Sign in to XPRT
Don't have an account? Get Started
Sign up to XPRT
Already have an account? Login here
Sign up to XPRT
Enter your email to restore your password
Courtesy of IWA Publishing
Effects of physicochemical factors on Cr(VI) removal from leachate by zero-valent iron and α-Fe2O3 ...
The effects of nanoparticle dosage, initial hexavalent chromium concentration, pH value, reaction temperature, and initial concentration of humic acid (HA) on chromate (CrO42−) removal from landfill leachate by nanoscale zero-valent iron (NZVI) and hematite (α-Fe2O3) nanoparticles were examined in the present investigations. The Cr(VI) removal rate decreased as the initial Cr(VI) concentration and the reaction temperature increased, whereas corresponding removal rate by NZVI was higher than that of α-Fe2O3. The...
AD26 System Performance – Iron / Manganese - Confidential Client - California
In the early 2004, AdEdge was engaged by Pacific Advanced Civil Engineers (PACE) to devise a treatment alternative for manganese and iron removal for a public water system in southern California. This high demand water supply well was yielding between 180 to 220 gpm. The needs were imminent as the currently designed system was not achieving compliance with the Safe Drinking Water Act secondary MCLs for iron and manganese. AdEdge proposed the retrofit of the current treatment system to include its AD26...
Application of a Medium Pressure UV System for the Treatment of N-Nitrosodimethylamine (NDMA)
Untitled Document N-nitrosodimethylamine (NDMA) was first detected in 1990 as a problem pollutant in drinking water wells at levels as high as 3,000 ppt in Elmira, Ontario, Canada. The waste from a large chemical plant over many years had led to the contamination of the drinking water wells for the community. After extensive evaluation and testing, it was determined that UV photolysis was the most effective treatment method which led to the installation of a Calgon 270 kW Rayox®...
Scale-up of a Medium Pressure UV System for the Treatment of N-Nitrosodimethylamine (NDMA) and its ...
Untitled Document Recently there has been considerable concern in California about the detection of N-nitrosodimethylamine (NDMA) in drinking water at levels as high as 900 ppt. NDMA was found to be a carcinogen in animals and assessed as a Class 1 carcinogen. It is currently listed as a priority pollutant on the US EPA National Priorities List. California has set an "action level" of 20 ppt for NDMA. NDMA is thermally stable in aqueous solutions. Conventional methods such...
Exploring Innovative Solutions
Progress in environmental management relies on innovation. Whether it's novel applications of new technologies, pioneering public policies, or groundbreaking partnerships – innovation leads to advances. Looking toward tomorrow's advances, the theme of A&WMA's 98th Annual Conference & Exhibition is “Exploring Innovative Solutions.” The conference will take place June 21-24, 2005, at the Minneapolis Convention Center in Minneapolis, MN. As a thriving, dynamic, and increasingly diverse metropolitan area,...
Recovery of Precious Metal Catalysts - A New Process Using Supercritical Water Oxidation
Up to now, the recovery of precious metals used as catalysts in chemical processes has involved the use of incineration. Now, however, a British-Swedish joint venture has developed a process which uses supercritical water oxidation instead, which provides many economic and environmental advantages. Precious metals are used extensively in catalysts in a wide range of industrial chemical processes. Sometimes they are used in a homogeneous form, but more often fixed to a solid support for ease of handling. In many...
Reductive Biotransformation of Explosives Compounds in Groundwater
Untitled Document ABSTRACT: Earth Tech Inc. has successfully completed two bench-scale studies demonstrating the treatment of explosives contaminated groundwater by amendment with Hydrogen Release Compound (HRC). The first of these two bench scale studies was intended to demonstrate the removal of explosive contaminants, with the second designed to assess transformation product formation and accumulation. Groundwater used in these bench scale studies was obtained...
Consideration of the Effects of Remediation Technologies on Natural Attenuation.
ABSTRACT: We have long understood and continue to improve our understanding of the geochemical conditions that favor biodegradation of petroleum hydrocarbons. Over the last several years our understanding of the conditions that are necessary for and/or promote reductive dechlorination of chlorinated hydrocarbons has improved substantially. Over this time in situ remediation technologies have proliferated. Many sites are being addressed with active remediation in conjunction with natural attenuation. For chlorinated...
Chemical Aspects of NOX Scrubbing
With the passage of the 1990 Clean Air Act Amendments, many chemical and metal industries and utility producers will now be required to further limit the amount of NOX (Nitrogen Oxides) produced. NOX is a precursor to ozone in the atmosphere, and is believed to be a major contributor to acidic deposition (acid rain). Formation of ozone: NO2 + Hv NO + O (Photochemical Reaction) O + O2 + M O3 + M, where M - Energy accepting third body. NOX is produced in a variety of different processes, including combustio...
Evaluation of Ecological Risks Associated with the use of Chlorine Dioxide for the Bleaching of ...
