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1.
J Environ Sci (China) ; 110: 55-72, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34593195

RESUMEN

Jiaxing created a precedent using bypass riparian marshes to purify micro-polluted water sources in China. Pond-wetland complex with constructed root channel technology becomes a paradigm which can be analogized as "human-body wetland model" based on bionics or biomimetics. Heterogeneous plant-bed/ditch system with highly active land/water ecotone interfaces, especially meandering boundaries, breeds many biochemical reactions "living areas". Optimization of hydraulic regulation promotes redox environment alternations and wetland treatment efficiency. Here we reported a series of upgrades and performances in Guanjinggang wetland after the Shijiuyang prototype. Morphological reform of plant-bed/ditch system played a vital role. Spatially root channel zone was main force of wetland purification, and temporally the treatment effect was higher in low-temperature seasons indicating non-temperature dependent mechanisms worked. Water pollution comprehensive index improved steadily from IV to III, and comprehensive pollution load was reduced by ca. 40%-60%. Comprehensive evaluation function value further showed the gradients purification effect of the upgraded wetland. Ecological wetlands ameliorated source water quality, and reduced drinking water treatment reagents, thereby bringing about economic benefits. Through wetlands operation, people can see how the micro-polluted surface water becomes clear and clean, so promoting a significant social benefit. As a viable component of urban green space, wetlands could beautify regional eco-environment, freshen the air, increase urban ecological taste, and enhance the eco-environmental protection publicity. Thus, the multifunctional service values and indirect benefits are substantial. Jiaxing ecological wetlands provide a typical paradigm for water pollution remediation in developing countries and plays a leading role in technology engineering radiation effect.


Asunto(s)
Purificación del Agua , Humedales , Humanos , Ríos , Agua , Contaminación del Agua
2.
J Environ Manage ; 300: 113823, 2021 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-34649318

RESUMEN

Forested wetland soils within the Piedmont and Coastal Plain physiographic provinces of Northern Virginia (NOVA) were investigated to determine the utility of a handheld colorimeter, the Nix Pro Color Sensor ("Nix"), for predicting carbon contents (TC) and stocks (TC stocks) from on-site color measurements. Both the color variables recorded with each Nix scan ("Nix color variables"; n = 15) and carbon contents significantly differed between sites, with redder soils (higher a and h) at Piedmont sites, and higher TC at sites with darker soils (lower values of L, or lightness; p < 0.05). Nix-carbon correlation analysis revealed strong relationships between L (lightness), X (a virtual spectral variable), R (additive red), and KK (black) and log-transformed TC (Ln[TC]; |r| = 0.70; p < 0.01 for all). Simple linear regressions were conducted to identify how well these four final Nix variables could predict soil carbon. Using all color measurements, about 50% of Ln(TC) variability could be explained by L, X, R, or KK (p < 0.01), yet with higher predictive power obtained for Coastal Plain soils (0.55 < R2 < 0.65; p < 0.01). Regression model strength was maximized between Ln(TC) and the four final Nix variables using simple linear regressions when color measurements observed at a specific depth were first averaged (0.66 < R2 < 0.70; p < 0.01). While further study is warranted to investigate Nix applicability within various soil settings, these results demonstrate potential for the Nix and its soil color measurements to assist with rapid field-based assessments of soil carbon in forested wetlands.


Asunto(s)
Suelo , Humedales , Carbono/análisis , Bosques , Virginia
3.
Environ Monit Assess ; 193(11): 710, 2021 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-34626241

RESUMEN

The knowledge on urban ecosystem dynamics is being increasingly felt due to unprecedented symptoms arising out of urbanization. This study is aimed to assess land use-land cover changes (LULCCs) around a wetland ecosystem using high spatial resolution CORONA and Google Basemap satellite imageries. The imageries were processed by digitizing land cover features at 1:3000 scale in ArcGIS 10.1. The imageries were classified into nine classes, and an estimation of accuracy was performed utilizing the Kappa coefficient and error matrices. The overall accuracy obtained was 94% for the 2017 dataset. The key findings indicated a loss of 23% in the wetland area from 1980 to 2017. While in the vicinity, a significant increase in green spaces (706.2%) and roads (89.4%) was observed. Morphometric analysis revealed that the wetland has lost a surface area of 10.2 ha from 1980 to 2017. The maximum length (Lmax) of the wetland was reduced by 722 m while the maximum width (Wmax) decreased by 78 m. Bathymetric analysis revealed that the wetland is shallow with a depth ranging from 10 to 174 cm. The Carlson's Trophic State Index (TSI) of wetland ranging from 74 to 87 indicates hyper-eutrophic waters. Overall, the loss of wetland area, together with the reduction in morphometric features, low depth, and higher trophic status speak of anthropogenic pressures that are compromising the ecological integrity of this wetland. Therefore, landscape planning and governance are of pivotal importance for the conservation and management of wetland ecosystems in this region.


