Wetland Biomass Research Articles

Pyrolysis of purun tikus (Eleocharis dulcis): Product distributions and reaction kinetics

Pyrolysis of typical wetland biomass, namely purun tikus (Eleocharis dulcis) was experimentally studied herein for the first time. The pyrolysis of purun tikus leaves for bio-oil production was conducted under different reaction temperatures (300, 400, and 500 °C) at fixed pressure and different particle size distributions (0.2, 0.4, and 0.6 mm). Characteristics of bio-oil and product distributions were studied. The bio-oil yield as high as 31% was obtained at 500 °C and 0.6 mm of particle size. Meanwhile, the highest bio-char yield of 62% was obtained at 300 °C and 0.2 mm of particle size. The bio-oil was characterized by gas chromatography/mass spectrometry (GC/MS). Phenol yield as high as 18.23% was achieved at 500 °C and 0.6 mm of particle size under atmospheric pressure. A reaction model was proposed, and the reaction kinetic parameters by assuming the first-order kinetics were determined. The reaction was observed to follow the Arrhenius behavior, and the kinetic model agreed well with the experimental data.

Biochemical activity and microbial biomass in wetlands (Vereda) and well-drained soils under native vegetation types in Brazilian Cerrado

The Cerrado is the second largest Brazilian biome, a world biodiversity hotspot and home to important hydrographic basins. In this biome, native vegetation types play crucial environmental roles as natural repositories of carbon, water and biodiversity. However, the Cerrado is threatened by deforestation and land degradation. The soil microbiology knowledge of these areas would provide a better understanding of how this threatened environment functions and a basis for monitoring and conservation. This study investigates soil respiration, microbial biomass and enzymes activity of the native wetlands (veredas), and well-drained soils under native cerrado sensu stricto and semi-deciduous dry forest. Vereda soils produced the highest levels of soil biological attributes, while the semi-deciduous dry forest produced intermediate values and the Cerrado, the lowest values. Regardless of season, differences in soil activity were best correlated with five biological attributes: basal respiration, FDA, urease, β-glucosidase and acid phosphatase activity. Partial redundancy analysis indicated that variance in soil microbial and biochemical attributes was better correlated with soil physicochemical attributes than with vegetation type. Redundancy analysis and a Pearson correlation showed that the differentiating biological variables were best correlated with nitrogen concentration. Vereda soils have a far greater biochemical potential for metabolizing organic carbon under standard (i.e. aerobic) conditions, suggesting that draining vereda soils may lead to losses of organic matter and increased greenhouse gas emissions. The findings of this study provide a basis of ecological information on native Cerrado soils that can be used to manage and monitor the quality of this threatened biome.

GHG Emissions and Efficiency of Energy Generation through Anaerobic Fermentation of Wetland Biomass

We conducted the Life Cycle Analysis (LCA) of energy production from biogas for maize and three types of wetland biomass: reed Phragmites australis, sedges Carex elata, and Carex gracilis, and “grassy vegetation” of wet meadows (WM). Biogas energy produced from maize reached over 90 GJ ha−1, which was more than four times higher than that gained from wetland biomass. However, an estimation of energy efficiency (EE) calculated as a ratio of energy input to the energy produced in a biogas plant showed that the wet fermentation (WF) of maize was similar to the values obtained for dry fermentation (DF) of sedge biomass (~0.30 GJ GJ−1). The greenhouse gases (GHG) emissions released during preparation of the feedstock and operation of the biogas plant were 150 g CO2 eq. kWhel.−1 for DF of sedges and 262 g CO2 eq. kWhel.−1 for WF of Phragmites. Compared to the prevailing coal-based power generation in Central Europe, anaerobic digestion (AD) of wetland biomass could contribute to a reduction in GHG emissions by 74% to 85%. However, calculations covering the GHG emissions during the entire process “from field to field” seem to disqualify AD of conservation biomass as valid low-GHG energy supply technology. Estimated emissions ranged between 795 g CO2 eq. kWhel.−1 for DF of Phragmites and 2738 g CO2 eq. kWhel.−1 for the WM and, in most cases, exceeded those related to fossil fuel technologies.

