Pub Date : 2017-01-01DOI: 10.1080/09542299.2017.1400924
Tao Ling, Q. Gao, Haolin Du, Qiancheng Zhao, Jun Ren
Abstract The effects of Cd on the growth and Cd uptaking in corn (Zea mays L.) were explored under different Cd stress. The results showed that no reduction in shoot and root dry matter yields were noted when the plants were grown at Cd supply levels ≤100 μmol l−1 nutrient solution. The Cd concentration in the shoots and roots of corn increased sharply with increasing external Cd supply levels, peaked at 50 μmol l−1, and then decreased slowly with further increasing Cd levels due to high Cd toxic effects on root growth. The concentrations of chlorophyll a, chlorophyll b and chlorophyll a + b in the leaf of corn decreased slowly with increasing external Cd supply levels. Proline concentrations of corn increased when the plants were grown under the external Cd influence. The lower concentration of Cd treatments did not influenced the growth of corn significantly, and increased the uptake of Cd, the higher levels of Cd supply caused significantly physiological resposes and decreased the Cd uptaking.
{"title":"Growing, physiological responses and Cd uptake of Corn (Zea mays L.) under different Cd supply","authors":"Tao Ling, Q. Gao, Haolin Du, Qiancheng Zhao, Jun Ren","doi":"10.1080/09542299.2017.1400924","DOIUrl":"https://doi.org/10.1080/09542299.2017.1400924","url":null,"abstract":"Abstract The effects of Cd on the growth and Cd uptaking in corn (Zea mays L.) were explored under different Cd stress. The results showed that no reduction in shoot and root dry matter yields were noted when the plants were grown at Cd supply levels ≤100 μmol l−1 nutrient solution. The Cd concentration in the shoots and roots of corn increased sharply with increasing external Cd supply levels, peaked at 50 μmol l−1, and then decreased slowly with further increasing Cd levels due to high Cd toxic effects on root growth. The concentrations of chlorophyll a, chlorophyll b and chlorophyll a + b in the leaf of corn decreased slowly with increasing external Cd supply levels. Proline concentrations of corn increased when the plants were grown under the external Cd influence. The lower concentration of Cd treatments did not influenced the growth of corn significantly, and increased the uptake of Cd, the higher levels of Cd supply caused significantly physiological resposes and decreased the Cd uptaking.","PeriodicalId":55264,"journal":{"name":"Chemical Speciation and Bioavailability","volume":"29 1","pages":"216 - 221"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09542299.2017.1400924","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46752121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-01-01DOI: 10.1080/09542299.2017.1352460
W. Yang, Hanran Xiao, Ye Li, D. Miao
Abstract Columnar sediment samples were collected from five representative estuaries of Dianchi Lake, China. And the vertical distribution of each fraction of nitrogen (IEF-N, CF-N, IMOF-N, OSF-N) were tested. The results showed that the TN content in sediments from areas A, B, C, D and E gradually decreased with depth between 0 and 15 cm, then sharply decreased with depth between 15 and 30 cm and stabilized at depth below 30 cm, indicating the exogenous input of N in these areas has not been controlled effectively. The proportion of TN occupied by various N fractions in the sediments ranked as follows: OSF-N > IMOF > CF-N > IEF-N. Correlation analysis results showed both IEF-N and IMOF-N were significantly correlated with the content of TFe2O3 + MnO + Al2O3 in deeper sediments, while no correlation in superficial sediments. The areas A and B have extremely high release risks for N in superficial sediments. However, the N in the sediments of areas C, D and E were in relative equilibrium with the overlying water, indicating release potential risk was relatively low.
