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Microbial Fuel Cells (MFC) can be fuelled using biomass derived from dead plant material and can operate on plant produced chemicals such as sugars, carbohydrates, polysaccharides and cellulose, as well as being “fed” on a regular diet of primary biomass from plants or algae. An even closer relationship can exist if algae (e.g., prokaryotic microalgae or eukaryotic and unicellular algae) can colonise the open to air cathode chambers of MFCs driving photosynthesis, producing a high redox gradient due to the oxygenic phase of collective algal cells. The hybrid system is symbiotic; the conditions within the cathodic chamber favour the growth of microalgae whilst the increased redox and production of oxygen by the algae, favour a more powerful cathode giving a higher maximum voltage and power to the photo-microbial fuel cell, which can ultimately be harvested for a range of end-user applications. MFCs can utilise a wide range of plant derived materials including detritus, plant composts, rhizodeposits, root exudates, dead or dying macro- or microalgae, via Soil-based Microbial Fuel Cells, Sediment Microbial Fuel Cells, Plant-based microbial fuel cells, floating artificial islands and constructed artificial wetlands. This review provides a perspective on this aspect of the technology as yet another attribute of the benevolent Bioelectrochemical Systems.

This study focused on the water quality of a river in Wuhan City, China, which is surrounded by ponds that were transformed into a bypass multipond wetland system to improve river water quality. The bypass multipond wetland system included surface-flow artificial wetlands, modified partition ponds, aeration reoxygenation ponds, ecological ponds, and other processes. After the stable operation of the process, the water transparency was higher than 60 cm and the dissolved oxygen (DO) was higher than 5 mg/L, while the ammonia nitrogen (NH3-N) concentration was less than 1.0 mg/L, total phosphorus (TP) was lower than 0.2 mg/L, and chemical oxygen demand (COD) was lower than 20 mg/L, achieving the treatment target. After monitoring the results of each process, the process which best enhanced the water transparency enhancement was the surface-flow of the artificial wetlands and ecological ponds. The aeration reoxygenation pond had the best effect on DO enhancement. The processes that most affected NH3-N and TP removal were the surface-flow artificial wetlands and ecological ponds. The modified parthenogenic pond had the greatest effect on COD removal. The bypass multipond wetland system not only improved the river water quality but also enhanced the river landscape, and can act as a reference for similar river water quality improvement actions.

Two wetland maps for the entire China have been produced based on Landsat data acquired around 1990 and 2000. Wetlands in China have been divided into 3 broad categories with 15 sub-categories except rice fields. In 1990, the total wetland area in China was 355208 km 2 whereas in 2000 it dropped to 304849 km 2 with a net loss of 50360 km 2 . During an approximate 10-year period, inland wetland reduced from 318326 to 257922 km 2 , coastal wetland dropped from 14335 to 12015 km 2 , while artificial wetland increased from 22546 to 34911 km 2 . The greatest natural wetland loss occurred in Heilongjiang, Inner Mongolia, and Jilin with a total loss of over 57000 km 2 of wetland. In western China, over 13000 km 2 of wetlands were newly formed in Xinjiang, Tibet, and Qinghai. About 12000 km 2 of artificial wetlands were also added for fish farm and reservoir constructions. The newly formed wetlands in western China were caused primarily by climate warming over that region whereas the newly created artificial wetlands were caused by economic developments. China’s wetland loss is caused mainly by human activities.

There are special locational value and natural resources in coastal wetlands. Studying their changes and evaluating their ecosystem service value (ESV) is beneficial for protecting the ecology of coastal wetlands and for maintaining sustainable human development. In this paper, the coastal wetland of Jiaozhou Bay is selected as the research area, an object-oriented method is used to extract shoreline and wetland information, and the coastal wetland reclamation process in Jiaozhou Bay is evaluated. The value equivalent method and market value method are used to evaluate the service value of wetland ecosystems from the perspective of ecological economics. The results show that the reclamation area of Jiaozhou Bay reached 75.2 km 2 in 40 years, with nearly 23% of the bay area eroding. Reclamation engineering, estuary engineering, policy implementation and urbanization are the main factors affecting the changes in the Jiaozhou Bay wetland, and the main direction of wetland succession is natural wetlands→artificial wetlands→nonwetlands. Wetland reclamation in Jiaozhou Bay has led to the continuous extension of the coastline to the sea, especially during the 2005–2020 period, and the wetland area has declined in area by 116 km 2 . The changes in the wetland in the past 40 years have affected the changes in the ESV of Jiaozhou Bay, and there have been different synergistic/trade-off relationships in different periods. This research provides data to support the comprehensive ecological management of coastal areas, which is conducive to maximizing the utilization value of wetlands and promoting wetland protection.

