Pub Date : 2024-09-01Epub Date: 2023-09-01DOI: 10.1080/09593330.2023.2253503
Chiedu E Edoamodu, Uchechukwu U Nwodo
Laccase is a multicopper enzyme that plays a unique role in bioremediation of environmental pollutants. Bacteria were isolated from hospital wastewater and screened for laccase production. The laccase production process condition was optimised, and the laccase obtained was characterised. The 16S rRNA molecular analysis conducted on the best laccase producer revealed a Bacillus sp. NU2 identified. The process conditions: pH5, 45°C, 100 rpm, 5% inoculum, and growth constituents viz: tangerine peel and wheat bran agro-wastes, beef extract, ammonium persulfate, glucose, galactose, xylose, sorbitol, fructose carbon sources; and 4-aminophenol inducer optimally stimulated laccase production. The Bacillus sp. NU2 laccase was optimal at pH and temperature conditions of 8.0°C and 60°C, with a noteworthy pH and thermal stability observed. Furthermore, NU2 laccase showed a moderate/high tolerance and relative activity effect on various chemical inhibitors, halides and surfactant of triton x-100 (105 ± 0.92%), PMSF (107 ± 0.81%), and NaCl (94 ± 0.81%) at 1, 3, and 6 (mM) concentration. Additionally, NU2 laccase maintained a relative activity of 101%, 104%, and 102% for Mg2+, Zn2+, and Fe3+ at 1, 3, and 6 mM respectively. Acetone and propanol significantly upregulated laccase activity at 114 ± 0.0008% and 118.24 ± 0.35 and also at 30 and 20 (%) concentrations. Conclusively, the tolerant effect of Bacillus sp. NU2 laccase in pH, temperature, inhibitors and organic solvents suggests its potential for biotechnological application and promotion of a greener environment.
{"title":"Optimisation and physicochemical characterisation of a thermo-alkali stable laccase produced by wastewater associated <i>Bacillus</i> sp. NU2.","authors":"Chiedu E Edoamodu, Uchechukwu U Nwodo","doi":"10.1080/09593330.2023.2253503","DOIUrl":"10.1080/09593330.2023.2253503","url":null,"abstract":"<p><p>Laccase is a multicopper enzyme that plays a unique role in bioremediation of environmental pollutants. Bacteria were isolated from hospital wastewater and screened for laccase production. The laccase production process condition was optimised, and the laccase obtained was characterised. The 16S rRNA molecular analysis conducted on the best laccase producer revealed a <i>Bacillus</i> sp. NU2 identified. The process conditions: pH5, 45°C, 100 rpm, 5% inoculum, and growth constituents v<i>iz:</i> tangerine peel and wheat bran agro-wastes, beef extract, ammonium persulfate, glucose, galactose, xylose, sorbitol, fructose carbon sources; and 4-aminophenol inducer optimally stimulated laccase production. The <i>Bacillus</i> sp. NU2 laccase was optimal at pH and temperature conditions of 8.0°C and 60°C, with a noteworthy pH and thermal stability observed. Furthermore, NU2 laccase showed a moderate/high tolerance and relative activity effect on various chemical inhibitors, halides and surfactant of triton x-100 (105 ± 0.92%), PMSF (107 ± 0.81%), and NaCl (94 ± 0.81%) at 1, 3, and 6 (mM) concentration. Additionally, NU2 laccase maintained a relative activity of 101%, 104%, and 102% for Mg<sup>2+</sup>, Zn<sup>2+</sup>, and Fe<sup>3+</sup> at 1, 3, and 6 mM respectively. Acetone and propanol significantly upregulated laccase activity at 114 ± 0.0008% and 118.24 ± 0.35 and also at 30 and 20 (%) concentrations. Conclusively, the tolerant effect of <i>Bacillus</i> sp. NU2 laccase in pH, temperature, inhibitors and organic solvents suggests its potential for biotechnological application and promotion of a greener environment.</p>","PeriodicalId":12009,"journal":{"name":"Environmental Technology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10134122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nitrate leaching from farmland pollutes the surrounding environment, such as groundwater, causing health hazards to inhabitants. To mitigate the leaching, biochar can be applied. The effect of biochar application differs depending on the application depth; however, the effect of the application depth remains unclear. To evaluate the effect, we conducted a pipe experiment with no plant using bagasse biochar with four treatments: no biochar application, surface application (0-5 cm), plow layer application (0-30 cm), and subsurface application (25-30 cm). The results showed that surface and plow layer applications reduced nitrate leaching, whereas subsurface application did not affect leaching. This difference was due to changes in the soil water movement and water budget. Surface application reduced evaporation, inducing increases in both drainage and the amount of water in the pipe. The increased amount of water might contribute to an increase in the amount of nitrogen in the pipe, reducing the leaching. Plow layer application increased evaporation, leading to decreased drainage and nitrate leaching. Subsurface application did not affect drainage and nitrate leaching; however, the change in the volumetric water content at a depth of 10 cm was the most significant among the treatments. Our study indicated that, although the same amount of biochar was applied, the effect of biochar application differs depending on the application depth.