Asunto(s)
Ecosistema , Humedales , Monitoreo del Ambiente , Imágenes Satelitales , Urbanización
4.
Sheng Wu Gong Cheng Xue Bao ; 37(9): 3276-3292, 2021 Sep 25.
Artículo en Chino | MEDLINE | ID: mdl-34622635

RESUMEN

Due to the special geographical location and the complex ecosystem types, plateau wetlands play important ecological roles in water supply, greenhouse gas regulation and biodiversity preservation. Napahai plateau wetland is a special wetland type with low latitude and high altitude, and its microbial diversity was rarely studied. The diversity of microbial communities in the Napahai plateau wetland was analyzed using metagenomics method. Among the microbes detected, 184 phyla, 3 262 genera and 24 260 species belong to the bacterial domain, 13 phyla and 32 genera belong to the archaeal domain, and 13 phyla and 47 genera belong to the fungal domain. Significant differences in species diversity between soil and water were observed. Acidobacteria, Proteobacteria and Actinobacteria were dominant phyla in soil, while Proteobacteria and Bacteroides were dominant phyla in water. Since the carbon and nitrogen metabolism genes were abundant, the pathways of carbon fixation and nitrogen metabolism were analyzed. Calvin cycle, reductive tricarboxylic acid cycle and 3-hydroxypropionic acid cycle were the main carbon fixation pathways, while Proteobacteria, Chloroflexi, and Crenarchaeota were the main carbon-fixing bacteria group. As for the nitrogen cycle, nitrogen fixation and dissimilatory nitrate reduction were dominant in water, while nitrification and denitrification were dominant in soil. Proteobacteria, Nitrospirae, Verrucomicrobia, Actinobacteria, Thaumarchaeota and Euryarchaeota contributed to the nitrogen cycle. The study on microbial diversity of Napahai plateau wetlands provides new knowledge for the comprehensive management and protection of wetland environment in China.


Asunto(s)
Carbono , Humedales , Ecosistema , Metagenómica , Nitrógeno , Microbiología del Suelo
5.
Ecotoxicol Environ Saf ; 226: 112845, 2021 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-34627042

RESUMEN

Avian biovector transport is an important mechanism for the movement of contaminants and nutrients to remote locations, usually bird colonies, through excretion, molting and decomposition of carcasses. Methylmercury (MeHg) is a bioaccumulative neurotoxin and endocrine disruptor which is present in many remote ecosystems. We collected guano samples biweekly from a herring gull (Larus smithsoniansus) colony over two summers and analyzed MeHg, total mercury (THg), water-extractable phosphate (PO43-) and sulfate (SO42-). Concentrations of THg in guano declined through the summer months while %MeHg significantly increased (ranging from 12% to 100% of THg), suggesting a switch in diet as gull nutritional needs or food availability changed through the summer. The percentage of PO43- in dry guano increased throughout the summer (ranging from 2.8% to 4.4% of dry weight) and SO42- varied throughout the season (ranging from 0.1% to 0.8% of dry weight). These data indicate that gulls are transporting considerable amounts of MeHg, PO43-, and likely other contaminants to Big Meadow Bog, Nova Scotia.


