Browsing by Author "Dong, Ziping"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
Item Open Access Arsenic transformation behaviour during thermal decomposition of P. vittata, an arsenic hyperaccumulator(Elsevier, 2017-01-22) Duan, Lunbo; Li, Xiaole; Jiang, Ying; Lei, Mei; Dong, Ziping; Longhurst, Philip J.Thermal treatment of P. vittata, an arsenic hyperaccumulator harvested from contaminated land is a promising method of achieving volume reduction, energy production and arsenic (As) recovery simultaneously. In this paper, the arsenic transformation characteristics of field-harvested P. vittata were investigated during its pyrolysis and gasification process. The produced solid residue and flue gas were analysed by a high performance liquid chromatography coupled with inductively coupled plasma mass spectrometry (HPLC-ICP-MS) to determine both the arsenic concentration and speciation. Moreover, the occurrence of arsenic in the solid residues was further identified as soluble and insoluble, which can feed information to the next arsenic recovery step. Results show that the fuel arsenic into gas phase increases firstly from 400 °C to 600 °C, but then drops from 600 °C to 800 °C, probably due to the self-retention of arsenic by CaO enriched in this P. vittata. Further increasing temperature to 900 °C will result in fast arsenic release. Gasification results in slightly higher arsenic release into the gas phase compared with pyrolysisItem Open Access Reaction mechanism of arsenic capture by a calcium-based sorbent during the combustion of arsenic-contaminated biomass: A pilot-scale experience(Springer, 2019-03-28) Lei, Mei; Dong, Ziping; Jiang, Ying; Longhurst, Philip; Wan, Xiaoming; Zhou, GuangdongLarge quantities of contaminated biomass due to phytoremediation were disposed through combustion in low-income rural regions of China. This process provided a solution to reduce waste volume and disposal cost. Pilot-scale combustion trials were conducted for in site disposal at phytoremediation sites. The reaction mechanism of arsenic capture during pilot-scale combustion should be determined to control the arsenic emission in flue gas. This study investigated three Pteris vittata L. biomass with a disposal capacity of 600 kg/d and different arsenic concentrations from three sites in China. The arsenic concentration in flue gas was greater than that of the national standard in the trial with no emission control, and the arsenic concentration in biomass was 486 mg/kg. CaO addition notably reduced arsenic emission in flue gas, and absorption was efficient when CaO was mixed with biomass at 10% of the total weight. For the trial with 10% CaO addition, arsenic recovery from ash reached 76%, which is an ∼8-fold increase compared with the control. Synchrotron radiation analysis confirmed that calcium arsenate is the dominant reaction product.