Zinc is one of the hazardous metals commonly found in municipal solid waste incineration （MSWI） ash, and this study reveals the stabilization mechanisms when sintering zinc-laden ash and ceramic precursors as a wast...Zinc is one of the hazardous metals commonly found in municipal solid waste incineration （MSWI） ash, and this study reveals the stabilization mechanisms when sintering zinc-laden ash and ceramic precursors as a waste-to-resource strategy. Using ZnO to simulate the zinc-laden ash and sintering with kaolinite and mullite ce- ramic precursors, both zinc aluminate spinel （ZnA1204） and willemite （Zn2SiO4） phases were found in the products under the tested thermal conditions. The results also indicate that kaolinite and mullite precursors exhibit different incorporation behavior, and ZnA1204 and Zn2SiO4 were found to be competitive as the Zn-hosting phases in the system. A prolonged leaching test was used to evaluate the leachability of potential product phases in the system. The concentrations of zinc in ZnO and Zn2SiO4 leachates were about two orders of magnitude higher than that in ZnA1204 leachate, indicating the preference of forming ZnA1204 for zinc stabilization. Furthermore, the alumi- num-rich sludge generated from waterworks could be beneficially used as a material resource to stabilize zinc in this study. The X-ray diffraction （XRD） pattern collected from the 1150 ~C and 3-h sintered sample shows the suc- cess of incorporating zinc into the ZnA1204 spinel structure with waterworks sludge precursor. The formation of ZnA1204 indicates a strong potential for employing aluminum- and silicon-based materials to thermally immobilize zinc and achieve the beneficial use of metal-laden MSWI ash.展开更多
The goal of our study is to present results about the effects of selected industrial wastes-sewage sludge, lime sludge, compost-on the physiological parameters of plants. Maize seedlings （Zea mays L cvs. Norma SC） w...The goal of our study is to present results about the effects of selected industrial wastes-sewage sludge, lime sludge, compost-on the physiological parameters of plants. Maize seedlings （Zea mays L cvs. Norma SC） were used in soil plant （rhizobox） and nutrient solution plant system. The filtrates of the examined materials were used in the nutrient solution and the raw materials in the soil. Dry matter accumulation of shoots and roots, relative chlorophyll contents and the contents of some elements were measured in the plants grown on the nutrient solution. The examined materials contain some useful elements for plants e.g. Cu, Fe, K, and Mg and plenty of toxic metals e.g. AI, Cr. Root growth in the rhizoboxes was monitored, as well as that of roots in the experiment using soil. This type of growth was more intensive with the use of lime sludge than with of sewage sludge. On the other hand, the results were better at the sewage sludge than the lime sludge on the nutrient solution.展开更多
基金Supported by the General Research Fund Scheme(HKU 716809E,HKU 716310E)Special Equipment Grant(SEG_HKU10) of the Research Grants Council of Hong Kong
文摘Zinc is one of the hazardous metals commonly found in municipal solid waste incineration （MSWI） ash, and this study reveals the stabilization mechanisms when sintering zinc-laden ash and ceramic precursors as a waste-to-resource strategy. Using ZnO to simulate the zinc-laden ash and sintering with kaolinite and mullite ce- ramic precursors, both zinc aluminate spinel （ZnA1204） and willemite （Zn2SiO4） phases were found in the products under the tested thermal conditions. The results also indicate that kaolinite and mullite precursors exhibit different incorporation behavior, and ZnA1204 and Zn2SiO4 were found to be competitive as the Zn-hosting phases in the system. A prolonged leaching test was used to evaluate the leachability of potential product phases in the system. The concentrations of zinc in ZnO and Zn2SiO4 leachates were about two orders of magnitude higher than that in ZnA1204 leachate, indicating the preference of forming ZnA1204 for zinc stabilization. Furthermore, the alumi- num-rich sludge generated from waterworks could be beneficially used as a material resource to stabilize zinc in this study. The X-ray diffraction （XRD） pattern collected from the 1150 ~C and 3-h sintered sample shows the suc- cess of incorporating zinc into the ZnA1204 spinel structure with waterworks sludge precursor. The formation of ZnA1204 indicates a strong potential for employing aluminum- and silicon-based materials to thermally immobilize zinc and achieve the beneficial use of metal-laden MSWI ash.
文摘The goal of our study is to present results about the effects of selected industrial wastes-sewage sludge, lime sludge, compost-on the physiological parameters of plants. Maize seedlings （Zea mays L cvs. Norma SC） were used in soil plant （rhizobox） and nutrient solution plant system. The filtrates of the examined materials were used in the nutrient solution and the raw materials in the soil. Dry matter accumulation of shoots and roots, relative chlorophyll contents and the contents of some elements were measured in the plants grown on the nutrient solution. The examined materials contain some useful elements for plants e.g. Cu, Fe, K, and Mg and plenty of toxic metals e.g. AI, Cr. Root growth in the rhizoboxes was monitored, as well as that of roots in the experiment using soil. This type of growth was more intensive with the use of lime sludge than with of sewage sludge. On the other hand, the results were better at the sewage sludge than the lime sludge on the nutrient solution.