Asunto(s)
Charadriiformes , Mercurio , Compuestos de Metilmercurio , Contaminantes Químicos del Agua , Animales , Ecosistema , Monitoreo del Ambiente , Mercurio/análisis , Fosfatos , Sulfatos , Contaminantes Químicos del Agua/análisis , Humedales
6.
Ying Yong Sheng Tai Xue Bao ; 32(8): 2915-2922, 2021 Aug.
Artículo en Chino | MEDLINE | ID: mdl-34664465

RESUMEN

Human activity intensity is mostly used to quantify the degree of human influence on natural systems, with obvious spatial variability. With Lashihai watershed in Yunnan Province as an example, we used SPOT remote sensing images to update land use data, and obtained a comprehensive index of land use intensity after gridding by assigning weights to different land types, which was considered as the basic human activity intensity. The local tourism activities (horseback riding and boating) were also included. The horseback riding and boating were spatially quantified according to the location of horse farms and the abundance of horses and boats which were superimposed with the basic human activity intensity on the spatial scale of 100 m×100 m to obtain a more accurate comprehensive human activity intensity and to analyze the spatial variations. The results showed that the gridding and the kernel density analysis improved the accuracy of spatial analysis and reflected the spatial superposition and diffusion effects. In the comprehensive human activity intensity map of Lashihai watershed, the highest intensity value of water area was at the mouth of the sea, the lowest intensity value was at the center of the sea, and the overall trend of intensity gradually decreased from the surrounding to the middle. The land settlement had the highest intensity, the intensity value of the agricultural land gathering area was at the middle level, and the intensity of human activities in the forestry area of higher altitude was lower. The comprehensive human activity intensity in the water area of the Lashihai watershed varied most obviously, and differed greatly from the basic human activity intensity. Although there were many local characteristic tourism activities in Yunnan-Guizhou Plateau Wetland scenic area, but their land use types did not change. We need to take them into account when quantifying the intensity of human activities.


Asunto(s)
Monitoreo del Ambiente , Humedales , Animales , China , Caballos , Actividades Humanas , Análisis Espacial
7.
Ying Yong Sheng Tai Xue Bao ; 32(8): 2958-2966, 2021 Aug.
Artículo en Chino | MEDLINE | ID: mdl-34664470

RESUMEN

We analyzed soil quality based on soil microbial characteristics of three different vegetation types in the wetlands of East Dongting Lake, including Carex tristachya wetland (CTW), Phragmites australis wetland (PAW), and Salix babylonica wetland (SBW). The soil microbial biomass carbon (MBC), nitrogen (MBN) and enzyme activities were measured and the key influen-cing factors were analyzed during the normal, flood, and dry periods. The results showed that: 1) The amounts of MBC, MBN, and the activities of invertase and cellulase (except cellulase of dry season) in 0-10 cm were higher than those in 10-20 cm for all wetlands, while the catalase activity showed an opposite pattern. 2) The amounts of MBC and MBN and the values of MBC/TOC and MBN/TN for the 0-20 cm soil layer of each vegetation type wetland were the lowest in flood period. 3) Soil invertase activity for each vegetation type wetland in the 0-20 cm soil layer peaked in the dry period, while soil cellulase activity peaked in the normal period. The seasonal fluctuation of soil catalase activities in all wetlands were small, with activities being slightly higher in flood period than the other two periods. 4) Among different vegetation types, soil invertase activity of PAW was significantly higher than that of other vegetation types, and cellulase activity of which was the lowest in both normal and flood periods. There was no difference in these two enzymes activities among wetlands during the dry period. The highest soil catalase activity was found in CTW during normal period and in SBW during dry period, respectively, while its lowest value was in PAW during flood period. 5) Soil MBC, MBN and invertase activity were correlated positively with soil TOC, TN and TP, and negatively correlated with soil pH. The activities of soil cellulase and catalase were significantly negatively correlated with TOC, TN, TP and positively correlated with pH. It suggested that the seasonal fluctuation of water level affected soil C, N, P contents and pH values, with consequences on soil MBC, MBN and enzyme activities.


