Assessing the toxicity of Pb-based and Sn-based perovskite solar cells in model organism Danio rerio
; Dinh Duy Thanh, ; et al
in Scientific Reports (in press)
Waiting for official publicationDetailed reference viewed: 199 (27 ULg)
Pb-based versus Sn-based perovskite solar cells: Toxicity and environmental burden
; Dinh Duy Thanh, ; et al
Poster (2015, May)
Organometal halide perovskites have rapidly evolved into strong contenders to compete with silicon in the quest for low-cost photovoltaics, with their added value being solution-processability. Their ... [more ▼]
Organometal halide perovskites have rapidly evolved into strong contenders to compete with silicon in the quest for low-cost photovoltaics, with their added value being solution-processability. Their primary drawback, however, is that so far the presence of lead (Pb) is required to obtain the highly favorable electro-optical properties of the most successful perovskite crystals such as CH3NH3PbI3. Together with their tendency to degrade under the influence of humidity, and the corresponding disintegration of the unit cell, this implies that Pb compounds can be released into the environment upon failure of a perovskite module. As already known from literature, Pb is a rather toxic element causing irreversible neurological, nephrotic and hepatic damage. Hence, finding a non-harmful alternative metal, exhibiting similar electro-optical characteristics in the resulting perovskite crystal, could be the solution to improve and ultimately commercialize perovskite-based solar cells. Tin (Sn), also being a group IV metal, has been deemed the most appropriate alternative. However, Sn is also enlisted as a harmful chemical. Animal and human volunteer studies have shown that toxicity symptoms like fever, nausea, nephropathy, etc. emerge upon excessive uptake, raising question marks regarding the suitability of Sn as a more environmentally friendly alternative to Pb in perovskite solar cells. This contribution aims to make a first step towards the assessment of the environmental burden of both Pb and Sn based solar cells in the form of a toxicity study. Well-established aquatic model organisms are exposed to the appropriate degradation products, according to well-defined guidelines of the Organization for Economic Co-operation and Development (OECD). This allows a systematic comparison of Sn and Pb-containing decayed compounds regarding their potentially harmful effects on the environment, and sheds light onto the applicability of both corresponding perovskite families in large-scale photovoltaic systems. [less ▲]Detailed reference viewed: 241 (4 ULg)
Estrogenic Evaluation and Organochlorine Identification in Blubber of North Sea Harbour Porpoise (Phocoena phocoena) Stranded on the North Sea Coast
Didimo Imazaki, Pedro Henrique ; Brose, François ; Jauniaux, Thierry et al
in BioMed Research International (2015), Volume 2015(Article ID 438295), 13
Thirteen individual organochlorine compounds at 3 concentrations (80, 400, and 2000 ng/mL culture medium), as well as mixtures, were assayed for the estrogen receptor (ER) activation or inhibition, using ... [more ▼]
Thirteen individual organochlorine compounds at 3 concentrations (80, 400, and 2000 ng/mL culture medium), as well as mixtures, were assayed for the estrogen receptor (ER) activation or inhibition, using a luciferase reporter gene assay (RGA). None of the PCB 138, 153, or 180 or their mixture induced a response in the RGA. o,p'-DDT was the most potent xenoestrogen fromthe DDT group, inducing a response already at 80 ng/mL. From the HCH and HCB group, only 𝛽-HCH (at 400 and 2000 ng/mL) and 𝛿-HCH (at 2000 ng/mL) displayed estrogenic activities.These 13 organochlorines were determined by GC-MS in 12 samples of North Sea harbor porpoise blubber. The PCBs were the main contaminants. Within each group, PCB 153 (6.0 × 102∼4.2 × 104 𝜇g/kg), p,p'- DDE (5.1 × 102∼8.6 × 103 𝜇g/kg), and HCB (7.6 × 101∼1.5 × 103 𝜇g/kg) were the compounds found in highest concentrations.The hormonal activity of the porpoise blubber samples was also assayed in RGA, where two samples showed estrogenic activity, seven samples showed antiestrogenic activity, and one sample showed both estrogenic and antiestrogenic activity. Our results suggest that the 13 POPs measured by GC-MS in the samples cannot explain alone the estrogenicity of the extracts. [less ▲]Detailed reference viewed: 37 (15 ULg)
Zebrafish bone and general physiology are differently affected by hormones or changes in gravity.
