Designing biochar for the efficient removal of specific pollutants remains a significant challenge. In this work, a graphitized biochar with large carbon clusters (HBC700) was synthesized specifically for the removal of tetracycline. HBC700 exhibited outstanding adsorption performance, with a maximum adsorption capacity of 257.04 mg·g⁻¹ , which is 4.72 times that of the pristine biochar. The superior performance is attributed to its low electrical resistance, which facilitates electron transfer at the interface, enabling rapid and efficient tetracycline removal. After tetracycline adsorption, the structure of HBC700 became more ordered, forming a stable honeycomb arrangement. HBC700 also demonstrated high regeneration stability, maintaining a 94.85 % removal rate after five cycles, and achieving 100 % removal after H₂O₂ purification. Furthermore, HBC700 achieved over 98 % tetracycline removal in both tap water and wastewater, highlighting its potential for real-world applications.
{"title":"Functionalized construction of highly aromatic condensed graphitized biochar for tetracycline adsorption","authors":"Xiaotong Zhang , Jinju Hou , Tong Cai , Shudong Zhang , Lichun Shen , Qiuzhuo Zhang","doi":"10.1016/j.eti.2024.104002","DOIUrl":"10.1016/j.eti.2024.104002","url":null,"abstract":"<div><div>Designing biochar for the efficient removal of specific pollutants remains a significant challenge. In this work, a graphitized biochar with large carbon clusters (HBC700) was synthesized specifically for the removal of tetracycline. HBC700 exhibited outstanding adsorption performance, with a maximum adsorption capacity of 257.04 mg·g⁻¹ , which is 4.72 times that of the pristine biochar. The superior performance is attributed to its low electrical resistance, which facilitates electron transfer at the interface, enabling rapid and efficient tetracycline removal. After tetracycline adsorption, the structure of HBC700 became more ordered, forming a stable honeycomb arrangement. HBC700 also demonstrated high regeneration stability, maintaining a 94.85 % removal rate after five cycles, and achieving 100 % removal after H₂O₂ purification. Furthermore, HBC700 achieved over 98 % tetracycline removal in both tap water and wastewater, highlighting its potential for real-world applications.</div></div>","PeriodicalId":11725,"journal":{"name":"Environmental Technology & Innovation","volume":"37 ","pages":"Article 104002"},"PeriodicalIF":6.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143178918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To reduce and utilize many mollusk shell wastes, they can be transferred to calcium carbonate (CaCO3) powders by mechanical grinding and then the obtained powders can be upcycled into various calcium phosphates. Triple super-, mono-and di-calcium phosphates were prepared by rapidly simple, cheap, and environmentally friendly processes using bivalve mollusk shell wastes. Triple superphosphate (TSP) powder was obtained by a reaction between phosphoric acid and mollusk shell-derived CaCO3 powder and then was dissolved with water to classify non-soluble and soluble fractions by filtration. Non-soluble fraction was dried to obtain a gray-white powder of dicalcium phosphate dihydrate (CaHPO4·2 H2O). The self-evaporating process recrystallized the solution fraction to get a white powder of monocalcium phosphate monohydrate (Ca(H2PO4)2·H2O). All synthesized calcium phosphate samples were characterized and confirmed by X-ray fluorescence, X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, and thermal analysis. Thermogravimetric analysis (TGA) and derivative thermogravimetric analysis (DTA) were conducted to evaluate phase stability and thermal behavior. The analyses revealed the crucial influence of temperature on phase transitions and stability, providing insights into decomposition patterns and confirming phase purity. All the calcium phosphates were found to be highly purified and phosphorus-rich, making them effective for use in fertilizers and mineral animal feed. Additionally, the green and low-cost preparation of three calcium phosphates proposed in this research will be valuable for reducing waste mollusk shells by reforming them into value-added chemical products that point out the viewpoint of a zero-waste operation for obtaining sustainable development of an effective waste management and recycling technique.
