Download or read book A Feasibility Study of the Chromyl Chloride Process for Hexavalent Chromium Recovery from Spent Plating Solutions written by Subbarao L. Guddati and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technical feasibility study on the chromium recovery from electroplating effluents written by Daniel Wiemken and published by diplom.de. This book was released on 2014-04-11 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt: Inhaltsangabe:Introduction: Rapid industrialisation and growth in population over the past two hundred years exert an increasing pressure on natural resources and the environment. Billions of tons of controlled and scheduled waste are generated every year by the industrial sector worldwide which is often either pre-treated on-site or at a licensed contractor prior to disposal in landfills. This practice if continued is leading to resource depletion and creates a potentially harmful legacy for future generations. In order to move towards a more sustainable development as outlined in the Bruntland Report, waste reduction, reuse and recycling coupled with pollution prevention measures play an important part to slow down if not reverse this practice. Heavy metals such as cadmium, mercury, lead and chromium are not degradable or renewable like biomass hence if they are to be used in future processes reuse and recycling are the only options. At present, heavy metals are used in the chemical industry sector for applications ranging from batteries to catalysts and surface coatings, and can be found at various concentrations in gaseous, liquid or solid waste. Chromium is of particular interest owing to its legislative status and unique chemistry. Chromium exists in nature primarily in one of two oxidation states. There are other chemical oxidation states of chromium, which include 0, II, IV, and V, but they are considered transitory compared to more stable Cr(III) and Cr(VI) species. Hexavalent chromium is a strong oxidizer which can react with DNA causing mutation, while the trivalent, organically complex form is a dietary supplement to help with proper glucose metabolism, weight loss and muscle tone. Unlike many other metals, Cr(VI) can combine with oxygen to form water-soluble, negatively charged anions known as yellow chromate (CrO42-) or orange dichromate (Cr2O72-), which adsorb to positively charged sites in contrast to cationic metal species. Therefore, hexavalent chromium species are not strongly bonded in many soils under alkaline to slightly acidic conditions, for example. Thus, they can be very mobile in subsurface environment while other metals precipitated out and exert toxic effects on biological systems. Various well-established methods may be used to treat industrial effluents and contaminated water such as reduction and precipitation, reverse osmosis, evaporation, ion exchange and adsorption. While these processes are able to remove [...]
Download or read book Mathematical Model for the Removal of Metallic Impurities and Regeneration Hexavalent Chromium from Spent Plating Solution written by Gautham Jegadeesan and published by . This book was released on 2002 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Removal of Metallic Impurities in Chromium Plating Solutions by Electrocoagulation written by S. B. Lalvani and published by . This book was released on 2002 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Reducing Chromium Losses from a Chromium Plating Bath written by Diane Achman and published by . This book was released on 1987 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Removal and Recovery of Hexavalent Chromium from an Industrial Metal treating Process written by Mark C. Roberts and published by . This book was released on 1992 with total page 115 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Biosorption of Toxic Hexavalent Chromium from Aqueous Solutions by Low Cost Waste Biomaterial written by Nilisha Itankar and published by . This book was released on 2014 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chromium metal has unique properties and therefore finds large number of applications in industries like chrome-plating, steel and alloy, leather tanning and ammunition factories. These industries consequently, discharge large quantities of hexavalent chromium (Cr6 ) containing effluents. Since chromium is toxic to all life forms, its removal from effluents is the key. Conventional processes used are highly energy-intensive and economically unattractive. Biosorption, a technically feasible and economical process has gained immense creditability in the recent years. The present study explores the possibility of using biosorption process for the removal of Cr6 from aqueous solutions using low-cost biomaterial viz. saw dust (SD). Optimum parameters for maximum biosorption of Cr6 (10 mg/L) were as follows: pH 1-4, contact time 60 min and biomass quantity of 1 g/10 mL. Biosorption conformed to the Langmuir and Freundlich adsorption isotherms (R2 = > 0.97). It was found that the equilibrium sorption capacity of the sorbent increased with increasing initial concentration of Cr6 from 5 to 300 mg/L. Overall, the study showed that SD has immense potential as “biomaterial” for its use in the removal/recovery of hexavalent chromium from aqueous industrial solutions.