{"title":"Vertical distribution and release characteristics of nitrogen fractions in sediments in the estuaries of Dianchi Lake, China","authors":"W. Yang, Hanran Xiao, Ye Li, D. Miao","doi":"10.1080/09542299.2017.1352460","DOIUrl":"https://doi.org/10.1080/09542299.2017.1352460","url":null,"abstract":"Abstract Columnar sediment samples were collected from five representative estuaries of Dianchi Lake, China. And the vertical distribution of each fraction of nitrogen (IEF-N, CF-N, IMOF-N, OSF-N) were tested. The results showed that the TN content in sediments from areas A, B, C, D and E gradually decreased with depth between 0 and 15 cm, then sharply decreased with depth between 15 and 30 cm and stabilized at depth below 30 cm, indicating the exogenous input of N in these areas has not been controlled effectively. The proportion of TN occupied by various N fractions in the sediments ranked as follows: OSF-N > IMOF > CF-N > IEF-N. Correlation analysis results showed both IEF-N and IMOF-N were significantly correlated with the content of TFe2O3 + MnO + Al2O3 in deeper sediments, while no correlation in superficial sediments. The areas A and B have extremely high release risks for N in superficial sediments. However, the N in the sediments of areas C, D and E were in relative equilibrium with the overlying water, indicating release potential risk was relatively low.","PeriodicalId":55264,"journal":{"name":"Chemical Speciation and Bioavailability","volume":"29 1","pages":"110 - 119"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09542299.2017.1352460","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44690050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The composite TiO2/Mo-TiO2 were prepared by a modified sol-gel method. The prepared catalysts were characterized by X-ray diffraction, BET analysis, SEM, X-ray photoelectron spectroscopy, and UV–vis diffused reflectance spectroscopy techniques. The structural characterization results demonstrated that Mo was successfully doped into the TiO2 lattice and caused slight changes in the physiochemical properties. The UV–vis DRS showed a red shift of the adsorption edge to the visible region. The photocatalytic decomposition efficiencies of the catalysts were examined with toluene as a typical VOC in a continuous flow reactor. The photocatalytic activity of the n-n heterogeneous TiO2/Mo-TiO2 was greater than that of pure TiO2 and Mo-TiO2, and the catalyst containing a Mo/Ti mole ratio of 2.5% exhibited optimum photocatalytic properties. In general, a relative humidity of 35%, a higher oxygen content, a lower initial toluene concentration, and a higher UV intensity were beneficial for toluene decomposition.
{"title":"Physiochemical properties of n-n heterostructured TiO2/Mo-TiO2 composites and their photocatalytic degradation of gaseous toluene","authors":"M. Cui, Shuai Pan, Zhe Tang, Xian Chen, X. Qiao, Qi Xu","doi":"10.1080/09542299.2017.1315617","DOIUrl":"https://doi.org/10.1080/09542299.2017.1315617","url":null,"abstract":"Abstract The composite TiO2/Mo-TiO2 were prepared by a modified sol-gel method. The prepared catalysts were characterized by X-ray diffraction, BET analysis, SEM, X-ray photoelectron spectroscopy, and UV–vis diffused reflectance spectroscopy techniques. The structural characterization results demonstrated that Mo was successfully doped into the TiO2 lattice and caused slight changes in the physiochemical properties. The UV–vis DRS showed a red shift of the adsorption edge to the visible region. The photocatalytic decomposition efficiencies of the catalysts were examined with toluene as a typical VOC in a continuous flow reactor. The photocatalytic activity of the n-n heterogeneous TiO2/Mo-TiO2 was greater than that of pure TiO2 and Mo-TiO2, and the catalyst containing a Mo/Ti mole ratio of 2.5% exhibited optimum photocatalytic properties. In general, a relative humidity of 35%, a higher oxygen content, a lower initial toluene concentration, and a higher UV intensity were beneficial for toluene decomposition.","PeriodicalId":55264,"journal":{"name":"Chemical Speciation and Bioavailability","volume":"29 1","pages":"60 - 69"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09542299.2017.1315617","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47228161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-01-01DOI: 10.1080/09542299.2017.1404437
Bo Li, Yibing Ma, Junxing Yang
Abstract Free Cu species in soils is a key issue to its bioavailability. However, predictive models for Cu speciation across a wide range of soils were still unavailable. In this study, Cu speciation in 34 contaminated soil samples were investigated via analytical technique and predictive models. The results showed that most of free Cu2+ was underestimated when using default log KCuFA and 65% active fulvic acid as inputs in models of WHAM VI and NICA-Donnan. The best prediction was found when using either adjusted active fulvic acid from 10% to 125% for WHAM VI or from 15% to 65% for NICA-Donnan model with the RMSE < 0.32 and r2 > 0.96. In contrast, NICA-Donnan demonstrated a slightly stronger binding for Cu than WHAM VI due to extra 26% of samples was underestimated. This work presents a comprehensive database of Cu speciation and an effective attempt of free Cu2+ prediction in a wide range of Chinese soils.