{"title":"Upcycling bivalve mollusk shell wastes into triple super-, mono-and di-calcium phosphates for fertilizers and mineral animal feed","authors":"Nongnuch Laohavisuti , Chaowared Seangarun , Banjong Boonchom , Pesak Rungrojchaipon , Wimonmat Boonmee , Somkiat Seesanong","doi":"10.1016/j.eti.2024.103988","DOIUrl":"10.1016/j.eti.2024.103988","url":null,"abstract":"<div><div>To reduce and utilize many mollusk shell wastes, they can be transferred to calcium carbonate (CaCO<sub>3</sub>) powders by mechanical grinding and then the obtained powders can be upcycled into various calcium phosphates. Triple super-, mono-and di-calcium phosphates were prepared by rapidly simple, cheap, and environmentally friendly processes using bivalve mollusk shell wastes. Triple superphosphate (TSP) powder was obtained by a reaction between phosphoric acid and mollusk shell-derived CaCO<sub>3</sub> powder and then was dissolved with water to classify non-soluble and soluble fractions by filtration. Non-soluble fraction was dried to obtain a gray-white powder of dicalcium phosphate dihydrate (CaHPO<sub>4</sub>·2 H<sub>2</sub>O). The self-evaporating process recrystallized the solution fraction to get a white powder of monocalcium phosphate monohydrate (Ca(H<sub>2</sub>PO<sub>4</sub>)<sub>2</sub>·H<sub>2</sub>O). All synthesized calcium phosphate samples were characterized and confirmed by X-ray fluorescence, X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, and thermal analysis. Thermogravimetric analysis (TGA) and derivative thermogravimetric analysis (DTA) were conducted to evaluate phase stability and thermal behavior. The analyses revealed the crucial influence of temperature on phase transitions and stability, providing insights into decomposition patterns and confirming phase purity. All the calcium phosphates were found to be highly purified and phosphorus-rich, making them effective for use in fertilizers and mineral animal feed. Additionally, the green and low-cost preparation of three calcium phosphates proposed in this research will be valuable for reducing waste mollusk shells by reforming them into value-added chemical products that point out the viewpoint of a zero-waste operation for obtaining sustainable development of an effective waste management and recycling technique.</div></div>","PeriodicalId":11725,"journal":{"name":"Environmental Technology & Innovation","volume":"37 ","pages":"Article 103988"},"PeriodicalIF":6.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143179489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.eti.2024.104005
Chang Liu , Xiu-Tong Li , Yuqian Han , Wenxing Li , Yongqiang Gao , Chengying Jiang , Ying Liu , Yanning Zheng
With the growing challenges of resource shortages and environmental pollution, bioleaching has attracted increasing attention for its high potential in processing refractory and low-grade ores. However, the slow growth rate and low biomass production of autotrophic bacteria commonly used in bioleaching limit their industrial application. Here, based on high-throughput sequencing analysis, which revealed a strong positive correlation between Sulfobacillus and Alicyclobacillus in mining environments, we developed a mixed-bacterial system composed of Sulfobacillus thermosulfidooxidans and Alicyclobacillus ferrooxydans to enhance the efficiency of bioleaching. The mixed-bacterial system achieved a pyrite leaching rate up to 91.14 %, compared to 67.54 % by S. thermosulfidooxidans and 17.63 % by A. ferrooxydans. The improved leaching performance was attributed to the increased production of total extracellular polymeric substances (EPS), higher cell density and stronger redox capacity in the bioleaching solution. This study contributes to the development of a greener and more sustainable metallurgical industry.
