Pub Date : 2016-02-05DOI: 10.1080/09542299.2016.1142833
Zhigang Liu, Yingwen Xue, Fei Gao, Xiaoru Cheng, Kai Yang
Abstract Biochars converted from agricultural residuals can effectively remove ammonium from water. This work further improved the sorption ability of biochars to aqueous ammonium through alkali modification. Three modified biochars were prepared from agricultural residuals pre-treated with NaOH solution through low-temperature (300 °C) slow pyrolysis. The modified biochars effectively removed ammonium ions from water under various conditions with relatively fast adsorption kinetics (reached equilibrium within 10 h) and extremely high adsorption capacity (>200 mg/g). The Langmuir maximum capacity of the three modified biochars were between 313.9 and 518.9 mg/g, higher than many other ammonium adsorbents. Although the sorption of ammonium onto the modified biochar was affected by pH and temperature, it was high under all of the tested conditions. Findings from this work indicated that alkali-modified biochars can be used as an alternative adsorbent for the removal of ammonium from wastewater.
{"title":"Removal of ammonium from aqueous solutions using alkali-modified biochars","authors":"Zhigang Liu, Yingwen Xue, Fei Gao, Xiaoru Cheng, Kai Yang","doi":"10.1080/09542299.2016.1142833","DOIUrl":"https://doi.org/10.1080/09542299.2016.1142833","url":null,"abstract":"Abstract Biochars converted from agricultural residuals can effectively remove ammonium from water. This work further improved the sorption ability of biochars to aqueous ammonium through alkali modification. Three modified biochars were prepared from agricultural residuals pre-treated with NaOH solution through low-temperature (300 °C) slow pyrolysis. The modified biochars effectively removed ammonium ions from water under various conditions with relatively fast adsorption kinetics (reached equilibrium within 10 h) and extremely high adsorption capacity (>200 mg/g). The Langmuir maximum capacity of the three modified biochars were between 313.9 and 518.9 mg/g, higher than many other ammonium adsorbents. Although the sorption of ammonium onto the modified biochar was affected by pH and temperature, it was high under all of the tested conditions. Findings from this work indicated that alkali-modified biochars can be used as an alternative adsorbent for the removal of ammonium from wastewater.","PeriodicalId":55264,"journal":{"name":"Chemical Speciation and Bioavailability","volume":"28 1","pages":"26 - 32"},"PeriodicalIF":0.0,"publicationDate":"2016-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09542299.2016.1142833","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60040606","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 : 2016-02-01DOI: 10.1080/09542299.2015.1136569
Ming Zhang, Li Xu, S. S. Lee, Y. Ok
Abstract The unintentional ingestion of carcinogenic xenobiotic substances leads to the high risk of cancer. Dietary fiber (DF) may protect against cancer by sorbing such chemicals. To this end, the sorption of four polycyclic aromatic hydrocarbons (PAHs) to DF extracted from wheat bran (WB) was studied. The strong affinity of PAHs to DF and WB indicated the effective binding of PAHs, and their distribution coefficients (Kd) positively increased with the increase in hydrophobicity of the PAHs. The DF had much higher Kd values for all PAHs compared to those of the unprocessed WB. The DF extraction process removed hydrophilic residues, such as starch, from WB, and increased the roughness of DF surface. Loss of hydrophilic components from WB to DF led to much higher affinity of DF with PAHs than WB. The results indicate that the DF can effectively sorb and remove xenobiotics, thereby having the potential to lower carcinogenic risk to humans.