Asunto(s)
Nitrógeno , Suelo , Biomasa , Carbono , Lagos , Nitrógeno/análisis , Microbiología del Suelo , Agua , Humedales
8.
Water Res ; 204: 117635, 2021 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-34530225

RESUMEN

The integrated vertical flow (IVF) constructed wetland consists of two or more chambers with heterogeneous flow patterns and strong aeration capability, possesses favorable remediation performance. The Constructed Wetland Model No.1 (CWM1) embedded in the OpenGeoSys # IPHREEQC was applied to investigate the wetland plant effects on treatment efficiency. Two fundamental functions of the plant roots (i) the radial oxygen loss (ROL) and (ii) exudation of internal organic carbon (IOC), are developed and implemented in the model to simulate the treating processes of planted laboratory-scale IVF wetlands fed by the synthetic wastewater. The good agreement between simulated results and measurements of the planted IVF wetland and the unplanted filters mimicking wetland demonstrates the combined effects of ROL and IOC and the model reliability. In summer the ammonia (NH4-N) and total nitrogen (TN) removals are high as above 90% in both IVF wetlands, and in winter they decline significantly to around 55% and 45% in unplanted wetland, contrastively to about 85% and 78% in the planted wetland. The nitrogen removal - COD/N ratio relation curves of IVF wetlands are proposed and obtained by modeling to evaluate organic carbon loading status. Based on the curves, the COD/N ratios of unplanted and planted wetlands are about 3∼7 and 3∼10 gCOD/gN for high TN removal respectively. Planted wetlands can tolerate a wider range of COD/N ratio influents than unplanted ones. The ROL in the unplanted wetland promotes COD and NH4-N removal, while may inhibit denitrification under low-temperature conditions. The single addition of IOC enhances the oxygen-consuming and restrains the nitrification under the full loaded COD condition. Summing up all organic carbon releases from substrate and roots as IOC, the quantification of IOC acts on nitrogen treatment was simulated and compared with the external organic carbon (EOC) loading from influent. IOC performs higher efficiency on TN removal than EOC at the same organic loading rates. The results provide the thoughts of the solution for low TN removal in the carbon deficient constructed wetlands.


Asunto(s)
Carbono , Humedales , Nitrógeno , Oxígeno , Reproducibilidad de los Resultados
9.
Water Res ; 204: 117656, 2021 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-34537628

RESUMEN

The current lack of research on the evaluation of marine ecosystem services makes the value of marine protection, development and restoration underestimated during the decision-making process. Based on the non-monetary ecosystem service evaluation framework, a marine ecosystem service classification and accounting method has been established in this study, and the world's coastal ecosystem services have been measured as an example. The results show that (1) the world's coastal ecosystem service value is about 4.13E+23 sej/yr, of which Asia and North America contribute about 55% of the total service value; (2) the top ten countries in terms of the world's coastal ecosystem service values are Canada, Indonesia, Australia, the United States, Brazil, the Russian Federation, Norway, the Philippines, Mexico, and China, which contribute about 60% of the total service value; (3) estuaries have the highest ecosystem service values, followed by mangroves, seagrass beds, tidal flats, salt marshes, and warm water coral reefs; (4) developed countries can make better use of their coastal resources and pay more attention to the marine protection while the opposite is true in developing countries, which means that developed countries still occupy an advantageous position in the process of marine protection, development and utilization. This study assesses the coastal ecosystem service values in various coastal countries from the perspective of ecosystem contributors, emphasizes the importance of protecting them in marine management, and provides a certain reference basis and theoretical support for decision-makers in formulating marine-related protection and development strategies.


Asunto(s)
Arrecifes de Coral , Ecosistema , Australia , Estuarios , Humedales
10.
Ecotoxicol Environ Saf ; 225: 112763, 2021 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-34544025

RESUMEN

In this research, micro Coix lacryma-jobi L. vertical flow constructed wetlands (VFCWs) were set up using domestic sewage (DWS) and 1/2 Hoagland nutrient solution (HNS) as VFCWs water sources. 0, 20 mg L-1 and 40 mg L-1 of Cr6+ (in the form of K2Cr7O2) were added into the water sources separately in order to study the response of Coix lacryma-jobi L. under Cr6+ stress. The results showed that the inhibition rates of Cr6 + on plant height, stem diameter, shoot and root dry weight treated with HNS were 2.88~10.16%, 5.12~11.86%, 3.53~6.51% and 2.89~6.34% higher than those in DWS treatment. SEM analysis showed that the nuclear bilayer membrane was slightly damaged, the chromatin decreased and the number of mitochondrial cristae decreased when treated with 20 mg L-1 of Cr6+, however, organelle damage was more severe under 40 mg L-1 of Cr6+exposure. The X-ray energy spectrum analysis results indicated that the accumulation of chromium in epidermis and endodermis were higher than those in stele. The contents of total Cr in roots, stems and leaves treated with HNS were higher than those of DWS treatment. The highest content of Cr was observed in cell wall (32.12-188.1 mg kg-1), followed by vacuole (5.0-38.14 mg kg-1). The contents of Cr in each subcellular component in roots, stems, and leaves treated with HNS were higher than those of DWS, except for organelle components in the 14th week. DWS was used as water influent, the contents of easily migrated combined Cr (ETM) in roots, stems and leaves were significantly lower than those in HNS treatment. Improving the nutritional conditions of constructed wetlands might be beneficial to the improvement of their ability to purify chrome-containing waste water.


