Zhangjiangkou Mangrove National Nature Reserve is a subtropical wetland ecosystem in southeast coast of China, which is of dense population and rapid development. The concentrations, sources, and pollution assessment of trace metals (Cu, Cd, Pb, Cr, Zn, As, and Hg) in surface sediment from 29 sites and the biota specimen were investigated for better ecological risk assessment and environmental management. The ranges of trace metals in mg/kg sediment were as follows: Cu (10.79–26.66), Cd (0.03–0.19), Pb (36.71–59.86), Cr (9.67–134.51), Zn (119.69–157.84), As (15.65–31.60), and Hg (0.00–0.08). The sequences of the bioaccumulation of studied metals are Zn > Cu > As > Cr > Pb > Cd > Hg with few exceptions. Cluster analysis and principal component analysis revealed that the trace metals in the studied area mainly derived from anthropogenic activities, such as industrial effluents, agricultural waste, and domestic sewage. Pollution load index and geoaccumulation index were calculated for trace metals in surface sediments, which indicated unpolluted status in general except Pb, Cr, and As.
Environmental monitoring is fundamental in assessing environmental quality and to fulfill protection and management measures with permit conditions. However, coastal environmental monitoring work faces many problems and challenges, including the fact that monitoring information cannot be linked up with evaluation, monitoring data cannot well reflect the current coastal environmental condition, and monitoring activities are limited by cost constraints. For these reasons, protection and management measures cannot be developed and implemented well by policy makers who intend to solve this issue. In this paper, Quanzhou Bay in southeastern China was selected as a case study; and the Kriging method and a geographic information system were employed to evaluate and optimize the existing monitoring network in a semienclosed bay. This study used coastal environmental monitoring data from 15 sites (including COD, DIN, and PO4-P) to adequately analyze the water quality from 2009 to 2012 by applying the Trophic State Index. The monitoring network in Quanzhou Bay was evaluated and optimized, with the number of sites increased from 15 to 24, and the monitoring precision improved by 32.9%. The results demonstrated that the proposed advanced monitoring network optimization was appropriate for environmental monitoring in Quanzhou Bay. It might provide technical support for coastal management and pollutant reduction in similar areas.
White wastes (unseparated plastics,
face masks, textiles, etc.)
pose a serious challenge to sustainable human development and the
ecosystem and have recently been exacerbated due to the surge in plastic
usage and medical wastes from COVID-19. Current recycling methods
such as chemical recycling, mechanical recycling, and incineration
require either pre-sorting and washing or releasing CO2. In this work, a carbon foam microwave plasma process is developed,
utilizing plasma discharge to generate surface temperatures exceeding
∼3000 K in a N2 atmosphere, to convert unsorted
white wastes into gases (H2, CO, C2H4, C3H6, CH4, etc.) and small amounts
of inorganic minerals and solid carbon, which can be buried as artificial
“coal”. This process is self-perpetuating, as the new
solid carbon asperities grafted onto the foam’s surface actually
increase the plasma discharge efficiency over time. This process has
been characterized by in situ optical probes and
infrared sensors and optimized to handle most of the forms of white
waste without the need for pre-sorting or washing. Thermal measurement
and modeling show that in a flowing reactor, the device can achieve
locally extremely high temperatures, but the container wall will still
be cold and can be made with cheap materials, and thus, a miniaturized
waste incinerator is possible that also takes advantage of intermittent
renewable electricity.
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