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Paul Brouwer - One of the best experts on this subject based on the ideXlab platform.
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Table_4_Far-Red Light-Induced Azolla filiculoides Symbiosis Sexual Reproduction: Responsive Transcripts of Symbiont Nostoc Azollae Encode Transporters Whilst Those of the Fern Relate to the Angiosperm Floral Transition.xlsx
'Frontiers Media SA', 2021Co-Authors: Laura W Dijkhuizen, Paul Brouwer, Valerie A Buijs, Badraldin Ebrahim Sayed Tabatabaei, Niels Rijken, Erbil Güngör, Henriette SchluepmannAbstract:Water ferns of the genus Azolla and the filamentous cyanobacteria Nostoc Azollae constitute a model symbiosis that enabled the colonization of the water surface with traits highly desirable for the development of more sustainable crops: their floating mats capture CO2 and fix N2 at high rates using light energy. Their mode of sexual reproduction is heterosporous. The regulation of the transition from the vegetative phase to the spore forming phase in ferns is largely unknown, yet a prerequisite for Azolla domestication, and of particular interest as ferns represent the sister lineage of seed plants. Sporocarps induced with far red light could be crossed so as to verify species attribution of strains from the Netherlands but not of the strain from the Anzali lagoon in Iran; the latter strain was assigned to a novel species cluster from South America. Red-dominated light suppresses the formation of dissemination stages in both gametophyte- and sporophyte-dominated lineages of plants, the response likely is a convergent ecological strategy to open fields. FR-responsive transcripts included those from MIKCC homologues of CMADS1 and miR319-controlled GAMYB transcription factors in the fern, transporters in N. Azollae, and ycf2 in chloroplasts. Loci of conserved microRNA (miRNA) in the fern lineage included miR172, yet FR only induced miR529 and miR535, and reduced miR319 and miR159. Phylogenomic analyses of MIKCC TFs suggested that the control of flowering and flower organ specification may have originated from the diploid to haploid phase transition in the homosporous common ancestor of ferns and seed plants.
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Data_Sheet_1_Far-Red Light-Induced Azolla filiculoides Symbiosis Sexual Reproduction: Responsive Transcripts of Symbiont Nostoc Azollae Encode Transporters Whilst Those of the Fern Relate to the Angiosperm Floral Transition.PDF
'Frontiers Media SA', 2021Co-Authors: Laura W Dijkhuizen, Paul Brouwer, Valerie A Buijs, Badraldin Ebrahim Sayed Tabatabaei, Niels Rijken, Erbil Güngör, Henriette SchluepmannAbstract:Water ferns of the genus Azolla and the filamentous cyanobacteria Nostoc Azollae constitute a model symbiosis that enabled the colonization of the water surface with traits highly desirable for the development of more sustainable crops: their floating mats capture CO2 and fix N2 at high rates using light energy. Their mode of sexual reproduction is heterosporous. The regulation of the transition from the vegetative phase to the spore forming phase in ferns is largely unknown, yet a prerequisite for Azolla domestication, and of particular interest as ferns represent the sister lineage of seed plants. Sporocarps induced with far red light could be crossed so as to verify species attribution of strains from the Netherlands but not of the strain from the Anzali lagoon in Iran; the latter strain was assigned to a novel species cluster from South America. Red-dominated light suppresses the formation of dissemination stages in both gametophyte- and sporophyte-dominated lineages of plants, the response likely is a convergent ecological strategy to open fields. FR-responsive transcripts included those from MIKCC homologues of CMADS1 and miR319-controlled GAMYB transcription factors in the fern, transporters in N. Azollae, and ycf2 in chloroplasts. Loci of conserved microRNA (miRNA) in the fern lineage included miR172, yet FR only induced miR529 and miR535, and reduced miR319 and miR159. Phylogenomic analyses of MIKCC TFs suggested that the control of flowering and flower organ specification may have originated from the diploid to haploid phase transition in the homosporous common ancestor of ferns and seed plants.
