Spartina alterniflora is a foreign introduced species and has far-reaching effects on salt marsh ecosystems, particularly on the biogeochemical cycle of heavy metals. To ascertain whether the invasive plant Spartina a...Spartina alterniflora is a foreign introduced species and has far-reaching effects on salt marsh ecosystems, particularly on the biogeochemical cycle of heavy metals. To ascertain whether the invasive plant Spartina alterniflora Loisel is a source of metals in the environment, we determined the bimonthly concentrations of heavy metals, chromium(Cr), lead(Pb), copper(Cu), zinc(Zn),and manganese(Mn), in the roots, stems, and leaves of S. alterniflora from a typical semidiurnal tidal zone in the coastal area of northern Jiangsu Province, China. Based on the measurements, we calculated annual metal primary accumulation and output. To calculate the annual output of heavy metals from S. alterniflora, a new method that calculates the annual rate of biomass loss and decomposition was developed. The annual primary accumulation of Cr, Pb, Cu, Zn, and Mn was 19.08, 84.19, 63.74, 442.58, and774.66 mg m^(-2), respectively, and the annual output from S. alterniflora to the surrounding environment was 4.01, 18.09, 14.00, 97.11,and 164.28 mg m^(-2), respectively. Spartina alterniflora only provides temporary storage, and its absorption of heavy metals could be used to remediate contaminated soil and for phytomining. The heavy metals released by S. alterniflora to the environment cannot be ignored; thus, S. alterniflora should be considered a source of metal contamination. Therefore, when we evaluate the remarkable ability of certain plant species to concentrate metals in their tissues, the balance between heavy metal accumulation and output should be considered.展开更多
A new way is described to recover nickel from common rock-types, by the use of nickel hyperaccumulator plants. The idea of phytomining nickel was suggested earlier, but never implemented. This situation may soon chang...A new way is described to recover nickel from common rock-types, by the use of nickel hyperaccumulator plants. The idea of phytomining nickel was suggested earlier, but never implemented. This situation may soon change, because the mining sector suffers from a poor image on account of the impact of mining on the environment, and would like to reduce the pollution and high energy consumption associated with metal extraction. Once phytomining is established as a viable way of nickel production, it is likely that governments will impose nickel mines to realize part of their nickel production by this method. This will lead to a considerable decrease of CO2 emissions. Phytomining from rocks rich in olivine or serpentine is CO2-negative. When metal extraction goes hand in hand with CO2 sequestration, it will improve the image of the mining sector. Other advantages include that unproductive soils can serve to grow nickel hyperaccumulator plants and recover nickel. The extensive mining technology can provide employment to many poor farmers/miners. Countries that want to be self-sufficient in strategic materials, and avoid spending foreign currency on importing them can switch to phytomining. This paper treats different aspects of future nickel farming.展开更多
基金supported by the National Basic Research Program of China (No. 2013CB956503)the Ocean Public Welfare Special Project “Space Development and Utilization and Environmental Ecological Assessment Technology in South Yellow Sand Ridge” of the National Oceanic Administration, China (No. 2010418006)the Open Fund of the Marine Sediments and Environmental Geology Bureau National Key Laboratory, China (No. MASEG201205)
文摘Spartina alterniflora is a foreign introduced species and has far-reaching effects on salt marsh ecosystems, particularly on the biogeochemical cycle of heavy metals. To ascertain whether the invasive plant Spartina alterniflora Loisel is a source of metals in the environment, we determined the bimonthly concentrations of heavy metals, chromium(Cr), lead(Pb), copper(Cu), zinc(Zn),and manganese(Mn), in the roots, stems, and leaves of S. alterniflora from a typical semidiurnal tidal zone in the coastal area of northern Jiangsu Province, China. Based on the measurements, we calculated annual metal primary accumulation and output. To calculate the annual output of heavy metals from S. alterniflora, a new method that calculates the annual rate of biomass loss and decomposition was developed. The annual primary accumulation of Cr, Pb, Cu, Zn, and Mn was 19.08, 84.19, 63.74, 442.58, and774.66 mg m^(-2), respectively, and the annual output from S. alterniflora to the surrounding environment was 4.01, 18.09, 14.00, 97.11,and 164.28 mg m^(-2), respectively. Spartina alterniflora only provides temporary storage, and its absorption of heavy metals could be used to remediate contaminated soil and for phytomining. The heavy metals released by S. alterniflora to the environment cannot be ignored; thus, S. alterniflora should be considered a source of metal contamination. Therefore, when we evaluate the remarkable ability of certain plant species to concentrate metals in their tissues, the balance between heavy metal accumulation and output should be considered.
文摘A new way is described to recover nickel from common rock-types, by the use of nickel hyperaccumulator plants. The idea of phytomining nickel was suggested earlier, but never implemented. This situation may soon change, because the mining sector suffers from a poor image on account of the impact of mining on the environment, and would like to reduce the pollution and high energy consumption associated with metal extraction. Once phytomining is established as a viable way of nickel production, it is likely that governments will impose nickel mines to realize part of their nickel production by this method. This will lead to a considerable decrease of CO2 emissions. Phytomining from rocks rich in olivine or serpentine is CO2-negative. When metal extraction goes hand in hand with CO2 sequestration, it will improve the image of the mining sector. Other advantages include that unproductive soils can serve to grow nickel hyperaccumulator plants and recover nickel. The extensive mining technology can provide employment to many poor farmers/miners. Countries that want to be self-sufficient in strategic materials, and avoid spending foreign currency on importing them can switch to phytomining. This paper treats different aspects of future nickel farming.
