The Experts below are selected from a list of 300 Experts worldwide ranked by ideXlab platform
Nurudeen A. Oladoja - One of the best experts on this subject based on the ideXlab platform.
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Coagulant derived from waste biogenic material for sustainable algae biomass harvesting
Algal Research, 2020Co-Authors: Nurudeen A. Oladoja, Jafar Ali, Wang Lei, Nie Yudong, Gang PanAbstract:Abstract Highly efficient and sustainable algae harvesting that produced biomass with enhanced characteristics and reusable culture medium were developed from the use of coagulant derived from the waste Shell of Gastropod. Thermally treated Gastropod Shell samples were screened for the algal cell harvesting efficiency (%) and the underlying mechanism was elucidated from the hydrodynamic equilibrium data and scanning electron microscopic analysis. The floc strength, settling rate parameters, settleability, and filterability were determined and compared with the flocs obtained from the pH induced autocoagulation system. The values of floc settling rate and the sludge volume index (mL/g) showed that the flocs obtained from the Gastropod Shell system (rate constant = 1.945 L·mol−1·s−1) settled faster and more compacted than those from the pH induced system (rate constant = 0.2155 (L·mol−1·s−1). Both the growing and harvested flocs from the Gastropod Shell system had better strength and breakage factors (>90%) than the pH induced system. The proximate and elemental compositions of the biomass from the Gastropod Shell system were comparable with those from centrifugation and pH induced systems. Both the separated culture medium and the harvested algae biomass were successfully reused, in separate systems, to cultivate fresh algae. This indicated the non-toxic effects of the coagulants on both the culture medium and the algae harvested biomass.
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Defluoridation efficiency of a green composite reactive material derived from lateritic soil and Gastropod Shell
Sustainable Chemistry and Pharmacy, 2019Co-Authors: Nurudeen A. Oladoja, G.a. Bello, Brigitte Helmreich, S. V. Obisesan, J. A. Ogunniyi, E.t. Anthony, T.d. SaliuAbstract:Abstract In the bid to exploit the synergy in mixed metal matrix that enhances substrate binding affinity, a composite reactive material (GLT) was prepared using lateritic soil and Gastropod Shell as precursors. The defluoridation efficiency of the GLT was studied in laboratory grade fluoride contaminated water and groundwater matrix. Using experimental evidences, insight into the underlying defluoridation mechanisms of GLT was provided. The monolayer adsorption capacity (qm, mg/g) of the GLT (43.7 mg/g) was higher than that of any of the precursors (i.e. lateritic soil (qm = 2.8 mg/g) and Gastropod Shell (qm = 19.8 mg/g)), which confirmed the synergistic effect of the constituents of the composite. Premised on the results of kinetic analysis, the Gibbs (∆G) free energy value of formation of insoluble metal fluoride and the results of the evaluation of the effects of water chemistry on the fluoride removal efficiency of the GLT, mechanism of the defluoridation process was found to be a combination of adsorption (via ion exchange or outer sphere complexation) and precipitation reaction. Relative to the performance of the GLT in laboratory grade water, the GLT was also effective in groundwater but the value of the Langmuir monolayer adsorption capacity (qm mg/g) was lower in the groundwater system (29.76 mg/g) than in the laboratory grade water system (43.7 mg/g). The leached constituents of the GLT enhanced the values of the pH, electrical conductivity and the total dissolved solids of the treated water.
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Expounding the role of interference on the recovery of nutrient fractions from aqua matrix using calcined Gastropod Shell
Journal of Water Process Engineering, 2019Co-Authors: T.d. Saliu, Isaac A. Ololade, O.j. Akinyeye, Emmanuel I. Unuabonah, Nurudeen A. OladojaAbstract:Abstract The need to elucidate the influence of the presence of the major components (i.e. organic matter phosphate and nitrate) of nutrient-rich wastewater on the process of nutrient recovery, using calcined Gastropod Shell (CGS), necessitated this study. The time–concentration profiles of the recovery of organic matter, phosphate and nitrate were studied in synthetic feed water that contained single adsorbate of interest. Both the single and binary component equilibrium isotherm parameters were derived to explicate and quantify the impact of the presence of each constituent of the nutrient rich wastewater on the process of resource recovery. The time-concentration profiles of all the recovery processes showed that the process of nitrate recovery is the rate limiting step in the use of CGS as the reactive material. The pseudo second order kinetic equation gave the best description of both the nutrient and organic matter recovery but the processes were described by different equilibrium isotherm equations. The determination of the efficiency of interference on nutrient recovery showed that nitrate and organic matter exhibited minimal influence on phosphate recovery but the presence of phosphate and organic matter significantly impacted nitrate recovery. The recovery of organic matter was not vitiated by the presence of either phosphate or nitrate. The real life implications of the findings from this study showed that the use of CGS as a reactive material in resource recovery from a nutrient-rich wastewater would provide a double-pronged approach for resource recovery and appreciable treatment of wastewater for reuse.