{"title":"Enhanced pyrite bioleaching through the synergistic interactions between Sulfobacillus thermosulfidooxidans and Alicyclobacillus ferrooxydans","authors":"Chang Liu , Xiu-Tong Li , Yuqian Han , Wenxing Li , Yongqiang Gao , Chengying Jiang , Ying Liu , Yanning Zheng","doi":"10.1016/j.eti.2024.104005","DOIUrl":"10.1016/j.eti.2024.104005","url":null,"abstract":"<div><div>With the growing challenges of resource shortages and environmental pollution, bioleaching has attracted increasing attention for its high potential in processing refractory and low-grade ores. However, the slow growth rate and low biomass production of autotrophic bacteria commonly used in bioleaching limit their industrial application. Here, based on high-throughput sequencing analysis, which revealed a strong positive correlation between <em>Sulfobacillus</em> and <em>Alicyclobacillus</em> in mining environments, we developed a mixed-bacterial system composed of <em>Sulfobacillus thermosulfidooxidans</em> and <em>Alicyclobacillus ferrooxydans</em> to enhance the efficiency of bioleaching. The mixed-bacterial system achieved a pyrite leaching rate up to 91.14 %, compared to 67.54 % by <em>S. thermosulfidooxidans</em> and 17.63 % by <em>A. ferrooxydans</em>. The improved leaching performance was attributed to the increased production of total extracellular polymeric substances (EPS), higher cell density and stronger redox capacity in the bioleaching solution. This study contributes to the development of a greener and more sustainable metallurgical industry.</div></div>","PeriodicalId":11725,"journal":{"name":"Environmental Technology & Innovation","volume":"37 ","pages":"Article 104005"},"PeriodicalIF":6.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143179491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.eti.2024.103957
Zhaobin Zhang , Yuxuan Li , Shouding Li , Jianming He , Zhuoran Xie , Xiao Li , Cheng Lu , Xuwen Qin
Excessive carbon dioxide emissions pose a global environmental issue, and carbon sequestration technology offers a solution. This study based on independently developed simulator proposes a novel approach for carbon dioxide sequestration in the overlying layers of methane hydrate reservoirs using carbon dioxide hydrate technology. The feasibility and risks of this method are evaluated over a time scale of 100,000 years. Results show that carbon dioxide migrates upwards after injection, forming highly saturated hydrate shells at the migration front. Within these carbon dioxide hydrate shells, a portion of the carbon dioxide is sequestered in liquid and dissolved forms; however, over tens of thousands of years, 20 % of the CO₂ will dissolve, while less than 1 % will escape. The study highlights the synergy between methane hydrate extraction and carbon sequestration, as the cold seawater down draw effect from extraction enhances sequestration efficiency and safety. Given the widespread distribution of methane hydrate reservoirs globally, this research provides new insights into carbon sequestration technology.
{"title":"Carbon sequestration in overlying methane hydrate layers via hydrate technology: Feasibility and synergistic benefits","authors":"Zhaobin Zhang , Yuxuan Li , Shouding Li , Jianming He , Zhuoran Xie , Xiao Li , Cheng Lu , Xuwen Qin","doi":"10.1016/j.eti.2024.103957","DOIUrl":"10.1016/j.eti.2024.103957","url":null,"abstract":"<div><div>Excessive carbon dioxide emissions pose a global environmental issue, and carbon sequestration technology offers a solution. This study based on independently developed simulator proposes a novel approach for carbon dioxide sequestration in the overlying layers of methane hydrate reservoirs using carbon dioxide hydrate technology. The feasibility and risks of this method are evaluated over a time scale of 100,000 years. Results show that carbon dioxide migrates upwards after injection, forming highly saturated hydrate shells at the migration front. Within these carbon dioxide hydrate shells, a portion of the carbon dioxide is sequestered in liquid and dissolved forms; however, over tens of thousands of years, 20 % of the CO₂ will dissolve, while less than 1 % will escape. The study highlights the synergy between methane hydrate extraction and carbon sequestration, as the cold seawater down draw effect from extraction enhances sequestration efficiency and safety. Given the widespread distribution of methane hydrate reservoirs globally, this research provides new insights into carbon sequestration technology.</div></div>","PeriodicalId":11725,"journal":{"name":"Environmental Technology & Innovation","volume":"37 ","pages":"Article 103957"},"PeriodicalIF":6.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143177874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.eti.2024.103960
Wei Xie , Xi-Yan Gao , Mei-Lin Zheng , Ze-Bao Tan , Ying Liu , Luyan Ma , Zhi-Pei Liu
Direct ammonia oxidation (Dirammox) is a novel inorganic nitrogen metabolism pathway identified in the genus Alcaligenes, which could convert ammonia to N2 under aerobic conditions. With the remarkable nitrogen removal capabilities of this pathway, the heterotrophic genus Alcaligenes has considerable potential to efficiently and simultaneously remove nitrogen and organic matter from high chemical oxygen demand (COD) content and ammonium-rich wastewater. A novel lab-scale continuous-flow process termed “Dirammox membrane bio-reactor” (DMBR) was run over 9 months to test its possibility and efficiency for treating artificial ammonium-rich wastewater. There was stable performance, achieving an average ammonia removal (AR) of 95.4 %, total nitrogen removal (TNR) of 88.1 %, and COD removal of 95.0 %, with influent NH4+-N concentrations up to 600 mg/L and COD of 7800 mg/L. Dirammox bacteria dominated the functional community with a relative abundance of 5.70 %. The total denitrifying bacteria was only 0.13 %. Nitrifying bacteria were not detected. The relative abundance of denitrification and ammonia oxidation genes (amoA, hao) was low. The copy number of dnfA was 7.59 × 109/mg SS (dry), exceeding nirS [2.23 × 104/mg SS (dry)]. Aerobic denitrification was inactive in the activated sludge. The Dirammox pathway removed ammonia and total nitrogen (TN), but not those employed in traditional nitrogen removal techniques. In summary, the Dirammox process efficiently removes organic matter and TN while preventing harmful nitrogen compound formation, offering a novel, sustainable, and more efficient solution for treating high COD content and ammonium-rich wastewater.