Aceto, Jessica ; ; Marée, Raphaël et al
in PLoS ONE (2015), 10(6), 1-42
Teleost fish such as zebrafish (Danio rerio) are increasingly used for physiological, genetic and developmental studies. Our understanding of the physiological consequences of altered gravity in an entire ... [more ▼]
Teleost fish such as zebrafish (Danio rerio) are increasingly used for physiological, genetic and developmental studies. Our understanding of the physiological consequences of altered gravity in an entire organism is still incomplete. We used altered gravity and drug treatment experiments to evaluate their effects specifically on bone formation and more generally on whole genome gene expression. By combining morphometric tools with an objective scoring system for the state of development for each element in the head skeleton and specific gene expression analysis, we confirmed and characterized in detail the decrease or increase of bone formation caused by a 5 day treatment (from 5dpf to 10 dpf) of, respectively parathyroid hormone (PTH) or vitamin D3 (VitD3). Microarray transcriptome analysis after 24 hours treatment reveals a general effect on physiology upon VitD3 treatment, while PTH causes more specifically developmental effects. Hypergravity (3g from 5dpf to 9 dpf) exposure results in a significantly larger head and a significant increase in bone formation for a subset of the cranial bones. Gene expression analysis after 24 hrs at 3g revealed differential expression of genes involved in the development and function of the skeletal, muscular, nervous, endocrine and cardiovascular systems. Finally, we propose a novel type of experimental approach, the "Reduced Gravity Paradigm", by keeping the developing larvae at 3g hypergravity for the first 5 days before returning them to 1g for one additional day. 5 days exposure to 3g during these early stages also caused increased bone formation, while gene expression analysis revealed a central network of regulatory genes (hes5, sox10, lgals3bp, egr1, edn1, fos, fosb, klf2, gadd45ba and socs3a) whose expression was consistently affected by the transition from hyper- to normal gravity. [less ▲]Detailed reference viewed: 151 (20 ULg)
BMP Signaling Regulates Bone Morphogenesis in Zebrafish through Promoting Osteoblast Function as Assessed by Their Nitric Oxide Production
Windhausen, Thomas ; ; Renn, Jörg et al
in Molecules (2015), 20
Bone morphogenetic proteins (BMPs) control many developmental and physiological processes, including skeleton formation and homeostasis. Previous studies in zebrafish revealed the crucial importance of ... [more ▼]
Bone morphogenetic proteins (BMPs) control many developmental and physiological processes, including skeleton formation and homeostasis. Previous studies in zebrafish revealed the crucial importance of proper BMP signaling before 48 h post-fertilization (hpf) for cartilage formation in the skull. Here, we focus on the involvement of the BMP pathway between 48 and 96 hpf in bone formation after 96 hpf. Using BMP inhibitors and the expression of a dominant-negative BMP receptor, we analyze whether the loss of BMP signaling affects osteoblastogenesis, osteoblast function and bone mineralization. To this end, we used the transgenic zebrafish line Tg(osterix:mCherry), detection of nitric oxide (NO) production, and alizarin red staining, respectively. We observed that inhibition of BMP signaling between 48 and 72 hpf led to a reduction of NO production and bone mineralization. Osteoblast maturation and chondrogenesis, on the other hand, seemed unchanged. Osteoblast function and bone formation were less affected when BMP signaling was inhibited between 72 and 96 hpf. These results suggest that for the onset of bone formation, proper BMP signaling between 48 and 72 hpf is crucial to ensure osteoblast function and ossification. Furthermore, detection of NO in developing zebrafish larvae appears as an early indicator of bone calcification activity. [less ▲]Detailed reference viewed: 25 (14 ULg)
Phenotype Classification of Zebrafish Embryos by Supervised Learning
Jeanray, Nathalie ; Marée, Raphaël ; et al
in PLoS ONE (2015), 10(1), 01169891-20