{"title":"Effects of biochar application depth on nitrate leaching and soil water conditions.","authors":"Kosuke Hamada, Satoshi Nakamura, Takashi Kanda, Minako Takahashi","doi":"10.1080/09593330.2023.2283403","DOIUrl":"10.1080/09593330.2023.2283403","url":null,"abstract":"<p><p>Nitrate leaching from farmland pollutes the surrounding environment, such as groundwater, causing health hazards to inhabitants. To mitigate the leaching, biochar can be applied. The effect of biochar application differs depending on the application depth; however, the effect of the application depth remains unclear. To evaluate the effect, we conducted a pipe experiment with no plant using bagasse biochar with four treatments: no biochar application, surface application (0-5 cm), plow layer application (0-30 cm), and subsurface application (25-30 cm). The results showed that surface and plow layer applications reduced nitrate leaching, whereas subsurface application did not affect leaching. This difference was due to changes in the soil water movement and water budget. Surface application reduced evaporation, inducing increases in both drainage and the amount of water in the pipe. The increased amount of water might contribute to an increase in the amount of nitrogen in the pipe, reducing the leaching. Plow layer application increased evaporation, leading to decreased drainage and nitrate leaching. Subsurface application did not affect drainage and nitrate leaching; however, the change in the volumetric water content at a depth of 10 cm was the most significant among the treatments. Our study indicated that, although the same amount of biochar was applied, the effect of biochar application differs depending on the application depth.</p>","PeriodicalId":12009,"journal":{"name":"Environmental Technology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136396978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-01Epub Date: 2023-11-09DOI: 10.1080/09593330.2023.2250545
Lei Gong, Xiaofan Ma, Shijun Zhang, Chunqian Guo, Jun Zhou, Yuhang Zhao
In this study, Chlorella and Scenedesmus were inoculated in biogas slurry medium with initial inoculum (OD680) of 0.05, 0.1, 0.2, and 0.3, respectively, and 5% CO2 was continuously injected. The study aimed to examine the carbon sequestration capacity of Chlorella and Scenedesmus, as well as the effectiveness of removing pollutants such as TN, TP, and COD in biogas slurry medium. Additionally, an economic efficiency analysis of energy consumption was conducted. The group with an initial inoculum (OD680) of 0.3 for both types of microalgae exhibited better tolerance to pollutants, entered the logarithmic growth stage earlier, promoted nutrient removal, achieved higher energy efficiency, and reduced carbon emissions compared to the other groups. The highest carbon sequestration rates were 18.03% for Chlorella and 11.05% for Scenedesmus. Furthermore, Chlorella demonstrated corresponding nutrient removal efficiencies of 83.03% for TN, 99.84% for TP, and 90.06% for COD, while Scenedesmus exhibited removal efficiencies of 66.35% for TN, 98.74% for TP, and 77.71% for COD. The highest energy efficiency for pollutants and CO2 removal rates for Chlorella were 49.51 ± 2.20 and 9.91 ± 0.44 USD-1, respectively. In conclusion, the findings demonstrate the feasibility of using microalgae for simultaneous purification of biogas and biogas slurry.
