There is a growing environmental and health concern associated with contamination by heavy metals. It has also been intensified due to an increase of the exposure to such pollutants as a result of industrial and technological growth. Therefore, it is necessary to remove heavy metals in contaminated water to eliminate the associated risks. This study focused on the removal of heavy metal ions using silica sulfuric acid (SSA). A comprehensive study was conducted to assess the effect of different factors on the adsorption by SSA as well as selectivity properties of the adsorbent, kinetic and thermodynamic studies of the adsorption process. A batch test was used to remove heavy metals from a multi-element solution containing Ni(II), Pb(II), Mn(II), Cu(II), and Cd(II). The results showed that removal rate reached its peak at pH, string time, and adsorbent amount equal to 8, 60 min, and 0.04 g/mL of solution, respectively. The removal efficiency of Ni2+, Cd2+, Mn2+ dropped by increasing the volume of solution and smoothed at 150 mL while the removal of Pb2+ and Cu2+ did not vary with the volume. The removal efficiency by SSA was decreased as Pb > >Mn > >Ni ≥ Cu > Cd. In general, SSA successfully removed heavy metals from contaminated water.
{"title":"Heavy metals’ removal from aqueous environments using silica sulfuric acid","authors":"Nasrin Hosseinahli, Maherram Hasanov, M. Abbasi","doi":"10.2166/WRD.2021.085","DOIUrl":"https://doi.org/10.2166/WRD.2021.085","url":null,"abstract":"\u0000 There is a growing environmental and health concern associated with contamination by heavy metals. It has also been intensified due to an increase of the exposure to such pollutants as a result of industrial and technological growth. Therefore, it is necessary to remove heavy metals in contaminated water to eliminate the associated risks. This study focused on the removal of heavy metal ions using silica sulfuric acid (SSA). A comprehensive study was conducted to assess the effect of different factors on the adsorption by SSA as well as selectivity properties of the adsorbent, kinetic and thermodynamic studies of the adsorption process. A batch test was used to remove heavy metals from a multi-element solution containing Ni(II), Pb(II), Mn(II), Cu(II), and Cd(II). The results showed that removal rate reached its peak at pH, string time, and adsorbent amount equal to 8, 60 min, and 0.04 g/mL of solution, respectively. The removal efficiency of Ni2+, Cd2+, Mn2+ dropped by increasing the volume of solution and smoothed at 150 mL while the removal of Pb2+ and Cu2+ did not vary with the volume. The removal efficiency by SSA was decreased as Pb > >Mn > >Ni ≥ Cu > Cd. In general, SSA successfully removed heavy metals from contaminated water.","PeriodicalId":17556,"journal":{"name":"Journal of Water Reuse and Desalination","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2021-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42993386","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}
Membrane fouling has been a major obstacle for stable operation of ultrafiltration. In this study, prevailing fouling models were applied to assess the fouling behavior of the denitrification filter (DNF) effluent during ozonation. In order to clarify the fouling mechanism, correlation analysis and redundancy analysis (RDA) were conducted to investigate the correlations among model parameters, fouling potential and water features of the DNF effluent. The combined intermediate-standard model exhibited superior determination coefficients (R2 > 0.99). Based on analytical results, the model parameter of intermediate blocking (Ki) and standard blocking (Ks) was fairly applicable to describe the fouling of higher molecular weight (F1, MW >4,000 Da) and lower molecular weight fractions (F2, MW = 2,000–4,000 Da and F3, MW < 2,000 Da), respectively. In comparison, F1 played a predominant role in the fouling behavior of the DNF effluent. Increased ozone dosage resulted in decreased membrane fouling contribution of F1 and increased fouling contribution of F2 and F3 during ozonation. The change of fouling contributions was attributed to the transformation of high MW fractions into lower MW fractions by ozonation. This study clarified the relationships between model parameters and the membrane fouling process caused by organic fractions with specific molecular weight, thus demonstrating the membrane fouling mechanism of the DNF effluent during ozonation.