Asunto(s)
Coix , Cromo/toxicidad , Aguas del Alcantarillado , Aguas Residuales , Humedales
11.
J Environ Manage ; 300: 113759, 2021 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-34543963

RESUMEN

Fire is an important disturbance in many wetlands, which are key carbon reservoirs at both regional and global scales. However, the effects of fire on wetland vegetation biomass and plant carbon dynamics are poorly understood. We carried out a burn experiment in a Calamagrostis angustifolia wetland in Sanjiang Plain (Northeast China), which is widespread wetland type in China and frequently exposed to fire. Using a series of replicated experimental annual burns over a three-year period (spring and autumn burns carried out one, two or three times over three consecutive years), together with a control unburned treatment, we assessed the effect of burn seasonality and frequency on aboveground biomass, stem density, and carbon content of aboveground plant parts and ground litter. We found that burning promoted plant growth and hence plant biomass in burned sites compared to the unburned control, with this effect being greatest after three consecutive burn years. Autumn burns promoted higher stem density and more total aboveground biomass than spring burns after three consecutive burn years. Burning increased stem density significantly, especially in twice and thrice burned plots, with stem densities in September over 2000 N/m2, which was much higher than in the control plots (987 ± 190 N/m2). Autumn burns had a larger effect than spring burns on total plant biomass and litter accumulated (e.g. 1236 ± 295 g/m2 after thrice autumn burns compared 796.2 ± 66.6 g/m2 after thrice spring burns), except after two burn treatments. With time since burning, total biomass loads increased in spring-burned plots, while autumn-burned plots showed the opposite trend, declining towards values found at unburned plots in year three. Our results suggest that, at short fire return intervals, autumn burns lead to a more pronounced increase in aboveground biomass and carbon accumulation than spring burns; however, the effects of spring burns on biomass and carbon accumulation are longer lasting than those observed for autumn burns.


Asunto(s)
Incendios , Poaceae , Estaciones del Año , Biomasa , China , Poaceae/crecimiento & desarrollo , Humedales
12.
Nat Commun ; 12(1): 5511, 2021 09 17.
Artículo en Inglés | MEDLINE | ID: mdl-34535650

RESUMEN

Harmful algal and bacterial blooms linked to deforestation, soil loss and global warming are increasingly frequent in lakes and rivers. We demonstrate that climate changes and deforestation can drive recurrent microbial blooms, inhibiting the recovery of freshwater ecosystems for hundreds of millennia. From the stratigraphic successions of the Sydney Basin, Australia, our fossil, sedimentary and geochemical data reveal bloom events following forest ecosystem collapse during the most severe mass extinction in Earth's history, the end-Permian event (EPE; c. 252.2 Ma). Microbial communities proliferated in lowland fresh and brackish waterbodies, with algal concentrations typical of modern blooms. These initiated before any trace of post-extinction recovery vegetation but recurred episodically for >100 kyrs. During the following 3 Myrs, algae and bacteria thrived within short-lived, poorly-oxygenated, and likely toxic lakes and rivers. Comparisons to global deep-time records indicate that microbial blooms are persistent freshwater ecological stressors during warming-driven extinction events.