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fern genomes elucidate land plant evolution and cyanobacterial symbioses
Nature plants, 2018Co-Authors: Lorenzo Carreteropaulet, Ariana N Eily, Nils Koppers, Shifeng Cheng, Pierre-marc Delaux, Jan De Vries, Paul Brouwer, Faywei Li, Zheng LiAbstract:Ferns are the closest sister group to all seed plants, yet little is known about their genomes other than that they are generally colossal. Here, we report on the genomes of Azolla filiculoides and Salvinia cucullata (Salviniales) and present evidence for episodic whole-genome duplication in ferns—one at the base of ‘core leptosporangiates’ and one specific to Azolla. One fern-specific gene that we identified, recently shown to confer high insect resistance, seems to have been derived from bacteria through horizontal gene transfer. Azolla coexists in a unique symbiosis with N2-fixing cyanobacteria, and we demonstrate a clear pattern of cospeciation between the two partners. Furthermore, the Azolla genome lacks genes that are common to arbuscular mycorrhizal and root nodule symbioses, and we identify several putative transporter genes specific to Azolla–cyanobacterial symbiosis. These genomic resources will help in exploring the biotechnological potential of Azolla and address fundamental questions in the evolution of plant life.
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is there foul play in the leaf pocket the metagenome of floating fern Azolla reveals endophytes that do not fix n2 but may denitrify
New Phytologist, 2018Co-Authors: Laura W Dijkhuizen, Henk Bolhuis, Nils Koppers, Paul Brouwer, Anthony Bolger, Faywei Li, Bruno Huettel, Gert-jan Reichart, Shifeng ChengAbstract:Summary Dinitrogen fixation by Nostoc Azollae residing in specialized leaf pockets supports prolific growth of the floating fern Azolla filiculoides. To evaluate contributions by further microorganisms, the A. filiculoides microbiome and nitrogen metabolism in bacteria persistently associated with Azolla ferns were characterized. A metagenomic approach was taken complemented by detection of N2O released and nitrogen isotope determinations of fern biomass. Ribosomal RNA genes in sequenced DNA of natural ferns, their enriched leaf pockets and water filtrate from the surrounding ditch established that bacteria of A. filiculoides differed entirely from surrounding water and revealed species of the order Rhizobiales. Analyses of seven cultivated Azolla species confirmed persistent association with Rhizobiales. Two distinct nearly full-length Rhizobiales genomes were identified in leaf-pocket-enriched samples from ditch grown A. filiculoides. Their annotation revealed genes for denitrification but not N2-fixation. 15N2 incorporation was active in ferns with N. Azollae but not in ferns without. N2O was not detectably released from surface-sterilized ferns with the Rhizobiales. N2-fixing N. Azollae, we conclude, dominated the microbiome of Azolla ferns. The persistent but less abundant heterotrophic Rhizobiales bacteria possibly contributed to lowering O2 levels in leaf pockets but did not release detectable amounts of the strong greenhouse gas N2O.
