Removal of phenol in a constructed wetland system and the relative contribution of plant roots, microbial activity and porous bed

2010 ◽  
Vol 62 (6) ◽  
pp. 1327-1334 ◽  
Author(s):  
E. Kurzbaum ◽  
Y. Zimmels ◽  
F. Kirzhner ◽  
R. Armon
Keyword(s):  
Constructed Wetland ◽  
Plant Biomass ◽  
Plant Roots ◽  
Organic Load ◽  
Phenol Removal ◽  
Relative Role ◽  
Relative Contribution ◽  
Depth Analysis ◽  
Biofilm Bacteria

Analysis of a low organic load constructed wetland (CW) system was performed in order to understand the relative role of its various components contribution in phenol removal (100 mg/L) under controlled plant biomass/gravel/water experimental ratios (50 g/450 g/100 mL). The results [expressed as phenol50/time (hours) required to remove 50% of the initial phenol concentration] showed that the highest phenol removal occurred by combined biofilms from roots and gravel attached (phenol50 = 19), followed by gravel biofilm (phenol50 = 105) and planktonic (suspended in water) bacteria (phenol50 = >200). An in depth analysis revealed that plants contribution alone (antibiotics sterilized) was minor (phenol50 = >89) while roots supported biofilm resulted in a significant phenol removal (phenol50 = 15). Therefore in this type of CW, the main phenol removal active fraction could be attributed to plant roots' biofilm bacteria.

scholarly journals Air-to-sea flux of soluble iron: is it driven more by HNO<sub>3</sub> or SO<sub>2</sub>? – an examination in the light of dust aging

2007 ◽  
Vol 7 (4) ◽  
pp. 10043-10063 ◽  
Author(s):  
H. Yang ◽  
Y. Gao
Keyword(s):  
Atmospheric Chemistry ◽  
Transport Model ◽  
World Ocean ◽  
Global Ocean ◽  
Relative Role ◽  
Chemistry Transport Model ◽  
Acidic Gases ◽  
Relative Contribution ◽  
The World

Abstract. Aeolian dust provides the major micronutrient of soluble Fe to organisms in certain regions of the global ocean. In this study, we conduct numerical experiments using the MOZART-2 atmospheric chemistry transport model to simulate the global distribution of soluble Fe flux and Fe solubility. One of the mechanisms behind the hypothesis of acid mobilization of Fe in the atmosphere is that the coating of acidic gases changes dust from hydrophobic to hydrophilic, a prerequisite of Fe mobilization. We therefore include HNO3, SO2 and sulfate (SO42−) as dust transformation agents in the model. General agreement in Fe solubility within a factor of 2 is achieved between model and observations. The total flux of soluble Fe to the world ocean is estimated to be 731–924×109 g yr−1, and the average Fe solubility is 6.4–8.0%. Wet deposition contributes over 80% to total soluble Fe flux to most of the world oceans. Special attention is paid to the relative role of HNO3 versus SO2 and sulfate. We demonstrate that coating by HNO3 produces over 36% of soluble Fe fluxes compared to that by SO2 and sulfate combined in every major oceanic basin. Given present trends in the emissions of NOx and SO2, the relative contribution of HNO3 to Fe mobilization may get even larger in the future.

scholarly journals The role of genomic vs. epigenomic variation in shaping patterns of convergent transcriptomic variation across continents in a young species complex

2019 ◽  
Author(s):  
Clément Rougeux ◽  
Martin Laporte ◽  
Pierre-Alexandre Gagnaire ◽  
Louis Bernatchez
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Adaptive Divergence ◽  
Relative Role ◽  
Gene Expression Variation ◽  
Genomic Changes ◽  
Expression Variation ◽  
Relative Contribution ◽  
Variation Explained