Asunto(s)
Ecosistema , Extinción Biológica , Agua Dulce , Floraciones de Algas Nocivas , Australia , Bacterias/metabolismo , Fósiles , Geografía , Factores de Tiempo , Humedales
13.
Biol Lett ; 17(9): 20210329, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34520682

RESUMEN

In fish, vision may be impaired when eye tissue is in direct contact with environmental conditions that limit aerobic ATP production. We hypothesized that the visual acuity of fishes exposed to hydrogen sulfide (H2S)-rich water would be altered owing to changes in cytochrome c oxidase (COX) activity. Using the H2S-tolerant mangrove rivulus (Kryptolebias marmoratus), we showed that a 10 min exposure to greater than or equal to 200 µM of H2S impaired visual acuity and COX activity in the eye. Visual acuity and COX activity were restored in fish allowed to recover in H2S-free water for up to 1 h. Since K. marmoratus are found in mangrove pools with H2S concentrations exceeding 1000 µM, visual impairment may impact predator avoidance, navigation and foraging behaviour in the wild.


Asunto(s)
Ciprinodontiformes , Sulfuro de Hidrógeno , Animales , Sulfuros , Agudeza Visual , Humedales
14.
J Environ Manage ; 300: 113703, 2021 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-34509818

RESUMEN

Wetland plants play a major role in the process of wastewater treatment in constructed wetlands (CWs). The inhibitory effect of salt stress on plants may reduce the performance of CWs. In this study, salicylic acid (SA) and/or calcium ion (Ca2+) were used for root pretreatment to alleviate the salt stress in Iris pseudacorus L. The results showed that root pretreatment with SA and/or Ca2+ improved the response of Iris pseudacorus L. to salinity by increasing growth, photosynthetic pigments, Pro content, enzymes activities and K+ content. In addition, SA and/or Ca2+ application in saline conditions decreased the relative conductivity and content of malondialdehyde. RNA-seq analysis showed the expression of hormone signaling genes, potassium ion transporter genes, oxidative stress genes and photosynthesis genes were up-regulated after pretreating with SA and CaCl2. In conclusion, the addition of SA and Ca2+ could improve the saline wastewater treatment efficiency of CWs by enhancing the salt tolerance of Iris pseudacorus L.


Asunto(s)
Iris (Planta) , Humedales , Cloruro de Calcio , Iris (Planta)/genética , Ácido Salicílico/farmacología , Tolerancia a la Sal/genética
15.
J Environ Manage ; 300: 113720, 2021 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-34521007

RESUMEN

The pollutant removal efficiency of traditionally constructed wetlands (CWs) is often limited due to low interaction time between wastewater and the CW matrix (plants, microbes, and substrates). A zigzag-horizontal subsurface flow constructed wetland with effluent recirculation (Z-HSSF + ER) was developed to improve removal efficiency. Echinodorus cordifolius plants were used in this study. The efficiency of the systems was evaluated using eutrophic wastewater. The results showed that the developed systems exhibited the high removal efficiency of algal cells, PO43-, and NO3- (97%, 70%, and 100%, respectively), within 5 days. Algal cells were removed by the interception mechanism of gravel and zigzag baffles. PO43- and NO3- in the eutrophic wastewater was mainly removed by E. cordifolius including rhizobacteria and other microorganisms. The long flow pathway created by the installation of zigzag baffles combined with effluent recirculation provides high dissolved oxygen (DO) in the systems and increases the interaction time between wastewater and the CW matrix, thus improving the pollutant removal efficiency of CWs.


Asunto(s)
Alismataceae , Humedales , Plantas , Eliminación de Residuos Líquidos , Aguas Residuales
16.
J Environ Manage ; 300: 113799, 2021 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-34560464