{"title":"The novel Dirammox process for advanced nitrogen removal from high COD content and ammonium-rich wastewater","authors":"Wei Xie , Xi-Yan Gao , Mei-Lin Zheng , Ze-Bao Tan , Ying Liu , Luyan Ma , Zhi-Pei Liu","doi":"10.1016/j.eti.2024.103960","DOIUrl":"10.1016/j.eti.2024.103960","url":null,"abstract":"<div><div>Direct ammonia oxidation (Dirammox) is a novel inorganic nitrogen metabolism pathway identified in the genus <em>Alcaligenes</em>, which could convert ammonia to N<sub>2</sub> under aerobic conditions. With the remarkable nitrogen removal capabilities of this pathway, the heterotrophic genus <em>Alcaligenes</em> has considerable potential to efficiently and simultaneously remove nitrogen and organic matter from high chemical oxygen demand (COD) content and ammonium-rich wastewater. A novel lab-scale continuous-flow process termed “Dirammox membrane bio-reactor” (DMBR) was run over 9 months to test its possibility and efficiency for treating artificial ammonium-rich wastewater. There was stable performance, achieving an average ammonia removal (AR) of 95.4 %, total nitrogen removal (TNR) of 88.1 %, and COD removal of 95.0 %, with influent NH<sub>4</sub><sup>+</sup>-N concentrations up to 600 mg/L and COD of 7800 mg/L. Dirammox bacteria dominated the functional community with a relative abundance of 5.70 %. The total denitrifying bacteria was only 0.13 %. Nitrifying bacteria were not detected. The relative abundance of denitrification and ammonia oxidation genes (<em>amoA</em>, <em>hao</em>) was low. The copy number of <em>dnfA</em> was 7.59 × 10<sup>9</sup>/mg SS (dry), exceeding <em>nirS</em> [2.23 × 10<sup>4</sup>/mg SS (dry)]. Aerobic denitrification was inactive in the activated sludge. The Dirammox pathway removed ammonia and total nitrogen (TN), but not those employed in traditional nitrogen removal techniques. In summary, the Dirammox process efficiently removes organic matter and TN while preventing harmful nitrogen compound formation, offering a novel, sustainable, and more efficient solution for treating high COD content and ammonium-rich wastewater.</div></div>","PeriodicalId":11725,"journal":{"name":"Environmental Technology & Innovation","volume":"37 ","pages":"Article 103960"},"PeriodicalIF":6.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143178346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.eti.2024.103952
Azeem Tariq , Line Vinther Hansen , Andreas Brændholt , Lars Stoumann Jensen , Sander Bruun
The use of nitrification inhibitors (NIs) with fertilisers holds the potential to reduce nitrous oxide (N2O) emissions and optimise nitrogen use efficiency (NUE). However, this potential of NIs needs to be quantified across diverse field conditions to comprehensively assess the influence of management practices, crop types, fertilisation strategies, climatic conditions, annual variations, and soil types. In 2020, a field experiment was conducted using spring barley, followed by a similar experiment with winter wheat in 2021, aimed at studying N2O mitigation, crop nitrogen uptake and crop yield effects of three additives containing commercially available NIs: 3,4-dimethylpyrazole phosphate (DMPP), nitrapyrin (NP), and a mixture of 1,2,4-triazole and 3-metylpyrazole (TM) together with synthetic (ammonium sulphate nitrate (NS), urea ammonium nitrate (UAN)) and organic (pig slurry (PS)) fertilisers. DMPP was applied with NS and PS, while NP and TM were applied with UAN and PS. Fertilisers were applied during early spring in both years, following the recommended optimal rate of synthetic fertiliser and PS. Control treatments included fertilisers applied at the same rate without NIs and no fertiliser. N2O fluxes were assessed throughout the growing seasons of both years utilising manual static flux chambers. The study found that N2O emissions were significantly reduced from PS with DMPP (by 77 %) and TM (by 67 %), and that DMPP significantly reduced N2O emissions from NS (by 60 %) in 2021. Crop yield and N uptake were increased with NIs in both years. These findings suggest that DMPP and TM effectively reduce N2O emissions from both PS and synthetic N sources. Notably, the mitigation effects were more pronounced in PS compared to synthetic N. Nonetheless, the efficiency of N2O reduction through these nitrification inhibitors varied depending on crop type and specific management conditions.