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Phosphorus recovery from aquaculture wastewater using thermally treated Gastropod Shell
Process Safety and Environmental Protection, 2015Co-Authors: Nurudeen A. Oladoja, R.o.a. Adelagun, Abdul Latif Ahmad, Isaac A. OloladeAbstract:Abstract In tandem with the quest for the development of sustainable strategies for the recovery of P from P-rich aqua waste streams, thermally treated Gastropod Shell (GS) was investigated as a reactive material for P-recovery from aquaculture wastewater (AQW). The enhanced defects in the surficial physiognomies, imparted by the thermal treatment process, accounted for the higher P-recovery efficiency. This contradicted the claim that the conversion of the carbonate form of calcium to the oxide form was the reason for the higher P-recovery efficiency of thermally treated calcium rich materials. The fittings of the time–concentration profiles of the P-recovery process to different kinetic models and the determinations of the thermodynamic parameters of the precipitation reaction showed that both adsorption and precipitation were the underlying mechanism of the P-recovery process, using the thermally treated GS. In addition to the removal of P, substantial amount of the total nitrogen in the AQW was also removed. The evaluation of the effects of the P-recovery process on the quality characteristics of the AQW showed that there was significant improvement in the overall physicochemical characteristics.
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synthesis of nano sized hydrocalumite from a Gastropod Shell for aqua system phosphate removal
Separation and Purification Technology, 2014Co-Authors: Nurudeen A. Oladoja, Isaac A. Ololade, R.o.a. Adelagun, E.t. Anthony, Moses O AlfredAbstract:Abstract Material with high affinity for oxyanions, Hydrocalumite (HC), was synthesized using a waste biogenic resource as a precursor and its ability to remove phosphate from aqua system was studied. The synthesis of HC samples with particle sizes that ranged between 116 and 135 nm was confirmed by XRD analysis. High correlation coefficient values ( r 2 = 1.000) were obtained when the time–concentration profile data were fitted to the pseudo second order kinetic model. The formation of supersaturated Ca and Al phosphate salts were confirmed by the positive saturation index values and the feasibility of precipitate formation by the supersaturated salts were confirmed by the thermodynamic parameters (i.e. Δ G 2 ) showed that the greater percentage (>99%) of the phosphate was distributed within the calcium matrix. Comparison of the EDAX spectra of the virgin HC with the PHC 2 showed that anion exchange could also be a player in phosphate removal by the HC.
Christian Sturmbauer - One of the best experts on this subject based on the ideXlab platform.
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Phylogeny and phylogeography of Altolamprologus: ancient introgression and recent divergence in a rock-dwelling Lake Tanganyika cichlid genus
Hydrobiologia, 2017Co-Authors: Stephan Koblmuller, Christian Sturmbauer, Bruno Nevado, Lawrence Makasa, Maarten Steenberge, Maarten P. M. Vanhove, Erik Verheyen, Kristina M SefcAbstract:Stenotopic specialization to a fragmented habitat promotes the evolution of genetic structure. It is not yet clear whether small-scale population structure generally translates into large-scale intraspecific divergence. In the present survey of mitochondrial genetic structure in the Lake Tanganyika endemic Altolamprologus (Teleostei, Cichlidae), a rock-dwelling cichlid genus comprising A. compressiceps and A. calvus , habitat-induced population fragmentation contrasts with weak phylogeographic structure and recent divergence among genetic clades. Low rates of dispersal, perhaps along Gastropod Shell beds that connect patches of rocky habitat, and periodic secondary contact during lake level fluctuations are apparently sufficient to maintain genetic connectivity within each of the two Altolamprologus species. The picture of genetic cohesion was interrupted by a single highly divergent haplotype clade in A. compressiceps restricted to the northern part of the lake. Comparisons between mitochondrial and nuclear phylogenetic reconstructions suggested that the divergent mitochondrial clade originated from ancient interspecific introgression. Finally, ‘isolation-with-migration’ models indicated that divergence between the two Altolamprologus species was recent (67–142 KYA) and proceeded with little if any gene flow. As in other rock-dwelling cichlids, recent population expansions were inferred in both Altolamprologus species, which may be connected with drastic lake level fluctuations.