{"title":"Is the computed speciation of copper in a wide range of Chinese soils reliable?","authors":"Bo Li, Yibing Ma, Junxing Yang","doi":"10.1080/09542299.2017.1404437","DOIUrl":"https://doi.org/10.1080/09542299.2017.1404437","url":null,"abstract":"Abstract Free Cu species in soils is a key issue to its bioavailability. However, predictive models for Cu speciation across a wide range of soils were still unavailable. In this study, Cu speciation in 34 contaminated soil samples were investigated via analytical technique and predictive models. The results showed that most of free Cu2+ was underestimated when using default log KCuFA and 65% active fulvic acid as inputs in models of WHAM VI and NICA-Donnan. The best prediction was found when using either adjusted active fulvic acid from 10% to 125% for WHAM VI or from 15% to 65% for NICA-Donnan model with the RMSE < 0.32 and r2 > 0.96. In contrast, NICA-Donnan demonstrated a slightly stronger binding for Cu than WHAM VI due to extra 26% of samples was underestimated. This work presents a comprehensive database of Cu speciation and an effective attempt of free Cu2+ prediction in a wide range of Chinese soils.","PeriodicalId":55264,"journal":{"name":"Chemical Speciation and Bioavailability","volume":"29 1","pages":"205 - 215"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09542299.2017.1404437","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43272684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-01-01DOI: 10.1080/09542299.2017.1403294
J. Fang, B. Gao, A. Mosa, Lu Zhan
Abstract Hickory and peanut hydrochars were chemically activated with KOH and H3PO4 and tested for their ability to remove methylene blue and lead from aqueous solutions. The physicochemical characteristics of the activated hydrochars determined were surface area, pore volume, and elemental composition. Kinetics and isotherm studies were then conducted on methylene blue adsorption. Compared to their nonactivated counterparts, the chemically activated hydrochars had higher surface areas and more functional groups. Activated hydrochars also had greater methylene blue and lead adsorption rates, which can be attributed to the improved physicochemical characteristics. H3PO4 activated hydrochars removed more contaminants than the corresponding KOH ones.
