Effect of Pumice and Sand on the Sustainability of Granular Iron Beds for the Aqueous Removal of CuII,NiII, and ZnII     

Stefania Bilardi  Paolo S. Calabrò  Sabine Caré  Nicola Moraci  Chicgoua Noubactep 《洁净——土壤、空气、水》2013,41(9):835-843

Current knowledge of the basic principles underlying the design of Fe⁰ beds is weak. The volumetric expansive nature of iron corrosion was identified as the major factor determining the sustainability of Fe⁰ beds. This work attempts to systematically verify developed concepts. Pumice and sand were admixed to 200 g of Fe⁰ in column studies (50:50 volumetric proportion). Reference systems containing 100% of each material have been also investigated. The mean grain size of the used materials (in mm) were 0.28 (sand), 0.30 (pumice), and 0.50 (Fe⁰). The five studied systems were characterized (i) by the time dependent evolution of their hydraulic conductivity (permeability) and (ii) for their efficiency for aqueous removal of Cu^II, Ni^II, and Zn^II (about 0.3 mM of each). Results showed unequivocally that (i) quantitative contaminant removal was coupled to the presence of Fe⁰, (ii) additive admixture lengthened the service life of Fe⁰ beds, and (iii) pumice was the best admixing agent for sustaining permeability while the Fe⁰/sand column was the most efficient for contaminant removal. The evolution of the permeability was well‐fitted by the approach that the inflowing solution contained dissolved O₂. The achieved results are regarded as starting point for a systematic research to optimize/support Fe⁰ filter design.  相似文献   

Designing Iron‐Amended Biosand Filters for Decentralized Safe Drinking Water Provision     

Chicgoua Noubactep  Emile Temgoua  Mohammad A. Rahman 《洁净——土壤、空气、水》2012,40(8):798-807

There are ongoing efforts to render conventional biosand filters (BSF) more efficient for safe drinking water provision. One promising option is to amend BSF with a reactive layer containing metallic iron (Fe⁰). The present communication presents some conceptual options for efficient Fe⁰‐amended BSF in its fourth generation. It is shown that a second fine‐sand layer should be placed downwards from the Fe⁰‐reactive layer to capture dissolved iron. This second fine‐sand layer could advantageously contain adsorbing materials (e.g. activated carbons, wooden charcoals). An approach for sizing the Fe⁰‐reactive layer is suggested based on 3 kg Fe⁰ per filter. Working with the same Fe⁰ load will ease comparison of results with different materials and the scaling up of household BSF to large scale community slow sand filters (SSF).  相似文献   

Extending Service Life of Household Water Filters by Mixing Metallic Iron with Sand     

Chicgoua Noubactep  Sabine Caré  Fulbert Togue‐Kamga  Angelika Schöner  Paul Woafo 《洁净——土壤、空气、水》2010,38(10):951-959

The use of metallic iron filters (Fe⁰ filters) has been discussed as a promising low‐cost option for safe drinking water production at household level. Filter clogging due to the volumetric expansive nature of iron corrosion has been identified as the major problem of Fe⁰ filters. Mixing Fe⁰ and sand (yielding Fe⁰/sand filters) has been proposed as a tool to extent filter service life. However, no systematic discussion rationalizing Fe⁰/sand mixtures is yet available. This communication theoretically discussed suitable Fe⁰/sand proportions for efficient filters. Results suggested that Fe⁰/sand filters should not contain more that 50 vol% Fe⁰ (25 wt% when Fe⁰ is mixed with quartz). The actual Fe⁰ percentage in a filter will depend on its intrinsic reactivity.  相似文献