Publications by authors named "PoKeung Eric Tsang"

Phyllanthus emblica L. fruit extract (PFE) was introduced to improve ZVI/HO technology, and the efficiency and mechanism of PFE promoting ZVI/HO technology were explored. With the introduction of PFE, the Norfloxacin (NOR) removal rate and k of the process were improved by 41.

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Molecularly imprinted magnetic biochar (MBC@MIPs) was synthesized through molecular imprinting precipitation polymerization. This material demonstrated a selective adsorption capacity of oxytetracycline (OTC) from water samples. Upon characterization of MBC@MIPs, results revealed the formation of a memory cavity shell layer on the magnetic biochar's surface, exhibiting a distinctive recognition effect alongside commendable magnetic and thermal stability.

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The conventional ZVI/HO technology suffers from poor reagent utilization, excess iron sludge generation, and strong low pH dependence. Therefore, eucalyptus leaf extract (ELE) was introduced to improve ZVI/HO technology, and the efficacy and mechanism of ELE promoting ZVI/HO technology were deeply explored. The results showed that the norfloxacin (NOR) removal and k of the ZVI/HO/ELE process were enhanced by 35.

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To overcome the bottlenecks of the conventional zero-valent iron Fenton-like (ZVI/HO) process, such as low reagent utilization, low applicable pH, and iron sludge contamination, guava leaf extract (GLE) was used as a green promoter to enhance ZVI/HO process in this study. Compared with the ZVI/HO system, the removal rate and k of norfloxacin by the ZVI/HO/GLE system were increased by 33.76% and 2.

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The problem of low adsorption capacity of pristine magnetic biochar for organic pollutants always occurs. It is of great significance to select a suitable method to improve the adsorption performance of magnetic biochar. In this study, magnetic biochar was treated by ball milling and tested for its fluconazole adsorption capacity.

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Mechanochemistry has been proved to be an effective method to remediation of organic-contaminated sites. However, the high ball-to-powder mass ratio (C) limits the large-scale application of mechanochemistry. In this study, co-milling additives were introduced to enhance the mechanochemical degradation of decabromodiphenyl ether (BDE209)-contaminated soil under the condition of low C.

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Aging effects play a crucial role in determining applications of green-synthesised iron-based nanoparticles in wastewater treatment from laboratory scale to practical applications. In this study, iron-based nanoparticles (Ec-Fe-NPs) were synthesised using the extract of Eichhornia crassipes and ferric chloride. Scanning electron microscopy (SEM) revealed that the fresh Ec-Fe-NPs were spherical and had a narrow particle size range (50 to 80 nm).

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In this study, Fenton-like catalysts (magnetic biochar) were synthesised by pyrolysis the different biomass pre-impregnated with steel pickling waste liquor. The results of degradation of metronidazole illustrated that the catalytic performance of magnetic biochar was significantly affected by biomass feedstocks. Electron spin resonance (ESR) and radical quenching experiments showed that the hydroxide radicals (OH) were the key reactive oxygen species responsible for the metronidazole removal.

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The removal of contaminants by iron-based nanomaterials was inevitably affected by the natural organic matter (NOM), which is one of the most abundant material on earth and exists in natural waters. This study was performed to investigate the main influence of humic acid (HA, representing NOM) on the behavior and reactivity of Ni/Fe nanoparticles in the removal of deca-brominated diphenyl ether (BDE209). Generally, the inhibitory effect of HA on the removal of BDE209 by Ni/Fe showed greater significance with an increase of HA concentration.

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In vivo studies of the interactions of polybrominated diphenyl ethers (PBDEs) in plants have generally focused on uptake, translocation, metabolism and accumulation, but there were limited reports about the phytotoxicity and translocation of PBDEs in contaminated soil with the effects of nanoparticles. In this study, the effects of Ni/Fe bimetallic nanoparticles on translocation of polybrominated diphenyl ethers (PBDEs) in contaminated soil and its phytotoxicity to Chinese cabbage were investigated by soil culture experiments. The results showed that the plant biomass, germination rate, and shoot and root lengths of treated soil (S-5) increased by 0.

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In this study, a kind of biochar-supported nano-hydroxyapatite (nHAP@BC) material was used in in-situ remediation of lead-contaminated soil. Column experiments were performed to compare the mobility of nHAP@BC and Bare-nHAP. The immobilization, accumulation and toxic effects of Pb in the after-amended soil were assessed by the in vitro toxicity tests and pot experiments.