{"title":"Sorption of polycyclic aromatic hydrocarbons (PAHs) by dietary fiber extracted from wheat bran","authors":"Ming Zhang, Li Xu, S. S. Lee, Y. Ok","doi":"10.1080/09542299.2015.1136569","DOIUrl":"https://doi.org/10.1080/09542299.2015.1136569","url":null,"abstract":"Abstract The unintentional ingestion of carcinogenic xenobiotic substances leads to the high risk of cancer. Dietary fiber (DF) may protect against cancer by sorbing such chemicals. To this end, the sorption of four polycyclic aromatic hydrocarbons (PAHs) to DF extracted from wheat bran (WB) was studied. The strong affinity of PAHs to DF and WB indicated the effective binding of PAHs, and their distribution coefficients (Kd) positively increased with the increase in hydrophobicity of the PAHs. The DF had much higher Kd values for all PAHs compared to those of the unprocessed WB. The DF extraction process removed hydrophilic residues, such as starch, from WB, and increased the roughness of DF surface. Loss of hydrophilic components from WB to DF led to much higher affinity of DF with PAHs than WB. The results indicate that the DF can effectively sorb and remove xenobiotics, thereby having the potential to lower carcinogenic risk to humans.","PeriodicalId":55264,"journal":{"name":"Chemical Speciation and Bioavailability","volume":"28 1","pages":"13 - 17"},"PeriodicalIF":0.0,"publicationDate":"2016-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09542299.2015.1136569","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60040494","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 : 2016-02-01DOI: 10.1080/09542299.2015.1136570
Dingfeng Jin, Yuanjun Xu, Ming Zhang, Yeongsang Jung, Y. Ok
Abstract Sorption kinetics and isotherms of phenol by four carbonaceous sorbents (activated carbon (AC), mesoporous carbon (MPC), bamboo biochar (BBC) and oak wood biochar (OBC)) were compared in this study. MPC has the fastest sorption rate and initial sorption potential, which were indicated by sorption rate constants and initial sorption rate “h” in a pseudo-second-order kinetic model. The ordered and straight pore structure of MPC facilitated the accessibility of phenol. The AC showed the greatest sorption capacity towards phenol with maximum sorption of 123 mg/g as calculated by the Langmuir model. High surface area, complexity of pore structure, and the strong binding force of the π–π electron-donor-acceptor interaction between phenol molecules and AC were the main mechanisms. The BBC and OBC had much slower sorption and lower sorption capacity (33.04 and 29.86 mg/g, respectively), compared to MPC (73.00 mg/g) and AC, indicating an ineffective potential for phenol removal from water.
{"title":"Comparative evaluation for the sorption capacity of four carbonaceous sorbents to phenol","authors":"Dingfeng Jin, Yuanjun Xu, Ming Zhang, Yeongsang Jung, Y. Ok","doi":"10.1080/09542299.2015.1136570","DOIUrl":"https://doi.org/10.1080/09542299.2015.1136570","url":null,"abstract":"Abstract Sorption kinetics and isotherms of phenol by four carbonaceous sorbents (activated carbon (AC), mesoporous carbon (MPC), bamboo biochar (BBC) and oak wood biochar (OBC)) were compared in this study. MPC has the fastest sorption rate and initial sorption potential, which were indicated by sorption rate constants and initial sorption rate “h” in a pseudo-second-order kinetic model. The ordered and straight pore structure of MPC facilitated the accessibility of phenol. The AC showed the greatest sorption capacity towards phenol with maximum sorption of 123 mg/g as calculated by the Langmuir model. High surface area, complexity of pore structure, and the strong binding force of the π–π electron-donor-acceptor interaction between phenol molecules and AC were the main mechanisms. The BBC and OBC had much slower sorption and lower sorption capacity (33.04 and 29.86 mg/g, respectively), compared to MPC (73.00 mg/g) and AC, indicating an ineffective potential for phenol removal from water.","PeriodicalId":55264,"journal":{"name":"Chemical Speciation and Bioavailability","volume":"28 1","pages":"18 - 25"},"PeriodicalIF":0.0,"publicationDate":"2016-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09542299.2015.1136570","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60040543","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 : 2016-01-28DOI: 10.1080/09542299.2015.1133238
Yulu Wang, Xianqiang Yin, Huimin Sun, Changzhao Wang
Abstract Vanadium, a hazardous pollutant, has been frequently detected in soil and groundwater, however, its transport behavior in porous media were not clearly understood. In this study, the effects of solution pH, ionic strength (IS) and the effect of clay mineral on the transport of vanadium in saturated porous media were investigated. Laboratory experiments using a series of columns packed with quartz sand were carried out to explore the retention and transport of vanadium with a range of ionic-strength (0.001–0.1 M) and pH (4–8) and two different types of clay minerals montmorillonite and kaolinite. Results of the breakthrough experiments showed that vanadium was highly mobile in the saturated porous media. The increase in pH rendered a higher transport of vanadium in saturated porous media. The study also indicated an easier transfer of vanadium with an increase in IS. Montmorillonite enhanced the mobility of vanadium in the column when compared to kaolinite. A mathematical model based on advection-dispersion equation coupled with equilibrium and kinetic reactions was used to describe the retention and transport of vanadium in the columns very well.