{"title":"Revealing the membrane fouling mechanism caused by the denitrification filter effluent during ozonation by model assessment","authors":"Yuan Bai, Yin-Hu Wu, Xin Tong, Yun-Hong Wang, Nozomu Ikuno, Wen Wang, Yu-Long Shi, Hong-Ying Hu","doi":"10.2166/WRD.2021.005","DOIUrl":"https://doi.org/10.2166/WRD.2021.005","url":null,"abstract":"\u0000 Membrane fouling has been a major obstacle for stable operation of ultrafiltration. In this study, prevailing fouling models were applied to assess the fouling behavior of the denitrification filter (DNF) effluent during ozonation. In order to clarify the fouling mechanism, correlation analysis and redundancy analysis (RDA) were conducted to investigate the correlations among model parameters, fouling potential and water features of the DNF effluent. The combined intermediate-standard model exhibited superior determination coefficients (R2 > 0.99). Based on analytical results, the model parameter of intermediate blocking (Ki) and standard blocking (Ks) was fairly applicable to describe the fouling of higher molecular weight (F1, MW >4,000 Da) and lower molecular weight fractions (F2, MW = 2,000–4,000 Da and F3, MW < 2,000 Da), respectively. In comparison, F1 played a predominant role in the fouling behavior of the DNF effluent. Increased ozone dosage resulted in decreased membrane fouling contribution of F1 and increased fouling contribution of F2 and F3 during ozonation. The change of fouling contributions was attributed to the transformation of high MW fractions into lower MW fractions by ozonation. This study clarified the relationships between model parameters and the membrane fouling process caused by organic fractions with specific molecular weight, thus demonstrating the membrane fouling mechanism of the DNF effluent during ozonation.","PeriodicalId":17556,"journal":{"name":"Journal of Water Reuse and Desalination","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2021-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44127068","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}
Phosphate removal is an important measure to control eutrophication in aquatic environments, as it inhibits algal bloom. Salinity exists in these media along with high phosphate and currently available phosphate removal methods function poorly under this condition. In this study, the main objective is to fabricate a nanocomposite to improve and accelerate phosphate removal from saline solutions. To achieve this goal, Fe3O4/ZnO and a novel nanoadsorbent, Fe3O4/ZnO/CuO, were synthesized. Their characteristics were determined using FE-SEM, EDX, FT-IR, and XRD analyses, and their capability to adsorb phosphate from saline solutions was investigated and compared. The overall results suggest that the trimetallic oxide nanocomposite has great potential for the efficient removal of phosphate, in comparison with Fe3O4/ZnO. Experiments showed that Fe3O4/ZnO/CuO exhibited a remarkable sorption capacity of 156.35 mg P/g, fast sorption kinetic, strong selectivity for phosphate even in the presence of a high concentration of salinity (60 mg/L), and a wide applicable pH range of 3–6. Furthermore, using Fe3O4/ZnO/CuO, even a low dosage of 0.1 g/L was sufficient to reach an adsorption efficiency of 96.13% within 15 min compared to Fe3O4/ZnO (80.47% within 30 min). Moreover, the pseudo-second-order kinetic model best described the experimental adsorption data for both nanocomposites.