Download or read book The Purification of Spent Chromium Plating Solutions Using an Electrolytic System written by Kuo-Lin Huang and published by . This book was released on 2001 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of Zero Emission Chromium Plating Process written by Susheel Yadav and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Hard chromium plating is extensively used in the industry to improve the wear characteristics of metal parts. EPA has identified hexavalent chromium, used in chromium plating, as one of the 17 high-priority toxic chemicals. The purpose of this project was to design a new process that will prevent the release of chromic-acid mist into the workplace. Traditionally, temperature control and mixing have been achieved by bubbling air at the bottom of the plating bath using a sparger. These air bubbles burst at the surface of the plating solution and produce aerosols that are responsible for the chromium emissions. The proposed process uses a silicone fluid layer at the top of the plating solution to trap the aerosols. Mixing and heat transfer are achieved by sparging this fluid. Mathematical models have been developed to predict hexavalent chromium emissions, heat transfer, and health risks associated with conventional plating tanks.
Download or read book Anagram Solver written by Bloomsbury Publishing and published by Bloomsbury Publishing. This book was released on 2009-01-01 with total page 719 pages. Available in PDF, EPUB and Kindle. Book excerpt: Anagram Solver is the essential guide to cracking all types of quiz and crossword featuring anagrams. Containing over 200,000 words and phrases, Anagram Solver includes plural noun forms, palindromes, idioms, first names and all parts of speech. Anagrams are grouped by the number of letters they contain with the letters set out in alphabetical order so that once the letters of an anagram are arranged alphabetically, finding the solution is as easy as locating the word in a dictionary.
Download or read book Radiochemical Analysis written by and published by . This book was released on 1964 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monograph Series written by American Chemical Society and published by . This book was released on 1922 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Annual Report on Carcinogens written by and published by . This book was released on 1998 with total page 576 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Role of Ecological Chemistry in Pollution Research and Sustainable Development written by Ali Mufit Bahadir and published by Springer. This book was released on 2009-08-03 with total page 313 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sustainable Development has become the leading concept of the 21 century. It describes a development, which agrees with the needs of the present generation but does not endanger the chances of the coming generations to satisfy also their needs. “Sustainable development” has become an important general goal for all fields of life like economy, ecology and social balance. The development and shaping of our future has been discussed internationally like on the summits of the Conferences in Rio and in Johannesburg. But this is also a topic on national base in various countries. Leading authorities in various fields of economy and politics have also accepted this concept. Although the concept of sustainable development has been generally accepted, there are still problems how to achieve and evaluate these general goals. It is clear that the definitions about the prime needs vary from man to man, from country to country and from continent to continent. But pollution does not respect national borders. Therefore, it is necessary to develop the politics of economy, ecology and social demands by a synergistic way that they are strengthened by each other. If it is not possible to stop tendencies, which threaten the future quality of life, the cost demands of societies will dramatically increase and negative tendencies will become irreversible.
Download or read book First Annual Report on Carcinogens written by National Toxicology Program (U.S.) and published by . This book was released on 1980 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sisters Super Creeps and Slushy Gushy Love Songs written by Karen McCombie and published by . This book was released on 2011 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ally knows her super-efficient big sis Linn finds their chaotic family a bit ... exasperating. But when Linn falls for Q, the tearaway lead singer in a local band, all her sensible ways go out of the window. Everyone else can see that Q's a creep, but does Ally have the courage to burst Linn's heart-shaped bubble?
Download or read book Crossword Solver written by Anne Stibbs and published by Bloomsbury Pub Limited. This book was released on 2000 with total page 423 pages. Available in PDF, EPUB and Kindle. Book excerpt: An aid to solving crosswords. It contains over 100,000 potential solutions, including plurals, comparative and superlative adjectives, and inflections of verbs. The list extends to first names, place names and technical terms, euphemisms and compound expressions, as well as abbreviations.
