Effect of pyrolysis conditions on bone char characterization and its ability for arsenic and fluoride removal
- Authors: Alkurdi, Susan , Al-Juboori, Raed , Bundschuh, Jochen , Bowtell, Les , McKnight, Stafford
- Date: 2020
- Type: Text , Journal article
- Relation: Environmental Pollution Vol. 262, no. (2020), p.
- Full Text: false
- Reviewed:
- Description: This study examined arsenite [As(III)], arsenate [As(V)] and fluoride (F−) removal potential of bone char produced from sheep (Ovis aries) bone waste. Pyrolysis conditions tested were in the 500 °C–900 °C range, for a holding time of 1 or 2 h, with or without N2 gas purging. Previous bone char studies mainly focused on either low or high temperature range with limited information provided on As(III) removal. This study aims to address these gaps and provide insights into the effect of pyrolysis conditions on bone char sorption capacity. A range of advanced chemical analyses were employed to track the change in bone char properties. As pyrolysis temperature and holding time increased, the resulting pH, surface charge, surface roughness, crystallinity, pore size and CEC all increased, accompanied by a decrease in the acidic functional groups and surface area. Pyrolysis temperature was a key parameter, showing improvement in the removal of both As(III) and As(V) as pyrolysis temperature was increased, while As(V) removal was higher than As(III) removal overall. F− removal displayed an inverse relationship with increasing pyrolysis temperature. Bone char prepared at 500 °C released significantly more dissolved organic carbon (DOC) then those prepared at a higher temperature. The bone protein is believed to be a major factor. The predominant removal mechanisms for As were surface complexation, precipitation and interaction with nitrogenous functional groups. Whereas F− removal was mainly influenced by interaction with oxygen functional groups and electrostatic interaction. This study recommends that the bone char pyrolysis temperature used for As and F− removal are 900 °C and 650 °C, respectively. © 2020 Elsevier Ltd
- Description: This research was performed as a part of PhD research which was supported in part by the Iraqi Government and the Australian Research Training Program.
Pulsed ultrasound as an energy saving mode for ultrasound treatment of surface water with terrestrial aquatic carbon
- Authors: Al-Juboori, Raed , Yusaf, Talal , Bowtell, Leslie
- Date: 2018
- Type: Text , Journal article
- Relation: Desalination and Water Treatment Vol. 135, no. (2018), p. 167-176
- Full Text: false
- Reviewed:
- Description: The use of ultrasound technology in water treatment has gained great popularity in recent years owing to its benign environmental effects. The evaluation of this technology for water treatment purposes has mostly been conducted using synthetic water samples. This study however investigated the use of ultrasound for treating natural water with organic carbon predominantly derived from terrestrial sources. Ultrasound treatments were applied in continuous and pulsed modes with a range of On: Off ratios (R) and power intensity of 21.5 W/cm2 for 4 min. Physio-chemical and spectroscopic measurements were applied to determine the effect of ultrasound treatments on the concentration and structure of dissolved organic carbon (DOC) in the treated water. Post-hoc statistical analysis at a significance level of 0.05 showed that the performance of pulsed ultrasound treatments at least at one of pulse settings was better than that of continuous treatment. Overall, it was found that ultrasound treatments decreased DOC in the treated water and altered its nature to become more reactive towards oxidation and electrochemical reactions. Energy and cost analysis for DOC removal have also been conducted and results showed that applying the appropriate pulse settings can reduce the cost of the treatment by more than a half.