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reticulate phylogeny of Gastropod Shell breeding cichlids from lake tanganyika the result of repeated introgressive hybridization
BMC Evolutionary Biology, 2007Co-Authors: Stephan Koblmuller, Nina Duftner, Kristina M Sefc, Mitsuto Aibara, Martina Stipacek, Michel Blanc, Bernd Egger, Christian SturmbauerAbstract:The tribe Lamprologini is the major substrate breeding lineage of Lake Tanganyika's cichlid species flock. Among several different life history strategies found in lamprologines, the adaptation to live and breed in empty Gastropod Shells is probably the most peculiar. Although Shell-breeding arose several times in the evolutionary history of the lamprologines, all obligatory and most facultative Shell-breeders belong to the so called "ossified group", a monophyletic lineage within the lamprologine cichlids. Since their distinctive life style enables these species to live and breed in closest vicinity, we hypothesized that these cichlids might be particularly prone to accidental hybridization, and that introgression might have affected the evolutionary history of this cichlid lineage. Our analyses revealed discrepancies between phylogenetic hypotheses based on mitochondrial and nuclear (AFLP) data. While the nuclear phylogeny was congruent with morphological, behavioral and ecological characteristics, several species – usually highly specialized Shell-breeders – were placed at contradicting positions in the mitochondrial phylogeny. The discordant phylogenies strongly suggest repeated incidents of introgressive hybridization between several distantly related Shell-breeding species, which reticulated the phylogeny of this group of cichlids. Long interior branches and high bootstrap support for many interior nodes in the mitochondrial phylogeny argue against a major effect of ancient incomplete lineage sorting on the phylogenetic reconstruction. Moreover, we provide morphological and genetic (mtDNA and microsatellites) evidence for ongoing hybridization among distantly related Shell-breeders. In these cases, the territorial males of the inferred paternal species are too large to enter the Shells of their mate, such that they have to release their sperm over the entrance of the Shell to fertilize the eggs. With sperm dispersal by water currents and wave action, trans-specific fertilization of clutches in neighboring Shells seem inevitable, when post-zygotic isolation is incomplete. From the direct observation of hybrids we conclude that hybridization between distantly related Gastropod-Shell-breeding cichlids of Lake Tanganyika follows inevitably from their ecological specialization. Moreover, the observed incongruence between mtDNA and nuclear multilocus phylogeny suggests that repeated hybridization events among quite distantly related taxa affected the diversification of this group, and introduced reticulation into their phylogeny.