{"title":"Chemical activation of hickory and peanut hull hydrochars for removal of lead and methylene blue from aqueous solutions","authors":"J. Fang, B. Gao, A. Mosa, Lu Zhan","doi":"10.1080/09542299.2017.1403294","DOIUrl":"https://doi.org/10.1080/09542299.2017.1403294","url":null,"abstract":"Abstract Hickory and peanut hydrochars were chemically activated with KOH and H3PO4 and tested for their ability to remove methylene blue and lead from aqueous solutions. The physicochemical characteristics of the activated hydrochars determined were surface area, pore volume, and elemental composition. Kinetics and isotherm studies were then conducted on methylene blue adsorption. Compared to their nonactivated counterparts, the chemically activated hydrochars had higher surface areas and more functional groups. Activated hydrochars also had greater methylene blue and lead adsorption rates, which can be attributed to the improved physicochemical characteristics. H3PO4 activated hydrochars removed more contaminants than the corresponding KOH ones.","PeriodicalId":55264,"journal":{"name":"Chemical Speciation and Bioavailability","volume":"29 1","pages":"197 - 204"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09542299.2017.1403294","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41336163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-01-01DOI: 10.1080/09542299.2017.1403293
Yanji Jiang, Lin Yu, Huimin Sun, Xianqiang Yin, Changzhao Wang, Shiny Mathews, Nong Wang
Abstract To understand the effects of ionic strength and pH on the transport of natural soil nanoparticles (NS) in saturated porous media, aeolian sandy soil nanoparticles (AS), cultivated loessial soil nano particles (CS), manural loessial soil nanoparticles (MS) and red soil nanoparticles (RS) were leached with solutions of varying pH and ionic strength. The recovery rate of soil nanoparticles decreased in the order AS > RS > MS > CS. Transport of soil nanoparticles was enhanced with increasing pH and decreasing ionic strength and was attributable to changes in the Zeta potential of NS. Deposition of NS was also affected by the composition of soil nanoparticles and the surface charge. Column experiments showed that the interaction between soil nanoparticles and saturated quartz sand was mainly due to the physical and chemical properties of soil nanoparticles. The Derjaguin–Landau–Verwey–Overbeek interaction energies between NS and sand were affected by pHs and ionic strengths. Soil nanoparticles transport through saturated porous media could be accurately simulated by the one-dimensional advection-dispersion-reaction equation.
摘要为了解离子强度和pH对天然土壤纳米颗粒(NS)在饱和多孔介质中运移的影响，采用不同pH和离子强度的溶液对风沙土纳米颗粒(AS)、人工黄土土纳米颗粒(CS)、人工黄土土纳米颗粒(MS)和红壤纳米颗粒(RS)进行浸出。土壤纳米颗粒的回收率依次为AS > RS > MS > CS。随着pH值的增加和离子强度的降低，土壤纳米颗粒的迁移增强，这与NS的Zeta电位的变化有关。土壤纳米粒子的组成和表面电荷对NS的沉积也有影响。柱试验表明，土壤纳米颗粒与饱和石英砂的相互作用主要是由土壤纳米颗粒的物理化学性质决定的。ph值和离子强度对NS与砂的Derjaguin-Landau-Verwey-Overbeek相互作用能有影响。采用一维平流-分散-反应方程可以准确模拟土壤纳米颗粒在饱和多孔介质中的运移过程。
{"title":"Transport of natural soil nanoparticles in saturated porous media: effects of pH and ionic strength","authors":"Yanji Jiang, Lin Yu, Huimin Sun, Xianqiang Yin, Changzhao Wang, Shiny Mathews, Nong Wang","doi":"10.1080/09542299.2017.1403293","DOIUrl":"https://doi.org/10.1080/09542299.2017.1403293","url":null,"abstract":"Abstract To understand the effects of ionic strength and pH on the transport of natural soil nanoparticles (NS) in saturated porous media, aeolian sandy soil nanoparticles (AS), cultivated loessial soil nano particles (CS), manural loessial soil nanoparticles (MS) and red soil nanoparticles (RS) were leached with solutions of varying pH and ionic strength. The recovery rate of soil nanoparticles decreased in the order AS > RS > MS > CS. Transport of soil nanoparticles was enhanced with increasing pH and decreasing ionic strength and was attributable to changes in the Zeta potential of NS. Deposition of NS was also affected by the composition of soil nanoparticles and the surface charge. Column experiments showed that the interaction between soil nanoparticles and saturated quartz sand was mainly due to the physical and chemical properties of soil nanoparticles. The Derjaguin–Landau–Verwey–Overbeek interaction energies between NS and sand were affected by pHs and ionic strengths. Soil nanoparticles transport through saturated porous media could be accurately simulated by the one-dimensional advection-dispersion-reaction equation.","PeriodicalId":55264,"journal":{"name":"Chemical Speciation and Bioavailability","volume":"29 1","pages":"186 - 196"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09542299.2017.1403293","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46849786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-01-01DOI: 10.1080/09542299.2017.1324740