{"title":"The effect of initial inoculation amount of microalgae on synergistic purification of biogas slurry.","authors":"Lei Gong, Xiaofan Ma, Shijun Zhang, Chunqian Guo, Jun Zhou, Yuhang Zhao","doi":"10.1080/09593330.2023.2250545","DOIUrl":"10.1080/09593330.2023.2250545","url":null,"abstract":"<p><p>In this study, <i>Chlorella</i> and <i>Scenedesmus</i> were inoculated in biogas slurry medium with initial inoculum (OD<sub>680</sub>) of 0.05, 0.1, 0.2, and 0.3, respectively, and 5% CO<sub>2</sub> was continuously injected. The study aimed to examine the carbon sequestration capacity of <i>Chlorella</i> and <i>Scenedesmus</i>, as well as the effectiveness of removing pollutants such as TN, TP, and COD in biogas slurry medium. Additionally, an economic efficiency analysis of energy consumption was conducted. The group with an initial inoculum (OD<sub>680</sub>) of 0.3 for both types of microalgae exhibited better tolerance to pollutants, entered the logarithmic growth stage earlier, promoted nutrient removal, achieved higher energy efficiency, and reduced carbon emissions compared to the other groups. The highest carbon sequestration rates were 18.03% for <i>Chlorella</i> and 11.05% for <i>Scenedesmus</i>. Furthermore, <i>Chlorella</i> demonstrated corresponding nutrient removal efficiencies of 83.03% for TN, 99.84% for TP, and 90.06% for COD, while <i>Scenedesmus</i> exhibited removal efficiencies of 66.35% for TN, 98.74% for TP, and 77.71% for COD. The highest energy efficiency for pollutants and CO<sub>2</sub> removal rates for <i>Chlorella</i> were 49.51 ± 2.20 and 9.91 ± 0.44 USD<sup>-1</sup>, respectively. In conclusion, the findings demonstrate the feasibility of using microalgae for simultaneous purification of biogas and biogas slurry.</p>","PeriodicalId":12009,"journal":{"name":"Environmental Technology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41126946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-01Epub Date: 2023-08-30DOI: 10.1080/09593330.2023.2251656
Dongmei Wang, Qianxi Chen, Binyu Hui, Kai Yuan, Xianbing Zou, Nan Ma, Zhengjun Gong, Meikun Fan
Proper disinfection treatment is the basic guarantee for safe utilisation of sewage. However, the commonly used disinfection methods are not suitable for nutrients containing reclaimed water. In this work, the microwave disinfection method assisted by a microwave-absorbing material in recycled water samples was investigated. Magnetic corn stalk biochar (MCSB), the microwave absorbing material, was prepared by high temperature carbonisation of corn stalk particles impregnated with ferrous sulfate. Escherichia coli and fecal coliforms were selected as target microorganisms to investigate the disinfection efficiency of MCSB assisted microwave radiation (MW/MCSB). The addition of microwave absorbing materials significantly improves the disinfection effect of water samples. Compared with the microwave radiation (MW) without MCSB, the bactericidal rate by using 107 CFU/L E. coli suspension increased from 63.5% to 100% at 480 W for 30 s after adding 4 g/L MCSB. Besides, the effects of MCSB dosage, microwave power, microwave radiation time, and initial bacterial concentration on disinfection efficiency were explored. Moreover, the bactericidal efficiency for actual sewage samples was also demonstrated by treating the effluent from septic tank sewage. The residual fecal coliforms in treated water samples met China's farmland irrigation water standard (GB 5084-2021). The result indicates that the proposed method of microwave disinfection strengthened by MCSB has a promising application prospect for reclaimed water disinfection.
{"title":"Microwave disinfection strengthened by a biochar-based microwave absorbing material for sewage resource utilization.","authors":"Dongmei Wang, Qianxi Chen, Binyu Hui, Kai Yuan, Xianbing Zou, Nan Ma, Zhengjun Gong, Meikun Fan","doi":"10.1080/09593330.2023.2251656","DOIUrl":"10.1080/09593330.2023.2251656","url":null,"abstract":"<p><p>Proper disinfection treatment is the basic guarantee for safe utilisation of sewage. However, the commonly used disinfection methods are not suitable for nutrients containing reclaimed water. In this work, the microwave disinfection method assisted by a microwave-absorbing material in recycled water samples was investigated. Magnetic corn stalk biochar (MCSB), the microwave absorbing material, was prepared by high temperature carbonisation of corn stalk particles impregnated with ferrous sulfate. <i>Escherichia coli</i> and <i>fecal coliforms</i> were selected as target microorganisms to investigate the disinfection efficiency of MCSB assisted microwave radiation (MW/MCSB). The addition of microwave absorbing materials significantly improves the disinfection effect of water samples. Compared with the microwave radiation (MW) without