{"title":"Assessing nitrous oxide mitigation efficiency of three nitrification inhibitors with synthetic and organic fertilisers in Eastern Denmark","authors":"Azeem Tariq , Line Vinther Hansen , Andreas Brændholt , Lars Stoumann Jensen , Sander Bruun","doi":"10.1016/j.eti.2024.103952","DOIUrl":"10.1016/j.eti.2024.103952","url":null,"abstract":"<div><div>The use of nitrification inhibitors (NIs) with fertilisers holds the potential to reduce nitrous oxide (N<sub>2</sub>O) emissions and optimise nitrogen use efficiency (NUE). However, this potential of NIs needs to be quantified across diverse field conditions to comprehensively assess the influence of management practices, crop types, fertilisation strategies, climatic conditions, annual variations, and soil types. In 2020, a field experiment was conducted using spring barley, followed by a similar experiment with winter wheat in 2021, aimed at studying N<sub>2</sub>O mitigation, crop nitrogen uptake and crop yield effects of three additives containing commercially available NIs: 3,4-dimethylpyrazole phosphate (DMPP), nitrapyrin (NP), and a mixture of 1,2,4-triazole and 3-metylpyrazole (TM) together with synthetic (ammonium sulphate nitrate (NS), urea ammonium nitrate (UAN)) and organic (pig slurry (PS)) fertilisers. DMPP was applied with NS and PS, while NP and TM were applied with UAN and PS. Fertilisers were applied during early spring in both years, following the recommended optimal rate of synthetic fertiliser and PS. Control treatments included fertilisers applied at the same rate without NIs and no fertiliser. N<sub>2</sub>O fluxes were assessed throughout the growing seasons of both years utilising manual static flux chambers. The study found that N<sub>2</sub>O emissions were significantly reduced from PS with DMPP (by 77 %) and TM (by 67 %), and that DMPP significantly reduced N<sub>2</sub>O emissions from NS (by 60 %) in 2021. Crop yield and N uptake were increased with NIs in both years. These findings suggest that DMPP and TM effectively reduce N<sub>2</sub>O emissions from both PS and synthetic N sources. Notably, the mitigation effects were more pronounced in PS compared to synthetic N. Nonetheless, the efficiency of N<sub>2</sub>O reduction through these nitrification inhibitors varied depending on crop type and specific management conditions.</div></div>","PeriodicalId":11725,"journal":{"name":"Environmental Technology & Innovation","volume":"37 ","pages":"Article 103952"},"PeriodicalIF":6.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143178338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.eti.2024.103981
Dingxiang Zhuang, Song Chen, Jun Li, Shuxin Han, Yan Guo
To realize the recycling of resources and reduce environmental pollution, waste sand was used as the inner core, waste powder and binding material were used as outer core, and the recycled coarse aggregate was prepared by using cold bonding ball forming technology. The comprehensive qualities were further improved by microbially induced calcium carbonate precipitation (MICP) that strengthening the inner core and outer core, respectively. This paper has studied the effects of the Ca2 + concentration and biomineralized time on the mass gain and water absorption of the waste sand. The results show that the optimal experimental conditions for strengthening waste sand were Ca2+ concentration of 0.8 mol /L and biomineralized time of 3 days. Moreover, the surface morphology, phase composition and special functional groups of the recycled coarse aggregate were determined by Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). The results show that spherical particles with a diameter of about 20 µm were filled in the cracks and pores, forming a layer of crystal protection layer with a dense structure. The comprehensive qualities of the recycled coarse aggregate were improved by analyzing the conglomeration rate, crushing index, apparent density, and water absorption rate. The results of the thermogravimetric analyses show that recycled coarse aggregate had high thermal stability and crystalline degree. Therefore, the qualities of recycled coarse aggregate strengthened by MICP can effectively alleviate the problem of insufficient aggregate supply. It is conducive to solve the problem of construction waste and realize sustainable development.