A. Usman, Abdulelah Almutairi, Salem Elmaghraby, A. Al-Farraj
Abstract Heavy metals in the site received industrial effluents were investigated to assess the pollution levels, distribution of metal among solid-phase fractions and possible metal sources. The soil samples at different depths of 0–5, 5–25 and 25–50 cm were collected and analyzed for Fe, Mn, Cd, Zn, Cu, Ni and Pb. Among all metals, Cd content was not detected in all soil samples. The average contents of Pb and Zn are higher than the corresponding values of common range in earth crust. Meanwhile, the maximum contents of Cu and Zn are higher than those of Dutch optimum value but lower that the Dutch protection act target value. The maximum contents of Cu, Pb and Zn are higher than the average shale value. The most investigated heavy metals are mostly found in the potentially labile pool (>50.0%) including metal bound to carbonate, Fe/Mn oxides, or organically fractions. Enrichment factor (EF) in combination with multivariate analysis including principal component analysis (PCA) and hierarchical cluster analysis (HCA) suggest that Mn and Ni associated with Fe in the soil samples were primarily originated from lithogenic sources. Pb was largely derived only from anthropogenic source, while Cu and Zn in the soil samples were controlled by the mixed natural and anthropogenic sources. These results suggest that discharging the industrial effluents into dumping site increased pollution level of Pb, Zn and Cu as well as enhanced their potentially labile pool that may be responsible for occurring potential toxic impacts on environmental quality.
{"title":"Levels, solid-phase fractions and sources of heavy metals at site received industrial effluents: a case study","authors":"A. Usman, Abdulelah Almutairi, Salem Elmaghraby, A. Al-Farraj","doi":"10.1080/09542299.2017.1324740","DOIUrl":"https://doi.org/10.1080/09542299.2017.1324740","url":null,"abstract":"Abstract Heavy metals in the site received industrial effluents were investigated to assess the pollution levels, distribution of metal among solid-phase fractions and possible metal sources. The soil samples at different depths of 0–5, 5–25 and 25–50 cm were collected and analyzed for Fe, Mn, Cd, Zn, Cu, Ni and Pb. Among all metals, Cd content was not detected in all soil samples. The average contents of Pb and Zn are higher than the corresponding values of common range in earth crust. Meanwhile, the maximum contents of Cu and Zn are higher than those of Dutch optimum value but lower that the Dutch protection act target value. The maximum contents of Cu, Pb and Zn are higher than the average shale value. The most investigated heavy metals are mostly found in the potentially labile pool (>50.0%) including metal bound to carbonate, Fe/Mn oxides, or organically fractions. Enrichment factor (EF) in combination with multivariate analysis including principal component analysis (PCA) and hierarchical cluster analysis (HCA) suggest that Mn and Ni associated with Fe in the soil samples were primarily originated from lithogenic sources. Pb was largely derived only from anthropogenic source, while Cu and Zn in the soil samples were controlled by the mixed natural and anthropogenic sources. These results suggest that discharging the industrial effluents into dumping site increased pollution level of Pb, Zn and Cu as well as enhanced their potentially labile pool that may be responsible for occurring potential toxic impacts on environmental quality.","PeriodicalId":55264,"journal":{"name":"Chemical Speciation and Bioavailability","volume":"29 1","pages":"78 - 88"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09542299.2017.1324740","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44070465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract We investigated the distribution and chemical speciation of Cd, Cr, Cu, Pb and Zn in the water level-fluctuating (WLF) zone of the main stream (MS) and tributaries (ZX and MX) of the Three Gorges Reservoir. We evaluated the ecological risk and pollution level from heavy metals based on the Potential Ecological Risk Index (RI), Risk Assessment Code (RAC), and Ratio of Secondary Phase and Primary Phase (RSP). Our results indicated that the total and bio-available heavy metal contents were higher in the tributaries than in the MS. Moderate pollution from Cd and light pollution from Pb were observed both at the MS and ZX sites, whereas the MX site exhibited a pattern of heavy Cd pollution and light Cr and Pb pollution. In our study area, the results indicated that Cd exhibited a higher ecological risk than did the other heavy metals. Finally, the pH and nitrogen content of sediments may play a key role in controlling the amount of heavy metal bioavailability, further inducing a higher potential ecological risk.