{"title":"Transport of vanadium (V) in saturated porous media: effects of pH, ionic-strength and clay mineral","authors":"Yulu Wang, Xianqiang Yin, Huimin Sun, Changzhao Wang","doi":"10.1080/09542299.2015.1133238","DOIUrl":"https://doi.org/10.1080/09542299.2015.1133238","url":null,"abstract":"Abstract Vanadium, a hazardous pollutant, has been frequently detected in soil and groundwater, however, its transport behavior in porous media were not clearly understood. In this study, the effects of solution pH, ionic strength (IS) and the effect of clay mineral on the transport of vanadium in saturated porous media were investigated. Laboratory experiments using a series of columns packed with quartz sand were carried out to explore the retention and transport of vanadium with a range of ionic-strength (0.001–0.1 M) and pH (4–8) and two different types of clay minerals montmorillonite and kaolinite. Results of the breakthrough experiments showed that vanadium was highly mobile in the saturated porous media. The increase in pH rendered a higher transport of vanadium in saturated porous media. The study also indicated an easier transfer of vanadium with an increase in IS. Montmorillonite enhanced the mobility of vanadium in the column when compared to kaolinite. A mathematical model based on advection-dispersion equation coupled with equilibrium and kinetic reactions was used to describe the retention and transport of vanadium in the columns very well.","PeriodicalId":55264,"journal":{"name":"Chemical Speciation and Bioavailability","volume":"42 1","pages":"12 - 7"},"PeriodicalIF":0.0,"publicationDate":"2016-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09542299.2015.1133238","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60039636","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 : 2016-01-12DOI: 10.1080/09542299.2015.1129290
C. Michel-López, Francisco L Espadas y Gil, G. Fuentes Ortíz, J. Santamaría, D. González-Mendoza, C. Ceceña-Durán, Onecimo Grimaldo Juarez
Abstract In the present study Prosopis juliflora plants grown in hydroponics solution were exposed to 50,100 and 1000 μM CdCl2. The cadmium uptake, transport and toxicity on the photosynthetic activities in the plants were measured at 48 h after starting cadmium treatments. The results showed that the concentration of Cd2+ in P. juliflora tended to increase with addition of Cd2+ to hydroponics solution. However, the increase of Cd2+ in roots and leaves varied largely. In this sense, the accumulation of Cd2+ in P. juliflora roots increased significantly in proportion with the addition of this metal. In contrast a relatively low level of Cd2+ transportation index, and bioaccumulation factor were found in P. juliflora at 48 h after of treatments. On the other hand the maximum photochemical efficiency of photosystem II (Fv/Fm) and the activity of photosystem II (Fv/Fo) ratios in P. juliflora leaf treated with Cd2+ not showed significantly changes during the experiment. These results suggested that the photosynthetic apparatus of P. juliflora was not the primary target of the Cd2+ action. Further studies will be focused in understanding the participation of the root system in Prosopis plants with the rhizosphere activation and root adsorption to soil Cd2+ under natural conditions.
{"title":"Bioaccumulation and effect of cadmium in the photosynthetic apparatus of Prosopis juliflora","authors":"C. Michel-López, Francisco L Espadas y Gil, G. Fuentes Ortíz, J. Santamaría, D. González-Mendoza, C. Ceceña-Durán, Onecimo Grimaldo Juarez","doi":"10.1080/09542299.2015.1129290","DOIUrl":"https://doi.org/10.1080/09542299.2015.1129290","url":null,"abstract":"Abstract In the present study Prosopis juliflora plants grown in hydroponics solution were exposed to 50,100 and 1000 μM CdCl2. The cadmium uptake, transport and toxicity on the photosynthetic activities in the plants were measured at 48 h after starting cadmium treatments. The results showed that the concentration of Cd2+ in P. juliflora tended to increase with addition of Cd2+ to hydroponics solution. However, the increase of Cd2+ in roots and leaves varied largely. In this sense, the accumulation of Cd2+ in P. juliflora roots increased significantly in proportion with the addition of this metal. In contrast a relatively low level of Cd2+ transportation index, and bioaccumulation factor were found in P. juliflora at 48 h after of treatments. On the other hand the maximum photochemical efficiency of photosystem II (Fv/Fm) and the activity of photosystem II (Fv/Fo) ratios in P. juliflora leaf treated with Cd2+ not showed significantly changes during the experiment. These results suggested that the photosynthetic apparatus of P. juliflora was not the primary target of the Cd2+ action. Further studies will be focused in understanding the participation of the root system in Prosopis plants with the rhizosphere activation and root adsorption to soil Cd2+ under natural conditions.","PeriodicalId":55264,"journal":{"name":"Chemical Speciation and Bioavailability","volume":"28 1","pages":"1 - 6"},"PeriodicalIF":0.0,"publicationDate":"2016-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09542299.2015.1129290","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60039540","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 : 2015-10-02DOI: 10.1080/09542299.2015.1113389