Zebrafish is increasingly used to assess biological properties of chemical substances and thus is becoming a specific tool for toxicological and pharmacological studies. The effects of chemical substances ... [more ▼]
Zebrafish is increasingly used to assess biological properties of chemical substances and thus is becoming a specific tool for toxicological and pharmacological studies. The effects of chemical substances on embryo survival and development are generally evaluated manually through microscopic observation by an expert and documented by several typical photographs. Here, we present a methodology to automatically classify brightfield images of wildtype zebrafish embryos according to their defects by using an image analysis approach based on supervised machine learning. We show that, compared to manual classification, automatic classification results in 90 to 100 % agreement with consensus voting of biological experts in nine out of eleven considered defects in 3 days old zebrafish larvae. Automation of the analysis and classification of zebrafish embryo pictures reduces the workload and time required for the biological expert and increases the reproducibility and objectivity of this classification. [less ▲]Detailed reference viewed: 58 (13 ULg)
Effects of some controversial food additives on zebrafish embryonic development
Dinh Duy Thanh, ; ; et al
Poster (2014, December 04)
Background information: There are rising concerns about potential hazardous properties of food additives, forcing legislator to tighten management policy and requiring extensive, yet animal- minimized ... [more ▼]
Background information: There are rising concerns about potential hazardous properties of food additives, forcing legislator to tighten management policy and requiring extensive, yet animal- minimized, testing strategies. The zebrafish embryo is an emerging model system for chemical testing with many advantages that made it amenable to high-throughput assays at the in vivo level. In this study, we applied a panel of tests to evaluate toxicity, particularly neurobehavioral effects, of seven substances including standard compounds and controversial food additives. Methods: Zebrafish wildtype and transgenic fluorescent embryos were exposed to different concentrations of four food additives: Sodium benzoate (SB), Monosodium glutamate (MSG), Tartrazine (TTZ), and Quinoline yellow (QY). Method validation was carried out using three other substances: Ethanol (EtOH), Dimethyl sulfoxide (DMSO), 3,4-Dichloroaniline (DCA). Morphological and lethal effects were recorded and the data were analysed to determine median lethal concentration (LC50), median effective concentration (EC50), effective concentration 10% (EC10), and teratogenic index (TI) values as well as concentration-response equations. Delayed effects of substances on larval locomotion were inspected using the light/dark challenge. Gene expression analysis was carried out using transgenic fluorescent lines. Results: LC50 values of three standard compounds (EtOH, DMSO, and DCA) reveal a high correlation with previously validated data, proving the reliability of our method. Effects of each substance on zebrafish embryonic morphology and lethality were determined as well as the corresponding concentration-response curves. Calculated toxicological indexes revealed that SB belongs to Cat.3 aquatic toxicity class, while QY is the most teratogenic substance. At EC10, all additives exhibited a delayed effect on zebrafish larval locomotion in compound-specific patterns. Observation of transgenic fluorescent embryos and locomotion analysis of hatched larvae reveal that SB could decrease the zebrafish motoneuron differentiation rate, while TTZ exhibited anti-angiogenic effects. Conclusion: Our results demonstrate that our test panel is reliable as a means to assess and categorise chemical toxicity. Also, our data suggest the need to reconsider the safety of food additives SB, TTZ, and QY as well as other controversial food additives in further studies. [less ▲]Detailed reference viewed: 30 (4 ULg)
Detection of nitric oxide by diaminofluorescein visualizes the skeleton in living zebrafish.