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Reticulate phylogeny of Gastropod-Shell-breeding cichlids from Lake Tanganyika – the result of repeated introgressive hybridization
BMC evolutionary biology, 2007Co-Authors: Stephan Koblmuller, Nina Duftner, Kristina M Sefc, Mitsuto Aibara, Martina Stipacek, Michel Blanc, Bernd Egger, Christian SturmbauerAbstract:The tribe Lamprologini is the major substrate breeding lineage of Lake Tanganyika's cichlid species flock. Among several different life history strategies found in lamprologines, the adaptation to live and breed in empty Gastropod Shells is probably the most peculiar. Although Shell-breeding arose several times in the evolutionary history of the lamprologines, all obligatory and most facultative Shell-breeders belong to the so called "ossified group", a monophyletic lineage within the lamprologine cichlids. Since their distinctive life style enables these species to live and breed in closest vicinity, we hypothesized that these cichlids might be particularly prone to accidental hybridization, and that introgression might have affected the evolutionary history of this cichlid lineage. Our analyses revealed discrepancies between phylogenetic hypotheses based on mitochondrial and nuclear (AFLP) data. While the nuclear phylogeny was congruent with morphological, behavioral and ecological characteristics, several species – usually highly specialized Shell-breeders – were placed at contradicting positions in the mitochondrial phylogeny. The discordant phylogenies strongly suggest repeated incidents of introgressive hybridization between several distantly related Shell-breeding species, which reticulated the phylogeny of this group of cichlids. Long interior branches and high bootstrap support for many interior nodes in the mitochondrial phylogeny argue against a major effect of ancient incomplete lineage sorting on the phylogenetic reconstruction. Moreover, we provide morphological and genetic (mtDNA and microsatellites) evidence for ongoing hybridization among distantly related Shell-breeders. In these cases, the territorial males of the inferred paternal species are too large to enter the Shells of their mate, such that they have to release their sperm over the entrance of the Shell to fertilize the eggs. With sperm dispersal by water currents and wave action, trans-specific fertilization of clutches in neighboring Shells seem inevitable, when post-zygotic isolation is incomplete. From the direct observation of hybrids we conclude that hybridization between distantly related Gastropod-Shell-breeding cichlids of Lake Tanganyika follows inevitably from their ecological specialization. Moreover, the observed incongruence between mtDNA and nuclear multilocus phylogeny suggests that repeated hybridization events among quite distantly related taxa affected the diversification of this group, and introduced reticulation into their phylogeny.
Stephan Koblmuller - One of the best experts on this subject based on the ideXlab platform.
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Phylogeny and phylogeography of Altolamprologus: ancient introgression and recent divergence in a rock-dwelling Lake Tanganyika cichlid genus
Hydrobiologia, 2017Co-Authors: Stephan Koblmuller, Christian Sturmbauer, Bruno Nevado, Lawrence Makasa, Maarten Steenberge, Maarten P. M. Vanhove, Erik Verheyen, Kristina M SefcAbstract:Stenotopic specialization to a fragmented habitat promotes the evolution of genetic structure. It is not yet clear whether small-scale population structure generally translates into large-scale intraspecific divergence. In the present survey of mitochondrial genetic structure in the Lake Tanganyika endemic Altolamprologus (Teleostei, Cichlidae), a rock-dwelling cichlid genus comprising A. compressiceps and A. calvus , habitat-induced population fragmentation contrasts with weak phylogeographic structure and recent divergence among genetic clades. Low rates of dispersal, perhaps along Gastropod Shell beds that connect patches of rocky habitat, and periodic secondary contact during lake level fluctuations are apparently sufficient to maintain genetic connectivity within each of the two Altolamprologus species. The picture of genetic cohesion was interrupted by a single highly divergent haplotype clade in A. compressiceps restricted to the northern part of the lake. Comparisons between mitochondrial and nuclear phylogenetic reconstructions suggested that the divergent mitochondrial clade originated from ancient interspecific introgression. Finally, ‘isolation-with-migration’ models indicated that divergence between the two Altolamprologus species was recent (67–142 KYA) and proceeded with little if any gene flow. As in other rock-dwelling cichlids, recent population expansions were inferred in both Altolamprologus species, which may be connected with drastic lake level fluctuations.
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reticulate phylogeny of Gastropod Shell breeding cichlids from lake tanganyika the result of repeated introgressive hybridization
BMC Evolutionary Biology, 2007Co-Authors: Stephan Koblmuller, Nina Duftner, Kristina M Sefc, Mitsuto Aibara, Martina Stipacek, Michel Blanc, Bernd Egger, Christian SturmbauerAbstract:The tribe Lamprologini is the major substrate breeding lineage of Lake Tanganyika's cichlid species flock. Among several different life history strategies found in lamprologines, the adaptation to live and breed in empty Gastropod Shells is probably the most peculiar. Although Shell-breeding arose several times in the evolutionary history of the lamprologines, all obligatory and most facultative Shell-breeders belong to the so called "ossified group", a monophyletic lineage within the lamprologine cichlids. Since their distinctive life style enables these species to live and breed in closest vicinity, we hypothesized that these cichlids might be particularly prone to accidental hybridization, and that introgression might have affected the evolutionary history of this cichlid lineage. Our analyses revealed discrepancies between phylogenetic hypotheses based on mitochondrial and nuclear (AFLP) data. While the nuclear phylogeny was congruent with morphological, behavioral and ecological characteristics, several species – usually highly specialized Shell-breeders – were placed at contradicting positions in the mitochondrial phylogeny. The discordant phylogenies strongly suggest repeated incidents of introgressive hybridization between several distantly related Shell-breeding species, which reticulated the phylogeny of this group of cichlids. Long interior branches and high bootstrap support for many interior nodes in the mitochondrial phylogeny argue against a major effect of ancient incomplete lineage sorting on the phylogenetic reconstruction. Moreover, we provide morphological and genetic (mtDNA and microsatellites) evidence for ongoing hybridization among distantly related Shell-breeders. In these cases, the territorial males of the inferred paternal species are too large to enter the Shells of their mate, such that they have to release their sperm over the entrance of the Shell to fertilize the eggs. With sperm dispersal by water currents and wave action, trans-specific fertilization of clutches in neighboring Shells seem inevitable, when post-zygotic isolation is incomplete. From the direct observation of hybrids we conclude that hybridization between distantly related Gastropod-Shell-breeding cichlids of Lake Tanganyika follows inevitably from their ecological specialization. Moreover, the observed incongruence between mtDNA and nuclear multilocus phylogeny suggests that repeated hybridization events among quite distantly related taxa affected the diversification of this group, and introduced reticulation into their phylogeny.