RESUMEN

Given that the social and economic sustainability of rural areas is highly based on the protection of natural resources, biodiversity and human health, simple-operated and cost-effective wastewater treatment systems, like artificial constructed wetlands (CWs), are widely proposed for minimizing the environmental and human impact of both water and soil pollution. Considering that the optimization of wastewater treatment processes is vital for the reduction of effluents toxic potential, there is imperative need to establish appropriate management strategies for ensuring CW performance and operational efficiency. To this end, the present study aimed to assess the operational efficiency of a horizontal free water surface CW (HFWS-CW) located in a world heritage area of Western Greece, via a twelve-month duration Toxicity Identification Evaluation (TIE)-like approach, including both chemical and biological tracking tools. Conventional chemical tracking, by means of pH, conductivity, total COD, and nitrogen-derived components, like nitrates and ammonia-nitrogen, were monthly recorded in both influents and effluents to monitor whether water quality standards are maintained, and to assess potent CW operational deficiencies occurring over time. In parallel, Whole Effluent Toxicity (WET) bioassays were thoroughly applied, using freshwater algae and higher plant species (producers), crustaceans and rotifers (consumers), as well as human lymphocytes (in terms of Cytokinesis Block Micronucleus assay) to evaluate the acute and short-term toxic and hazardous potential of both influents and effluents. The integrated analysis of abiotic (physicochemical parameters) and biotic (toxic endpoints) parameters, as well as the existence of "cause-effect" interrelations among them, revealed that CW operational deficiencies, mainly based on poorly removal rates, could undermine the risk posed by treated sewage. Those findings reinforce the usage of WET testing, thus giving rise to the importance of applying appropriate water management strategies and optimization actions, like oxygen enrichment of surface and bottom of HFWS-CW basins, expansion of the available land, the enhancement of bed depth and seasonal harvesting of plants, for ensuring sewage quality, in favor of water resources protection and sustainable growth in rural areas.


Asunto(s)
Purificación del Agua , Humedales , Humanos , Saneamiento , Eliminación de Residuos Líquidos , Aguas Residuales
17.
J Hazard Mater ; 416: 126095, 2021 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-34492904

RESUMEN

The extent to which, and mechanisms by which, arbuscular mycorrhizal fungi (AMF) and dark septate endophytes (DSE) purify wetlands polluted by metallic nanoparticles (metallic NPs) are not well understood. In this study, micro-vertical flow constructed wetlands (MVFCWs) with the Phragmites australis (reeds)-AMF/DSE symbiont were used to treat CuO nanoparticles (CuO-NPs)-polluted wastewater. The results showed that (1) the removal efficiencies of chemical oxygen demand (COD), total nitrogen (TN), and CuO-NPs in three inoculated groups significantly exceeded those in the control check (CK) groups by 28.94-98.72%, 16.63-47.66%, and 0.53-19.12%, respectively; (2) inoculation with AMF and/or DSE significantly promoted the growth, nutrient content, and photosynthesis of reeds, increased the osmoregulation substance content and antioxidant enzyme activities, and decreased the malondialdehyde and reactive oxygen species contents of reeds under CuO-NPs stress; (3) higher Cu accumulation and smaller transport coefficients were found in the inoculated groups than in the CK group; (4) inoculation with AMF and/or DSE changed the subcellular structure distribution and chemical form of Cu in reeds. We therefore conclude that inoculation with AMF and/or DSE in MVFCWs improves the purification of CuO-NPs-polluted wastewater, and the MVFCW-reeds-AMF/DSE associations exhibit great potential for application in remediation of metallic-NPs-polluted wastewater.


Asunto(s)
Micorrizas , Nanopartículas , Cobre , Endófitos , Hongos , Raíces de Plantas , Aguas Residuales , Humedales
18.
Environ Monit Assess ; 193(10): 636, 2021 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-34498140

RESUMEN

Some wetlands in the northern Great Plains support hundreds to thousands of late-stage tadpoles providing important sources of recruitment to the Wood Frog (Lithobates sylvaticus) population while many other wetlands produce none. Relationships between water quality and late-stage tadpole abundance were determined to identify the water quality parameters associated with tadpole abundance. Water samples were collected, and late-stage tadpole abundances were assessed once each year in late June for 12 years in 26 wetlands. Catch or abundance was the number of tadpoles captured in 30 min with a dip-net. The catch of tadpoles was variable both among wetlands and over the long-term for individual wetlands, and ranged from 0 to several hundred individuals. Wood Frog tadpoles were especially sensitive to sodium and chloride concentrations. At Cl concentrations less than 5 mg/L, occupancy for late-stage tadpoles was 84%, and declined by about 8% for each 5 mg/L increase in Cl to 40.1 mg/L Cl, the maximum concentration associated with the detection of tadpoles. Optimal water quality for late-stage Wood Frog tadpoles included low concentrations of Na [Formula: see text] = 8.1 mg/L), and Cl [Formula: see text] = 4.2 mg/L) relative to total dissolved solids and other ions, and high concentrations of phosphorus. In a landscape where ion concentrations in wetlands can range over 3 orders of magnitude, water quality analyses suggest that abundant Wood Frog tadpole populations occur in wetlands dominated by snow-melt runoff with its characteristic low ion concentrations. The present study highlights the importance to amphibian conservation of the water quality environment of tadpole habitat.