{"title":"Recycled coarse aggregate from waste concrete strengthened by microbially induced calcium carbonate precipitation","authors":"Dingxiang Zhuang, Song Chen, Jun Li, Shuxin Han, Yan Guo","doi":"10.1016/j.eti.2024.103981","DOIUrl":"10.1016/j.eti.2024.103981","url":null,"abstract":"<div><div>To realize the recycling of resources and reduce environmental pollution, waste sand was used as the inner core, waste powder and binding material were used as outer core, and the recycled coarse aggregate was prepared by using cold bonding ball forming technology. The comprehensive qualities were further improved by microbially induced calcium carbonate precipitation (MICP) that strengthening the inner core and outer core, respectively. This paper has studied the effects of the Ca<sup>2 +</sup> concentration and biomineralized time on the mass gain and water absorption of the waste sand. The results show that the optimal experimental conditions for strengthening waste sand were Ca<sup>2+</sup> concentration of 0.8 mol /L and biomineralized time of 3 days. Moreover, the surface morphology, phase composition and special functional groups of the recycled coarse aggregate were determined by Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). The results show that spherical particles with a diameter of about 20 µm were filled in the cracks and pores, forming a layer of crystal protection layer with a dense structure. The comprehensive qualities of the recycled coarse aggregate were improved by analyzing the conglomeration rate, crushing index, apparent density, and water absorption rate. The results of the thermogravimetric analyses show that recycled coarse aggregate had high thermal stability and crystalline degree. Therefore, the qualities of recycled coarse aggregate strengthened by MICP can effectively alleviate the problem of insufficient aggregate supply. It is conducive to solve the problem of construction waste and realize sustainable development.</div></div>","PeriodicalId":11725,"journal":{"name":"Environmental Technology & Innovation","volume":"37 ","pages":"Article 103981"},"PeriodicalIF":6.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143178503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
CoOx and MnOx metal oxide composites were fabricated via co-precipitation varying the Co:Mn (CM) weight ratio as 4:1, 2:1, 1:1, 1:2 and 1:4, and they hydrothermally coupled with 30 wt% of graphene oxide (GO). XRD analysis revealed the presence of Co3O4 and CoO, and Mn2O3 and Mn3O4 phases in pure CoOx and MnOx metal oxides, respectively. The irregularly shaped metal oxide nanocomposites comprised Co3O4, Mn2O3 and Mn3O4 phases and were immobilized on GO. The band gap values of the composites varied in the range of 1.86 – 2.22 eV. The highest photocatalytic activity with a rate constant of 3.5 × 10−3 min−1 was obtained with CMG (1:4). The total removal of MB increased by 55.8 % when CM (1:4) were coupled with GO. The rate of photocatalysis was dramatically increased in the presence of S2O82- and was decreased in the presence of EDTA and isopropyl alcohol. The effect of catalyst dosage was determined by varying the weight to 25, 50, 75, and 100 mg, and the dye concentration was varied in the range of 25, 50, 75 and 100 mg/L. The presence of Pb2+ and Rhodamine B decreased the photocatalytic activity, while it remained the same in the presence of Cl- and PO43- as co-pollutants. The photocatalytic activity of CMG (1:4) was reduced to 72 % upon using the catalyst for five cycles. All the synthesized nanocomposites exhibited greater sensitivity to the Gram-positive strain than the Gram-negative strains.
