Paraquat adsorption on porous materials synthesized from rice husk silica

• Published in: Water science and technology Vol. 68; no. 4; pp. 863 - 869
• Main Authors: RONGCHAPO, Wina, ONSULANG SOPHIPHUN, RINTRAMEE, Kamolwan, PRAYOONPOKARACH, Sanchai, WITTAYAKUN, Jatuporn
• Format: Journal Article
• Language: English
• Published: London International Water Association 01.01.2013; IWA Publishing
• Subjects: Adsorbents; Adsorption; Applied sciences; Biopsy; Capacity; Cation exchange; Cation exchanging; Cations; Dyes; Exact sciences and technology; Herbicides; Herbicides - chemistry; Molecular Structure; Operating costs; Oryza; Oryza - chemistry; Oryza sativa; Paraquat; Paraquat - chemistry; Pollution; Porous materials; Production costs; Silica; Silicon dioxide; Silicon Dioxide - chemistry; Synthesis; Water Pollutants, Chemical - chemistry; Water treatment and pollution; Zeolites; Organic waste; Dyes; Zeolite; MCM-41; Rice by product; Porous material; Silica; Vegetal waste; blue dye; zeolites; Adsorption; rice husk silica; Paraquat; paraquat adsorption; Agricultural waste
• ISSN: 0273-1223; 1996-9732
• DOI: 10.2166/wst.2013.311

The goal of this work was to utilize rice husk silica (RHS) and porous materials synthesized with RHS, including mesoporous material (MCM-41) and microporous materials (zeolite NaY and NaBEA), for adsorption of herbicide paraquat. The adsorption occurred although cation exchange and the capacity decreased in the following order: NaY > NaBEA > MCM-41 > RHS, consistent with the amount of Al. The adsorption on all adsorbents fitted well with the Langmuir model and the maximum adsorption capacity of 185.2 mg/g-adsorbent was obtained on NaY. In addition, blue dye in commercial grade paraquat did not interfere with paraquat adsorption. Although MCM-41 was the most efficient adsorbent for the blue dye, RHS was favorable in terms of production cost. A mixture of NaY and RHS is recommended for simultaneous adsorption of paraquat and blue dye.