碩士 / 東海大學 / 環境科學與工程學系 / 104 / The thermoacidophilic red algae consist of three genus and seven species, which has been often found in sulfate-enriched hot spring. Such red algae were named as Cyanidiales that is able to tolerate high temperature and acidic environments. Due to such attributes, the Cyanidiales have been considered as a superior material to remove heavy metals such as lead from industrial wastewater and mining areas. In this study, we aimed to determine the retention capacity and develop the retention mechanisms of lead on Cyanidiales in relation to the lead speciation. The sorption isotherm of lead at pH 5.0 on six species of red algae including Galdieria maximum, Galdieria partita, Galdieria phlegrea, Galdieria sulphuraria, Cyanidium caldarium and Cyanidioschyzon merolae was first conducted. Lead retention mechanisms were determined using the Fourier Transform Infrared Spectroscopy (FTIR) and the linear combination fitting (LCF) of lead LIII-edge X-ray absorption spectroscopy (XAS).
The sorption isotherm showed there was more than one step of sorption behaviors for Pb to retain on Cyanidiales. In the first step, the sorption capacity of lead on red algae was in the sequence of Cm (67.57 mg g-1) > Gs (34.84 mg g-1) > Cc (29.07 mg g-1) > Gph (24.33 mg g-1) > Gp (22.42 mg g-1) > Gm (12.85 mg g-1). After the first step, the greatest sorption capacity for each read algae was found in the sequence of Cc (299.36 mg g-1) > Cm (214.04 mg g-1) > Gp (128.64 mg g-1) > Gph (115.53 mg g-1) > Gs (108.77 mg g-1) > Gm (38.20 mg g-1). The FTIR analyses revealed that Amide I (C=O) and Amide II (C-N) functional groups were mainly responsible for the sorption of lead. Linear combination fitting of the XAS data showed that lead is mainly reacted with organic fractions in the system. The organic species of lead was determined as lead bound to the cell wall of plant and humate. The XAS data also suggested that lead might be precipitated on the surfaces of red algae. Conclusionly, the retention mechanisms of lead on Cyanidioales might be (1) lead bound with proteins and surface functional groups of the algae and (2) lead precipitated on the surfaces of the algae.
| Identifer | oai:union.ndltd.org:TW/104THU00518014 |
| Date | January 2016 |
| Creators | CHO, YEN-LIN, 卓宴琳 |
| Contributors | PENG, YEN-PING, LIU, YU-TING, 彭彥彬, 劉雨庭 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 107 |
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