[Ecological Effects of Species Diversity on Plant Growth and Physico-Chemical Properties in a Pb-Zn Mine Tailings].

The remediation of metalliferous mine tailings remains a challenge in many regions of the world. A field experiment was conducted on representative Pb-Zn mine tailings with different species richness (1-, 4-, 8-, and 16-species) to evaluate the potential roles of species diversity in the phytoremediation of metalliferous mine tailings. The main results were ① high species diversity greatly enhanced vegetation cover and biomass.

A 100-Mhz Bandwidth 80-dB Dynamic Range Continuous-Time Delta-Sigma Modulator with a 2.4-Ghz Clock Rate.

The bandwidth of a ΔΣ modulator is limited by the clock rate due to the oversampling ratio requirement. As the nanoscale CMOS processes are developing rapidly, it is possible to design wide bandwidth and high dynamic range continuous-time ΔΣ modulators for high-frequency applications. This paper proposes a 3rd-order 4-bit continuous-time ΔΣ modulator with a single-loop feedforward topology.

[Effects of Amendments with Different C/N/P Ratios on Plant and Soil Properties of a Pb-Zn Mine Tailings].

A field trial was conducted with abandoned Pb-Zn mine tailings to evaluate the effectiveness of amendments with different C/N/P ratios on plant growth, soil nutrients and enzyme activities, and heavy metal concentrations in plant tissues and the mine tailings. The following results were noted. ①The application of amendments with different C/N/P ratios promoted plant growth and development.

Field comparison of the effectiveness of agricultural and nonagricultural organic wastes for aided phytostabilization of a Pb-Zn mine tailings pond in Hunan Province, China.

To date, very few attempts have been made to systematically compare the effectiveness of agricultural and nonagricultural organic wastes for aided phytostabilization of mine tailings under field conditions. In this study, we performed a field trial to compare the effectiveness of three agricultural organic wastes: chicken manure (CM), crop straw (CS), and spent mushroom compost (SMC), with that of three nonagricultural organic wastes, municipal sludge (MS), medicinal herb residues (MHR), and sweet sorghum vinasse (SSV) for aided phytostabilization of a Pb-Zn mine tailings pond in Hunan Province, China. Eight plant species naturally established in the vicinity of the mine were selected and seeded onto trial plots.

[Effects of Three Industrial Organic Wastes as Amendments on Plant Growth and the Biochemical Properties of a Pb/Zn Mine Tailings].

A field trial was conducted in an abandoned Pb/Zn mine tailings to evaluate the effectiveness of three industrial wastes [sweet sorghum vinasse (SSV), medicinal herb residues (MHR) and spent mushroom compost (SMC)] as organic amendments on plant growth, soil nutrients and enzyme activities, and heavy metal concentrations in plant tissues and the mine tailings. (1) The main findings were as follows: (1) The mean concentrations of diethylene-triamine-pentaacetic acid (DTPA)-extractable Cd, Cu, Pb and Zn in SSV, MHR and SMC treatments decreased by 24.2%-27.

Field evaluation of the effectiveness of three industrial by-products as organic amendments for phytostabilization of a Pb/Zn mine tailings.

Although the potential of industrial by-products as organic amendments for phytostabilization has long been recognized, most of the previous studies addressing this issue have been laboratory-based. In this study, a field trial was conducted to evaluate the effectiveness of three industrial by-products [sweet sorghum vinasse (SSV), medicinal herb residues (MHR) and spent mushroom compost (SMC)] as organic amendments for phytostabilization of abandoned Pb/Zn mine tailings. Our results showed the following: (i) when compared to the control tailings, the mean concentrations of diethylene-triamine-pentaacetic acid (DTPA)-extractable Cd, Cu, Pb and Zn in SSV, MHR and SMC treatments decreased by 20.