Effects of aquatic vegetation cover (Schoenoplectus decipiens) on microalgal biomass and assemblage structure in temporary wetlands of a semi-arid region (Eastern Cape Karoo, South Africa)

Temporary depression wetlands are often overlooked from a conservation and research perspective, despite recent evidence suggesting that their cumulative contribution to biodiversity at the landscape level is substantial. Here, we present observations aimed at understanding the significance of macrophyte cover in relation to the lower trophic levels, more particularly microalgae, within these highly dynamic wetlands. Thirteen such wetlands were sampled during October 2015, December 2015 and March 2016 in the Eastern Cape Karoo region of South Africa, to test the hypotheses that densely vegetated wetlands will have lower microalgal biomass and smaller algal size classes than sparsely vegetated wetlands. PERMANOVA results indicated that neither planktonic nor benthic microalgal biomass differed significantly between macrophyte cover categories (sparse, moderate and extensive cover), although there was a strong difference between the planktonic and benthic biotopes themselves. Planktonic and benthic microalgal assemblages were dominated by cryptophytes and chrysophytes (flagellates) throughout the study, with smaller nanoplankton being more abundant in wetlands with moderate or extensive macrophyte cover and larger microplankton dominating sparsely vegetated sites. Median benthic diatom species richness and diversity were higher under sparse macrophyte cover, but these differences were not significant, and no convincing evidence was found for an effect of macrophyte cover on microalgal biomass and assemblage composition in these temporary wetlands. Using distance-based Redundancy Analysis, dissolved inorganic nitrogen appeared to be the only environmental predictor for which a significant relationship with microalgal assemblage composition was reported. This study adds to the evidence from other assemblages (e.g. invertebrates) suggesting that the generalist nature of species occupying these systems allows them to adapt to the ever-changing conditions typical of ephemeral environments.

Are invertebrate herbivores of freshwater macrophytes scarce in tropical wetlands?

Abstract In this study we assessed the abundance and composition (taxa and feeding guilds) of invertebrate communities occurring on 11 aquatic plant species in Neotropical and Afrotropical wetlands. We tested the hypothesis that invertebrate herbivores form only a minor component of the invertebrate assemblages associated with freshwater macrophytes. The waterbodies experienced differing intensities of disturbance pressure (grazing, trampling, sediment disturbance) from large mammalian herbivores. General analysis of macrophyte samples collected during 2012–2013 from Zambia and Argentina showed that in Afrotropical wetlands invertebrate herbivores were significantly less abundant than non-herbivorous invertebrate taxa. In the Neotropical wetlands, the abundance of herbivorous and non-herbivorous invertebrate taxa did not differ significantly. Analysis per macrophyte species showed that invertebrate herbivores occurred in higher or similar abundance compared to non-herbivores in 83 % of macrophyte species in the Neotropics, but only in one macrophyte species in the Afrotropics. Taxa and feeding guilds of invertebrate herbivores varied between macrophyte species and ecozones, but were dominated by semiaquatic insects. TWINSPAN analysis of the plant samples hosting invertebrate morphospecies (n = 91) produced a sample-classification of four sample groups, with substantial differences in invertebrate morphospecies associated with each group of plant samples. The results show that invertebrate herbivores, mainly insects, are both numerically important and likely to form an important component of nutrient-cycling processes involving macrophyte biomass in warm-water wetlands. Whether the differences observed between the two ecozones are related to differences in large-herbivore presence, or to other inter-ecozone biogeographical differences in habitat conditions, or both, remains an issue for further research.