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Reticulate phylogeny of Gastropod-Shell-breeding cichlids from Lake Tanganyika – the result of repeated introgressive hybridization
BMC evolutionary biology, 2007Co-Authors: Stephan Koblmuller, Nina Duftner, Kristina M Sefc, Mitsuto Aibara, Martina Stipacek, Michel Blanc, Bernd Egger, Christian SturmbauerAbstract:The tribe Lamprologini is the major substrate breeding lineage of Lake Tanganyika's cichlid species flock. Among several different life history strategies found in lamprologines, the adaptation to live and breed in empty Gastropod Shells is probably the most peculiar. Although Shell-breeding arose several times in the evolutionary history of the lamprologines, all obligatory and most facultative Shell-breeders belong to the so called "ossified group", a monophyletic lineage within the lamprologine cichlids. Since their distinctive life style enables these species to live and breed in closest vicinity, we hypothesized that these cichlids might be particularly prone to accidental hybridization, and that introgression might have affected the evolutionary history of this cichlid lineage. Our analyses revealed discrepancies between phylogenetic hypotheses based on mitochondrial and nuclear (AFLP) data. While the nuclear phylogeny was congruent with morphological, behavioral and ecological characteristics, several species – usually highly specialized Shell-breeders – were placed at contradicting positions in the mitochondrial phylogeny. The discordant phylogenies strongly suggest repeated incidents of introgressive hybridization between several distantly related Shell-breeding species, which reticulated the phylogeny of this group of cichlids. Long interior branches and high bootstrap support for many interior nodes in the mitochondrial phylogeny argue against a major effect of ancient incomplete lineage sorting on the phylogenetic reconstruction. Moreover, we provide morphological and genetic (mtDNA and microsatellites) evidence for ongoing hybridization among distantly related Shell-breeders. In these cases, the territorial males of the inferred paternal species are too large to enter the Shells of their mate, such that they have to release their sperm over the entrance of the Shell to fertilize the eggs. With sperm dispersal by water currents and wave action, trans-specific fertilization of clutches in neighboring Shells seem inevitable, when post-zygotic isolation is incomplete. From the direct observation of hybrids we conclude that hybridization between distantly related Gastropod-Shell-breeding cichlids of Lake Tanganyika follows inevitably from their ecological specialization. Moreover, the observed incongruence between mtDNA and nuclear multilocus phylogeny suggests that repeated hybridization events among quite distantly related taxa affected the diversification of this group, and introduced reticulation into their phylogeny.
Isaac A. Ololade - One of the best experts on this subject based on the ideXlab platform.