Wei Wang, Hua Wang, Chun-Man Yu, Zhiqiang Jiang
Abstract This study was conducted to evaluate the acute toxicity of ammonia and nitrite to three developmental stages of Pacific cod (Gadus macrocephalus) larvae (11, 22, and 35 days after hatching, with mean total lengths of 4.63 ± 0.14, 5.83 ± 0.17, and 7.46 ± 0.23 mm, respectively). The results showed for the first time that the acute toxicity of ammonia and nitrite is closely related to the age of Pacific cod larvae, and the acute toxicity of ammonia or nitrite increased with increased Pacific cod larval growth. Lethal concentrations (LC50) of un-ionized ammonia nitrogen (UIAN) for a 48-h exposure in 11-day post-hatch, 22-day post-hatch, and 35-day post-hatch Pacific cod larvae were 1.72, 0.69, and 0.32 mg L−1, respectively. The 48-h LC50 of nitrite nitrogen to Pacific cod larvae 11-day post-hatch, 22-day post-hatch, and 35-day post-hatch were 831.76, 269.15, and 223.87 mg L−1, respectively. The present findings demonstrate that the acute toxicity of ammonia for Pacific cod larvae is much higher than that of nitrite.
{"title":"Acute toxicity of ammonia and nitrite to different ages of Pacific cod (Gadus macrocephalus) larvae","authors":"Wei Wang, Hua Wang, Chun-Man Yu, Zhiqiang Jiang","doi":"10.1080/09542299.2015.1113389","DOIUrl":"https://doi.org/10.1080/09542299.2015.1113389","url":null,"abstract":"Abstract This study was conducted to evaluate the acute toxicity of ammonia and nitrite to three developmental stages of Pacific cod (Gadus macrocephalus) larvae (11, 22, and 35 days after hatching, with mean total lengths of 4.63 ± 0.14, 5.83 ± 0.17, and 7.46 ± 0.23 mm, respectively). The results showed for the first time that the acute toxicity of ammonia and nitrite is closely related to the age of Pacific cod larvae, and the acute toxicity of ammonia or nitrite increased with increased Pacific cod larval growth. Lethal concentrations (LC50) of un-ionized ammonia nitrogen (UIAN) for a 48-h exposure in 11-day post-hatch, 22-day post-hatch, and 35-day post-hatch Pacific cod larvae were 1.72, 0.69, and 0.32 mg L−1, respectively. The 48-h LC50 of nitrite nitrogen to Pacific cod larvae 11-day post-hatch, 22-day post-hatch, and 35-day post-hatch were 831.76, 269.15, and 223.87 mg L−1, respectively. The present findings demonstrate that the acute toxicity of ammonia for Pacific cod larvae is much higher than that of nitrite.","PeriodicalId":55264,"journal":{"name":"Chemical Speciation and Bioavailability","volume":"27 1","pages":"147 - 155"},"PeriodicalIF":0.0,"publicationDate":"2015-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09542299.2015.1113389","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60039103","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 : 2015-10-02DOI: 10.1080/09542299.2015.1112751
S. Javed, A. Sarwar, Mohsin Tassawar, M. Faisal
Abstract The present research work is on the biotic transformation of highly soluble and toxic selenite to less toxic elemental selenium using bacterial strains Bacillus subtilis, Exiguobacterium sp., Bacillus licheniformis, and Pseudomonas pseudoalcaligenes. The conditions were optimized by changing different physical parameters such as pH, temperature, different Selenium (Se) concentration levels (200, 400, and 600 μg ml−1), aeration, and incubation time for increased selenite reduction. The Se reduction rate increased with increase in pH. On average, 28–90% selenite reduction was observed at pH 9, while 15–33% at pH 3. To check the optimum temperature, all strains were cultured at three temperatures 32, 37, and 42 °C. Selenite reduction was observed at various temperatures and the results show that each strain has different preferences for optimum Se reduction. Selenite reduction was also monitored using different initial selenite concentrations and the results showed that at lower initial concentration (200 μg ml−1) maximum Se was reduced. This study showed that selenite-reducing bacteria can remediate Se in both aerobic and anaerobic environments, as well as their reduction ability decreases with increase in incubation time.