{"title":"Remarkable phosphate removal from saline solution by using a novel trimetallic oxide nanocomposite","authors":"Mahsa Alimohammadi, B. Ayati","doi":"10.2166/WRD.2021.007","DOIUrl":"https://doi.org/10.2166/WRD.2021.007","url":null,"abstract":"Phosphate removal is an important measure to control eutrophication in aquatic environments, as it inhibits algal bloom. Salinity exists in these media along with high phosphate and currently available phosphate removal methods function poorly under this condition. In this study, the main objective is to fabricate a nanocomposite to improve and accelerate phosphate removal from saline solutions. To achieve this goal, Fe3O4/ZnO and a novel nanoadsorbent, Fe3O4/ZnO/CuO, were synthesized. Their characteristics were determined using FE-SEM, EDX, FT-IR, and XRD analyses, and their capability to adsorb phosphate from saline solutions was investigated and compared. The overall results suggest that the trimetallic oxide nanocomposite has great potential for the efficient removal of phosphate, in comparison with Fe3O4/ZnO. Experiments showed that Fe3O4/ZnO/CuO exhibited a remarkable sorption capacity of 156.35 mg P/g, fast sorption kinetic, strong selectivity for phosphate even in the presence of a high concentration of salinity (60 mg/L), and a wide applicable pH range of 3–6. Furthermore, using Fe3O4/ZnO/CuO, even a low dosage of 0.1 g/L was sufficient to reach an adsorption efficiency of 96.13% within 15 min compared to Fe3O4/ZnO (80.47% within 30 min). Moreover, the pseudo-second-order kinetic model best described the experimental adsorption data for both nanocomposites.","PeriodicalId":17556,"journal":{"name":"Journal of Water Reuse and Desalination","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2021-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45369757","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}
T. Schnabel, N. Jautzus, Simon Mehling, C. Springer, J. Londong
Photocatalytic disintegration is a novel approach to eliminate pollution. The method utilizes the semiconductor titanium dioxide to degrade organic molecules in the presence of ultraviolet (UV) light. In this study, it is shown how the capabilities of several types of catalyst designs degrade the non-polar substance diesel fuel and the polar substance methylene blue. The floating design of foam glass coated with titanium dioxide could reduce the concentration of diesel fuel by 329 mg/L in 16 h; the submerged designs for coated glass fiber and coated steel grit could reduce methylene blue concentration by 96.6% after 4 h and 99.1% after 6 h, respectively. It could be shown that photocatalysis is a promising cost- and energy-efficient method for managing air and water pollution. It can be established as a low-technology method without requiring the use of a conventional source of energy, given an adequate amount of sun hours, or as an additional cleaning stage in water treatment plants using UV-LEDs.
{"title":"Photocatalytic degradation of hydrocarbons and methylene blue using floatable titanium dioxide catalysts in contaminated water","authors":"T. Schnabel, N. Jautzus, Simon Mehling, C. Springer, J. Londong","doi":"10.2166/WRD.2021.118","DOIUrl":"https://doi.org/10.2166/WRD.2021.118","url":null,"abstract":"\u0000 Photocatalytic disintegration is a novel approach to eliminate pollution. The method utilizes the semiconductor titanium dioxide to degrade organic molecules in the presence of ultraviolet (UV) light. In this study, it is shown how the capabilities of several types of catalyst designs degrade the non-polar substance diesel fuel and the polar substance methylene blue. The floating design of foam glass coated with titanium dioxide could reduce the concentration of diesel fuel by 329 mg/L in 16 h; the submerged designs for coated glass fiber and coated steel grit could reduce methylene blue concentration by 96.6% after 4 h and 99.1% after 6 h, respectively. It could be shown that photocatalysis is a promising cost- and energy-efficient method for managing air and water pollution. It can be established as a low-technology method without requiring the use of a conventional source of energy, given an adequate amount of sun hours, or as an additional cleaning stage in water treatment plants using UV-LEDs.","PeriodicalId":17556,"journal":{"name":"Journal of Water Reuse and Desalination","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2021-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43773370","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}
The reverse osmosis (RO) system is widely applied to produce reclaimed water for high-standard industrial use. Chlorine disinfection is the main biofouling control method in the RO systems for wastewater reclamation. However, researchers reported the adverse effects of chlorine disinfection which aggravated biofouling in laboratory-scale RO systems. In this study, four parallel 4-inch spiral wound RO membranes were used to study the effect of chlorine on biofouling in a pilot-scale RO system. The free chlorine dosages in four experimental groups were 0, 1, 2 and 5 mg/L, respectively. After continuous chlorination and dechlorination, the feed water entered the RO system. It was found that chlorine pretreatment caused a 1.9–36.7% increase in relative feed water pressure of the RO system, suggesting that chlorine aggravated the membrane fouling in the pilot-scale RO system. The microbial community structures of living bacteria in the feed water of the RO system were determined by the PMA (propidium monoazide)-PCR method and showed that the relative abundance of chlorine-resistant bacteria (CRB) was significantly increased after disinfection. Nine major genera which maintained higher relative abundance in experimental groups with high chlorine dosage were considered as possible key species causing membrane fouling, including Pedobacter, Clostridium and Bradyrhizobium.
