Creation of amorphous ettringite using low temperature dehydration and influence of dehydration temperature on the boron removal amount

Shungo Hobo, Giuseppe Granata, Chiharu Tokoro, Yoshiyuki Tanaka, Takeshi Nakamura

Research output: Contribution to conferencePaper

Abstract

Boron is one of the most important elements in modern industry, in particular in semiconductor manufacturing where it is used as doping agent. Because boron is toxic and difficult to remove from wastewaters, the development of an efficient technology for boron removal is highly anticipated. Among the possible removal methods, the co-precipitation was found capable of determining higher removal performances compared to the adsorption method. In co-precipitation, the method using ettringite as co-precipitating and adsorbing agent seems to be promising. However, the adsorption of boron by previously synthesized ettringite must be improved in order to achieve efficient removal processes. One of the latest improvement implies the use of ettringite upon amorphization at 175? to increase the adsorption capacity towards boron. However, because the use of high temperatures in wastewater treatment dramatically affect the process sustainability, the use of lower temperatures is desirable. In this research, we studied the production of amorphous ettringite with high adsorption capacity at temperatures lower than 100? and we investigated the influence of the dehydration temperature on boron removal performances. In spite of literature data showing the impossibility of amorphization below 100?, our results showed that the ettringite dehydrated in the temperature range 75-95? became amorphous and efficient for boron removal. In particular, the ettringite sample dehydrated at 75? showed a removal efficiency equivalent to samples dehydrated at 175?.

Original languageEnglish
Publication statusPublished - 2017 Jan 1
Event14th International Symposium on East Asian Resources Recycling Technology, EARTH 2017 - Sapporo, Hokkaido, Japan
Duration: 2017 Sep 262017 Sep 29

Conference

Conference14th International Symposium on East Asian Resources Recycling Technology, EARTH 2017
CountryJapan
CitySapporo, Hokkaido
Period17/9/2617/9/29

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Keywords

  • Amorphous
  • Boron
  • Ettringite
  • Wastewater treatment

ASJC Scopus subject areas

  • Environmental Science(all)

Cite this

Hobo, S., Granata, G., Tokoro, C., Tanaka, Y., & Nakamura, T. (2017). Creation of amorphous ettringite using low temperature dehydration and influence of dehydration temperature on the boron removal amount. Paper presented at 14th International Symposium on East Asian Resources Recycling Technology, EARTH 2017, Sapporo, Hokkaido, Japan.