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In this study, a kind of high-efficiency and low-cost biochar-supported zero-valent iron nanoparticles (nZVI@BC) was synthesised and used in the remediation of Cr(VI)-contaminated soil. The remediation tests indicated that the immobilisation efficiency of Cr(VI) and Crtotal was 100% and 91.94%, respectively, by 8g nZVI@BC per kg soil for 15 d of remediation.

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In this study, a high efficiency and low cost biochar-supported nano-hydroxyapatite (nHAP@BC) material was used in the remediation of lead (Pb)-contaminated soil. The remediation effect of nHAP@BC on Pb-contaminated soil was evaluated through batch experiments. The stability, bioaccessibility of Pb in the soil and the change in soil characteristics are discussed.

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This paper was aimed to study the impact of "ageing" (aged in non-saturated soil for 2 and 4 weeks prior to exposure) nanoscale zero-valent iron (nZVI) on the terrestrial plant. The effects of nZVI on Oryza Sativa germination, seedlings growth, chlorophyll biosynthesis, oxidative stress and the activities of antioxidant enzymes at low (250 mg/kg) and high (1000 mg/kg) concentrations were investigated in this study. The results showed that neither the freshly added nor the "ageing" nZVI to the soil had a significant effect on germination, regardless of concentration.

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In this study, a biochar-supported nanoscale zero-valent iron (nZVI@BC) material was used for in situ remediation of hexavalent chromium-contaminated soil. Sedimentation tests and column experiments were used to compare the stability and mobility of nZVI@BC and bare-nZVI. The immobilisation efficiency of chromium, toxic effect of chromium and the content of iron were assessed through leaching tests and pot experiments.

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In this study, the effects of concentrations 0, 100, 250, 500, 750 and 1000 mg kg(-1) of nanoscale zero-valent iron (nZVI) on germination, seedlings growth, physiology and toxicity mechanisms were investigated. The results showed that nZVI had no effect on germination, but inhibited the rice seedlings growth in higher concentrations (>500 mg kg(-1) nZVI). The highest suppression rate of the length of roots and shoots reached 46.

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Polybrominated diphenyl ethers (PBDEs) are a new class of environmental pollutants which easily accumulated in the soil, especially at e-waste sites. However, knowledge about their phytotoxicity after degradation is not well understood. Nano zero valent iron (nZVI) immobilized in mesoporous silica microspheres covered with FeOOH (SiO2@FeOOH@Fe) synthesized in this study was utilized to remove decabromodiphenyl ether (BDE209) from soil.

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Abstract: In order to enhance the content of secondary metabolites patchouli alcohol in Pogostemon cablin, we induced polyploid hairy roots and their plant regeneration, and determined the content of patchouli alcohol through artificial chromosome doubling with colchicine. The highest rate of polyploidy induction was more than 40% when hairy roots were treated with 0.05% colchicine for 36 h.

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Polybrominated diphenyl ethers (PBDEs) are commonly used as additive flame retardants in all kinds of electronic products. PBDEs are now ubiquitous in the environment, with soil as a major sink, especially in e-waste recycling sites. This study investigated the degradation of decabromodiphenyl ether (BDE209) in a spiked soil using Ni/Fe bimetallic nanoparticles.

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Metronidazole (MNZ) is an antibiotic pollutant with a high occurrence in the ambient medium. In this study, the anode material Ti/SnO2-Sb-Ce prepared in the lab was employed to investigate the feasibility of the electrochemical process to treat antibiotic in wastewater. The result showed that metronidazole could be effectively removed using Ti/SnO2-Sb-Ce.

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In order to study the physiological mechanism of exogenous calcium on the toxicity of heavy metal cadmium (Cd) to Wedelia trilobata hairy roots, the effects of Cd alone, and in combination with different concentrations of Ca on growth, contents of soluble protein and malondialdehyde (MDA), activities of superoxide dismutase (SOD) and peroxidase (POD), Cd2+ absorption in W. trilobata hairy roots were investigated. Cd concentrations lower than 50 micromol/L enhanced the growth of hairy roots, while concentrations higher than 100 micromol/L inhibited growth, making the branched roots short and small, and also turning the root tips brown, even black.

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