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ω20-Hydroxy and ω9,ω10-dihydroxy biomarker lipids in ferns from the Salviniaceae family
Organic Geochemistry, 2018Co-Authors: Klaas G.j. Nierop, Paul Brouwer, Henriette Schluepmann, Rolande Dekker, Gert-jan ReichartAbstract:Abstract All seven species of floating ferns from the genus Azolla (family Salviniaceae) produce a unique series of long chain mid-chain ω20-hydroxy compounds (ω20-alkanols, 1,ω20-diols, ω20-hydroxy fatty acids) and structurally related ω9,ω10-dihydroxy compounds (ω9,ω10-diols, 1,ω9,ω10-triols and ω9,ω10-dihydroxy fatty acids). These very long chain fatty acid (VLCFA) derivatives occur in the ferns’ waxes in free and esterified form. The specific distribution of these lipids differed between species belonging to each of the two sections in the Azolla genus: in species of the section Azolla and Rhizosperma, the ratio of C31 over C35 ω20-alkanols averaged 7.0 and 0.40, and the ratio of C26 over C28 ω20-hydroxy fatty acids averaged 2.7 and 1.0, respectively. Similar compounds were identified in species of another genus in the Salviniaceae family, Salvinia, suggesting that their biosynthetic pathway evolved early during Salviniaceae evolution (>89 Ma). Salvinia species contain ω20-hydroxy and ω9,ω10-dihydroxy compounds in smaller concentrations and in a much different distribution compared to Azolla; the C31 1,ω20-diol is unique to Salvinia species. Closely related fern species from the genera Marsilea, Pilularia and Regnellidium did not contain these compounds, nor did unrelated aquatic plants from the genera Lemna and Pistia. All mid-chain hydroxy compounds detected in extant Azolla have been traced previously in Arctic Eocene sediments from the so-called ‘Azolla Event’ (48.5 Ma), implying that they are well preserved in the geological record and may therefore serve as Azolla biomarkers. Our findings indicate that ω20-hydroxy and ω9,ω10-dihydroxy compounds in sediments could be used as biomarkers of the whole Salviniaceae family. Subsequently, the clear differences in compound distribution between the Azolla and Salvinia genera and the more subtle ones between the two Azolla sections, may allow assigning the compound’s origin at the genus (and possibly section) level, depending on the preservation of compound classes in the sediment and the timing of the Azolla or Salvinia deposition. This is exemplified by a sediment interval of the so-called ‘Salvinia bed’ (Eemian), which contained trace amounts of the C31 1,ω20-diol, but none of the ω20-hydroxy and ω9,ω10-dihydroxy compounds common to Azolla, indicating the value of C31 1,ω20-diol as a biomarker for distinguishing Salvinia from Azolla.
Henriette Schluepmann - One of the best experts on this subject based on the ideXlab platform.
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Table_4_Far-Red Light-Induced Azolla filiculoides Symbiosis Sexual Reproduction: Responsive Transcripts of Symbiont Nostoc Azollae Encode Transporters Whilst Those of the Fern Relate to the Angiosperm Floral Transition.xlsx
'Frontiers Media SA', 2021Co-Authors: Laura W Dijkhuizen, Paul Brouwer, Valerie A Buijs, Badraldin Ebrahim Sayed Tabatabaei, Niels Rijken, Erbil Güngör, Henriette SchluepmannAbstract:Water ferns of the genus Azolla and the filamentous cyanobacteria Nostoc Azollae constitute a model symbiosis that enabled the colonization of the water surface with traits highly desirable for the development of more sustainable crops: their floating mats capture CO2 and fix N2 at high rates using light energy. Their mode of sexual reproduction is heterosporous. The regulation of the transition from the vegetative phase to the spore forming phase in ferns is largely unknown, yet a prerequisite for Azolla domestication, and of particular interest as ferns represent the sister lineage of seed plants. Sporocarps induced with far red light could be crossed so as to verify species attribution of strains from the Netherlands but not of the strain from the Anzali lagoon in Iran; the latter strain was assigned to a novel species cluster from South America. Red-dominated light suppresses the formation of dissemination stages in both gametophyte- and sporophyte-dominated lineages of plants, the response likely is a convergent ecological strategy to open fields. FR-responsive transcripts included those from MIKCC homologues of CMADS1 and miR319-controlled GAMYB transcription factors in the fern, transporters in N. Azollae, and ycf2 in chloroplasts. Loci of conserved microRNA (miRNA) in the fern lineage included miR172, yet FR only induced miR529 and miR535, and reduced miR319 and miR159. Phylogenomic analyses of MIKCC TFs suggested that the control of flowering and flower organ specification may have originated from the diploid to haploid phase transition in the homosporous common ancestor of ferns and seed plants.