MCSB, the bactericidal rate by using 10<sup>7</sup> CFU/L <i>E. coli</i> suspension increased from 63.5% to 100% at 480 W for 30 s after adding 4 g/L MCSB. Besides, the effects of MCSB dosage, microwave power, microwave radiation time, and initial bacterial concentration on disinfection efficiency were explored. Moreover, the bactericidal efficiency for actual sewage samples was also demonstrated by treating the effluent from septic tank sewage. The residual <i>fecal coliforms</i> in treated water samples met China's farmland irrigation water standard (GB 5084-2021). The result indicates that the proposed method of microwave disinfection strengthened by MCSB has a promising application prospect for reclaimed water disinfection.</p>","PeriodicalId":12009,"journal":{"name":"Environmental Technology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10157916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nitrospira is a common genus of nitrite-oxidising bacteria (NOB) found in wastewater treatment plants (WWTPs). To identify the key factors influencing the composition of NOB communities, research was conducted using both sequencing batch reactor (SBR) and continuous flow reactor under different conditions. High-throughput 16S rRNA gene sequencing revealed that Nitrospira (18.79% in R1 and 25.77% in R3) was the dominant NOB under low dissolved oxygen (DO) and low nitrite (-N) concentrations, while Nitrobacter (21.26% in R2) was the dominant NOB under high DO and high -N concentrations. Flocculent and granule sludge were cultivated with Nitrospira as the dominant genus. Compared to Nitrospira flocculent sludge, Nitrospira granule sludge had higher inhibition threshold concentrations for free ammonia (FA) and free nitrous acid (FNA). It was more likely to resist adverse environmental disturbances. Furthermore, the effects of environmental factors such as temperature, pH, and DO on the activity of Nitrospira granular sludge were also studied. The results showed that the optimum temperature and pH for Nitrospira granular sludge were 36°C and 7.0, respectively. Additionally, Nitrospira granular sludge showed a higher dissolved oxygen half-saturation constant (Ko) of 3.67 ± 0.71 mg/L due to its morphological characteristics. However, the majority of WWTPs conditions do not meet the conditions for the Nitrospira granular sludge. Thus, it can be speculated that future development of aerobic partial nitrification granular sludge may automatically eliminate the influence of Nitrospira. This study provides a theoretical basis for a deeper understanding of Nitrospira and the development of future water treatment processes.
{"title":"Influencing factors on the activity of an enriched <i>Nitrospira</i> culture with granular morphology.","authors":"Kunming Fu, Yihao Bian, Fan Yang, Minhui Liao, Jian Xu, Fuguo Qiu","doi":"10.1080/09593330.2023.2260122","DOIUrl":"10.1080/09593330.2023.2260122","url":null,"abstract":"<p><p><i>Nitrospira</i> is a common genus of nitrite-oxidising bacteria (NOB) found in wastewater treatment plants (WWTPs). To identify the key factors influencing the composition of NOB communities, research was conducted using both sequencing batch reactor (SBR) and continuous flow reactor under different conditions. High-throughput 16S rRNA gene sequencing revealed that <i>Nitrospira</i> (18.79% in R1 and 25.77% in R3) was the dominant NOB under low dissolved oxygen (DO) and low nitrite (<math><msubsup><mrow><mi>NO</mi></mrow><mn>2</mn><mo>-</mo></msubsup></math>-N) concentrations, while <i>Nitrobacter</i> (21.26% in R2) was the dominant NOB under high DO and high <math><msubsup><mrow><mi>NO</mi></mrow><mn>2</mn><mo>-</mo></msubsup></math>-N concentrations. Flocculent and granule sludge were cultivated with <i>Nitrospira</i> as the dominant genus. Compared to <i>Nitrospira</i> flocculent sludge, <i>Nitrospira</i> granule sludge had higher inhibition threshold concentrations for free ammonia (FA) and free nitrous acid (FNA). It was more likely to resist adverse environmental disturbances. Furthermore, the effects of environmental factors such as temperature, pH, and DO on the activity of <i>Nitrospira</i> granular sludge were also studied. The results showed that the optimum temperature and pH for <i>Nitrospira</i> granular sludge were 36°C and 7.0, respectively. Additionally, <i>Nitrospira</i> granular sludge showed a higher dissolved oxygen half-saturation constant (<i>K</i>o) of 3.67 ± 0.71 mg/L due to its morphological characteristics. However, the majority of WWTPs conditions do not meet the conditions for the <i>Nitrospira</i> granular sludge. Thus, it can be speculated that future development of aerobic partial nitrification granular sludge may automatically eliminate the influence of <i>Nitrospira</i>. This study provides a theoretical basis for a deeper understanding of <i>Nitrospira</i> and the development of future water treatment processes.</p>","PeriodicalId":12009,"journal":{"name":"Environmental Technology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10247144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-01Epub Date: 2024-02-26DOI: 10.1080/09593330.2023.2283085