Renn, Jörg ; ; Muller, Marc
in Journal of Applied Ichthyology (2014), 30(4), 701706
Several in vivo stainings, such as Calcein, Alizarin Red and Quercetin are commonly used to visualize ossification in living teleost specimen. These staining techniques represent important tools for bone ... [more ▼]
Several in vivo stainings, such as Calcein, Alizarin Red and Quercetin are commonly used to visualize ossification in living teleost specimen. These staining techniques represent important tools for bone research in fish, but do not visualize cartilage. In the present study, we show that nitric oxide (NO) labelling by DAF-FM DA visualizes both bone and cartilage in vivo during zebrafish skeletogenesis. NO detection performed in Tg(osterix:mCherry) or in combination with Alizarin Red in wild-type zebrafish reveals that intense staining through NO labelling colocalizes with the appearance of osteoblasts and characterizes ossified structures. Cartilage structures are clearly distinguished in the living larvae, although the labelling is less intensive when compared to ossified structures. This method is the first and easy to handle alternative to cartilage and bone double stainings on fixed samples. In contrast to most live skeletal stainings, which only stain the mineralized bone structures, this protocol in addition allows in vivo visualization of cartilage. [less ▲]Detailed reference viewed: 13 (6 ULg)
Functional study of the Ser/Arg-rich splicing factor SRSF5a during zebrafish embryonic development
Joris, Marine ; Muller, Marc ; Motte, Patrick
Poster (2014, June 05)
Nuclear pre-mRNA splicing is a key process regulating gene expression in eukaryotes. Splicing consists in the removal of introns and the joining of exons within a dynamic macromolecular complex called the ... [more ▼]
Nuclear pre-mRNA splicing is a key process regulating gene expression in eukaryotes. Splicing consists in the removal of introns and the joining of exons within a dynamic macromolecular complex called the spliceosome, which consist of five small nuclear ribonucleoproteins (snRNPs) and numerous non snRNPs proteins (1). Amongst these non snRNPs proteins, the SR proteins family constituted an important group of splicing factors that are involved in constitutive and alternative splicing (2,3). SR proteins are structurally related as they are characterized by one or two RNA-recognition motifs (RRMs) in N-ter and a C-terminal domain enriched in dipeptide Ser/Arg. Phylogenetic inference using the RRM domain allowed us to identify 13 encoding genes for SR proteins in the vertebrate model organism, Danio rerio. The Zebrafish is increasingly recognized as a powerful model for the study of vertebrate embryonic development in a physiological context. The roles of SR splicing factors during animal cell differentiation and development are largely unknown. The aim of the present research is to investigate SR proteins functions during zebrafish development by using molecular and genetic approaches. In this study, we investigated the role of the SR splicing factor SRSF5a. The expression profile was determined by in situ hybridization at 24, 48 and 72 hours post-fertilization and showed SRSF5a expression mainly in brain, retina and pharyngeal arches at these stages. Furthermore, SRSF5a knock-down by morpholinos microinjection strongly suggests an important role of this specific splicing factor during eyes and brain development. In order to gain insight into the molecular function of SRSF5a, we analysed control and morphant transcriptomes using high throughput RNA sequencing. Finally, we use a complementary approach to morpholinos and generate SRSF5a mutant fishes using TALENs (Tal effector nucleases)(4,5). 1. Wahl MC, Will CL, & Luhrmann R (2009) The spliceosome: design principles of a dynamic RNP machine. Cell 136(4):701-718. 2. Long JC & Caceres JF (2009) The SR protein family of splicing factors: master regulators of gene expression. Biochem J 417(1):15-27. 3. Graveley BR (2000) Sorting out the complexity of SR protein functions. RNA 6(9):1197-1211. 4. Moore et al. (2012) Improved Somatic Mutagenesis in Zebrafish Using Transcription Activator-Like Effector Nucleases (TALENs). Plos One 120(1):1-12. 5. Cade et al (2012) Highly efficient generation of heritable zebrafish gene mutations using homo- and heterodimeric TALENs. Nucleic acid research Vol 40, No 16:8001-8010. [less ▲]Detailed reference viewed: 61 (8 ULg)
Developmental defects in zebrafish for classification of EGF pathway inhibitors.