ABSTRACTRepeated adaptive divergence in replicates of phenotypic diversification offers a propitious context to identify the molecular bases associated to adaptive divergence. A currently hotly debated topic pertains to the relative role of genomic vs. epigenomic variation in shaping patterns of phenotypic variation at the gene expression level. Here, we combined genomic, epigenomic and transcriptomic information from 64 individuals in order to quantify the relative role of SNPs and DNA methylation variation in the repeated evolution of four limnetic-benthic whitefish species pairs from Europe and North America. We first found evidence for 149 convergent differentially methylated regions (DMRs) between species across continents, which significantly influenced levels of gene expression. Hyper-methylated DMRs in the limnetic species were globally associated to an expression repression relatively to benthic species, and inversely. Furthermore, we identified 108 convergent genetic variants (eQTLs) associated to gene expression differences between species. Gene expression differences were more pronounced in genes harbouring eQTL compared to those associated with DMRs, thus revealing a greater effect of eQTLs on gene expression. Multivariate analyses allowed partitioning the relative contribution of epi-/genomic changes and their association to gene expression variation. Most of the gene expression variation was significantly explained by genomic (4.1%) and putatively genomic-epigenomic interactive variation (46.7%), while “pure” epigenomic variation explained marginally 2.3% of the gene expression variation across continents. This study provides a rare qualitative and quantitative documentation of the relative role of genomic, DNA methylation and their interaction in shaping patterns of convergent gene expression during the process of ecological speciation.

Role of vegetation (Typha latifolia) on nutrient removal in a horizontal subsurface-flow constructed wetland treating UASB reactor–trickling filter effluent

2015 ◽  
Vol 71 (7) ◽  
pp. 1004-1010 ◽  
Author(s):  
Jocilene Ferreira da Costa ◽  
Weber Luiz Pinto Martins ◽  
Martin Seidl ◽  
Marcos von Sperling
Keyword(s):  
Constructed Wetland ◽  
Dry Matter ◽  
Plant Biomass ◽  
Subsurface Flow ◽  
Typha Latifolia ◽  
Trickling Filter ◽  
Nitrate N ◽  
Subsurface Flow Constructed Wetland ◽  
Horizontal Subsurface Flow

The main objective of the work is to characterize the role of plants in a constructed wetland in the removal of nitrogen (N) and phosphorus (P). The experiments were carried out in a full-scale system in the city of Belo Horizonte, Brazil, with two parallel horizontal subsurface-flow constructed wetland units (one planted with Typha latifolia and one unplanted) treating the effluent from a system composed of an upflow anaerobic sludge blanket reactor and a trickling filter (TF). Each wetland unit received a mean flow of approximately 8.5 m³ d−1 (population equivalent around 60 inhabitants each), with a surface hydraulic loading rate 0.12 m3m−2d−1. The experiments were conducted from September 2011 to July 2013. Mean effluent concentrations from the wetlands were: (a) planted unit total nitrogen (TN) 22 mg L−1, ammonia-N 19 mg L−1, nitrite-N 0.10 mg L−1, nitrate-N 0.25 mg L−1, P-total 1.31 mg L−1; and (b) unplanted unit TN 24 mg L−1, ammonia-N 20 mg L−1, nitrite-N 0.54 mg mL−1, nitrate-N 0.15 mg L−1, P-total 1.31 mg L−1. The aerial part of the plant contained mean values of 24.1 gN (kg dry matter)−1 and 4.4 gP (kg dry matter)−1, and the plant root zone was composed of 16.5 gN (kg dry matter)−1 and 4.1 gP (kg dry matter)−1. The mean extraction of N by the plant biomass was 726 kgN ha−1y−1, corresponding to 17% of the N load removed. For P, the extraction by the plant biomass was 105 kgP ha−1y−1, corresponding to 9% of the P load removed. These results reinforce the reports that N and P removal due to plant uptake is a minor mechanism in horizontal subsurface-flow constructed wetlands operating under similar loading rates, typical for polishing of sanitary effluent.