Hydrological Management for Submersed Aquatic Vegetation in South Carolina Coastal Impoundments

ABSTRACTWe conducted a field experiment to test effects of complete drawdown to dried substrates versus partial (shallow water, 0–10 cm) drawdown on widgeongrass (Ruppia maritima) and other native submersed aquatic vegetation (SAV) biomass (dry) in managed brackish tidal impoundments (hereafter, impoundments) in the Ashepoo, Combahee, and Edisto Rivers Basin, South Carolina, USA. We sampled SAV in 20 impoundments (complete drawdown, n = 8; partial drawdown, n = 12) during August 2016, November 2016, January 2017, and April 2017. We detected a drawdown effect on SAV biomass for August 2016 samples before Hurricane Matthew in October 2016, which subsequently confounded drawdown treatment effects. Mean SAV biomass in August 2016 was nearly 4 times greater in partially drawndown ( = 35.98 g/m2 ± 6.05 [SE]) than completely drawndown impoundments ( = 9.52 g/m2 ± 7.41). We suggest partial drawdowns to promote SAV biomass in coastal South Carolina and other south Atlantic brackish wetlands. We also encourage managers to conduct complete drawdowns periodically to reduce flocculent soils and organic matter and promote rooting by SAV. Our results may aid the Atlantic Coast Joint Venture of the North American Waterfowl Management Plan to estimate potential energetic carrying capacity of brackish impoundments in South Carolina and elsewhere as applicable for wintering ducks and American coots (Fulica americana), and to illustrate the effect of a hurricane that decreases SAV biomass in impounded wetlands. © 2020 The Wildlife Society.

Effect of Pyrolytic Temperature and Time on Characteristics of Typha angustifolia Derived Biochar and Preliminary Assessment of the Ecological Risk

A batch of biochar was produced from pyrolysis of Typha angustifolia (TBCs) at 200-500℃ for 2 h and 6 h to investigate the effects of pyrolytic temperature and heating retention time on the physico-chemical properties. Moreover, Escherichia coli (E. coli) HB101 and the seeds of Helianthus annuus were used to preliminarily test the ecological risk of the TBCs. Results showed that the heating retention time (i.e., 2 and 6 h) had no significant effect on the properties of TBCs, while pyrolytic temperature significantly affected TBCs' characteristics. As the pyrolysis temperature increased from 200 to 500℃, the mass yield and contents of hydrogen (H) and oxygen (O) decreased, while the contents of carbon (C) and ash increased. The pH and surface pores also increased with increasing pyrolytic temperature, whereas the O-containing functional group (e.g., -COOH and -OH) decreased. These results indicated the increased carbonization and aromatization of the TBCs. For the inherent nutrients of TBCs, the total phosphorus (TP) and available potassium (K) contents significantly increased as temperature increased. The main components of dissolved organic matter (DOM) of TBCs were humic acid-like and fulvic acid-like organic compounds. As the pyrolysis temperature increased, the content of humic acid-like organic compounds decreased, while the content of fulvic acid-like organic compounds increased. All the TBCs had no significant effect on the growth of E. coli HB101 and the seed germination of Helianthus annuus, indicating the little ecological risk of TBCs under the experimental conditions. These findings provide an alternative way for resource utilization of waste wetland biomass and provide important theoretical data for screening biochar in soil reclamation.

Impacts of coppicing on Tamarix chinensis growth and carbon stocks in coastal wetlands in northern China

Coppicing is a highly effective method of producing a great deal of fast growing, sustainable timber without the need for replanting. Tamarix chinensis, a native salt-tolerant species, plays an important role in the ecosystems of arid saline alkali soil and coastal wetlands in northern China. In this study, we conducted a coppicing field experiment on T. chinensis to study the vigor of resprouting over a 4-year monitoring period in the coastal wetland of Laizhou Bay, China. Results of this study show that the growth of coppiced T. chinensis was vigorous and conformed to an “S-curve” type growth pattern. The height and crown of coppiced T. chinensis recovered quickly to the initial level by the 2nd year of regrowth and its aboveground biomass regained 93.5% of the previous level by the 4th year. The carbon stock in the T. chinensis wetland was significantly increased by the coppicing operation. Carbon stocks in the aboveground parts and soil (0–100 cm) increased by 222.6 g m−2 and 588.9 g m−2, respectively, during the 4-year experimental period. These values are 43% and 74% higher, respectively, than those in the control plot over the same period. These results indicate that coppicing provides a practical means for promoting regeneration and rejuvenation of Tamarix spp. forests as well as a new approach to increasing biomass and carbon stocks in the coastal wetlands of northern China.