{"title":"Aggravated biofouling caused by chlorine disinfection in a pilot-scale reverse osmosis treatment system of municipal wastewater","authors":"Liwei Luo, Yin-Hu Wu, Yun-Hong Wang, Xin Tong, Yuan Bai, Gen-Qiang Chen, Hao-Bin Wang, Nozomu Ikuno, Hong-Ying Hu","doi":"10.2166/WRD.2021.108","DOIUrl":"https://doi.org/10.2166/WRD.2021.108","url":null,"abstract":"\u0000 The reverse osmosis (RO) system is widely applied to produce reclaimed water for high-standard industrial use. Chlorine disinfection is the main biofouling control method in the RO systems for wastewater reclamation. However, researchers reported the adverse effects of chlorine disinfection which aggravated biofouling in laboratory-scale RO systems. In this study, four parallel 4-inch spiral wound RO membranes were used to study the effect of chlorine on biofouling in a pilot-scale RO system. The free chlorine dosages in four experimental groups were 0, 1, 2 and 5 mg/L, respectively. After continuous chlorination and dechlorination, the feed water entered the RO system. It was found that chlorine pretreatment caused a 1.9–36.7% increase in relative feed water pressure of the RO system, suggesting that chlorine aggravated the membrane fouling in the pilot-scale RO system. The microbial community structures of living bacteria in the feed water of the RO system were determined by the PMA (propidium monoazide)-PCR method and showed that the relative abundance of chlorine-resistant bacteria (CRB) was significantly increased after disinfection. Nine major genera which maintained higher relative abundance in experimental groups with high chlorine dosage were considered as possible key species causing membrane fouling, including Pedobacter, Clostridium and Bradyrhizobium.","PeriodicalId":17556,"journal":{"name":"Journal of Water Reuse and Desalination","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2021-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43120186","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}
Zhu Yao, Xin Jin, Jiaxin Liang, Wang Rui, P. Jin, Guangping Li, Yao Liushuan, Zhe Wang
To solve the problems of unstable chemical oxygen demand (COD), turbidity and suspended solid (SS) removal for the electrocatalytic process and unstable operation of the subsequent ultrafiltration membrane–reverse osmosis membrane in a centralised fracturing wastewater treatment plant in Inner Mongolia, the integrated dissolved ozone flotation (DOF) process was proposed to replace the original electrocatalytic process. Multiple processes, such as ozonation, flotation, coagulation and decolourisation, can be achieved in one integrated DOF reactor. The results showed that the removal efficiency of COD, colour, turbidity and SS in the DOF process could reach 25.4, 49.9, 95 and 96%, respectively. Meanwhile, the treatment cost was reduced by 47% (i.e., 1.77 RMB/m3 for the DOF process) compared with the electrocatalytic process.