Riverscape-scale airborne TIR assessment of weirs and riparian cover effects on lowland river temperature 

2021 ◽  
Author(s):  
Baptiste Marteau ◽  
André Chandesris ◽  
Flavie Cernesson ◽  
Kristell Michel ◽  
Lise Vaudor ◽  
...  
Keyword(s):  
Maximum Temperature ◽  
Relative Role ◽  
Technological Advancement ◽  
River Temperature ◽  
Lowland Streams ◽  
Clear Cutting ◽  
Relative Contribution ◽  
Riparian Trees ◽  
High Maximum

&lt;p&gt;&lt;span&gt;The development of Airborne Infrared Thermal sensing (TIR) is an example of how technological advancement&lt;/span&gt;&lt;span&gt;s&lt;/span&gt;&lt;span&gt; and the field that they focus on have fostered one another. The pace at which global change is occurring has fed the demand for better understanding of the thermal behaviour of rivers. In turn, the improvement of remote sensing and data processing techniques has provided researchers and managers with new tools to apprehend such aspects at ever larger scales. Still, recent studies have mostly focussed on rivers showing little human alteration, with a particular interest on groundwater&amp;#8211;surface water interactions. Lowland streams are scarcely considered when it comes to the study of temperature despite their widespread occurrence, their relatively high degree of disturbance and the risks that they face in the light of temperature rising following climate change. Some of these streams already display critically high maximum summer temperatures and their state is likely to worsen in the future, putting all compartments of biota at risk.&lt;br&gt;&lt;/span&gt;&lt;/p&gt;&lt;p&gt;&lt;span&gt;The aims of this project were twofold. We first tested the applicability of airborne TIR to study lowland, slow-flowing stream reaches draining agricultural catchments, some of which being particularly narrow and sinuous. We then sought to understand the role of different environmental factors, observed in such context, on driving river temperature during the warmest days of the year. A number of anthropogenic actions such as clear-cutting of riparian trees, stream rectification and the construction of weirs are likely to influence the longitudinal temperature profile of such streams. By choosing rivers with no or limited groundwater inputs, we were able to quantify the relative role of each of the three tested factors and identify stream sections showing critically high maximum temperature over the summer.&lt;/span&gt;&lt;/p&gt;&lt;p&gt;&lt;span&gt;A final step was proposed to upscale these results in order to identify sections of streams showing high risks of reaching critically high summer temperature at a regional network scale. To do so, we used a combination of high resolution land-cover data, digital elevation models and other existing databases (e.g. national inventory of weirs). Identification of the risks in relation with the relative contribution of the different factors is key to process-based river management. This type of output is valuable to river basin managers and decision makers as it can be used to implement targeted restoration initiatives or remediation actions in areas where these have higher chances of being effective.&lt;/span&gt;&lt;/p&gt;

Multiple interactions in riverine biofilms - surfactant adsorption, bacterial attachment and biodegradation

1995 ◽  
Vol 31 (1) ◽  
pp. 61-70 ◽  
Author(s):  
Graham F. White
Keyword(s):  
Organic Pollutants ◽  
Bacterial Attachment ◽  
Solid Surfaces ◽  
Sediment Surface ◽  
Liquid Interfaces ◽  
Polluted Soils ◽  
Biofilm Bacteria ◽  
The Impact ◽  
Multiple Interactions

Many organic pollutants, especially synthetic surfactants, adsorb onto solid surfaces in natural and engineered aquatic environments. Biofilm bacteria on such surfaces make major contributions to microbial heterotrophic activity and biodegradation of organic pollutants. This paper reviews evidence for multiple interactions between surfactants, biodegradative bacteria, and sediment-liquid interfaces. Biodegradable surfactants e.g. SDS, added to a river-water microcosm were rapidly adsorb to sediment surface and stimulated the indigenous bacteria to attach to the sediment particles. Recalcitrant surfactants and non-surfactant organic nutrients did not stimulate attachment Attachment of bacteria was maximal when biodegradation was fastest, and was reversed when biodegradation was complete. Dodecanol, the primary product of SDS-biodegradation, markedly stimulated attachment. When SDS was added to suspensions containing sediment and either known degraders or known non-degraders, only the degraders became attached, and attachment accelerated surfactant biodegradation to dodecanol. These cyclical cooperative interactions have implications for the design of biodegradability-tests, the impact of surfactant adjuvants on biodegradability of herbicides/pesticides formulated with surfactants, and the role of surfactants used to accelerate bioremediation of hydrocarbon-polluted soils.