Zhenyu Shen, Zhexin Zhu, Gangqiang Wang, Yongquan Miao, Wangyang Lu
In this study, the porous graphite phase carbon nitride photocatalyst (P-g-C3N4) is prepared by the CaCO3 template method, and then P-g-C3N4/T-polyethylene terephthalate (T-PET) catalytic fibre is prepared by the padding method. P-g-C3N4 can provide more active sites than g-C3N4 as proved by the Brunauer-Emmett-Teller and the UV-Visible diffuse reflectance test. P-g-C3N4 powder catalyst successfully supports PET fibre as proved by scanning electron microscope, Fourier infrared spectroscopy and X-ray diffraction spectroscopy. The photocatalytic performance of P-g-C3N4/T-PET catalytic fibre is tested by constructing a single hexavalent chromium or hexavalent chromium/organic pollutant binary pollution system. The potential application value of P-g-C3N4/T-PET catalytic fibre is further explored by simulating the complex actual water environment. After five recycles, P-g-C3N4/T-PET catalytic fibre shows good catalytic performance. The mechanism of P-g-C3N4/PET photocatalytic degradation of organic pollutants is proposed through the capture agent experiment and electron paramagnetic resonance spectroscopy. Among them, •O2- is the most important active species of P-g-C3N4 catalytic fibre, which is used for the oxidation of organic pollutants. At the same time, photoelectrons generated by the catalytic fibre are used to reduce hexavalent chromium. The efficiency of P-g-C3N4 to remove pollutants is improved by using PET fibre as a carrier, which not only solves the problem of difficult recovery of powder catalysts but also provides more active sites.
本研究采用CaCO3模板法制备多孔石墨相氮化碳光催化剂(P-g-C3N4),然后采用填充法制备P-g-C3N4/ t -聚对苯二甲酸乙二醇酯(T-PET)催化纤维。brunauer - emmet - teller (BET)和uv -可见光漫反射试验证明P-g-C3N4能提供比g-C3N4更多的活性位点。P-g-C3N4粉末催化剂成功负载在PET纤维上,并通过扫描电镜、傅里叶红外光谱和x射线衍射光谱进行了验证。通过构建单六价铬或六价铬/有机污染物二元污染体系来测试P-g-C3N4/T-PET催化纤维的光催化性能。通过模拟复杂的实际水环境,进一步探索P-g-C3N4/T-PET催化纤维的潜在应用价值。经过5次循环使用,P-g-C3N4/T-PET催化纤维也具有良好的催化性能。通过捕集剂实验和电子顺磁共振波谱分析,提出了P-g-C3N4/PET光催化降解有机污染物的机理。其中,•O2-是P-g-C3N4催化纤维中最重要的活性物质,用于氧化有机污染物。同时,利用催化纤维产生的光电子还原六价铬。采用PET纤维作为载体,提高了P-g-C3N4对污染物的去除效率,不仅解决了粉末催化剂难以回收的问题,而且提供了更多的活性位点。
{"title":"Porous organic semiconductor/PET composite fibre for the synergistic removal of hexavalent chromium and organic pollutants under sunlight.","authors":"Zhenyu Shen, Zhexin Zhu, Gangqiang Wang, Yongquan Miao, Wangyang Lu","doi":"10.1080/09593330.2023.2283085","DOIUrl":"10.1080/09593330.2023.2283085","url":null,"abstract":"<p><p>In this study, the porous graphite phase carbon nitride photocatalyst (P-g-C<sub>3</sub>N<sub>4</sub>) is prepared by the CaCO<sub>3</sub> template method, and then P-g-C<sub>3</sub>N<sub>4</sub>/T-polyethylene terephthalate (T-PET) catalytic fibre is prepared by the padding method. P-g-C<sub>3</sub>N<sub>4</sub> can provide more active sites than g-C<sub>3</sub>N<sub>4</sub> as proved by the Brunauer-Emmett-Teller and the UV-Visible diffuse reflectance test. P-g-C<sub>3</sub>N<sub>4</sub> powder catalyst successfully supports PET fibre as proved by scanning electron microscope, Fourier infrared spectroscopy and X-ray diffraction spectroscopy. The photocatalytic performance of P-g-C<sub>3</sub>N<sub>4</sub>/T-PET catalytic fibre is tested by constructing a single hexavalent chromium or hexavalent chromium/organic pollutant binary pollution system. The potential application value of P-g-C<sub>3</sub>N<sub>4</sub>/T-PET catalytic fibre is further explored by simulating the complex actual water environment. After five recycles, P-g-C<sub>3</sub>N<sub>4</sub>/T-PET catalytic fibre shows good catalytic performance. The mechanism of P-g-C<sub>3</sub>N<sub>4</sub>/PET photocatalytic degradation of organic pollutants is proposed through the capture agent experiment and electron paramagnetic resonance spectroscopy. Among them, •O<sub>2</sub><sup>-</sup> is the most important active species of P-g-C<sub>3</sub>N<sub>4</sub> catalytic fibre, which is used for the oxidation of organic pollutants. At the same time, photoelectrons generated by the catalytic fibre are used to reduce hexavalent chromium. The efficiency of P-g-C<sub>3</sub>N<sub>4</sub> to remove pollutants is improved by using PET fibre as a carrier, which not only solves the problem of difficult recovery of powder catalysts but also provides more active sites.