In this study, two saline mangrove artificial wetlands, Datang Saline Constructed Wetland (DSCW) created for treating mariculture wastewater and sewage, vegetated with Avicennia marina, and Mangrove Wetland Park (MWP) created for mangrove conservation, vegetated with Rhizophora stylosa, were selected for assessment of carbon sequestration and carbon budget based on measuring greenhouse gas (GHG) emissions and net primary productivities. The average GHG flux and net carbon sequestration flux as carbon dioxide equivalent (CO2 eq.) were measured. The results showed that the GHG flux emitted from DSCW and MWP were 2,128 and 2,148 g CO2 eq./m2-yr, respectively, while the flux of net sequestered carbon was 2,909 and 3,178 g CO2 eq./m2-yr, respectively, which achieved carbon budget values of −676 and −230 g CO2 eq./m2-yr, respectively, exhibiting carbon source effects. Some amounts of N2O, with a high global warming potential of 265, emitted from both artificial wetland systems might cause high GHG flux as CO2 eq. emitted from the wetland systems. It was concluded that both the nitrogenous contents and environmental conditions suitable for microbial production of N2O might be the main factors to change the wetland systems from carbon sinks to carbon sources.

【Objective】Constructed wetlands are an effective technology for wastewater treatment. This study experimentally investigates their effectiveness in reducing the acute toxicity of reclaimed water.【Method】The experiment was conducted in two wetlands, one in Niantan and the other in Annan. In both wetlands, the acute toxicity of reclaimed water was evaluated using the luminescent bacteria assay. The effectiveness of the constructed wetlands was assessed by measuring the equivalent concentration of the toxic reference substance zinc sulfate heptahydrate (ZnSO₄·7H₂O).【Result】Subsurface-flow wetland was found to be more effective than subsurface-flow wetland, particularly in reducing the acute toxicity of reclaimed water. The subsurface-flow wetland in Niantan reduced toxicity levels by 16.16%, and decreased the average luminescence inhibition rate by 19.31%. The subsurface-flow wetland in Annan reduced the inhibition rate by 18.55%, with a final effluent inhibition rate of 10.64%, representing a 9.39% reduction compared to the influent. In the Niantan system, the equivalent concentrations of ZnSO4·7H2O in the influent, surface-flow wetland, and effluent were 0.930, 0.553, and 0.466 mg/L, respectively, while in the Annan system, the concentration of ZnSO4·7H2O in reclaimed water, wetland effluent, surface-flow wetland effluent, and final outlet were 0.535, 0.109, 0.277, and 0.262 mg/L, respectively. After treatment, the reclaimed water quality remained within safe thresholds, with acute toxicity levels considerably low.【Conclusion】Constructed wetlands effectively reduce the acute toxicity of reclaimed water, with subsurface-flow wetlands demonstrating superior performance compared to surface-flow systems.

Black-odorous water has become a common and widespread problem in recent decades. In this study, nine constructed wetlands (CWs) with different flow types, filters, plants, and hydraulic loadings were designed according to an orthogonal array (L9 (34), and were used for the purification of black-odorous water in summer and winter. The results showed that CWs are regarded as effective to purify black-odorous water in both seasons. Microbial degradation is the major removal pathway of pollutants in CWs during summer, while the joint effect of biodegradation and adsorption is the main treatment route during winter. Flow type and hydraulic loading appear to be the most important factors impacting the purification performance of CWs, by changing the redox condition of systems and retention time of contaminants, respectively. ‘Vertical flow-zeolite filter-high loading’ is proposed as the best parameter selection for CWs on the purification of black-odorous water: among them, CWs with vertical flow have better oxygen transport capacity that is conductive to aerobic processes of pollutants, zeolite substrates may adsorb more nitrogen via ion exchange, higher hydraulic loadings can extend the contact time between contaminants and filters, and regulate the water temperature for microbial activity.

