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Bench-Scale Operation of a Concrete Sludge Recycling Plant / Atsushi Iizuka in Industrial & engineering chemistry research, Vol. 51 N° 17 (Mai 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 17 (Mai 2012) . - pp. 6099–6104 Titre : Bench-Scale Operation of a Concrete Sludge Recycling Plant Type de document : texte imprimé Auteurs : Atsushi Iizuka, Auteur ; Yuka Sakai, Auteur ; Akihiro Yamasaki, Auteur Année de publication : 2012 Article en page(s) : pp. 6099–6104 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Concrete  sludge  recycling Résumé : A bench-scale plant for waste concrete sludge recycling was designed, constructed, and operated. Real concrete sludge generated from a pile and pole production plant and groundwater were used for the experiments. The process mainly consists of the extraction of calcium ions from the concrete sludge into the aqueous phase and the crystallization of calcium carbonate from the solution with CO2. The CO2 was supplied from boilers installed in the plant, where heavy oil is combusted. High-purity calcium carbonate (>99%) was obtained in the process, with particle sizes distributed in the range of 3–30 μm (volume-based), peaking at about 10 μm. A net reduction in CO2 emissions can be achieved based on the process power consumption and the amount of product. The effects of operating conditions on process performance data such as calcium extraction rate and calcium carbonate crystallization rate were examined, which can lead to scaling-up of the plant. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300620u [article] Bench-Scale Operation of a Concrete Sludge Recycling Plant [texte imprimé] / Atsushi Iizuka, Auteur ; Yuka Sakai, Auteur ; Akihiro Yamasaki, Auteur . - 2012 . - pp. 6099–6104. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 17 (Mai 2012) . - pp. 6099–6104 Mots-clés : Concrete  sludge  recycling Résumé : A bench-scale plant for waste concrete sludge recycling was designed, constructed, and operated. Real concrete sludge generated from a pile and pole production plant and groundwater were used for the experiments. The process mainly consists of the extraction of calcium ions from the concrete sludge into the aqueous phase and the crystallization of calcium carbonate from the solution with CO2. The CO2 was supplied from boilers installed in the plant, where heavy oil is combusted. High-purity calcium carbonate (>99%) was obtained in the process, with particle sizes distributed in the range of 3–30 μm (volume-based), peaking at about 10 μm. A net reduction in CO2 emissions can be achieved based on the process power consumption and the amount of product. The effects of operating conditions on process performance data such as calcium extraction rate and calcium carbonate crystallization rate were examined, which can lead to scaling-up of the plant. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300620u

Desulfurization characteristics of waste cement particles as a sorbent in dry desulfurization / Jiawei Wu ; Atsushi Iizuka ; Kazukiyo Kumagai in Industrial & engineering chemistry research, Vol. 47 n°24 (Décembre 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 n°24 (Décembre 2008) . - p. 9871–9877 Titre : Desulfurization characteristics of waste cement particles as a sorbent in dry desulfurization Type de document : texte imprimé Auteurs : Jiawei Wu, Auteur ; Atsushi Iizuka, Auteur ; Kazukiyo Kumagai, Auteur Année de publication : 2009 Article en page(s) : p. 9871–9877 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Sulfur--Characteristics--Desulfurization Résumé : Dry desulfurization characteristics of waste cement particles were examined with laboratory-scale experimental apparatus based on the weight change of the sample exposed to a gas flow containing SO2. The waste cement particles, a byproduct of recycling aggregates from waste concrete, are fine particles with diameters ranging from 10 to 200 μm and an average diameter of 105 μm. The effects of the operation parameters, i.e., the reaction temperature (650−950 °C), SO2 concentration (61−1543 ppm), oxygen concentration (0−10%), NO2 concentration (0−500 ppm), absolute humidity (0−15000 ppm), and particle size (10−200 μm), on the desulfurization performance were investigated. The desulfurization rates were found to depend on the 1.26th order of the SO2 concentration and to slightly depend on the absolute humidity and the particle size, but they were almost independent of the concentrations of oxygen and NO2 in the gas flow. Arrhenius type temperature dependence was observed up to 850 °C with activation energy of 12 kJ/mol. The observed dry desulfurization rates of the waste cement particle were almost equivalent to those of the conventional sorbents such as limestone and calcium hydroxide. Therefore, it is confirmed that the waste cement particles could be applicable in dry desulfurization as an inexpensive sorbent derived from wastes. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8009654#afn1 [article] Desulfurization characteristics of waste cement particles as a sorbent in dry desulfurization [texte imprimé] / Jiawei Wu, Auteur ; Atsushi Iizuka, Auteur ; Kazukiyo Kumagai, Auteur . - 2009 . - p. 9871–9877. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 n°24 (Décembre 2008) . - p. 9871–9877 Mots-clés : Sulfur--Characteristics--Desulfurization Résumé : Dry desulfurization characteristics of waste cement particles were examined with laboratory-scale experimental apparatus based on the weight change of the sample exposed to a gas flow containing SO2. The waste cement particles, a byproduct of recycling aggregates from waste concrete, are fine particles with diameters ranging from 10 to 200 μm and an average diameter of 105 μm. The effects of the operation parameters, i.e., the reaction temperature (650−950 °C), SO2 concentration (61−1543 ppm), oxygen concentration (0−10%), NO2 concentration (0−500 ppm), absolute humidity (0−15000 ppm), and particle size (10−200 μm), on the desulfurization performance were investigated. The desulfurization rates were found to depend on the 1.26th order of the SO2 concentration and to slightly depend on the absolute humidity and the particle size, but they were almost independent of the concentrations of oxygen and NO2 in the gas flow. Arrhenius type temperature dependence was observed up to 850 °C with activation energy of 12 kJ/mol. The observed dry desulfurization rates of the waste cement particle were almost equivalent to those of the conventional sorbents such as limestone and calcium hydroxide. Therefore, it is confirmed that the waste cement particles could be applicable in dry desulfurization as an inexpensive sorbent derived from wastes. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8009654#afn1