Hydrological connectivity: One of the driving factors of plant communities in the Yellow River Delta

Abstract Coastal wetlands play an important role in regional and even continental sustainable development because of their valuable ecosystem services. The coupling mechanism among hydrology, edaphic factors, and vegetation is the key to coastal wetland management. The current study conducted in the Yellow River Delta used an improved-comprehensive hydrological connectivity structure index, Topographic Over Field Capacity Index (TOFCI), based on both soil water conditions (SWC) and topography to highlight the role of hydrological connectivity on intertidal flat (IF), tidal marsh (TM), semi-artificial pond (AP) and riverside intermittent flooded (RS) wetland classes among other environmental variables. The results showed plant community distributions and structures among wetland classes differed from each other significantly, and hydrological connectivity structure is one of the driving factors. The results provided three pieces of evidence for this inference: 1) according to PCA results, the contribution of TOFCI is the highest among all environmental variables; 2) TOFCI values show significant difference among different plant communities; 3) TOFCI is also significantly correlated to species composition and distribution according to the CCA and RDA results. TOFCI values are positively linearly correlated to the plant coverage and biomass in intertidal flat wetlands according to linear regression analysis. Furthermore, salinity, soil total nitrogen and soil total phosphorus also influence plant community distribution and species composition. Finally, simple parameters for soil water conditions or topographic characteristics do not show significant explanatory power to hydrology-vegetation interaction. The results of the current study provide a new perspective for coastal wetland conservation and restoration.

Effects of water and salinity on soil labile organic carbon in estuarine wetlands of the Yellow River Delta, China

Changes in labile organic carbon in wetland soils as indicators of soil quality and climate change have received many attention worldwide. Soil samples were collected in 2012 and 2013 in estuarine wetlands with different groundwater tables in the Yellow River Delta, and soil salinity, water content (WC), microbial biomass carbon (MBC), and dissolved organic carbon (DOC) were determined to investigate the effects of water and salinity on labile organic carbon in wetland soils. Our results showed that the response of labile organic carbon to salt and water conditions varied varied in soil samples with different groundwater tables. The MBC in soils with low groundwater tables (LW) was the lowest when soil WC was 25% and then exhibited an increase with increasing WC. The DOC in LW soils has increased and MBC and DOC contents in soils with middle groundwater tables (MW) and high groundwater tables (HW) has decreased with increasing WC. MBC in three wetlands presented a “decreasing before increasing” tendency with increasing salinity, whereas DOC showed an “increasing before decreasing” tendency. Soil microbial biomass and soil fertility in estuarine wetlands with salinity between 1.8 and 2.0 ppt were relatively high, which was conducive to plant growth. The findings of this study provide a better understanding of the relationships between soil labile organic carbon and water and salt conditions as also deliver basic data for carbon sequestration and blue carbon management in estuarine wetlands.

Closing the loop - Recovery of nutrients and energy from wetland biomass

The aim of our research was to estimate the amount of energy, C, N and P that potentially could be extracted from the plant biomass harvested annually in the Narew National Park (NE Poland). We found that the conversion of biomass through anaerobic digestion (AD) delivers not only power and heat but also ensures the recovery of nutrients and organic matter for their reuse in agriculture. The most productive community with the highest biomass yield was reed bed of Phragmites australis (9.78 ± 1.66 t d.w. ha−1). It was followed by Phalaridetum and tall sedge communities with Carex elata and C. gracilis (6–7 t d.w. ha−1), rushes of Glyceria maxima (3.61 ± 0.63 t d.w. ha−1), and sedge moss communities with C. lasiocarpa (~1 t d.w. ha−1). Annual vegetation management would result in ~33·103 t d.w. of biomass. The primary net energy output was related to the productivity of the vegetation and ranged from ~17 GJ ha−1 for the sedge moss communities to 160 GJ ha−1 for Phragmitetum australis. The methane potential of the studied species was low and varied between 89 Nm3 t−1 d.w. for Phragmites and 188 NL kg−1 d.w. for Glyceria maxima. Consequently, the unit related net gain of energy in CH4 ranged between 23 and 30 GJ ha−1 for the perennial grasses and tall-sedge communities, and 3.5 GJ ha−1 for the low-productivity sedge-moss communities.As a result of low energy inputs for harvesting, the wetland biomass exhibited a favorable energy balance. The annual potential of CH4 for the whole studied valley section was 3286 ± 439·103 m3 resulting in net electricity potential of ~9.1 GWh and waste heat –32.3 TJ.An “average” hectare of wetland could power 1.2 household and provide 1010.4 ± 169.4 kg of C, 117.8 ± 19.6 kg of N, and 11.9 ± 2.0 of P applied do crop soils along with a digestate.