Asunto(s)
Monitoreo del Ambiente , Calidad del Agua , Animales , Humanos , Larva , Ranidae , Humedales
19.
Environ Sci Technol ; 55(18): 12652-12663, 2021 09 21.
Artículo en Inglés | MEDLINE | ID: mdl-34478283

RESUMEN

The microbial characteristics related to nitrogen (N), phosphorus (P), and chemical oxygen demand (COD) removal were investigated in three pilot scale constructed wetlands (CWs). Compared to horizontal subsurface flow (HSSF) and surface flow (SF) CWs, the aerobic vertical flow (VF) CW enriched more functional bacteria carrying genes for nitrification (nxrA, amoA), denitrification (nosZ), dephosphorization (phoD), and methane oxidation (mmoX), while the removal of COD, total P, and total N increased by 33.28%, 255.28%, and 299.06%, respectively. The co-occurrence network of functional bacteria in the HSSF CW was complex, with equivalent bacterial cooperation and competition. Both the VF and SF CWs exhibited a simple functional topological structure. The VF CW reduced functional redundancy by forming niche differentiation, which filtered out keystone species that were closely related to each other, thus achieving effective sewage purification. Alternatively, bacterial niche overlap protected a single function in the SF CW. Compared with the construction type, temperature, and plants had less effect on nutrient removal in the CWs from this subtropical region. Partial least-squares path modeling (PLS-PM) suggests that high dissolved oxygen and oxidation-reduction potential promoted a diverse bacterial community and that the nonkeystone bacteria reduced external stress for functional bacteria, thereby indirectly promoting nutrient removal.


Asunto(s)
Aguas del Alcantarillado , Humedales , Análisis de la Demanda Biológica de Oxígeno , Desnitrificación , Nitrificación , Nitrógeno/análisis , Eliminación de Residuos Líquidos , Aguas Residuales
20.
BMC Genomics ; 22(1): 697, 2021 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-34579659

RESUMEN

BACKGROUND: Nitrogen (N) is one of the main factors limiting the wood yield in poplar cultivation. Understanding the molecular mechanism of N utilization could play a guiding role in improving the nitrogen use efficiency (NUE) of poplar. RESULTS: In this study, three N-efficient genotypes (A1-A3) and three N-inefficient genotypes (C1-C3) of Populus deltoides were cultured under low N stress (5 µM NH4NO3) and normal N supply (750 µM NH4NO3). The dry matter mass, leaf morphology, and chlorophyll content of both genotypes decreased under N starvation. The low nitrogen adaptation coefficients of the leaves and stems biomass of group A were significantly higher than those of group C (p < 0.05). Interestingly, N starvation induced fine root growth in group A, but not in group C. Next, a detailed time-course analysis of enzyme activities and gene expression in leaves identified 2062 specifically differentially expressed genes (DEGs) in group A and 1118 in group C. Moreover, the sensitivity to N starvation of group A was weak, and DEGs related to hormone signal transduction and stimulus response played an important role in the low N response this group. Weighted gene co-expression network analysis identified genes related to membranes, catalytic activity, enzymatic activity, and response to stresses that might be critical for poplar's adaption to N starvation and these genes participated in the negative regulation of various biological processes. Finally, ten influential hub genes and twelve transcription factors were identified in the response to N starvation. Among them, four hub genes were related to programmed cell death and the defense response, and PodelWRKY18, with high connectivity, was involved in plant signal transduction. The expression of hub genes increased gradually with the extension of low N stress time, and the expression changes in group A were more obvious than those in group C. CONCLUSIONS: Under N starvation, group A showed stronger adaptability and better NUE than group C in terms of morphology and physiology. The discovery of hub genes and transcription factors might provide new information for the analysis of the molecular mechanism of NUE and its improvement in poplar.


Asunto(s)
Populus , Células Clonales/metabolismo , Regulación de la Expresión Génica de las Plantas , Nitrógeno/metabolismo , Hojas de la Planta/genética , Hojas de la Planta/metabolismo , Populus/genética , Populus/metabolismo , Estrés Fisiológico/genética , Humedales
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