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Data_Sheet_1_Far-Red Light-Induced Azolla filiculoides Symbiosis Sexual Reproduction: Responsive Transcripts of Symbiont Nostoc Azollae Encode Transporters Whilst Those of the Fern Relate to the Angiosperm Floral Transition.PDF
'Frontiers Media SA', 2021Co-Authors: Laura W Dijkhuizen, Paul Brouwer, Valerie A Buijs, Badraldin Ebrahim Sayed Tabatabaei, Niels Rijken, Erbil Güngör, Henriette SchluepmannAbstract:Water ferns of the genus Azolla and the filamentous cyanobacteria Nostoc Azollae constitute a model symbiosis that enabled the colonization of the water surface with traits highly desirable for the development of more sustainable crops: their floating mats capture CO2 and fix N2 at high rates using light energy. Their mode of sexual reproduction is heterosporous. The regulation of the transition from the vegetative phase to the spore forming phase in ferns is largely unknown, yet a prerequisite for Azolla domestication, and of particular interest as ferns represent the sister lineage of seed plants. Sporocarps induced with far red light could be crossed so as to verify species attribution of strains from the Netherlands but not of the strain from the Anzali lagoon in Iran; the latter strain was assigned to a novel species cluster from South America. Red-dominated light suppresses the formation of dissemination stages in both gametophyte- and sporophyte-dominated lineages of plants, the response likely is a convergent ecological strategy to open fields. FR-responsive transcripts included those from MIKCC homologues of CMADS1 and miR319-controlled GAMYB transcription factors in the fern, transporters in N. Azollae, and ycf2 in chloroplasts. Loci of conserved microRNA (miRNA) in the fern lineage included miR172, yet FR only induced miR529 and miR535, and reduced miR319 and miR159. Phylogenomic analyses of MIKCC TFs suggested that the control of flowering and flower organ specification may have originated from the diploid to haploid phase transition in the homosporous common ancestor of ferns and seed plants.
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ω20-Hydroxy and ω9,ω10-dihydroxy biomarker lipids in ferns from the Salviniaceae family
Organic Geochemistry, 2018Co-Authors: Klaas G.j. Nierop, Paul Brouwer, Henriette Schluepmann, Rolande Dekker, Gert-jan ReichartAbstract:Abstract All seven species of floating ferns from the genus Azolla (family Salviniaceae) produce a unique series of long chain mid-chain ω20-hydroxy compounds (ω20-alkanols, 1,ω20-diols, ω20-hydroxy fatty acids) and structurally related ω9,ω10-dihydroxy compounds (ω9,ω10-diols, 1,ω9,ω10-triols and ω9,ω10-dihydroxy fatty acids). These very long chain fatty acid (VLCFA) derivatives occur in the ferns’ waxes in free and esterified form. The specific distribution of these lipids differed between species belonging to each of the two sections in the Azolla genus: in species of the section Azolla and Rhizosperma, the ratio of C31 over C35 ω20-alkanols averaged 7.0 and 0.40, and the ratio of C26 over C28 ω20-hydroxy fatty acids averaged 2.7 and 1.0, respectively. Similar compounds were identified in species of another genus in the Salviniaceae family, Salvinia, suggesting that their biosynthetic pathway evolved early during Salviniaceae evolution (>89 Ma). Salvinia species contain ω20-hydroxy and ω9,ω10-dihydroxy compounds in smaller concentrations and in a much different distribution compared to Azolla; the C31 1,ω20-diol is unique to Salvinia species. Closely related fern species from the genera Marsilea, Pilularia and Regnellidium did not contain these compounds, nor did unrelated aquatic plants from the genera Lemna and Pistia. All mid-chain hydroxy compounds detected in extant Azolla have been traced previously in Arctic Eocene sediments from the so-called ‘Azolla Event’ (48.5 Ma), implying that they are well preserved in the geological record and may therefore serve as Azolla biomarkers. Our findings indicate that ω20-hydroxy and ω9,ω10-dihydroxy compounds in sediments could be used as biomarkers of the whole Salviniaceae family. Subsequently, the clear differences in compound distribution between the Azolla and Salvinia genera and the more subtle ones between the two Azolla sections, may allow assigning the compound’s origin at the genus (and possibly section) level, depending on the preservation of compound classes in the sediment and the timing of the Azolla or Salvinia deposition. This is exemplified by a sediment interval of the so-called ‘Salvinia bed’ (Eemian), which contained trace amounts of the C31 1,ω20-diol, but none of the ω20-hydroxy and ω9,ω10-dihydroxy compounds common to Azolla, indicating the value of C31 1,ω20-diol as a biomarker for distinguishing Salvinia from Azolla.