{"title":"Total nitrogen and pH-controlled chemical speciation, bioavailability and ecological risk from Cd, Cr, Cu, Pb and Zn in the water level-fluctuating zone sediments of the Three Gorges Reservoir","authors":"Li-ping He, Dan Liu, Jun-jie Lin, Zhi-guo Yu, Xiaoxia Yang, Chuan Fu, Zheng-xue Liu, Qiao-hua Zhao","doi":"10.1080/09542299.2017.1335179","DOIUrl":"https://doi.org/10.1080/09542299.2017.1335179","url":null,"abstract":"Abstract We investigated the distribution and chemical speciation of Cd, Cr, Cu, Pb and Zn in the water level-fluctuating (WLF) zone of the main stream (MS) and tributaries (ZX and MX) of the Three Gorges Reservoir. We evaluated the ecological risk and pollution level from heavy metals based on the Potential Ecological Risk Index (RI), Risk Assessment Code (RAC), and Ratio of Secondary Phase and Primary Phase (RSP). Our results indicated that the total and bio-available heavy metal contents were higher in the tributaries than in the MS. Moderate pollution from Cd and light pollution from Pb were observed both at the MS and ZX sites, whereas the MX site exhibited a pattern of heavy Cd pollution and light Cr and Pb pollution. In our study area, the results indicated that Cd exhibited a higher ecological risk than did the other heavy metals. Finally, the pH and nitrogen content of sediments may play a key role in controlling the amount of heavy metal bioavailability, further inducing a higher potential ecological risk.","PeriodicalId":55264,"journal":{"name":"Chemical Speciation and Bioavailability","volume":"29 1","pages":"89 - 96"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09542299.2017.1335179","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48714193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-01-01DOI: 10.1080/09542299.2017.1395712
Shengsen Wang, Mingyue Zhao, Yiting Zhao, Nong Wang, J. Bai, K. Feng, Yanxia Zhou, Wangshu Chen, F. Wen, Saisai Wang, Xiaozhi Wang, Jun Wang
Abstract Particle size of nanoscaled zero valent iron (nZVI) in nanocomposites can be affected by support materials. In this work, nZVI was supported by bamboo-derived biochars produced at 450 °C (BBL) and 600 °C (BBH). Total iron (Fe) contents were 14.4 and 11.9% for nZVI immobilized in BBL (nZVI/BBL) and BBH (nZVI/BBH), respectively. The resultant nanocomposites were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), and scanning electron microscopy/energy-dispersive X-ray analyses (SEM/EDS). The nZVI was successfully embedded in biochar pores and surfaces as confirmed by SEM/EDS and XRD. TEM revealed that particle sizes of nZVI in nZVI/BBL and nZVI/BBH were roughly 26 and 40 nm, respectively. The Ag+ sorption isotherms (25–300 mg L−1 Ag+) suggested that 1 kg of nZVI in nZVI/BBL and nZVI/BBH removed as much as 745.5 and 534.5 g Ag+, respectively. The results suggested that Ag+ removal capacity was related to particle size of nZVI, which was also affected by pyrogenic temperature.