{"title":"Application of an integrated dissolved ozone flotation process in centralised fracturing wastewater treatment plant","authors":"Zhu Yao, Xin Jin, Jiaxin Liang, Wang Rui, P. Jin, Guangping Li, Yao Liushuan, Zhe Wang","doi":"10.2166/WRD.2021.096","DOIUrl":"https://doi.org/10.2166/WRD.2021.096","url":null,"abstract":"\u0000 To solve the problems of unstable chemical oxygen demand (COD), turbidity and suspended solid (SS) removal for the electrocatalytic process and unstable operation of the subsequent ultrafiltration membrane–reverse osmosis membrane in a centralised fracturing wastewater treatment plant in Inner Mongolia, the integrated dissolved ozone flotation (DOF) process was proposed to replace the original electrocatalytic process. Multiple processes, such as ozonation, flotation, coagulation and decolourisation, can be achieved in one integrated DOF reactor. The results showed that the removal efficiency of COD, colour, turbidity and SS in the DOF process could reach 25.4, 49.9, 95 and 96%, respectively. Meanwhile, the treatment cost was reduced by 47% (i.e., 1.77 RMB/m3 for the DOF process) compared with the electrocatalytic process.","PeriodicalId":17556,"journal":{"name":"Journal of Water Reuse and Desalination","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2021-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45484963","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}
Sergio J. Álvarez-Méndez, Isidro Padrón-Armas, J. Mahouachi
The current lack of natural water resources, mainly due to the absence of sufficient precipitation and the deterioration of irrigation water (IW) quality, urgently requires a search for alternative resources, especially in arid and semiarid areas. Desalination of sea water is well established in numerous regions where water is scarce. To investigate the effects of the combination of regular fresh water and desalinated sea water (DSW) on mineral nutrient changes in crops, an experimental system based on Musa acuminata AAA plants was performed in Frontera (El Hierro, Canary Islands). Data showed that banana crops irrigated with a mixture of fresh water and DSW exhibited an adequate nutritional status and did not suffer any injuries of salt ions (Naþ and Cl ) or B toxicity. Moreover, plants may tolerate higher concentrations of these elements and a major supply of the other essential micronutrients. The obtained results suggest that irrigating crops with a combination of fresh water and DSW is a good strategy to respond to the high water requirements, at least under the tested experimental conditions. This strategy could be very helpful in arid regions, as well as in other areas where precipitation is seasonal and scarce, like the Mediterranean or the Canaries.
{"title":"Irrigation management strategies through the combination of fresh water and desalinated sea water for banana crops in El Hierro, Canary Islands","authors":"Sergio J. Álvarez-Méndez, Isidro Padrón-Armas, J. Mahouachi","doi":"10.2166/WRD.2021.078","DOIUrl":"https://doi.org/10.2166/WRD.2021.078","url":null,"abstract":"The current lack of natural water resources, mainly due to the absence of sufficient precipitation and the deterioration of irrigation water (IW) quality, urgently requires a search for alternative resources, especially in arid and semiarid areas. Desalination of sea water is well established in numerous regions where water is scarce. To investigate the effects of the combination of regular fresh water and desalinated sea water (DSW) on mineral nutrient changes in crops, an experimental system based on Musa acuminata AAA plants was performed in Frontera (El Hierro, Canary Islands). Data showed that banana crops irrigated with a mixture of fresh water and DSW exhibited an adequate nutritional status and did not suffer any injuries of salt ions (Naþ and Cl ) or B toxicity. Moreover, plants may tolerate higher concentrations of these elements and a major supply of the other essential micronutrients. The obtained results suggest that irrigating crops with a combination of fresh water and DSW is a good strategy to respond to the high water requirements, at least under the tested experimental conditions. This strategy could be very helpful in arid regions, as well as in other areas where precipitation is seasonal and scarce, like the Mediterranean or the Canaries.","PeriodicalId":17556,"journal":{"name":"Journal of Water Reuse and Desalination","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2021-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43099840","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}
N. Elboughdiri, B. Azeem, D. Ghernaout, Saad Ghareba, K. Kriaa
This research study encompasses the utilization of new adsorbents fabricated from pine sawdust for the adsorption of heavy metals and phenol from simulated industrial wastewater. Batch trials are conducted to evaluate the activity of these adsorbents for a possible substitution of the costly commercial adsorbents. The maximum adsorption capacities are evaluated and linked to the physicochemical characteristics of the adsorbents. The maximum monolayer adsorption capacity (qmax) of the adsorbents corresponds to the specific surface area of the adsorbents. The adsorbents with the larger specific surface area have shown higher qmax estimates (phenol adsorption is an exception). The highest amount of the phenol pollutant adsorbed by steam-activated sawdust (SAS) is 10.0 mg/g. The performance of SAS is found to be of the same order as the commercial activated carbon for the removal of Pb and Zn. Equilibrium data for the metal removal are in concordance with the Freundlich adsorption isotherm, whereas the phenol elimination has satisfied the Langmuir adsorption isotherm model. Kinetic data are fitted to Lagergren pseudo-first-order, pseudo-second-order, and the intraparticle diffusion models. Thus, kinetic parameters, rate constants, equilibrium adsorption capacities, and related correlation coefficients for each kinetic model are determined and discussed. The results suggest that the adsorption of Cr follows pseudo-second-order kinetics, indicating chemisorption for the tested adsorbents such that the intraparticle diffusion is not the only step that controls the overall process for Cr adsorption. At the end of this study, the production cost of the SAS adsorbent is estimated ($52 per kg) and compared to the cost of the commercial AC adsorbent in the industrial sector which has a great variation ($80–300 per kg) based on size and location plant. The results of this study can be used for the design of a suitable ecological control procedure to mitigate the harmful effects of industrial wastewater.