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Azolla domestication towards a biobased economy
New Phytologist, 2014Co-Authors: Paul Brouwer, Klaas G.j. Nierop, Andrea Brautigam, Canan Kulahoglu, Anne O E Tazelaar, Samantha Kurz, Adrie Van Der Werf, Andreas P M Weber, Henriette SchluepmannAbstract:Due to its phenomenal growth requiring neither nitrogen fertilizer nor arable land and its biomass composition, the mosquito fern Azolla is a candidate crop to yield food, fuels and chemicals sustainably. To advance Azolla domestication, we research its dissemination, storage and transcriptome. Methods for dissemination, cross-fertilization and cryopreservation of the symbiosis Azolla filiculoides–Nostoc Azollae are tested based on the fern spores. To study molecular processes in Azolla including spore induction, a database of 37 649 unigenes from RNAseq of microsporocarps, megasporocarps and sporophytes was assembled, then validated. Spores obtained year-round germinated in vitro within 26 d. In vitro fertilization rates reached 25%. Cryopreservation permitted storage for at least 7 months. The unigene database entirely covered central metabolism and to a large degree covered cellular processes and regulatory networks. Analysis of genes engaged in transition to sexual reproduction revealed a FLOWERING LOCUS T-like protein in ferns with special features induced in sporulating Azolla fronds. Although domestication of a fern–cyanobacteria symbiosis may seem a daunting task, we conclude that the time is ripe and that results generated will serve to more widely access biochemicals in fern biomass for a biobased economy.
Laura W Dijkhuizen - One of the best experts on this subject based on the ideXlab platform.
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Data_Sheet_1_Far-Red Light-Induced Azolla filiculoides Symbiosis Sexual Reproduction: Responsive Transcripts of Symbiont Nostoc Azollae Encode Transporters Whilst Those of the Fern Relate to the Angiosperm Floral Transition.PDF
'Frontiers Media SA', 2021Co-Authors: Laura W Dijkhuizen, Paul Brouwer, Valerie A Buijs, Badraldin Ebrahim Sayed Tabatabaei, Niels Rijken, Erbil Güngör, Henriette SchluepmannAbstract:Water ferns of the genus Azolla and the filamentous cyanobacteria Nostoc Azollae constitute a model symbiosis that enabled the colonization of the water surface with traits highly desirable for the development of more sustainable crops: their floating mats capture CO2 and fix N2 at high rates using light energy. Their mode of sexual reproduction is heterosporous. The regulation of the transition from the vegetative phase to the spore forming phase in ferns is largely unknown, yet a prerequisite for Azolla domestication, and of particular interest as ferns represent the sister lineage of seed plants. Sporocarps induced with far red light could be crossed so as to verify species attribution of strains from the Netherlands but not of the strain from the Anzali lagoon in Iran; the latter strain was assigned to a novel species cluster from South America. Red-dominated light suppresses the formation of dissemination stages in both gametophyte- and sporophyte-dominated lineages of plants, the response likely is a convergent ecological strategy to open fields. FR-responsive transcripts included those from MIKCC homologues of CMADS1 and miR319-controlled GAMYB transcription factors in the fern, transporters in N. Azollae, and ycf2 in chloroplasts. Loci of conserved microRNA (miRNA) in the fern lineage included miR172, yet FR only induced miR529 and miR535, and reduced miR319 and miR159. Phylogenomic analyses of MIKCC TFs suggested that the control of flowering and flower organ specification may have originated from the diploid to haploid phase transition in the homosporous common ancestor of ferns and seed plants.