Evaluation of the capacity of hydroxyapaptite prepared from concrete sludge to remove lead from water / Takeshi Sasaki in Industrial & engineering chemistry research, Vol. 50 N° 16 (Août 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 16 (Août 2011) . - pp. 9564-9568 Titre : Evaluation of the capacity of hydroxyapaptite prepared from concrete sludge to remove lead from water Type de document : texte imprimé Auteurs : Takeshi Sasaki, Auteur ; Yuka Sakai, Auteur ; Atsushi Iizuka, Auteur Année de publication : 2011 Article en page(s) : pp. 9564-9568 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Hydroxyapaptite Résumé : Low-crystallinity hydroxyapatite (HAP) was prepared from concrete sludge as a recycling method for concrete waste. The HAP was prepared from model samples of concrete sludge and phosphorus wastewater, and its capacity to remove lead from water was investigated. Lead ions were quickly removed by the HAP particles. Some of the prepared HAP samples reduced the lead concentration of the water to within the Japanese standard for industrial effluent (0.1 ppm). The lead removal capacity of the concrete sludge-derived HAP (506 mg/g) was comparable to that of reagent grade HAP. Lead in water was removed in the form of Pb3(CO3)2(OH)2. These results indicate that HAP prepared from concrete sludge can be applied to removal of lead ions from water. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200233s [article] Evaluation of the capacity of hydroxyapaptite prepared from concrete sludge to remove lead from water [texte imprimé] / Takeshi Sasaki, Auteur ; Yuka Sakai, Auteur ; Atsushi Iizuka, Auteur . - 2011 . - pp. 9564-9568. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 16 (Août 2011) . - pp. 9564-9568 Mots-clés : Hydroxyapaptite Résumé : Low-crystallinity hydroxyapatite (HAP) was prepared from concrete sludge as a recycling method for concrete waste. The HAP was prepared from model samples of concrete sludge and phosphorus wastewater, and its capacity to remove lead from water was investigated. Lead ions were quickly removed by the HAP particles. Some of the prepared HAP samples reduced the lead concentration of the water to within the Japanese standard for industrial effluent (0.1 ppm). The lead removal capacity of the concrete sludge-derived HAP (506 mg/g) was comparable to that of reagent grade HAP. Lead in water was removed in the form of Pb3(CO3)2(OH)2. These results indicate that HAP prepared from concrete sludge can be applied to removal of lead ions from water. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200233s

Improvement of desulfurization performances of waste cement particles by acid treatment / Jiawei Wu in Industrial & engineering chemistry research, Vol. 48 N° 7 (Avril 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 7 (Avril 2009) . - pp. 3303–3307 Titre : Improvement of desulfurization performances of waste cement particles by acid treatment Type de document : texte imprimé Auteurs : Jiawei Wu, Auteur ; Atsushi Iizuka, Auteur ; Kazukiyo Kumagai, Auteur Année de publication : 2009 Article en page(s) : pp. 3303–3307 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Waste  cement  Desulfurization  rate  Acid  treatments Résumé : We studied the effect of acid treatments on the desulfurization rate of waste cement, a byproduct in the recycling of aggregates from waste concrete. Calcium components in the waste cement were partially extracted by treatment with carbonic acid (aqueous solution of high-pressure CO2), hydrochloric acid, or acetic acid. The desulfurization rate was examined using a thermogravimetric method. The desulfurization rates in the initial stage of the reaction (<5 min) were almost unaffected by the treatments with acetic acid and hydrochloric acid, provided the degree of calcium extraction was lower than about 30%. However, the desulfurization rates at a later stage were lower than that of the original waste cement. The desulfurization rates of the waste cement treated with carbonic acid were higher than those of the original sample for all reaction times studied when the degree of calcium extraction was in the range of 4.13−8.54%. The desulfurization rate normalized by the amount of calcium remaining in the waste cement was higher for all samples with acid treatment than for the original sample when the degree of calcium extraction was lower than 60%. The desulfurization rates of the acid-treated waste cements were significantly higher than that of limestone, a conventional sorbent used in dry desulfurization. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801312b [article] Improvement of desulfurization performances of waste cement particles by acid treatment [texte imprimé] / Jiawei Wu, Auteur ; Atsushi Iizuka, Auteur ; Kazukiyo Kumagai, Auteur . - 2009 . - pp. 3303–3307. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 7 (Avril 2009) . - pp. 3303–3307 Mots-clés : Waste  cement  Desulfurization  rate  Acid  treatments Résumé : We studied the effect of acid treatments on the desulfurization rate of waste cement, a byproduct in the recycling of aggregates from waste concrete. Calcium components in the waste cement were partially extracted by treatment with carbonic acid (aqueous solution of high-pressure CO2), hydrochloric acid, or acetic acid. The desulfurization rate was examined using a thermogravimetric method. The desulfurization rates in the initial stage of the reaction (<5 min) were almost unaffected by the treatments with acetic acid and hydrochloric acid, provided the degree of calcium extraction was lower than about 30%. However, the desulfurization rates at a later stage were lower than that of the original waste cement. The desulfurization rates of the waste cement treated with carbonic acid were higher than those of the original sample for all reaction times studied when the degree of calcium extraction was in the range of 4.13−8.54%. The desulfurization rate normalized by the amount of calcium remaining in the waste cement was higher for all samples with acid treatment than for the original sample when the degree of calcium extraction was lower than 60%. The desulfurization rates of the acid-treated waste cements were significantly higher than that of limestone, a conventional sorbent used in dry desulfurization. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801312b