{"title":"Steam-activated sawdust efficiency in treating wastewater contaminated by heavy metals and phenolic compounds","authors":"N. Elboughdiri, B. Azeem, D. Ghernaout, Saad Ghareba, K. Kriaa","doi":"10.2166/WRD.2021.114","DOIUrl":"https://doi.org/10.2166/WRD.2021.114","url":null,"abstract":"\u0000 This research study encompasses the utilization of new adsorbents fabricated from pine sawdust for the adsorption of heavy metals and phenol from simulated industrial wastewater. Batch trials are conducted to evaluate the activity of these adsorbents for a possible substitution of the costly commercial adsorbents. The maximum adsorption capacities are evaluated and linked to the physicochemical characteristics of the adsorbents. The maximum monolayer adsorption capacity (qmax) of the adsorbents corresponds to the specific surface area of the adsorbents. The adsorbents with the larger specific surface area have shown higher qmax estimates (phenol adsorption is an exception). The highest amount of the phenol pollutant adsorbed by steam-activated sawdust (SAS) is 10.0 mg/g. The performance of SAS is found to be of the same order as the commercial activated carbon for the removal of Pb and Zn. Equilibrium data for the metal removal are in concordance with the Freundlich adsorption isotherm, whereas the phenol elimination has satisfied the Langmuir adsorption isotherm model. Kinetic data are fitted to Lagergren pseudo-first-order, pseudo-second-order, and the intraparticle diffusion models. Thus, kinetic parameters, rate constants, equilibrium adsorption capacities, and related correlation coefficients for each kinetic model are determined and discussed. The results suggest that the adsorption of Cr follows pseudo-second-order kinetics, indicating chemisorption for the tested adsorbents such that the intraparticle diffusion is not the only step that controls the overall process for Cr adsorption. At the end of this study, the production cost of the SAS adsorbent is estimated ($52 per kg) and compared to the cost of the commercial AC adsorbent in the industrial sector which has a great variation ($80–300 per kg) based on size and location plant. The results of this study can be used for the design of a suitable ecological control procedure to mitigate the harmful effects of industrial wastewater.","PeriodicalId":17556,"journal":{"name":"Journal of Water Reuse and Desalination","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2021-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43091515","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}
Heather Nixdorff, J. Noga, D. Amsalu, J. Springett, N. Ashbolt
Globally there is a need to rethink water use and wastewater disposal. One view is to consider wastewater as a resource via treatment for fit-for-purpose water and resource recovery (WRR). To understand what has worked in Canada according to those directly involved in WRR, we used interviews with individuals involved in various WRR projects. Seventeen semi-structured interviews were completed with participants from regions across Canada. Three main findings pertaining to the question ‘what is needed for WRR project implementation?’ emerged from the interviews: government and institutional support; community engagement, education, and acceptance; and comprehensive planning. Based on the interview findings, WRR projects require foundational guidance, something that is currently lacking in the Canadian context. To improve WRR implementation and success in Canada, guidance on community engagement, technology, costs, and impact assessments should be built into a policy for WRR.