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Expounding the role of interference on the recovery of nutrient fractions from aqua matrix using calcined Gastropod Shell
Journal of Water Process Engineering, 2019Co-Authors: T.d. Saliu, Isaac A. Ololade, O.j. Akinyeye, Emmanuel I. Unuabonah, Nurudeen A. OladojaAbstract:Abstract The need to elucidate the influence of the presence of the major components (i.e. organic matter phosphate and nitrate) of nutrient-rich wastewater on the process of nutrient recovery, using calcined Gastropod Shell (CGS), necessitated this study. The time–concentration profiles of the recovery of organic matter, phosphate and nitrate were studied in synthetic feed water that contained single adsorbate of interest. Both the single and binary component equilibrium isotherm parameters were derived to explicate and quantify the impact of the presence of each constituent of the nutrient rich wastewater on the process of resource recovery. The time-concentration profiles of all the recovery processes showed that the process of nitrate recovery is the rate limiting step in the use of CGS as the reactive material. The pseudo second order kinetic equation gave the best description of both the nutrient and organic matter recovery but the processes were described by different equilibrium isotherm equations. The determination of the efficiency of interference on nutrient recovery showed that nitrate and organic matter exhibited minimal influence on phosphate recovery but the presence of phosphate and organic matter significantly impacted nitrate recovery. The recovery of organic matter was not vitiated by the presence of either phosphate or nitrate. The real life implications of the findings from this study showed that the use of CGS as a reactive material in resource recovery from a nutrient-rich wastewater would provide a double-pronged approach for resource recovery and appreciable treatment of wastewater for reuse.
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Phosphorus recovery from aquaculture wastewater using thermally treated Gastropod Shell
Process Safety and Environmental Protection, 2015Co-Authors: Nurudeen A. Oladoja, R.o.a. Adelagun, Abdul Latif Ahmad, Isaac A. OloladeAbstract:Abstract In tandem with the quest for the development of sustainable strategies for the recovery of P from P-rich aqua waste streams, thermally treated Gastropod Shell (GS) was investigated as a reactive material for P-recovery from aquaculture wastewater (AQW). The enhanced defects in the surficial physiognomies, imparted by the thermal treatment process, accounted for the higher P-recovery efficiency. This contradicted the claim that the conversion of the carbonate form of calcium to the oxide form was the reason for the higher P-recovery efficiency of thermally treated calcium rich materials. The fittings of the time–concentration profiles of the P-recovery process to different kinetic models and the determinations of the thermodynamic parameters of the precipitation reaction showed that both adsorption and precipitation were the underlying mechanism of the P-recovery process, using the thermally treated GS. In addition to the removal of P, substantial amount of the total nitrogen in the AQW was also removed. The evaluation of the effects of the P-recovery process on the quality characteristics of the AQW showed that there was significant improvement in the overall physicochemical characteristics.
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synthesis of nano sized hydrocalumite from a Gastropod Shell for aqua system phosphate removal
Separation and Purification Technology, 2014Co-Authors: Nurudeen A. Oladoja, Isaac A. Ololade, R.o.a. Adelagun, E.t. Anthony, Moses O AlfredAbstract:Abstract Material with high affinity for oxyanions, Hydrocalumite (HC), was synthesized using a waste biogenic resource as a precursor and its ability to remove phosphate from aqua system was studied. The synthesis of HC samples with particle sizes that ranged between 116 and 135 nm was confirmed by XRD analysis. High correlation coefficient values ( r 2 = 1.000) were obtained when the time–concentration profile data were fitted to the pseudo second order kinetic model. The formation of supersaturated Ca and Al phosphate salts were confirmed by the positive saturation index values and the feasibility of precipitate formation by the supersaturated salts were confirmed by the thermodynamic parameters (i.e. Δ G 2 ) showed that the greater percentage (>99%) of the phosphate was distributed within the calcium matrix. Comparison of the EDAX spectra of the virgin HC with the PHC 2 showed that anion exchange could also be a player in phosphate removal by the HC.