</p>","PeriodicalId":12009,"journal":{"name":"Environmental Technology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138458774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Antibiotic contamination from hospitals, animal husbandry, and municipal wastewater is graver than imagined, and it possess serious risks to the health of humans and animals, with the emergence of multidrug resistant bacteria; those affect the growth of higher plants too. Conventional wastewater treatment methods adopted today are inadequate for removing antibiotics from wastewater. Intuitively, the remediation process using mixed algae should be effective enough, for which algae-based remediation technologies have emerged as sustainable remedial methods. This review summarized the detection of antibiotics in field water in most countries; a comprehensive overview of algae-based technologies, algal adsorption, accumulation, biodegradation, photodegradation, hydrolysis, and the use of algae-bacteria consortia for the remediation of antibiotics in wastewaters in done. Green algae namely, Chlamydomonas sp., Chlorella sp., C. vulgaris, Spyrogira sp. Scenedesmus quadricauda, S. obliquus, S. dimorphus, Haematoccus pluvialis, and Nannochlopsis sp., had been reporting have 90-100% antibiotic removal efficiency. The integration of bioelectrochemical systems and genetically engineered prokaryotic algal species offer promising avenues for improving antibiotic removal in the future. Overall, this review highlights the need for tenacious research and development of algae-based technologies to reduce antibiotic contamination in aquatic environments, for holistic good.
{"title":"Recent advancements on antibiotic bioremediation in wastewaters with a focus on algae: an overview.","authors":"Shuvasree Bej, Surendra Swain, Ajit Kumar Bishoyi, Chinmayee Priyadarsani Mandhata, Chita Ranjan Sahoo, Rabindra Nath Padhy","doi":"10.1080/09593330.2023.2245166","DOIUrl":"10.1080/09593330.2023.2245166","url":null,"abstract":"<p><p>Antibiotic contamination from hospitals, animal husbandry, and municipal wastewater is graver than imagined, and it possess serious risks to the health of humans and animals, with the emergence of multidrug resistant bacteria; those affect the growth of higher plants too. Conventional wastewater treatment methods adopted today are inadequate for removing antibiotics from wastewater. Intuitively, the remediation process using mixed algae should be effective enough, for which algae-based remediation technologies have emerged as sustainable remedial methods. This review summarized the detection of antibiotics in field water in most countries; a comprehensive overview of algae-based technologies, algal adsorption, accumulation, biodegradation, photodegradation, hydrolysis, and the use of algae-bacteria consortia for the remediation of antibiotics in wastewaters in done. Green algae namely, <i>Chlamydomonas</i> sp<i>., Chlorella</i> sp<i>., C. vulgaris, Spyrogira</i> sp. <i>Scenedesmus quadricauda, S. obliquus, S. dimorphus, Haematoccus pluvialis,</i> and <i>Nannochlopsis</i> sp., had been reporting have 90-100% antibiotic removal efficiency. The integration of bioelectrochemical systems and genetically engineered prokaryotic algal species offer promising avenues for improving antibiotic removal in the future. Overall, this review highlights the need for tenacious research and development of algae-based technologies to reduce antibiotic contamination in aquatic environments, for holistic good.</p>","PeriodicalId":12009,"journal":{"name":"Environmental Technology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10046259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To improve the homogeneity of heating, the magnetic absorbing material Fe3O4 is considered to use in microwave pyrolysis of oily sludge. Therefore, the effect of Fe3O4 on the microwave pyrolysis of oily sludge is investigated based on gas volatile products. Thermogravimetric mass spectrometry result certifies that Fe3O4 will increase the weight-loss ratio from 13.0% to 14.1%. Also, the characteristic peak intensity of CO in gas products decreases from 5.41 × 10-10 A/g to 1.95 × 10-10 A/g, while H2O increases from 3.57 × 10-10 A/g to 7.32 × 10-10 A/g and CO2 increases from 6.87 × 10-10 A/g to 8.92 × 10-10 A/g. This is caused by the esterification of alcohols and esters and the reduction of Fe3O4 by CO. Based on the decrease in activation energy and enthalpy values of Stage II and IV, it infers that Fe3O4 catalyzes the pyrolysis process of oily sludge to some extent. Similarly, gas chromatography-mass spectrometry results show that Fe3O4 can make the types of gas products increase. Especially, the number of molecular species increases from 5 to 46 under 200-300 °C. Finally, a simple molecular dynamics simulation model is conducted, and the results are in agreement with the experimental results. This study shows that Fe3O4 improves the pyrolysis homogeneity and the pyrolysis efficiency also improves.