Pruvot, Benoist ; Curé, Yoann ; et al
in Toxicology and Applied Pharmacology (2014), 274Detailed reference viewed: 36 (11 ULg)
Tg(sox4b∆C:HSE:GFP) zebrafish to analyze Sox4 function for bone formation in vivo.
Renn, Jörg ; Aceto, Jessica ; Muller, Marc
Poster (2013, April 23)Detailed reference viewed: 89 (20 ULg)
Functional study of the Ser/Arg-rich splicing factor SRSF5a during zebrafish embryonic development.
Joris, Marine ; Larbuisson, Arnaud ; Muller, Marc et al
Poster (2013, April 18)
To investigate the role of the splicing factor SRSF5a during zebrafish embryonic development, we performed SRSF5a knockdown by morpholino microinjection and we analysed control and morphant transcriptomes ... [more ▼]
To investigate the role of the splicing factor SRSF5a during zebrafish embryonic development, we performed SRSF5a knockdown by morpholino microinjection and we analysed control and morphant transcriptomes using RNA sequencing. [less ▲]Detailed reference viewed: 63 (18 ULg)
Removal of natural hormones in dairy farm wastewater using reactive and sorptive materials
; ; et al
in Science of the Total Environment (2013), 461-462Detailed reference viewed: 15 (9 ULg)
Fgf receptors Fgfr1a and Fgfr2 control the function of pharyngeal endoderm in late cranial cartilage development.
Larbuisson, Arnaud ; Dalcq, Julia ; Martial, Joseph et al
in Differentiation; research in biological diversity (2013), 86
Cranial cartilage derives mainly from cranial neural crest cells and its formation requires fibroblast growth factor (Fgf) signaling for early differentiation and survival of developing chondrocytes as ... [more ▼]
Cranial cartilage derives mainly from cranial neural crest cells and its formation requires fibroblast growth factor (Fgf) signaling for early differentiation and survival of developing chondrocytes as well as patterning of the endodermal pouches. Here, we investigate the role of Fgf receptors in chondrocyte maturation at later stages, beyond 24hpf. Using inducible expression of a dominant-negative Fgf receptor, we show that Fgf signaling is required around 30hpf for correct cartilage formation. The receptor genes fgfr1a and fgr2 are expressed in pharyngeal endodermal pouches after 24hpf or 26hpf, respectively. Depletion of any of these two receptors by microinjection of antisense morpholinos results in severe defects in cartilage formation at 4dpf and a decrease in expression of the late chondrocyte markers barx1 and runx2b. Although endodermal pouches are correctly formed and patterned, receptor knock down leads to decreased expression of runx3, egr1 and sox9b in this tissue, while expression of fsta, coding for a secreted BMP/Tgfss inhibitor, is clearly increased. Rescue experiments revealed that each Fgfr1a or Fgfr2 receptor is able to compensate for the loss of the other. Thus, we show that minimal amounts of Fgfr1a or Fgfr2 are required to initiate a regulatory cascade in pharyngeal endoderm reducing expression of fsta, thereby allowing correct BMP signaling to the maturing chondrocytes of the head cartilage. [less ▲]Detailed reference viewed: 40 (12 ULg)
Runx3, Egr1 AND Sox9b form a regulatory cascade required to modulate BMP-signaling during cranial cartilage development in zebrafish.