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Appraisal of Gastropod Shell as calcium ion source for phosphate removal and recovery in calcium phosphate minerals crystallization procedure
Chemical Engineering Research & Design, 2013Co-Authors: Nurudeen A. Oladoja, Adeniyi Olufemi Adesina, Isaac A. Ololade, R.o.a. Adelagun, Y.m. SaniAbstract:a b s t r a c t On the basis of the perspective of wastes recycling and minimization of cost of phosphate removal via the chemical precipitation procedure, the present studies evaluated the ability of waste biogenic Gastropod Shell to serve as a source of Ca 2+ ion in the removal and recovery of phosphate in calcium phosphate mineral (CPM) crystallization procedure. Phosphate removal efficiency values >99% was achieved when 2 g of snail Shell was used in water of phosphate concentrations ranging between 25 and 1000 mg/L. pH and ionic strength exhibited no influence on the phosphate removal efficiency. Concomitant removal of phosphate and organic matter revealed that phosphate removal efficiency was not impacted but the magnitude of the organics removed increased with increase in the organic load. Kinetic analysis showed that second order kinetic model gave a better description of the process. XRD analysis of the derived sludge showed the crystallinity and peaks synonymous with the presence of whitlockite, hydroxyapatite and calcium phosphate hydrate. The FTIR of the sludge showed the disappearance of some naturally occurring functional groups and the appearance of phosphate peaks which confirmed the formation of CPM. © 2012 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
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Intercalation of Gastropod Shell Derived Calcium Oxide in Clay and Application in Phosphate Removal from Aqua Medium
Industrial & Engineering Chemistry Research, 2012Co-Authors: Nurudeen A. Oladoja, Isaac A. Ololade, C. O. Aboluwoye, O. L Adebayo, S.e. Olaseni, R.o.a. AdelagunAbstract:The phosphate sorption potential of the layered framework of naturally occurring clay, which acts as a host in the sorption process, was boosted via intercalation of CaO derived from a Gastropod Shell (GS). GS was used as precursor for the synthesis of the CaO in the perspective of waste recycling and cost minimization in environmental remediation. The phosphate sorption potential, PZC, and the surface area of raw clay sample were substantially enhanced by the intercalation process. The value of the Langmuir monolayer sorption capacity (qm mg/g) increased from 49.02 to 71.43, PZC values increased from 4.70 to 7.20, and the surface area (m2/g) value increased from 23 to 103 after the intercalation process. The modification caused no change in the clay surficial microstructure but increased the lattice spacing of the clay framework. Increase in phosphate solution pH triggered monotonical reduction in the magnitude of phosphate sorbed while increase in phosphate solution ionic strength and concentration of a...
Kristina M Sefc - One of the best experts on this subject based on the ideXlab platform.
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Phylogeny and phylogeography of Altolamprologus: ancient introgression and recent divergence in a rock-dwelling Lake Tanganyika cichlid genus
Hydrobiologia, 2017Co-Authors: Stephan Koblmuller, Christian Sturmbauer, Bruno Nevado, Lawrence Makasa, Maarten Steenberge, Maarten P. M. Vanhove, Erik Verheyen, Kristina M SefcAbstract:Stenotopic specialization to a fragmented habitat promotes the evolution of genetic structure. It is not yet clear whether small-scale population structure generally translates into large-scale intraspecific divergence. In the present survey of mitochondrial genetic structure in the Lake Tanganyika endemic Altolamprologus (Teleostei, Cichlidae), a rock-dwelling cichlid genus comprising A. compressiceps and A. calvus , habitat-induced population fragmentation contrasts with weak phylogeographic structure and recent divergence among genetic clades. Low rates of dispersal, perhaps along Gastropod Shell beds that connect patches of rocky habitat, and periodic secondary contact during lake level fluctuations are apparently sufficient to maintain genetic connectivity within each of the two Altolamprologus species. The picture of genetic cohesion was interrupted by a single highly divergent haplotype clade in A. compressiceps restricted to the northern part of the lake. Comparisons between mitochondrial and nuclear phylogenetic reconstructions suggested that the divergent mitochondrial clade originated from ancient interspecific introgression. Finally, ‘isolation-with-migration’ models indicated that divergence between the two Altolamprologus species was recent (67–142 KYA) and proceeded with little if any gene flow. As in other rock-dwelling cichlids, recent population expansions were inferred in both Altolamprologus species, which may be connected with drastic lake level fluctuations.