Microbial Biofilms and Biotechnology – Some Perceptions

2020 ◽  
Vol 09 ◽  
Author(s):  
Subba Rao Toleti
Keyword(s):  
Tissue Culture ◽  
Synthetic Biology ◽  
Industrial Effluents ◽  
Aquatic Environments ◽  
Biochemical Processes ◽  
Microbial Biofilms ◽  
Biofilm Bacteria ◽  
Prophylactic Vaccines ◽  
Design Construction

: The review is an attempt to introduce the readers in brief about biofilms and their implications as well as some new perceptions in biotechnology. Biofilms are adherent microbial communities, which are developed on submerged surfaces in aquatic environments. Biofilms play a significant role in exopolymer production, material deterioration and also cause harmful infections. Further, the role of corrosion causing biofilm bacteria in deterioration of different materials, microbial biofilms and their enzymatic processes in reducing the toxicity of pollutants in industrial effluents are elaborated, along with clean technologies for wastewater treatment. Biotechnology is defined as any technological application that uses biological systems to synthesize or modify products or processes. The applications include biochemical processes, medical care, cell and tissue culture as well as synthetic biology and others. Synthetic biology details about the design, construction of new biological components and systems for useful purposes. Finally, to overcome the limitations that are inherent to the use of cellular host’s, cell-free systems as critical platforms for synthetic biology applications. This mini-review also mentions about new diagnostic products based on enzymes, monoclonal antibodies and engineered proteins as well as novel prophylactic vaccines.

A Developmental Perspective on the Genetic Basis of Alcohol Use Disorder

2018 ◽  
Author(s):  
Elisa M. Trucco ◽  
Gabriel L. Schlomer ◽  
Brian M. Hicks
Keyword(s):  
Alcohol Use ◽  
Alcohol Use Disorder ◽  
Developmental Perspective ◽  
Relative Contribution ◽  
Intermediate Phenotypes ◽  
Problematic Alcohol ◽  
Age Related ◽  
Genetic And Environmental Factors ◽  
Problematic Alcohol Use

Approximately 48–66% of the variation in alcohol use disorders is heritable. This chapter provides an overview of the genetic influences that contribute to alcohol use disorder within a developmental perspective. Namely, risk for problematic alcohol use is framed as a function of age-related changes in the relative contribution of genetic and environmental factors and an end state of developmental processes. This chapter discusses the role of development in the association between genes and the environment on risk for alcohol use disorder. Designs used to identify genetic factors relevant to problematic alcohol use are discussed. Studies examining developmental pathways to alcohol use disorder with a focus on endophenotypes and intermediate phenotypes are reviewed. Finally, areas for further investigation are offered.

scholarly journals Nano Zero Valent Iron (nZVI) as an Amendment for Phytostabilization of Highly Multi-PTE Contaminated Soil

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2559
Author(s):  
Maja Radziemska ◽  
Zygmunt M. Gusiatin ◽  
Jiri Holatko ◽  
Tereza Hammerschmiedt ◽  
Andrzej Głuchowski ◽  
...  
Keyword(s):  
Plant Biomass ◽  
Absorption Spectrometry ◽  
Zero Valent Iron ◽  
Festuca Rubra ◽  
Control Series ◽  
Flame Atomic Absorption ◽  
Zn Content ◽  
Nano Zero Valent Iron ◽  
Average Plant

In recent years, a lot of attention has been given to searching for new additives which will effectively facilitate the process of immobilizing contaminants in the soil. This work considers the role of the enhanced nano zero valent iron (nZVI) strategy in the phytostabilization of soil contaminated with potentially toxic elements (PTEs). The experiment was carried out on soil that was highly contaminated with PTEs derived from areas in which metal waste had been stored for many years. The plants used comprised a mixture of grasses—Lolium perenne L. and Festuca rubra L. To determine the effect of the nZVI on the content of PTEs in soil and plants, the samples were analyzed using flame atomic absorption spectrometry (FAAS). The addition of nZVI significantly increased average plant biomass (38%), the contents of Cu (above 2-fold), Ni (44%), Cd (29%), Pb (68%), Zn (44%), and Cr (above 2-fold) in the roots as well as the soil pH. The addition of nZVI, on the other hand, was most effective in reducing the Zn content of soil when compared to the control series. Based on the investigations conducted, the application of nZVI to soil highly contaminated with PTEs is potentially beneficial for the restoration of polluted lands.

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