{"title":"Conversion of selenite to elemental selenium by indigenous bacteria isolated from polluted areas","authors":"S. Javed, A. Sarwar, Mohsin Tassawar, M. Faisal","doi":"10.1080/09542299.2015.1112751","DOIUrl":"https://doi.org/10.1080/09542299.2015.1112751","url":null,"abstract":"Abstract The present research work is on the biotic transformation of highly soluble and toxic selenite to less toxic elemental selenium using bacterial strains Bacillus subtilis, Exiguobacterium sp., Bacillus licheniformis, and Pseudomonas pseudoalcaligenes. The conditions were optimized by changing different physical parameters such as pH, temperature, different Selenium (Se) concentration levels (200, 400, and 600 μg ml−1), aeration, and incubation time for increased selenite reduction. The Se reduction rate increased with increase in pH. On average, 28–90% selenite reduction was observed at pH 9, while 15–33% at pH 3. To check the optimum temperature, all strains were cultured at three temperatures 32, 37, and 42 °C. Selenite reduction was observed at various temperatures and the results show that each strain has different preferences for optimum Se reduction. Selenite reduction was also monitored using different initial selenite concentrations and the results showed that at lower initial concentration (200 μg ml−1) maximum Se was reduced. This study showed that selenite-reducing bacteria can remediate Se in both aerobic and anaerobic environments, as well as their reduction ability decreases with increase in incubation time.","PeriodicalId":55264,"journal":{"name":"Chemical Speciation and Bioavailability","volume":"27 1","pages":"162 - 168"},"PeriodicalIF":0.0,"publicationDate":"2015-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09542299.2015.1112751","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60039226","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 : 2015-10-02DOI: 10.1080/09542299.2015.1118360
Jing Zhang, Tao Yang, Hongyu Wang, Kai Yang, Cheng-xiang Fang, Bin Lv, Xiao-jun Yang
Abstract In this study, the “Ultrasound/Fenton oxidation – MAP chemical precipitation” method was used to remove chemical oxygen demand (COD) and ammonia nitrogen from the old landfill leachate which was collected from one sanitary landfill in Wuhan. Firstly, Ultrasound treatment and Fenton oxidation treatment were separately used to treat the old landfill leachate, and under their optimum reaction conditions, the COD concentration was degraded from 842 to 697 mg L−1 and from 842 to 133 mg L−1, respectively. Then, Ultrasound/Fenton oxidation treatment was used to treat the same old landfill leachate. Compared with the single Fenton treatment, Ultrasound/Fenton oxidation treatment could raise the COD removal efficiency from 84.05 to 90.88% with the same H2O2 consumption. After the Ultrasound/Fenton oxidation treatment, Na2HPO4·12H2O and MgSO4·7H2O were used as precipitation reagents to remove ammonia nitrogen from the old landfill leachate, and the ammonia nitrogen concentration degraded from 910 to 11 mg L−1. The experiment results indicated that “Ultrasound/Fenton oxidation – MAP chemical precipitation” method was an effective and economic method to treat old landfill leachate.