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Table_4_Far-Red Light-Induced Azolla filiculoides Symbiosis Sexual Reproduction: Responsive Transcripts of Symbiont Nostoc Azollae Encode Transporters Whilst Those of the Fern Relate to the Angiosperm Floral Transition.xlsx
'Frontiers Media SA', 2021Co-Authors: Laura W Dijkhuizen, Paul Brouwer, Valerie A Buijs, Badraldin Ebrahim Sayed Tabatabaei, Niels Rijken, Erbil Güngör, Henriette SchluepmannAbstract:Water ferns of the genus Azolla and the filamentous cyanobacteria Nostoc Azollae constitute a model symbiosis that enabled the colonization of the water surface with traits highly desirable for the development of more sustainable crops: their floating mats capture CO2 and fix N2 at high rates using light energy. Their mode of sexual reproduction is heterosporous. The regulation of the transition from the vegetative phase to the spore forming phase in ferns is largely unknown, yet a prerequisite for Azolla domestication, and of particular interest as ferns represent the sister lineage of seed plants. Sporocarps induced with far red light could be crossed so as to verify species attribution of strains from the Netherlands but not of the strain from the Anzali lagoon in Iran; the latter strain was assigned to a novel species cluster from South America. Red-dominated light suppresses the formation of dissemination stages in both gametophyte- and sporophyte-dominated lineages of plants, the response likely is a convergent ecological strategy to open fields. FR-responsive transcripts included those from MIKCC homologues of CMADS1 and miR319-controlled GAMYB transcription factors in the fern, transporters in N. Azollae, and ycf2 in chloroplasts. Loci of conserved microRNA (miRNA) in the fern lineage included miR172, yet FR only induced miR529 and miR535, and reduced miR319 and miR159. Phylogenomic analyses of MIKCC TFs suggested that the control of flowering and flower organ specification may have originated from the diploid to haploid phase transition in the homosporous common ancestor of ferns and seed plants.
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is there foul play in the leaf pocket the metagenome of floating fern Azolla reveals endophytes that do not fix n2 but may denitrify
New Phytologist, 2018Co-Authors: Laura W Dijkhuizen, Henk Bolhuis, Nils Koppers, Paul Brouwer, Anthony Bolger, Faywei Li, Bruno Huettel, Gert-jan Reichart, Shifeng ChengAbstract:Summary Dinitrogen fixation by Nostoc Azollae residing in specialized leaf pockets supports prolific growth of the floating fern Azolla filiculoides. To evaluate contributions by further microorganisms, the A. filiculoides microbiome and nitrogen metabolism in bacteria persistently associated with Azolla ferns were characterized. A metagenomic approach was taken complemented by detection of N2O released and nitrogen isotope determinations of fern biomass. Ribosomal RNA genes in sequenced DNA of natural ferns, their enriched leaf pockets and water filtrate from the surrounding ditch established that bacteria of A. filiculoides differed entirely from surrounding water and revealed species of the order Rhizobiales. Analyses of seven cultivated Azolla species confirmed persistent association with Rhizobiales. Two distinct nearly full-length Rhizobiales genomes were identified in leaf-pocket-enriched samples from ditch grown A. filiculoides. Their annotation revealed genes for denitrification but not N2-fixation. 15N2 incorporation was active in ferns with N. Azollae but not in ferns without. N2O was not detectably released from surface-sterilized ferns with the Rhizobiales. N2-fixing N. Azollae, we conclude, dominated the microbiome of Azolla ferns. The persistent but less abundant heterotrophic Rhizobiales bacteria possibly contributed to lowering O2 levels in leaf pockets but did not release detectable amounts of the strong greenhouse gas N2O.
Roohan Rakhshaee - One of the best experts on this subject based on the ideXlab platform.