{"title":"Homogenizing microwave pyrolysis of oily sludge using nano-Fe<sub>3</sub>O<sub>4</sub>: volatile gas product analysis.","authors":"Jing Yan, Zhiguo Shao, Wencai Cheng, Shipei Xu, Qian Wen, Zhicheng He, Dujiang Liu, Jiangbo Li, Xirui Lu","doi":"10.1080/09593330.2023.2283057","DOIUrl":"10.1080/09593330.2023.2283057","url":null,"abstract":"<p><p>To improve the homogeneity of heating, the magnetic absorbing material Fe<sub>3</sub>O<sub>4</sub> is considered to use in microwave pyrolysis of oily sludge. Therefore, the effect of Fe<sub>3</sub>O<sub>4</sub> on the microwave pyrolysis of oily sludge is investigated based on gas volatile products. Thermogravimetric mass spectrometry result certifies that Fe<sub>3</sub>O<sub>4</sub> will increase the weight-loss ratio from 13.0% to 14.1%. Also, the characteristic peak intensity of CO in gas products decreases from 5.41 × 10<sup>-10</sup> A/g to 1.95 × 10<sup>-10</sup> A/g, while H<sub>2</sub>O increases from 3.57 × 10<sup>-10</sup> A/g to 7.32 × 10<sup>-10</sup> A/g and CO<sub>2</sub> increases from 6.87 × 10<sup>-10</sup> A/g to 8.92 × 10<sup>-10</sup> A/g. This is caused by the esterification of alcohols and esters and the reduction of Fe<sub>3</sub>O<sub>4</sub> by CO. Based on the decrease in activation energy and enthalpy values of Stage II and IV, it infers that Fe<sub>3</sub>O<sub>4</sub> catalyzes the pyrolysis process of oily sludge to some extent. Similarly, gas chromatography-mass spectrometry results show that Fe<sub>3</sub>O<sub>4</sub> can make the types of gas products increase. Especially, the number of molecular species increases from 5 to 46 under 200-300 °C. Finally, a simple molecular dynamics simulation model is conducted, and the results are in agreement with the experimental results. This study shows that Fe<sub>3</sub>O<sub>4</sub> improves the pyrolysis homogeneity and the pyrolysis efficiency also improves.</p>","PeriodicalId":12009,"journal":{"name":"Environmental Technology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72014005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Polyhydroxyalkanoates(PHAs) are considered a good alternative to petroleum-based plastics because of their good biodegradability and biocompatibility. The synthesis of PHAs using activated sludge can not only solve the problem of the high cost of pure cultures but also improve the utilization value of activated sludge. In this study, sludge activity recovery experiments were firstly conducted and the effects of different initial sludge concentrations on the activated sludge PHAs synthesis system were further investigated. the initial sludge concentrations were 1#SBR (2800 ± 50) mg/L, 2#SBR (4200 ± 50) mg/L, and 3#SBR (5500 ± 50) mg/L. The results showed that the activity, sedimentation performance and PHAs synthesis capacity of activated sludge were enhanced after the sludge activity recovery experiment. At the initial sludge concentration of 4200 mg/L, the activated sludge PHAs synthesis system was operated stably and the synthesis efficiency of PHAs was enhanced. In contrast, at the initial sludge concentration of 2800 and 5500 mg/L, the steady state of the activated sludge PHAs synthesis system was damaged to different degrees at different times, and the synthesis efficiency of PHAs was greatly reduced.