摘要纳米零价铁（nZVI）在纳米复合材料中的粒径会受到载体材料的影响。在这项工作中，nZVI由在450°C（BBL）和600°C（BBSH）下生产的竹衍生生物炭支持。固定在BBL（nZVI/BBL）和BBH（nZV/BBH）中的nZVI的总铁（Fe）含量分别为14.4%和11.9%。通过透射电子显微镜（TEM）、X射线衍射（XRD）和扫描电子显微镜/能量色散X射线分析（SEM/EDS）对所得纳米复合材料进行了表征。通过SEM/EDS和XRD证实，nZVI成功地嵌入了生物炭的孔和表面。TEM显示，nZVI/BBL和nZVIBBH中的nZVI的颗粒尺寸分别约为26和40nm。Ag+吸附等温线（25–300 mg L−1 Ag+）表明，在nZVI/BBL和nZVI/BBH中，1 kg的nZVI分别去除了745.5和534.5 g Ag+。研究结果表明，nZVI对Ag+的去除能力与粒径有关，同时也受热解温度的影响。
{"title":"Pyrogenic temperature affects the particle size of biochar-supported nanoscaled zero valent iron (nZVI) and its silver removal capacity","authors":"Shengsen Wang, Mingyue Zhao, Yiting Zhao, Nong Wang, J. Bai, K. Feng, Yanxia Zhou, Wangshu Chen, F. Wen, Saisai Wang, Xiaozhi Wang, Jun Wang","doi":"10.1080/09542299.2017.1395712","DOIUrl":"https://doi.org/10.1080/09542299.2017.1395712","url":null,"abstract":"Abstract Particle size of nanoscaled zero valent iron (nZVI) in nanocomposites can be affected by support materials. In this work, nZVI was supported by bamboo-derived biochars produced at 450 °C (BBL) and 600 °C (BBH). Total iron (Fe) contents were 14.4 and 11.9% for nZVI immobilized in BBL (nZVI/BBL) and BBH (nZVI/BBH), respectively. The resultant nanocomposites were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), and scanning electron microscopy/energy-dispersive X-ray analyses (SEM/EDS). The nZVI was successfully embedded in biochar pores and surfaces as confirmed by SEM/EDS and XRD. TEM revealed that particle sizes of nZVI in nZVI/BBL and nZVI/BBH were roughly 26 and 40 nm, respectively. The Ag+ sorption isotherms (25–300 mg L−1 Ag+) suggested that 1 kg of nZVI in nZVI/BBL and nZVI/BBH removed as much as 745.5 and 534.5 g Ag+, respectively. The results suggested that Ag+ removal capacity was related to particle size of nZVI, which was also affected by pyrogenic temperature.","PeriodicalId":55264,"journal":{"name":"Chemical Speciation and Bioavailability","volume":"29 1","pages":"179 - 185"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09542299.2017.1395712","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44949266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-10-01DOI: 10.1080/09542299.2016.1247657
Qiulai He, Hongyu Wang, Congyuan Xu, Jing Zhang, Wei Zhang, Zhuocheng Zou, Kai Yang
Abstract Carbon and nutrients as well as suspended solids (SS) removal by chemically enhanced primary treatment (CEPT) were conducted in the Qingshan wastewater treatment plant in Huangshi, Hubei Province. Feasibility of this process for wastewater treatment were investigated in detail by comparing the removal performance of three inorganic chemical coagulants (polyaluminium chloride, polyaluminium ferric chloride [PAFC] and poly ferric sulfate) individual or couple with poly acrylamide, optimizing the conditions during CEPT by both single factor analysis and orthogonal test designs. The results of this study demonstrated that CEPT turned out to be an effective method for wastewater treatment, with PAFC as the optimal coagulant, which showed preeminent removal capacity for chemical oxygen demand, total phosphorus and SS. The optimal working condition could be at pH 7.0, settling time 15 min, and velocity gradient of 174.80 and 15.56 s−1 for mixing and reaction phase respectively. While the coagulant dosage depends on raw water attributes, which had a decisive effect on CEPT treatment performances. However, the three coagulants behaved poorly in nitrogen removal.
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