Dalcq, Julia ; ; Ghaye, Aurélie et al
in PLoS ONE (2012), 7(11), 50140
The cartilaginous elements forming the pharyngeal arches of the zebrafish derive from cranial neural crest cells. Their proper differentiation and patterning are regulated by reciprocal interactions ... [more ▼]
The cartilaginous elements forming the pharyngeal arches of the zebrafish derive from cranial neural crest cells. Their proper differentiation and patterning are regulated by reciprocal interactions between neural crest cells and surrounding endodermal, ectodermal and mesodermal tissues. In this study, we show that the endodermal factors Runx3 and Sox9b form a regulatory cascade with Egr1 resulting in transcriptional repression of the fsta gene, encoding a BMP antagonist, in pharyngeal endoderm. Using a transgenic line expressing a dominant negative BMP receptor or a specific BMP inhibitor (dorsomorphin), we show that BMP signaling is indeed required around 30 hpf in the neural crest cells to allow cell differentiation and proper pharyngeal cartilage formation. Runx3, Egr1, Sox9b and BMP signaling are required for expression of runx2b, one of the key regulator of cranial cartilage maturation and bone formation. Finally, we show that egr1 depletion leads to increased expression of fsta and inhibition of BMP signaling in the pharyngeal region. In conclusion, we show that the successive induction of the transcription factors Runx3, Egr1 and Sox9b constitutes a regulatory cascade that controls expression of Follistatin A in pharyngeal endoderm, the latter modulating BMP signaling in developing cranial cartilage in zebrafish. [less ▲]Detailed reference viewed: 56 (36 ULg)
The HMG-Box Transcription Factor Sox4b Is Required for Pituitary Expression of gata2a and Specification of Thyrotrope and Gonadotrope Cells in Zebrafish.
Quiroz O'Donova, Yobhana ; ; et al
in Molecular Endocrinology (2012), 26(6), 1014-1027
The pituitary is a complex gland comprising different cell types each secreting specific hormones. The extensive network of signaling molecules and transcription factors required for determination and ... [more ▼]
The pituitary is a complex gland comprising different cell types each secreting specific hormones. The extensive network of signaling molecules and transcription factors required for determination and terminal differentiation of specific cell types is still not fully understood. The SRY-like HMG-box (SOX) transcription factor Sox4 plays important roles in many developmental processes and has two homologs in zebrafish, Sox4a and Sox4b. We show that the sox4b gene is expressed in the pituitary anlagen starting at 24 h after fertilization (hpf) and later in the entire head region including the pituitary. At 48 hpf, sox4b mRNA colocalizes with that for TSH (tshbeta), glycoprotein subunit alpha (gsualpha), and the Zn finger transcription factor Gata2a. Loss of Sox4b function, using morpholino knockdown or expression of a dominant-negative Sox4 mutant, leads to a drastic decrease in tshbeta and gsualpha expression and reduced levels of gh, whereas other anterior pituitary gland markers including prl, slbeta, pomc, and lim3 are not affected. Sox4b is also required for expression of gata2a in the pituitary. Knockdown of gata2a leads to decreased tshbeta and gsualpha expression at 48 hpf, similar to sox4b morphants. Injection of gata2a mRNA into sox4b morphants rescued tshbeta and gsualpha expression in thyrotrope cells. Finally, sox4b or gata2a knockdown causes a significant decrease of gonadotropin expression (lhbeta and fshbeta) at 4 d after fertilization. In summary, our results indicate that Sox4b is expressed in zebrafish during pituitary development and plays a crucial role in the differentiation of thyrotrope and gonadotrope cells through induction of gata2a expression in the developing pituitary. [less ▲]Detailed reference viewed: 49 (24 ULg)
A panel of biological tests reveals developmental effects of pharmaceutical pollutants on late stage zebrafish embryos.
Pruvot, Benoist ; Quiroz O' Donova, Yobhana ; Voncken, Audrey et al
in Reproductive Toxicology (2012)
Standard toxicological assays using the zebrafish model system evaluate lethality and teratogenicity upon exposure during the first two days after fertilization. We tested the biological effects of ... [more ▼]
Standard toxicological assays using the zebrafish model system evaluate lethality and teratogenicity upon exposure during the first two days after fertilization. We tested the biological effects of several widely used drugs on zebrafish by acute treatment for 24hours starting at late embryonic stages, between 48 and 72hours post-fertilization. For 4 out of 6 compounds, we observed a higher sensitivity of late stage zebrafish embryos for general toxicity (lethality) compared to younger embryos. Morphological defects such as edema, body curvature, delayed growth, decreased heart rate and locomotion were observed for each of the compounds tested, often at sublethal concentrations. Gene expression studies on a set of four selected genes revealed a specific regulatory pattern for the different compounds tested. Our results allow us to compare various toxicological endpoints and may contribute to the design of a rational high throughput approach using the zebrafish model. [less ▲]Detailed reference viewed: 93 (55 ULg)
Structurally conserved C-RFa revealed prolactin releasing activity in vitro and gene expression changes in pituitary of seasonally acclimatized carp.
