Stabilization of arsenic and fluoride bearing spent adsorbent in clay bricks: Preparation, characterization and leaching studies
| Autor: | Vineet Kumar Rathore, Prasenjit Mondal |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Environmental Engineering
Absorption of water 0211 other engineering and technologies chemistry.chemical_element 02 engineering and technology 010501 environmental sciences Management Monitoring Policy and Law 01 natural sciences Arsenic Water Purification chemistry.chemical_compound Fluorides Adsorption Waste Management and Disposal 0105 earth and related environmental sciences 021110 strategic defence & security studies Waste management General Medicine Hydrogen-Ion Concentration Efflorescence Compressive strength chemistry Hydroxide Clay Aluminum Silicates Leaching (metallurgy) Fluoride Water Pollutants Chemical Nuclear chemistry |
| Zdroj: | Journal of environmental management. 200 |
| ISSN: | 1095-8630 |
| Popis: | The presence of arsenic and fluoride in groundwater has been observed throughout the world. Many technologies have been developed by various research groups in order to tackle this problem. Adsorption has emerged as one of the best possible technique for the removal of arsenic, fluoride and many other pollutants from drinking water. Although a considerable amount of work has been published on the adsorptive removal of arsenic and fluoride, the area related to the management of spent adsorbent is not well explored. Present paper deals with the adsorptive removal of arsenic and fluoride from aqueous solution by three different types of adsorbents, namely, thermally treated laterite (TTL), acid-base treated laterite (ABTL) and aluminum oxide/hydroxide nanoparticles (AHNP). Under the experimental conditions in batch operation, the adsorption capacities of TTL, ABLT and AHNP for arsenic are found to be 6.43 μg/g, 9.25 μg/g and 48.5 μg/g respectively, whereas for fluoride, these values are found as 0.21 mg/g, 0.85 mg/g and 4.65 mg/g respectively. After adsorption, the spent adsorbents have been stabilized in the form of clay bricks. The effects of spent adsorbent concentration on the properties of bricks and their leaching properties are investigated. The bricks have been tested for various properties like density, percentage water absorption, shrinkage, compressive strength and efflorescence. The maximum values of density and shrinkage of the bricks formed are found as 2.3 g/cm3 and 10.2%, whereas the percentage water absorption and compressive strength of the bricks are found between 11 and 14% and 35 to 150 kgf/cm2 respectively. All the test results are in accordance with the criteria set by Indian Standards. The leaching test of arsenic and fluoride from the bricks reveals that their maximum values in leachate are 510 μg/L and 2.1 mg/L respectively, which are below the permissible limits of USEPA standards. |
| Databáze: | OpenAIRE |
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