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kinetic modeling and thermodynamic study to remove pb ii cd ii ni ii and zn ii from aqueous solution using dead and living Azolla filiculoides
Journal of Hazardous Materials, 2006Co-Authors: Roohan Rakhshaee, Morteza Khosravi, Masoud Taghi GanjiAbstract:Abstract Dead Azolla filiculoides can remove Pb 2+ ,Cd 2+ , Ni 2+ and Zn 2+ corresponding to second-order kinetic model. The maximum adsorption capacity ( Q max ) to remove these metal ions by the alkali and CaCl 2 /MgCl 2 /NaCl (2:1:1, molar ratio) activated Azolla from 283 to 313 K was 1.431–1.272, 1.173–0.990, 1.365–1.198 and 1.291–0.981 mmol/g dry biomass, respectively. Q max to remove these heavy metals by the non-activated Azolla at the mentioned temperature range was obtained 1.131–0.977, 1.092–0.921, 1.212–0.931 and 1.103–0.923 mmol/g dry biomass, respectively. In order to remove these metal ions by the activated Azolla , the enthalpy change (Δ H ) was −4.403, −4.495, −4.557 and −4.365 kcal/mol and the entropy change (Δ S ) was 2.290, 1.268, 1.745 and 1.006 cal/mol K, respectively. While, to remove these metal ions by the non-activated Azolla , Δ H was −3.685, −3.766, −3.967 and −3.731 kcal/mol and Δ S was 2.440, 1.265, 1.036 and 0.933 cal/mol K, respectively. On the other hand, the living Azolla removed these heavy metals corresponding to first-order kinetic model. It was also shown that pH, temperature and photoperiod were effective both on the rate of Azolla growth and the rate of heavy metals uptake during 10 days. It was appeared the use of Ca(NO 3 ) 2 increased both Azolla growth rate and the rate of heavy metals uptake while the using KNO 3 although increased Azolla growth rate but decreased the rate of heavy metals uptake.
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pre treatment processes of Azolla filiculoides to remove pb ii cd ii ni ii and zn ii from aqueous solution in the batch and fixed bed reactors
Journal of Hazardous Materials, 2005Co-Authors: Morteza Khosravi, Roohan Rakhshaee, Masuod Taghi GanjiAbstract:Abstract Intact and treated biomass can remove heavy metals from water and wastewater. This study examined the ability of the activated, semi-intact and inactivated Azolla filiculoides (a small water fern) to remove Pb2+, Cd2+, Ni2+ and Zn2+ from the aqueous solution. The maximum uptake capacities of these metal ions using the activated Azolla filiculoides by NaOH at pH 10.5 ± 0.2 and then CaCl2/MgCl2/NaCl with total concentration of 2 M (2:1:1 mole ratio) in the separate batch reactors were obtained about 271, 111, 71 and 60 mg/g (dry Azolla), respectively. The obtained capacities of maximum adsorption for these kinds of the pre-treated Azolla in the fixed-bed reactors (No) were also very close to the values obtained for the batch reactors (Qmax). On the other hand, it was shown that HCl, CH3OH, C2H5OH, FeCl2, SrCl2, BaCl2 and AlCl3 in the pre-treatment processes decreased the ability of Azolla to remove the heavy metals in comparison to the semi-intact Azolla, considerably. The kinetic studies showed that the heavy metals uptake by the activated Azolla was done more rapid than those for the semi-intact Azolla.
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biosorption of pb cd cu and zn from the wastewater by treated Azolla filiculoides with h2o2 mgcl2
International Journal of Environmental Science and Technology, 2005Co-Authors: Taghi M Ganji, M Khosravi, Roohan RakhshaeeAbstract:The adsorption of heavy metals onto treated Azolla filiculoides by H2O2/MgCl2, as a cosmopolitan free-floating waterfern, was investigated from aqueous solutions in the batch biosorption experiments. The maximum uptake capacities of the collected Azolla from rice field at the optimal conditions for Pb, Cd, Cu and Zn ions were approximately 228, 86, 62 and 48 mg/g (dry Azolla), respectively. On the other hand, the maximum uptake capacities of the collected Azolla from the Anzali International Wetland in the north part of Iran at the same conditions for these heavy metals were about 124, 58, 33 and 34 mg/g (dry Azolla), respectively. Such decrease of uptakes is due to the pollution of Anzali International Wetland, which reduces the capacity uptake of metals. The recovery of biosorbed heavy metals from the rice field Azolla was carried out by HCl and NaCl desorbents that the recovery of 64–86% and 51–72% was occurred, respectively.
