns requires an advanced technology which makes the deck profile expensive. Fastening studs by welding weakens the joint strength and also escalates the cost. The present investigation is attempted to arrive at a better, simple interface mechanism. Three types of mechanical connector schemes are identified and investigated experimentally. All of the three shear connector schemes exhibited full shear interaction with negligible slip. The strength and stiffness of the composite slabs with shear connectors are superior about one and half time compared to these of the conventional reinforced concrete slabs and about twice compared to these of composite slabs without mechanical shear connectors. The scheme2 and scheme3 shear connector mechanisms integrate deck webs and improve strength and stiffness of the deck, which can effectively reduce the cost of formworks and supports efficiently.

Changing the “When” and “What” of Intended Actions

2009 ◽  
Vol 102 (5) ◽  
pp. 2755-2762 ◽  
Author(s):  
Sukhvinder S. Obhi ◽  
Shannon Matkovich ◽  
Robert Chen
Keyword(s):  
Reaction Time ◽  
Simple Reaction Time ◽  
Index Finger ◽  
Sensory Information ◽  
Motor Preparation ◽  
Warning Stimulus ◽  
Inhibitory Mechanism ◽  
Preparatory Period ◽  
The Cost ◽  
Reaction Time Condition

Humans often have to modify the timing and/or type of their planned actions on the basis of new sensory information. In the present experiments, participants planned to make a right index finger keypress 3 s after a warning stimulus but on some trials were interrupted by a temporally unpredictable auditory tone prompting the same action ( experiment 1) or a different action ( experiment 2). In experiment 1, by comparing the reaction time (RT) to tones presented at different stages of the preparatory period to RT in a simple reaction time condition, we determined the cost of switching from an internally generated mode of response production to an externally triggered mode in situations requiring only a change in when an action is made (i.e., when the tone prompts the action at a different time from the intended time of action). Results showed that the cost occurred for interruption tones delivered 200 ms after a warning stimulus and remained relatively stable throughout most of the preparatory period with a reduction in the magnitude of the cost during the last 200 ms prior to the intended time of movement. In experiment 2, which included conditions requiring a change in both when and what action is produced on the tone, results show a larger cost when the switched to action is different from the action being prepared. We discuss our results in the light of neurophysiological experiments on motor preparation and suggest that intending to act is accompanied by a general inhibitory mechanism preventing premature motor output and a specific excitatory process pertaining to the intended movement. Interactions between these two mechanisms could account for our behavioral results.

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