1.1 Scope and Objectives A small number of viable options are presently available for the bleaching of wood pulp (delignification and brightening) during the manufacture of pulp and paper. The use of chlorine dioxide (ClO2) in the bleaching process has largely superceded the earlier use of Cl2, or elemental chlorine, in the majority of North American pulp mills: It was discovered over a decade ago that the previous widespread use of Cl2 contributed to the production and subsequent release to the environment of...
Performance-Based Measurement Systems
Many of the Environmental Protection Agency`s (EPA`s) methods used to monitor air, water and soil for environmental contaminants prescribe step-by-step details on how the chemical analysis must be conducted and prohibit any deviations or variations. The EPA has recognized that monitoring equipment and technology have improved tremendously over the last few years; that environmental media do not always act the same way for each analysis; and that the matrix may affect the analysis and results. The EPA has been...
Waste Free Offices. Eco-Efficiency Case Study.
Introduction Xerox Limited, an arm of Xerox Corporation, has responsibility for European markets. Xerox Limited offers a wide array of document-related business solutions, products and services, and recently moved into the digital office equipment market. Xerox produces copiers, printers, scanners, faxes and provides solutions for document transfer. Xerox Limited is dedicated to environmental issues. They are a signatory to the International Chamber of Commerce’s Business Charter for Sustainable Development ....
Electronics Manufacturing Industry - Pollution Prevention Guidelines
Introduction Pollution Prevention Guidelines to provide technical advice and guidance to staff and consultants involved in pollution-related projects. The guidelines represent state-of-the-art thinking on how to reduce pollution emissions from the production process. In many cases, the guidelines provide numerical targets for reducing pollution, as well as maximum emissions levels that are normally achievable through a combination of cleaner production and end-of-pipe treatment. The guidelines are designed to...
Spiral-Wound Elements for Potable Water Treatment
Introduction Any new technology must overcome perceptions of the marketplace, which are not accurate. As a technology moves into new areas of application, new misconceptions also arise. Crossflow membrane technology is no exception. The first man-made, pressure-driven `crossflow` membranes were made in flat sheet form. This membrane had to be configured in a device, and was first made in tile obvious `plate-and-frame` design. The spiral-wound design resulted as a response to the high cost, large size, and...
Properties and Behavior of Inorganics in Contaminated Soil
Often, specific technologies may be ruled out, or the list of potential technologies may be immediately narrowed, on the basis of the presence or absence of one or more of the chemical groups. The relative amounts of each may tend to favor certain technologies. Metals may be found in the elemental form, but more often they are found as salts mixed in the soil. At the present time, treatment options for radioactive materials are limited to volume reduction/concentration and immobilization. Asbestos fibers require...
RO Feedwater: Treat It Right
Summary Crossflow membrane filtration systems, such as reverse osmosis (RO), nanofiltration (NF) or ultrafiltration (UF), are good alternatives to traditional filtration and chemical treatment. However, to get the best performance from them, careful attention must be paid to feedwater conditions. Pretreating feedwater can lengthen the life of membrane elements, improve the quality of the water produced and reduce the amount of maintenance and cleaning a system requires. The importance of feedwater conditions...
Membranes, the Finest Filtration
Introduction The notion that salt could be removed from seawater without a phase change took hold of Dr. Sourirajan`s imagination in the late 1950`s. The actual invention of the reverse osmosis (RO) membrane took place in his laboratory at UCLA around 1960. (Thus Sourirajan could be called not only the `Father of Reverse Osmosis,` but the initiator of all crossflow membrane technology.) The full commercialization of RO and its sister crossflow technology, ultrafiltration (UF), occurred in the early 1970`s. About...
Application of a Medium Pressure UV System for the Treatment of N-Nitrosodimethylamine (NDMA)
N-nitrosodimethylamine (NDMA) was first detected in 1990 as a problem pollutant in drinking water wells at levels as high as 3,000 ppt in Elmira, Ontario, Canada. The waste from a large chemical plant over many years had led to the contamination of the drinking water wells for the community. After extensive evaluation and testing, it was determined that UV photolysis was the most effective treatment method which led to the installation of a Calgon 270 kW Rayox® UV system in 1991. The system has been continuously...
Scale-up of a Medium Pressure UV System for the Treatment of N-Nitrosodimethylamine (NDMA) and its ...
Recently there has been considerable concern in California about the detection of N-nitrosodimethylamine (NDMA) in drinking water at levels as high as 900 ppt. NDMA was found to be a carcinogen in animals and assessed as a Class 1 carcinogen. It is currently listed as a priority pollutant on the US EPA National Priorities List. California has set an `action level` of 20 ppt for NDMA. NDMA is thermally stable in aqueous solutions. Conventional methods such as biological treatment, air stripping and activated...
No comments were found for Adsorption/reduction of N-dimethylnitrosamine from aqueous solution using nano zero-valent iron nanoparticles supported on ordered mesoporous silica. Be the first to comment!