Morteza Khosravi - One of the best experts on this subject based on the ideXlab platform.
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kinetic modeling and thermodynamic study to remove pb ii cd ii ni ii and zn ii from aqueous solution using dead and living Azolla filiculoides
Journal of Hazardous Materials, 2006Co-Authors: Roohan Rakhshaee, Morteza Khosravi, Masoud Taghi GanjiAbstract:Abstract Dead Azolla filiculoides can remove Pb 2+ ,Cd 2+ , Ni 2+ and Zn 2+ corresponding to second-order kinetic model. The maximum adsorption capacity ( Q max ) to remove these metal ions by the alkali and CaCl 2 /MgCl 2 /NaCl (2:1:1, molar ratio) activated Azolla from 283 to 313 K was 1.431–1.272, 1.173–0.990, 1.365–1.198 and 1.291–0.981 mmol/g dry biomass, respectively. Q max to remove these heavy metals by the non-activated Azolla at the mentioned temperature range was obtained 1.131–0.977, 1.092–0.921, 1.212–0.931 and 1.103–0.923 mmol/g dry biomass, respectively. In order to remove these metal ions by the activated Azolla , the enthalpy change (Δ H ) was −4.403, −4.495, −4.557 and −4.365 kcal/mol and the entropy change (Δ S ) was 2.290, 1.268, 1.745 and 1.006 cal/mol K, respectively. While, to remove these metal ions by the non-activated Azolla , Δ H was −3.685, −3.766, −3.967 and −3.731 kcal/mol and Δ S was 2.440, 1.265, 1.036 and 0.933 cal/mol K, respectively. On the other hand, the living Azolla removed these heavy metals corresponding to first-order kinetic model. It was also shown that pH, temperature and photoperiod were effective both on the rate of Azolla growth and the rate of heavy metals uptake during 10 days. It was appeared the use of Ca(NO 3 ) 2 increased both Azolla growth rate and the rate of heavy metals uptake while the using KNO 3 although increased Azolla growth rate but decreased the rate of heavy metals uptake.
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pre treatment processes of Azolla filiculoides to remove pb ii cd ii ni ii and zn ii from aqueous solution in the batch and fixed bed reactors
Journal of Hazardous Materials, 2005Co-Authors: Morteza Khosravi, Roohan Rakhshaee, Masuod Taghi GanjiAbstract:Abstract Intact and treated biomass can remove heavy metals from water and wastewater. This study examined the ability of the activated, semi-intact and inactivated Azolla filiculoides (a small water fern) to remove Pb2+, Cd2+, Ni2+ and Zn2+ from the aqueous solution. The maximum uptake capacities of these metal ions using the activated Azolla filiculoides by NaOH at pH 10.5 ± 0.2 and then CaCl2/MgCl2/NaCl with total concentration of 2 M (2:1:1 mole ratio) in the separate batch reactors were obtained about 271, 111, 71 and 60 mg/g (dry Azolla), respectively. The obtained capacities of maximum adsorption for these kinds of the pre-treated Azolla in the fixed-bed reactors (No) were also very close to the values obtained for the batch reactors (Qmax). On the other hand, it was shown that HCl, CH3OH, C2H5OH, FeCl2, SrCl2, BaCl2 and AlCl3 in the pre-treatment processes decreased the ability of Azolla to remove the heavy metals in comparison to the semi-intact Azolla, considerably. The kinetic studies showed that the heavy metals uptake by the activated Azolla was done more rapid than those for the semi-intact Azolla.