{"title":"Optimization of activated sludge polyhydroxyalkanoates(PHAs) synthesis system by performing sludge activity recovery experiments and varying the initial sludge concentration.","authors":"Ruoyu Shen, Qian Fang, Kequan Zhang, Yanyu Xiao, Meiying Cheng, Bowen Xiong, Wuyang Zhou","doi":"10.1080/09593330.2023.2283059","DOIUrl":"10.1080/09593330.2023.2283059","url":null,"abstract":"<p><p>Polyhydroxyalkanoates(PHAs) are considered a good alternative to petroleum-based plastics because of their good biodegradability and biocompatibility. The synthesis of PHAs using activated sludge can not only solve the problem of the high cost of pure cultures but also improve the utilization value of activated sludge. In this study, sludge activity recovery experiments were firstly conducted and the effects of different initial sludge concentrations on the activated sludge PHAs synthesis system were further investigated. the initial sludge concentrations were 1#SBR (2800 ± 50) mg/L, 2#SBR (4200 ± 50) mg/L, and 3#SBR (5500 ± 50) mg/L. The results showed that the activity, sedimentation performance and PHAs synthesis capacity of activated sludge were enhanced after the sludge activity recovery experiment. At the initial sludge concentration of 4200 mg/L, the activated sludge PHAs synthesis system was operated stably and the synthesis efficiency of PHAs was enhanced. In contrast, at the initial sludge concentration of 2800 and 5500 mg/L, the steady state of the activated sludge PHAs synthesis system was damaged to different degrees at different times, and the synthesis efficiency of PHAs was greatly reduced.</p>","PeriodicalId":12009,"journal":{"name":"Environmental Technology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136396981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-01Epub Date: 2023-09-04DOI: 10.1080/09593330.2023.2252607
Nicola Brown, Matthew Sells, Nihal Jayamaha, Andrew Shilton
Algal-based waste stabilisation ponds (WSP) are a common wastewater treatment system for small communities but have poor phosphorus removal. Under certain conditions algae in WSPs will perform 'luxury uptake' increasing their phosphorus content to over 3% (gP/gSS) by storing polyphosphate. For the first time in the literature this paper presents a systematic study which determines the conditions needed to maximise phosphorus accumulation within WSP biomass taking into account the interactions between key variables. The key variables of temperature, phosphorus concentration, light intensity, mixing intensity, organic load, and pH were evaluated in 40 batch factorial experiments using a WSP algal culture. All six variables examined had significant main effects or interactions on the phosphorus content of the biomass. These were incorporated into a regression equation which was successfully validated against independent data sets from the literature. The conditions required to maximise the phosphorus content of the biomass were predicted for both summer (high light and high temperature) and winter (low light and low temperature) scenarios. The required conditions were revealed to be high phosphorus concentration, high mixing intensity, no supplementary CO2 addition, and low organic load. Interestingly, these conditions were consistent for both summer and winter suggesting that year-round treatment is possible. Practical methods of achieving these conditions were proposed. While further work will be needed to evaluate the effect of growth and potential influence of algal species, the findings presented provide a vital step towards developing a new phosphorus removal treatment process based on an enhanced understanding of environmental biotechnology.
{"title":"Predicting phosphorus accumulation and proposing conditions needed for an algal-based phosphorus uptake process.","authors":"Nicola Brown, Matthew Sells, Nihal Jayamaha, Andrew Shilton","doi":"10.1080/09593330.2023.2252607","DOIUrl":"10.1080/09593330.2023.2252607","url":null,"abstract":"<p><p>Algal-based waste stabilisation ponds (WSP) are a common wastewater treatment system for small communities but have poor phosphorus removal. Under certain conditions algae in WSPs will perform 'luxury uptake' increasing their phosphorus content to over 3% (gP/gSS) by storing polyphosphate. For the first time in the literature this paper presents a systematic study which determines the conditions needed to maximise phosphorus accumulation within WSP biomass taking into account the interactions between key variables. The key variables of temperature, phosphorus concentration, light intensity, mixing intensity, organic load, and pH were evaluated in 40 batch factorial experiments using a WSP algal culture. All six variables examined had significant main effects or interactions on the phosphorus content of the biomass. These were incorporated into a regression equation which was successfully validated against independent data sets from the literature. The conditions required to maximise the phosphorus content of the biomass were predicted for both summer (high light and high temperature) and winter (low light and low temperature) scenarios. The required conditions were revealed to be high phosphorus concentration, high mixing intensity, no supplementary CO<sub>2</sub> addition, and low organic load. Interestingly, these conditions were consistent for both summer and winter suggesting that year-round treatment is possible. Practical methods of achieving these conditions were proposed. While further work will be needed to evaluate the effect of growth and potential influence of algal species, the findings presented provide a vital step towards developing a new phosphorus removal treatment process based on an enhanced understanding of environmental biotechnology.</p>","PeriodicalId":12009,"journal":{"name":"Environmental Technology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10498704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}