In the present study, different grades of indigenously available activated alumina (AA) were screened for their arsenic removal capacity. For both As(III) and As(V), A1 (Grade 1, 0.3-0.6 mm) activated alumina has shown better removal efficiency. The optimum pH for the adsorption phenomena was around 7.0. Chlorine at a dose of 20 mg/l could completely oxidize As(III) to As(V), which also assured the bacteriological quality of the water. Among various anions studied, sulfate seems to have maximum competition with arsenic for adsorption sites. A portable filter with a flow rate of 6 l/h and a contact time of 5 minutes could effectively be used for the treatment of arsenic contaminated water. The exhausted activated alumina could regenerate with 4% NaOH solution without much reduction in efficiency.
The removal of arsenic from drinking water by filtration through modified fly-ash bed is discussed. The preparation and characteristics of the bed material and the effects of different parameters like pH and the presence of other constituents are described. Various arsenic compounds in synthetic mixtures as well as drinking water samples containing arsenic have been investigated. The effectiveness of the modified fly-ash bed for the control of arsenic has been demonstrated by taking different quantities of...
Water systems of varying sizes that are affected with arsenic contamination are looking to implement treatment solutions to meet more stringent standards for arsenic of 10 ppb in drinking water. However, before a full-scale treatment system can be installed, its performance must sometimes be verified through laboratory or field pilot testing.
Adsorption using metal oxide media is one of the most promising commercially available technologies for arsenic removal from ground water sources. Adsorption is best...
Untitled Document
SmartSponge technology captures oil and hydrocarbons from stormwater runoff, preventing its discharge into receiving waters.
Water quality is being bolstered in dozens of locations around the United States through the use of a rather simple system. The concept is simple – a polymer “sponge” that removes contaminants from water before it winds up passing through catch basins and storm drains and back into the environment.
In fact, both local officials and community groups have...
Chromated copper arsenate (CCA) has been the most widely used wood preservative for decks, playgrounds and exterior housing structures. However, in recent years, issues surrounding the use of CCA preservative chemical have escalated, prompting manufacturers to voluntarily stop producing it as of the end of 2003 and begin using alternative wood preservatives. There are concerns of possible arsenic (As) leaching into soil both during the wood’s in-use life, and if discarded wood is placed in un-lined landfills....
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...
Adelaide’s water quality has been the subject of adverse media comment in regard to taste and odour for years. At times, algal taste and odours are evident due to the majority of water being sourced from the River Murray plus reservoirs in the Adelaide Hills – a primary agricultural area. Further, customers complain about chlorinous taste and odour in the distribution systems. Despite all reticulated water being treated by conventional processes, the high dissolved organic carbon (DOC) requires high coagulant...
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...
OVERVIEW
When chlorine is added to a water supply containing certain organics, the formation of halogenated organics occurs. Called `trihalogenated methanes` (THM`s) these reaction products are suspected carcinogens and maximum allowable limits in municipal supplies are imposed by the U.S. Environmental Protection Agency (EPA). To reduce the potential for the formation of THM`s, many U.S. municipal supplies are converting their chlorine (Cl2) disinfection method to chloramine addition. Chloramines have a low...
Untitled Document
Summary:
A granular activated carbon system developed by Calgon Corp., is being used
to remove various toxic materials from contaminated groundwater at the U.S.
Army's huge Rocky Mountain Arsenal near Denver, Colo. The pilot containment/treatment
project, which went into full operation in late August, 1978, has been described
as one of the largest efforts in the world to treat contaminated groundwater.
It consists of a 1,500-foot-long underground water barrier...
In all, the 1990s have been good for the biosolids recycling community. Greater quantities of biosolids are being beneficially used than ever before, there are national biosolids regulations that are widely accepted as a good baseline, and there is an extensive, accessible network of researchers, practitioners, advisers and public officials who when combined, provide thousands of years worth of valuable knowledge and experience.
We end this decade, however, with perhaps a greater challenge than we started with —...
Imagine being in charge of a chemical company. One day a fire breaks out, and an employee, designated as a first responder, is killed fighting the blaze. Then OSHA investigators discover that the man died primarily because both his training and his equipment were inadequate. This scenario is why CPL 2-2.59A should put anyone who runs a HAZMAT facility into a state of introspection. These employers need to ask themselves: `When was the last time that our Emergency Response Plan was brought up to date? Do our...
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...
Sites where halogenated VOCs may be found include burn pits, chemical manufacturing plants or disposal areas, contaminated marine sediments, disposal wells and leach fields, electroplating/metal finishing shops, firefighting training areas, hangars/aircraft maintenance areas, landfills and burial pits, leaking collection and system sanitary lines, leaking storage tanks, radioactive/mixed waste disposal areas, oxidation ponds/lagoons, paint stripping and spray booth areas, pesticide/herbicide mixing areas, solvent...
Synopsis
Industry, Fresh Water, and Sustainable Development is published jointly by the World Business Council for Sustainable Development and the United Nations Environment Programme (UNEP).
The growing demands for water for human consumption, agriculture and industry means that fresh water must not be taken for granted, but be carefully used.
Industry has an important part to play in this, and our report looks at what industry is doing to improve and increase the supply and quality of fresh water.
The...
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...
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...
Introduction:
The process involves raising the temperature of the contaminated equipment or material to 260 °C (500 °F) for a specified period of time. The gas effluent from the material is treated in an afterburner system to destroy all volatilized contaminants. The method eliminates a waste that currently is stockpiled and requires disposal as a hazardous material. This method will permit reuse or disposal of scrap as nonhazardous material.
Hot gas decontamination can also be used for decontamination of...
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...
On 12th March 1997, the European Commission adopted a proposal from the Environment Commissioner Ritt Bjerregaard on a European Union strategy to combat acidification. The strategy will, by 2010, reduce significantly the extent of the areas in the European Union where the tolerance of sensitive ecosystems to acidity is exceeded. Main elements of the strategy include establishment of national emission ceilings for each acid rain pollutant; ratification of the UN protocol on further reductions of sulphur emissions;...
` In order to determine the impacts of a particular discharge on ambient water quality, it is usually necessary to model the diffusion and dispersion of the discharge in the relevant water body. The approach applies both to new discharges and to upgrading of existing sources. This note provides guidance on models that may be applicable in the context of typical Bank projects.`
Introduction
Mathematical models can be used to predict changes in ambient water quality due to changes in discharges of wastewater. In...
STEP ONE: ASSESSMENT AND SURVEYThe first step of the Asbestos Management Program is to do an asbestos survey to assess the location, identify the type of asbestos, the condition of the asbestos and identify a maintenance record. This asbestos inventory or assessment is usually carried out by an independent consulting firm. This assessment or survey will include:
Identification and location of the Asbestos Containing Materials (ACM) Assessing the condition of asbestos and its accessibility. Preparing a long term...
Customer comments
No comments were found for Development of a portable filter for arsenic removal from drinking water. Be the first to comment!