Mapping Aboveground Biomass of Four Typical Vegetation Types in the Poyang Lake Wetlands Based on Random Forest Modelling and Landsat Images.

Wetland biomass is an important indicator of wetland ecosystem health. In this study, four dominant vegetation communities (Carex cinerascens, Phalaris arundinacea, Artemisia selengensis, and Miscanthus sacchariflorus) in the Poyang Lake wetland from 2010 to 2016 were classified from Landsat images using spectral information divergence (SID). We combined aboveground biomass (AGB) field measurements and remote sensing data to establish a suitable model for estimating wetland AGB in Poyang Lake, which is on the Ramsar Convention’s list of Wetlands of International Importance. The results showed that (1) overall, the classification accuracy for vegetation pixels across 5 years ranged from 59.1% to 73.7% and (2) the inter-annual and spatial variations in the AGB of the four vegetation types were clear. C. cinerascens had an average AGB density value of 1.28 kg m−2 in Poyang Lake from 2010 to 2016; M. sacchariflorus had the highest AGB density with an average value of 1.39 kg m−2; A. selengensis had almost the same level at 1.26 kg m−2; and P. arundinacea had the lowest AGB density at 0.64 kg m−2. This study provides useful experience for estimating carbon sequestration of vegetation in freshwater wetlands.

Wetland Biomass and Productivity in Coastal Louisiana: Base Line Data (1976–2015) and Knowledge Gaps for the Development of Spatially Explicit Models for Ecosystem Restoration and Rehabilitation Initiatives

Coastal Louisiana hosts 37% of the coastal wetland area in the conterminous US, including one of the deltaic coastal regions more susceptible to the synergy of human and natural impacts causing wetland loss. As a result of the construction of flood protection infrastructure, dredging of channels across wetlands for oil/gas exploration and maritime transport activities, coastal Louisiana has lost approximately 4900 km2 of wetland area since the early 1930s. Despite the economic relevance of both wetland biomass and net primary productivity (NPP) as ecosystem services, there is a lack of vegetation simulation models to forecast the trends of those functional attributes at the landscape level as hydrological restoration projects are implemented. Here, we review the availability of peer-reviewed biomass and NPP wetland data (below and aboveground) published during the period 1976–2015 for use in the development, calibration and validation of high spatial resolution (<200 m × 200 m) vegetation process-based ecological models. We discuss and list the knowledge gaps for those species that represent vegetation community associations of ecological importance, including the long-term research issues associated to limited number of paired belowground biomass and productivity studies across hydrological basins currently undergoing different freshwater diversions management regimes and hydrological restoration priorities.

Transformation of Phosphorus in Wetland Biomass during Pyrolysis and Hydrothermal Treatment