{"title":"The photocatalytic and antibacterial activity of graphene oxide coupled CoOx /MnOx nanocomposites","authors":"Heshan Liyanaarachchi , Charitha Thambiliyagodage , Madara Jayanetti , Geethma Ekanayake , Supuni Wijayawardana , Upeka Samarakoon","doi":"10.1016/j.eti.2024.103984","DOIUrl":"10.1016/j.eti.2024.103984","url":null,"abstract":"<div><div>CoO<sub>x</sub> and MnO<sub>x</sub> metal oxide composites were fabricated via co-precipitation varying the Co:Mn (CM) weight ratio as 4:1, 2:1, 1:1, 1:2 and 1:4, and they hydrothermally coupled with 30 wt% of graphene oxide (GO). XRD analysis revealed the presence of Co<sub>3</sub>O<sub>4</sub> and CoO, and Mn<sub>2</sub>O<sub>3</sub> and Mn<sub>3</sub>O<sub>4</sub> phases in pure CoO<sub>x</sub> and MnO<sub>x</sub> metal oxides, respectively. The irregularly shaped metal oxide nanocomposites comprised Co<sub>3</sub>O<sub>4</sub>, Mn<sub>2</sub>O<sub>3</sub> and Mn<sub>3</sub>O<sub>4</sub> phases and were immobilized on GO. The band gap values of the composites varied in the range of 1.86 – 2.22 eV. The highest photocatalytic activity with a rate constant of 3.5 × 10<sup>−3</sup> min<sup>−1</sup> was obtained with CMG (1:4). The total removal of MB increased by 55.8 % when CM (1:4) were coupled with GO. The rate of photocatalysis was dramatically increased in the presence of S<sub>2</sub>O<sub>8</sub><sup>2-</sup> and was decreased in the presence of EDTA and isopropyl alcohol. The effect of catalyst dosage was determined by varying the weight to 25, 50, 75, and 100 mg, and the dye concentration was varied in the range of 25, 50, 75 and 100 mg/L. The presence of Pb<sup>2+</sup> and Rhodamine B decreased the photocatalytic activity, while it remained the same in the presence of Cl<sup>-</sup> and PO<sub>4</sub><sup>3-</sup> as co-pollutants. The photocatalytic activity of CMG (1:4) was reduced to 72 % upon using the catalyst for five cycles. All the synthesized nanocomposites exhibited greater sensitivity to the Gram-positive strain than the Gram-negative strains.</div></div>","PeriodicalId":11725,"journal":{"name":"Environmental Technology & Innovation","volume":"37 ","pages":"Article 103984"},"PeriodicalIF":6.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143178508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This research quantified microplastics in greenhouse soils subjected to varying durations of plastic mulching and investigated the relationship between soil properties and microplastic contamination levels. Topsoil and subsoil samples were collected from two sites featuring plots without plastic film, and plots with plastic film for short and medium mulching durations. The results indicated that at Site A, no significant differences were observed between the non-plastic film plot and the plots with plastic film. The highest average number of microplastics in the subsoil was found in the plot with medium-duration mulching. However, there were no statistically significant differences between plots with no plastic mulching and those with plastic film after short or medium mulching durations. At Site B, the lowest average number of microplastics was observed in the non-mulching plot in both the topsoil and subsoil. There was no significant difference compared to plots with short or medium-duration mulching. The majority of microplastics in both the topsoil and subsoil were smaller than 50 µm. Microplastics, primarily composed of PVDF, PP, and PE, were not solely derived from plastic mulching but originated from plastic ropes, and fertilizer bags. Notably, the medium mulching durations exhibited higher PE microplastics. The concentrations of microplastics were positively correlated with total nitrogen and exchangeable potassium levels. In conclusion, microplastic contamination in the study areas came from additional sources beyond film mulching. Additionally, farmers can significantly reduce microplastic contamination in their soil by collecting plastic mulch from their fields before tilling at the start of each growing season.