; ; et al
in Biological Research (2012), 45(2), 183-92
Here we show the cloning and characterization of a novel homolog of prepro C-RFa cDNA from Cyprinus carpio. The deduced preprohormone precursor of 115 amino acids leads to a mature bioactive peptide of 20 ... [more ▼]
Here we show the cloning and characterization of a novel homolog of prepro C-RFa cDNA from Cyprinus carpio. The deduced preprohormone precursor of 115 amino acids leads to a mature bioactive peptide of 20 amino acids with identical sequence to other teleost C-RFa. Modeling of the mature C-RFa peptide highlighted significant similarity to homologous human PrRP20, specifically the conserved amphipathic system defined by the C-terminal alpha-helix. Clearly, the synthetic C-RFa peptide stimulated prolactin release from primary cultured fish pituitary cells. For the first time, significant variation was shown in C-RFa mRNA and protein levels in the hypothalamus and pituitary between summer- and winter-acclimatized carp. Furthermore, C-RFa protein distribution in carp central nervous tissue was visualized by immunodetection in fibers and cells in hypothalamus, olfactory tract, cerebellum and pituitary stalk. In conclusion, we demonstrated the structure conservation of C-RFa in teleosts and mammals and immunopositive cells and fibers for C-RFa in brain areas. Finally, the increase of C-RFa expression suggests the participation of this hypothalamic factor in the mechanism of modulation in PRL expression in carp. [less ▲]Detailed reference viewed: 25 (6 ULg)
Treatment of estrogens and androgens in dairy wastewater by a constructed wetland system.
; ; et al
in Water Research (2012), 46(7), 2333-43
Constructed wetland systems (CWS) have been used as a low cost bio-filtration system to treat farm wastewater. While studies have shown that CWS are efficient in removing organic compounds and pathogens ... [more ▼]
Constructed wetland systems (CWS) have been used as a low cost bio-filtration system to treat farm wastewater. While studies have shown that CWS are efficient in removing organic compounds and pathogens, there is limited data on the presence of hormones in this type of treatment system. The objective of this study was to evaluate the ability of the CWS to reduce estrogenic and androgenic hormone concentration in dairy wastewater. This was achieved through a year long study on dairy wastewater samples obtained from a surface flow CWS. Analysis of hormonal levels was performed using a solid phase extraction (SPE) sample clean-up method, combined with reporter gene assays (RGAs) which incorporate relevant receptors capable of measuring total estrogenic or androgenic concentrations as low as 0.24 ng L(-1) and 6.9 ng L(-1) respectively. Monthly analysis showed a mean removal efficiency for estrogens of 95.2%, corresponding to an average residual concentration of 3.2 ng L(-1) 17beta-estradiol equivalent (EEQ), below the proposed lowest observable effect concentration (LOEC) of 10 ng L(-1). However, for one month a peak EEQ concentration of 115 ng L(-1) was only reduced to 18.8 ng L(-1). The mean androgenic activity peaked at 360 ng L(-1) and a removal efficiency of 92.1% left an average residual concentration of 32.3 ng L(-1) testosterone equivalent (TEQ). The results obtained demonstrate that this type of CWS is an efficient system for the treatment of hormones in dairy wastewater. However, additional design improvements may be required to further enhance removal efficiency of peak hormone concentrations. [less ▲]Detailed reference viewed: 61 (15 ULg)
Phenotype Classification of Zebrafish Embryos by Supervised Learning
Jeanray, Nathalie ; Marée, Raphaël ; Pruvot, Benoist et al
Poster (2011, December 08)Detailed reference viewed: 55 (22 ULg)