{"title":"Improving the implementation of water and resource recovery in Canada","authors":"Heather Nixdorff, J. Noga, D. Amsalu, J. Springett, N. Ashbolt","doi":"10.2166/WRD.2021.087","DOIUrl":"https://doi.org/10.2166/WRD.2021.087","url":null,"abstract":"\u0000 Globally there is a need to rethink water use and wastewater disposal. One view is to consider wastewater as a resource via treatment for fit-for-purpose water and resource recovery (WRR). To understand what has worked in Canada according to those directly involved in WRR, we used interviews with individuals involved in various WRR projects. Seventeen semi-structured interviews were completed with participants from regions across Canada. Three main findings pertaining to the question ‘what is needed for WRR project implementation?’ emerged from the interviews: government and institutional support; community engagement, education, and acceptance; and comprehensive planning. Based on the interview findings, WRR projects require foundational guidance, something that is currently lacking in the Canadian context. To improve WRR implementation and success in Canada, guidance on community engagement, technology, costs, and impact assessments should be built into a policy for WRR.","PeriodicalId":17556,"journal":{"name":"Journal of Water Reuse and Desalination","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2021-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45066023","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}
This study investigated the seasonal variations of pollutants removal and microbial activity in constructed wetland–microbial fuel cell systems (CW–MFCs). The results showed that the atmospheric temperature significantly influenced the bioelectricity generation and removal of organics and nitrogen in CW–MFCs by primarily influencing the microbial enzymatic activity. The electricity output of CW-MFCs was extremely low below 5 °C, and reached the maximum above 25 °C. The organics and nitrogen removal of closed-circuit CW–MFC reached the highest in summer and autumn, followed by spring, and decreased by an average of 10.5% COD, 14.2% NH3-N and 10.7% TN in winter, demonstrating smaller seasonal fluctuations compared to open-circuit CW–MFC in which the difference between summer and winter was 13.4% COD, 15.1% NH3-N and 15.1% TN. Even at low temperatures, the MFC current could enhance the enzymatic activity and stabilize the growth of microorganisms on the electrodes, moreover, the closed circuit operation can promote the bacteria diversity on CW–MFC anodes as well as the abundance of electrogens on CW–MFC anodes and cathodes, and thus reduce the adverse effect of cooling on organics and nitrogen removal in CWs. However, neither MFC nor temperature had a significant influence on phosphorus removal in CW–MFCs.
{"title":"Seasonal variations of pollutants removal and microbial activity in integrated constructed wetland–microbial fuel cell systems","authors":"Xiaoou Wang, Yi-mei Tian","doi":"10.2166/WRD.2021.094","DOIUrl":"https://doi.org/10.2166/WRD.2021.094","url":null,"abstract":"\u0000 This study investigated the seasonal variations of pollutants removal and microbial activity in constructed wetland–microbial fuel cell systems (CW–MFCs). The results showed that the atmospheric temperature significantly influenced the bioelectricity generation and removal of organics and nitrogen in CW–MFCs by primarily influencing the microbial enzymatic activity. The electricity output of CW-MFCs was extremely low below 5 °C, and reached the maximum above 25 °C. The organics and nitrogen removal of closed-circuit CW–MFC reached the highest in summer and autumn, followed by spring, and decreased by an average of 10.5% COD, 14.2% NH3-N and 10.7% TN in winter, demonstrating smaller seasonal fluctuations compared to open-circuit CW–MFC in which the difference between summer and winter was 13.4% COD, 15.1% NH3-N and 15.1% TN. Even at low temperatures, the MFC current could enhance the enzymatic activity and stabilize the growth of microorganisms on the electrodes, moreover, the closed circuit operation can promote the bacteria diversity on CW–MFC anodes as well as the abundance of electrogens on CW–MFC anodes and cathodes, and thus reduce the adverse effect of cooling on organics and nitrogen removal in CWs. However, neither MFC nor temperature had a significant influence on phosphorus removal in CW–MFCs.","PeriodicalId":17556,"journal":{"name":"Journal of Water Reuse and Desalination","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2021-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47313992","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}
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