{"title":"Contamination of microplastics in greenhouse soil subjected to plastic mulching","authors":"Panipak Boonsong, Achara Ussawarujikulchai, Benjaphorn Prapagdee, Wanwisa Pansak","doi":"10.1016/j.eti.2024.103991","DOIUrl":"10.1016/j.eti.2024.103991","url":null,"abstract":"<div><div>This research quantified microplastics in greenhouse soils subjected to varying durations of plastic mulching and investigated the relationship between soil properties and microplastic contamination levels. Topsoil and subsoil samples were collected from two sites featuring plots without plastic film, and plots with plastic film for short and medium mulching durations. The results indicated that at Site A, no significant differences were observed between the non-plastic film plot and the plots with plastic film. The highest average number of microplastics in the subsoil was found in the plot with medium-duration mulching. However, there were no statistically significant differences between plots with no plastic mulching and those with plastic film after short or medium mulching durations. At Site B, the lowest average number of microplastics was observed in the non-mulching plot in both the topsoil and subsoil. There was no significant difference compared to plots with short or medium-duration mulching. The majority of microplastics in both the topsoil and subsoil were smaller than 50 µm. Microplastics, primarily composed of PVDF, PP, and PE, were not solely derived from plastic mulching but originated from plastic ropes, and fertilizer bags. Notably, the medium mulching durations exhibited higher PE microplastics. The concentrations of microplastics were positively correlated with total nitrogen and exchangeable potassium levels. In conclusion, microplastic contamination in the study areas came from additional sources beyond film mulching. Additionally, farmers can significantly reduce microplastic contamination in their soil by collecting plastic mulch from their fields before tilling at the start of each growing season.</div></div>","PeriodicalId":11725,"journal":{"name":"Environmental Technology & Innovation","volume":"37 ","pages":"Article 103991"},"PeriodicalIF":6.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143178895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.eti.2024.104000
Kemeng Feng , Ashley J. Ansari , Na Zhang , Yongzhen Peng , Xiaoye Song
The high oil content in food wastewater often limits the process of anaerobic digestion by suppressing microbial activity and growth, both essential for organic conversion and consequently methane production. The objective of this study was to optimize biochar dosage for enhancing anaerobic digestion of food wastewater. Thus, the synthetic food wastewater containing 4 g/L of sodium oleate (oleate-Na) and an initial organic concentration of 5000 mg/L COD was used. Results show that methane production was severely suppressed during the anaerobic digestion of food wastewater with the addition of oleate-Na, reducing cumulative methane yield by 36.61 %. The inhibitory effect was mitigated with biochar addition, particularly at 5 g/L, which facilitated oleate-Na biodegradation to increase the cumulative methane production by 196.50 %. Sludge characterization and microbial analysis indicated that adding 5 g/L of biochar significantly enhanced biomass growth and selectively enriched functional bacteria, such as Thermotogae and Bacteroidetes, along with archaea like Methanoculleus and Methanosarcina, promoting hydrogenotrophic methanogenesis for methane production. Nevertheless, this benefit was reduced when biochar addition was increased from 5 g/L to 8 g/L, likely due to its excessive adsorption of compounds, like volatile fatty acids, to limit further methanogenesis.
{"title":"Biochar addition to mitigate oil inhibition in anaerobic digestion of food wastewater: Microbial insights from biochemical methane potential tests","authors":"Kemeng Feng , Ashley J. Ansari , Na Zhang , Yongzhen Peng , Xiaoye Song","doi":"10.1016/j.eti.2024.104000","DOIUrl":"10.1016/j.eti.2024.104000","url":null,"abstract":"<div><div>The high oil content in food wastewater often limits the process of anaerobic digestion by suppressing microbial activity and growth, both essential for organic conversion and consequently methane production. The objective of this study was to optimize biochar dosage for enhancing anaerobic digestion of food wastewater. Thus, the synthetic food wastewater containing 4 g/L of sodium oleate (oleate-Na) and an initial organic concentration of 5000 mg/L COD was used. Results show that methane production was severely suppressed during the anaerobic digestion of food wastewater with the addition of oleate-Na, reducing cumulative methane yield by 36.61 %. The inhibitory effect was mitigated with biochar addition, particularly at 5 g/L, which facilitated oleate-Na biodegradation to increase the cumulative methane production by 196.50 %. Sludge characterization and microbial analysis indicated that adding 5 g/L of biochar significantly enhanced biomass growth and selectively enriched functional bacteria, such as Thermotogae and Bacteroidetes, along with archaea like <em>Methanoculleus</em> and <em>Methanosarcina</em>, promoting hydrogenotrophic methanogenesis for methane production. Nevertheless, this benefit was reduced when biochar addition was increased from 5 g/L to 8 g/L, likely due to its excessive adsorption of compounds, like volatile fatty acids, to limit further methanogenesis.</div></div>","PeriodicalId":11725,"journal":{"name":"Environmental Technology & Innovation","volume":"37 ","pages":"Article 104000"},"PeriodicalIF":6.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143178921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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