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reticulate phylogeny of Gastropod Shell breeding cichlids from lake tanganyika the result of repeated introgressive hybridization
BMC Evolutionary Biology, 2007Co-Authors: Stephan Koblmuller, Nina Duftner, Kristina M Sefc, Mitsuto Aibara, Martina Stipacek, Michel Blanc, Bernd Egger, Christian SturmbauerAbstract:The tribe Lamprologini is the major substrate breeding lineage of Lake Tanganyika's cichlid species flock. Among several different life history strategies found in lamprologines, the adaptation to live and breed in empty Gastropod Shells is probably the most peculiar. Although Shell-breeding arose several times in the evolutionary history of the lamprologines, all obligatory and most facultative Shell-breeders belong to the so called "ossified group", a monophyletic lineage within the lamprologine cichlids. Since their distinctive life style enables these species to live and breed in closest vicinity, we hypothesized that these cichlids might be particularly prone to accidental hybridization, and that introgression might have affected the evolutionary history of this cichlid lineage. Our analyses revealed discrepancies between phylogenetic hypotheses based on mitochondrial and nuclear (AFLP) data. While the nuclear phylogeny was congruent with morphological, behavioral and ecological characteristics, several species – usually highly specialized Shell-breeders – were placed at contradicting positions in the mitochondrial phylogeny. The discordant phylogenies strongly suggest repeated incidents of introgressive hybridization between several distantly related Shell-breeding species, which reticulated the phylogeny of this group of cichlids. Long interior branches and high bootstrap support for many interior nodes in the mitochondrial phylogeny argue against a major effect of ancient incomplete lineage sorting on the phylogenetic reconstruction. Moreover, we provide morphological and genetic (mtDNA and microsatellites) evidence for ongoing hybridization among distantly related Shell-breeders. In these cases, the territorial males of the inferred paternal species are too large to enter the Shells of their mate, such that they have to release their sperm over the entrance of the Shell to fertilize the eggs. With sperm dispersal by water currents and wave action, trans-specific fertilization of clutches in neighboring Shells seem inevitable, when post-zygotic isolation is incomplete. From the direct observation of hybrids we conclude that hybridization between distantly related Gastropod-Shell-breeding cichlids of Lake Tanganyika follows inevitably from their ecological specialization. Moreover, the observed incongruence between mtDNA and nuclear multilocus phylogeny suggests that repeated hybridization events among quite distantly related taxa affected the diversification of this group, and introduced reticulation into their phylogeny.
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Reticulate phylogeny of Gastropod-Shell-breeding cichlids from Lake Tanganyika – the result of repeated introgressive hybridization
BMC evolutionary biology, 2007Co-Authors: Stephan Koblmuller, Nina Duftner, Kristina M Sefc, Mitsuto Aibara, Martina Stipacek, Michel Blanc, Bernd Egger, Christian SturmbauerAbstract:The tribe Lamprologini is the major substrate breeding lineage of Lake Tanganyika's cichlid species flock. Among several different life history strategies found in lamprologines, the adaptation to live and breed in empty Gastropod Shells is probably the most peculiar. Although Shell-breeding arose several times in the evolutionary history of the lamprologines, all obligatory and most facultative Shell-breeders belong to the so called "ossified group", a monophyletic lineage within the lamprologine cichlids. Since their distinctive life style enables these species to live and breed in closest vicinity, we hypothesized that these cichlids might be particularly prone to accidental hybridization, and that introgression might have affected the evolutionary history of this cichlid lineage. Our analyses revealed discrepancies between phylogenetic hypotheses based on mitochondrial and nuclear (AFLP) data. While the nuclear phylogeny was congruent with morphological, behavioral and ecological characteristics, several species – usually highly specialized Shell-breeders – were placed at contradicting positions in the mitochondrial phylogeny. The discordant phylogenies strongly suggest repeated incidents of introgressive hybridization between several distantly related Shell-breeding species, which reticulated the phylogeny of this group of cichlids. Long interior branches and high bootstrap support for many interior nodes in the mitochondrial phylogeny argue against a major effect of ancient incomplete lineage sorting on the phylogenetic reconstruction. Moreover, we provide morphological and genetic (mtDNA and microsatellites) evidence for ongoing hybridization among distantly related Shell-breeders. In these cases, the territorial males of the inferred paternal species are too large to enter the Shells of their mate, such that they have to release their sperm over the entrance of the Shell to fertilize the eggs. With sperm dispersal by water currents and wave action, trans-specific fertilization of clutches in neighboring Shells seem inevitable, when post-zygotic isolation is incomplete. From the direct observation of hybrids we conclude that hybridization between distantly related Gastropod-Shell-breeding cichlids of Lake Tanganyika follows inevitably from their ecological specialization. Moreover, the observed incongruence between mtDNA and nuclear multilocus phylogeny suggests that repeated hybridization events among quite distantly related taxa affected the diversification of this group, and introduced reticulation into their phylogeny.