{"title":"Study on treating old landfill leachate by Ultrasound–Fenton oxidation combined with MAP chemical precipitation","authors":"Jing Zhang, Tao Yang, Hongyu Wang, Kai Yang, Cheng-xiang Fang, Bin Lv, Xiao-jun Yang","doi":"10.1080/09542299.2015.1118360","DOIUrl":"https://doi.org/10.1080/09542299.2015.1118360","url":null,"abstract":"Abstract In this study, the “Ultrasound/Fenton oxidation – MAP chemical precipitation” method was used to remove chemical oxygen demand (COD) and ammonia nitrogen from the old landfill leachate which was collected from one sanitary landfill in Wuhan. Firstly, Ultrasound treatment and Fenton oxidation treatment were separately used to treat the old landfill leachate, and under their optimum reaction conditions, the COD concentration was degraded from 842 to 697 mg L−1 and from 842 to 133 mg L−1, respectively. Then, Ultrasound/Fenton oxidation treatment was used to treat the same old landfill leachate. Compared with the single Fenton treatment, Ultrasound/Fenton oxidation treatment could raise the COD removal efficiency from 84.05 to 90.88% with the same H2O2 consumption. After the Ultrasound/Fenton oxidation treatment, Na2HPO4·12H2O and MgSO4·7H2O were used as precipitation reagents to remove ammonia nitrogen from the old landfill leachate, and the ammonia nitrogen concentration degraded from 910 to 11 mg L−1. The experiment results indicated that “Ultrasound/Fenton oxidation – MAP chemical precipitation” method was an effective and economic method to treat old landfill leachate.","PeriodicalId":55264,"journal":{"name":"Chemical Speciation and Bioavailability","volume":"26 1","pages":"175 - 182"},"PeriodicalIF":0.0,"publicationDate":"2015-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09542299.2015.1118360","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60038867","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 This study aimed to analyze the changes in the activity of superoxide dismutase and catalase in Gadus macrocephalus Tilesius exposed to different concentrations of dibromodiphenyl ether, tetrabromodiphenyl ether, and decabromodiphenyl ether. Comet assay was used to explore the degree of DNA damage caused by tetrabromodiphenyl ether. The results revealed that different concentrations of these compounds and different exposure times could inhibit the antioxidant enzyme activity. Dibromodiphenyl ether had the highest inhibitory effect, followed by tetrabromodiphenyl ether and decabromodiphenyl ether. The results of the comet assay showed that high concentrations of tetrabromodiphenyl ether can cause DNA damage to G. macrocephalus. Furthermore, the DNA damage caused by tetrabromodiphenyl ether showed a significant concentration- and time-dependent effect.
{"title":"Effect of polybrominated diphenyl ether exposure on Gadus macrocephalus Tilesius","authors":"Wei Wang, Jianjun Hao, Saisai Zhang, Hua Wang, Zhiqiang Jiang","doi":"10.1080/09542299.2015.1118359","DOIUrl":"https://doi.org/10.1080/09542299.2015.1118359","url":null,"abstract":"Abstract This study aimed to analyze the changes in the activity of superoxide dismutase and catalase in Gadus macrocephalus Tilesius exposed to different concentrations of dibromodiphenyl ether, tetrabromodiphenyl ether, and decabromodiphenyl ether. Comet assay was used to explore the degree of DNA damage caused by tetrabromodiphenyl ether. The results revealed that different concentrations of these compounds and different exposure times could inhibit the antioxidant enzyme activity. Dibromodiphenyl ether had the highest inhibitory effect, followed by tetrabromodiphenyl ether and decabromodiphenyl ether. The results of the comet assay showed that high concentrations of tetrabromodiphenyl ether can cause DNA damage to G. macrocephalus. Furthermore, the DNA damage caused by tetrabromodiphenyl ether showed a significant concentration- and time-dependent effect.","PeriodicalId":55264,"journal":{"name":"Chemical Speciation and Bioavailability","volume":"58 1","pages":"183 - 190"},"PeriodicalIF":0.0,"publicationDate":"2015-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/09542299.2015.1118359","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60039264","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 : 2015-10-02DOI: 10.1080/09542299.2015.1118361
S. Qian, Weimin Ding, Yuncong C. Li, Guodong Liu, Jiuai Sun, Qishuo Ding
Abstract Understanding chemistry and the effects of humic substances on plant growth is important for using organic fertilizer or soil amendment for sustainable snap bean production. The objective of this study was to characterize different fractions of humic acid (HA) derived from Leonardite and evaluate their effects on seedling growth and nutrient uptake of snap bean (Phaseolus vulgaris L.). HAs extracted from Leonardite were separated based on molecular weights into three fractions (HS1, HS2, HS3) plus sediment (SED). With direct polarization combined with spectral editing techniques, functional groups of HAs were quantified and the results indicated that HAs with low molecular weights had more O-alkyl and carboxyl C groups than those with large molecular sizes. A plant growth experiment was conducted as a randomized split-plot design with three replications and repeated for three plantings. The results show that addition of HAs was beneficial to leaf and root growth of snap bean compared with the control (no HA). Plants treated with low-molecular weight HAs had significantly greater root length, root surface area, and uptake of potassium by shoot than those treated with other HAs, while leaf growth was affected mainly by HAs with high molecular weight.
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