The reclamation of phosphorus (P) in wetland biomass is a potential strategy to alleviate the P resource shortage, and (hydro)thermal treatment is considered a promising technique for biomass waste treatment and valuable product manufacturing. In order to understand the evolution of P during the (hydro)thermal process, we systematically determined P speciation during pyrolysis (300–600 °C) and hydrothermal carbonization (HTC, 200–260 °C) of Napier grass via combining 31P NMR, XRD, and sequential chemical extraction, and the derived chars were characterized. The biochars showed higher pH, higher ash content as well as greater stability, and the hydrochars had more oxygen-containing groups and better energy density. Temperature-dependent (hydro)thermal treatments can effectively reduce the risk of P leaching loss by transforming P into stable pools. Pyrolysis could increase the portion of potentially plant-available P (NaHCO3–Pi) from 3.6% to 29.0% with increasing pyrolysis temperature, while HTC treatment favored the formation of more stable P pools (HCl–P). Ortho-P (93.4%) and monoester-P (6.6%) were the main P species in Napier grass, while a considerate amount of amorphous pyrophosphate (20.0–40.3%) formed after pyrolysis. In contrast, orthophosphate (e.g., Ca3(PO4)2) was the dominant P species in hydrochars. Therefore, P availability and speciation are greatly affected by (hydro)thermal treatment conditions, and these findings provide guidance for P reclamation and biomass waste utilization.

Evaluation of hydrothermally carbonized alternative biomass (Lepironia articulata) as a source of alternative energy and adsorbent

Lepironia articulata (LA) widely available wetland biomass was successfully converted into a solid coal-like material called hydrochar. Hydrothermal carbonization (HTC) being a technically-attractive thermal conversion process of biomass into hydrochar at mild conditions was adopted in this study. The effect of process parameters on the physicochemical properties and the yield of hydrochar was studied by varying carbonization temperature and residence time over the range of 180, 200, 220, 240 oC and 6, 12, 24 h, respectively. With an increase in temperature, the hydrochar yield decreased rapidly from 68.8% at 180 oC to 55.2% at 240 oC. In addition, the increase in carbon percentage was observed with an increase in temperature from 10.28% (180 oC) to 38.69 %( 240 oC). The H/C and O/C atomic ratios reduced from 1.392 and 0.541 to 1.072 and 0.271, respectively, which was typically related to decarboxylation, demethanation, and dehydration reactions. Hydrochar obtained was characterized appropriately, i.e., proximate analysis, TGA, HHV, FT-IR and BET. The highest surface area (SBET) of hydrochar obtained was 72.2 m2/g. The maximum iodine number calculated was 220 mg/g. HHV of hydrochar was in the range of 22.52 to 25.1 MJ/kg. Overall results conclude the effectiveness of LA in the field of environmental remediation, sustainable and alternative energy.

Modelación del efecto de la reproducción colonial de Bubulcus ibis (Aves: Ardeidae) en el flujo de biomasa y energía de los manglares costeros

Modeling the effect of colonial breeding in Bubulcus ibis (Aves: Ardeidae) on biomass and energy flows in coastal mangrove wetlands. The colonies of wading birds reach thousands of highly grouped nests, which have a marked influence on the characteristics of the soil or the water that surrounds them due to a hyperfertilization effect. This causes the harmful accumulation of nitrogen compounds altering the chemistry of the substrate and causing defoliation and death of vegetation. The impact of these colonies on the mangroves in Cuba has not been evaluated, due to the logistical difficulties involved and the complexity of their processes. Mathematical modeling is a useful tool in these situations, so in this work the estimation of the quantities of biomass, energy and nutrients mobilized in a colony of herons was carried out, through a bioenergetic model of system dynamics. We used 29 primary variables, 3 bioenergetic equations and the postnatal growth equation of this species, implemented in the STELLA 9.1.3 program. From the interaction of these variables, the energy required by the reproduction cycle, the biomass consumed and the nutrients deposited in the colony were obtained. A sensitivity analysis and an uncertainty analysis were carried out to explore the variables that have the most influence on the results. The model was validated by the consistency in the units, the test of extreme values and the comparison with values recorded in the literature. Finally, disturbances scenarios that can affect a real colony were simulated. According to the model, for the growth the chicks require 10 219.2 Kcal total. The colony must totally invest 6.71x106 Kcal, which represents consumption close to 2.2 tons of dams. Due to this consumption, the nutrients deposited in the colony by the excreta were 49 kg of nitrogen, 7 kg of phosphorus and 56 kg of calcium. According to the sensitivity analysis, the variables that produce the strongest changes in the result are the number of adults in the colony and the average clutch size. The uncertainty analysis showed little influence of the variables selected on the response variables. The most harmful simulated disturbances for the colony were the affectations to the recruitment and the increase of the mortality of the pigeons.