Phosphorus adsorbent derived from concrete sludge (PAdeCS) and its phosphorus recovery performance / Atsushi Iizuka in Industrial & engineering chemistry research, Vol. 51 N° 34 (Août 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11266-11273 Titre : Phosphorus adsorbent derived from concrete sludge (PAdeCS) and its phosphorus recovery performance Type de document : texte imprimé Auteurs : Atsushi Iizuka, Auteur ; Takeshi Sasaki, Auteur ; Teruhisa Hongo, Auteur Année de publication : 2012 Article en page(s) : pp. 11266-11273 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Adsorbents  phosphorus Résumé : Solid adsorbents for phosphorus recovery (PAdeCS) were prepared from real concrete sludge sampled from an industrial site that produces concrete poles and piles. The concrete sludge was diluted with water at dilution ratios from 1 to 15 to prevent hardening of the cement components. The diluted concrete sludge was then filtered, dried, and used as a solid adsorbent. Two drying methods were examined: natural drying under atmospheric conditions and forced drying in an oven at 105 °C. The phosphorus recovery performances of prepared adsorbents were examined using a potassium dihydrogen phosphate (KH2PO4) solution containing 100 mg-P/L (close to the effluent produced by the sewage sludge dewatering process) as a synthetic for wastewater. All the prepared adsorbents were able to recover phosphorus. Using the forced drying treatment during adsorbent preparation greatly improved the rate of phosphorus recovery from solution. The adsorbent prepared with dilution ratio 10 and forced drying exhibited the highest phosphorus recovery performance. The final phosphorus concentration in solution was 0.83 mg/L, 4 h after addition of the optimized adsorbent, which is extremely promising for application in inexpensive phosphorus recovery processes. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301225g [article] Phosphorus adsorbent derived from concrete sludge (PAdeCS) and its phosphorus recovery performance [texte imprimé] / Atsushi Iizuka, Auteur ; Takeshi Sasaki, Auteur ; Teruhisa Hongo, Auteur . - 2012 . - pp. 11266-11273. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11266-11273 Mots-clés : Adsorbents  phosphorus Résumé : Solid adsorbents for phosphorus recovery (PAdeCS) were prepared from real concrete sludge sampled from an industrial site that produces concrete poles and piles. The concrete sludge was diluted with water at dilution ratios from 1 to 15 to prevent hardening of the cement components. The diluted concrete sludge was then filtered, dried, and used as a solid adsorbent. Two drying methods were examined: natural drying under atmospheric conditions and forced drying in an oven at 105 °C. The phosphorus recovery performances of prepared adsorbents were examined using a potassium dihydrogen phosphate (KH2PO4) solution containing 100 mg-P/L (close to the effluent produced by the sewage sludge dewatering process) as a synthetic for wastewater. All the prepared adsorbents were able to recover phosphorus. Using the forced drying treatment during adsorbent preparation greatly improved the rate of phosphorus recovery from solution. The adsorbent prepared with dilution ratio 10 and forced drying exhibited the highest phosphorus recovery performance. The final phosphorus concentration in solution was 0.83 mg/L, 4 h after addition of the optimized adsorbent, which is extremely promising for application in inexpensive phosphorus recovery processes. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301225g

Reaction of tricalcium aluminate with hydrogen chloride under simulated bag filter conditions / Kouki Kasuya in Industrial & engineering chemistry research, Vol. 51 N° 19 (Mai 2012) 

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Simultaneous decomposition and fixation of F - gases using waste concrete / Atsushi Iizuka in Industrial & engineering chemistry research, Vol. 50 N° 21 (Novembre 2011) 

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Utilization of bipolar membrane electrodialysis for the removal of boron from aqueous solution / Hiroki Nagasawa in Industrial & engineering chemistry research, Vol. 50 N° 10 (Mai 2011) 

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