With the loss of substantial natural wetlands in coastal zones, artificial wetlands provide alternative habitats for many shorebirds. Scientific management of artificial wetlands used by shorebirds plays an important role in maintaining the stability of shorebird population. Satellite tracking technique can obtain high-precision location information of individuals day and night, providing a good technical support for the study of quantitative relationship between waterfowls and their habitats. In this study, satellite tracking method, Remote Sensing (RS) and Geographic Information System (GIS) technology were used to analyze the activity pattern and habitat utilization characteristics of Pied Avocet during breeding period in an artificial wetland complex in the Yellow River Delta (YRD), China. The results showed that the breeding Pied Avocets had a small range of activity, with a total core and main home range of 33.10 km 2 and 216.30 km 2 , respectively. This species tended to forage in the pond and salt pan during the day and night, respectively, with an unfixed staying time in the breeding ground. The distance between breeding ground and feeding ground was less than 6 km. It is emphasized that in addition to improving the conditions of the remaining natural habitats, effective managing artificial habitats is a priority for shorebird conservation. This research could provide reference for the management of artificial wetlands in coastal zones and supply technique support for the protection of shorebirds and their habitats, and alleviate human-bird conflicts and sustainable development of coastal zones.

The addition of physical field enhancement measures to improve the purification effect of vertical flow artificial wetlands has gradually become popular. In this study, a vertical flow artificial wetland system reinforced by electric and magnetic fields was constructed. These fields were first optimized using finite element 3D simulation software to obtain the optimal electric and magnetic field parameters. Then, the pollutant removal effects and changes in microbial community structure were comparatively analyzed. The optimal electromagnetic field parameters (applied voltage of 15 V and applied magnetic field of 20 mT) resulted in significantly enhanced removal rates of chemical oxygen demand (COD), nitrate nitrogen (NH4+-N), total phosphorus (TP), and orthophosphorus (PO43−-P) in wastewater, with rates of 74.47%, 45.44%, 89.85%, and 90.04%, respectively. These rates were notably higher than those observed in the vertical flow artificial wetland system. The microbial community structure analysis revealed that the vertical flow constructed wetland with enhanced electric and magnetic fields exhibited (EM-VFCW) a more diverse and complex microbial community structure. Notably, the abundance of bacteria capable of removing NH4+-N and COD, including Aspergillus, Fusarium, and Actinobacteria, was significantly elevated.

Land use and land cover change (LUCC) has been increasingly recognized as having important effects on climate systems. Paddy fields, one kind of artificial wetland, have seen a significant increase in the Sanjiang Plain, China since 2000 and have become the most typical LUCC at the regional scale. Against this background, in this paper, we discuss the effects of this artificial wetland increase on surface temperature, in addition to its driving mechanisms. Firstly, the spatiotemporal variations of land surface temperature (LST) and its two driving variables (albedo and latent heat flux (LE)) in the Sanjiang Plain are analyzed and assessed based on remote sensing observation information from 2001 to 2015. Our results from both spatial distribution difference and time series analysis show that paddy field expansion led to day-time cooling and night-time warming over the study area. However, the LST changes show different characteristics and magnitudes in the spring (May to June) compared to the other months of the growing season (July to September). The daytime cooling trend is found to be −0.3842 K/year and the warming trend at night 0.1988 K/year during the period 2001 to 2015, resulting in an overall cooling effect in May and June. In July–September, the LST changes have the same sign but a smaller magnitude, with a −0.0686 K/year temperature trend seen for the day-time and a 0.0569 K/year increase for the night-time. As a consequence, a pronounced decrease in the diurnal temperature range is detected in the growing season, especially in spring. Furthermore, albedo and LE are demonstrated to be very sensitive to land use changes, especially in the earlier periods of the growing season. Correlation analysis between LST and albedo and LE also indicates the dominant role played by evapotranspiration in paddy fields in regulating local temperature.