Harvesting Biomass-Based Ni–N Doped Carbonaceous Materials with High Capacitance by Fast Pyrolysis of Ni Enriched Spent Wetland Biomass

In this study, taking Ni enriched water hyacinth (WH, Eichhornia crassipes) as an example, we prepared porous Ni–N doped carbon material (WHPC@Ni) with high supercapacitive performance via fast pyr...

Combining bioenergy and nature conservation: An example in wetlands

Conservation and restoration are crucial to maintaining a wide range of functions and services in wetlands, but it is difficult to find a reasonable and resource-efficient management option without sacrificing ecological values. In the present paper, we analyse the variability and dynamics of the chemical composition and energy potential of biomass from reedbeds, floodplain meadows, coastal meadows and reed canary grass cultivation in extracted peatlands. We observed that the chemical characteristics that are crucial for bioenergy production vary by biomass origin and over time. The bioenergy potential depends on biomass production and on the conversion method. The results indicate that the energy potential ranges from 122 to 190 GJ/ha per year in semi-natural floodplain meadows in the boreal zone. About 160 GJ/ha per year can be obtained from natural reedbeds but only about 120 GJ/ha per year from cultivated extracted peatlands. Using methane conversion, we can obtain only about 50%, and using ethanol conversion we can obtain less than 20% of the total energy potential of the herbaceous biomass of floodplain meadows. Although long-term studies on homo- and heterogeneous biomass production are required, we conclude that the local biomass of natural, semi-natural and artificial wetlands could contribute significantly to sustainable development.

Revealing the impact of pyrolysis temperature on dissolved organic matter released from the biochar prepared from Typha orientalis

Biochars derived from wetland biomass have been extensively applied in water and wastewater treatments. This study investigated the quantity and chemical quality of dissolved organic matter (DOM) released from the biochar prepared from the typical wetland plant (Typha orientalis) at different pyrolysis temperatures (300–700 °C) by using fluorescence excitation-emission (EEM) spectrophotometry with parallel factor analysis (PARAFAC) and UV–Visible spectroscopy. The results showed that the content of DOM released from biochars at low pyrolysis temperatures (300–500 °C) was higher than that observed at high pyrolysis temperatures (600–700 °C). The distribution of DOM components (mainly including three humic acid-like substances, one fulvic acid-like substance and one tyrosine-like substance) varied significantly due to the increase of pyrolysis temperatures. The fulvic acid-like material was the key DOM component at the low pyrolysis temperature while the humic acid-like material became dominant at the high temperature. DOM quality indices also indicated that the percentage of the low molecular-weight DOM increased with the decreasing DOC concentration due to the higher temperatures. The results obtained in this study would be beneficial to guide the rational application of biochars in waste treatments.

Study of bioremediation of water environment using constructed wetland for ecological engineering and bioenergy generation from biomass recycling

Environmental water ecosystems are facing serious hypoxia challenges because of high nutrient loadings from point and non-point sources. Therefore, the use of Vertical sub-surface flow constructed wetlands (VSSFCWs) for mitigating environmental water pollution through enhanced nitrification and denitrification processes. They offer a promising nutrient removal mechanism while also providing an ideal environment for the growth of perennial grasses. VSSFCWs not only play a role in providing safe sanitation, they produce biomass that can be harvested and used to produce fodder and biofuel in this complex global world. Biochar offers best habitation for microorganisms to decompose organic matter. The potential of constructed wetland biomass for bioenergy production through carbon sequestration had been observed. Planted with common reed macrophytes to promote biodiversity, the 0.251 m2 constructed wetland has been treating 0.03 cubic meter per day (CMD) of farm wastewater. The overall aboveground biomass was 1277 kg and total carbon content 471 kg at the peak of aboveground accumulation for the system emergent macrophyte. Incinerating of 80% biomass harvested of experimental area in an incineration plant could produce 2446 kWh for one month.