作者机构：
[Li, Zhi; Zhu, Mingshan; Zhou, Daixi] Jinan Univ, Sch Environm, Guangdong Key Lab Environm Pollut & Hlth, Guangzhou 511443, Peoples R China.;[Hu, Xinjiang] Cent South Univ Forestry & Technol, Coll Environm Sci & Engn, Changsha 410004, Peoples R China.;[Chen, Li] Chinese Peoples Liberat Army Gen Hosp, Med Ctr 1, Dept Gen Practice, Beijing 100853, Peoples R China.
通讯机构：
[Chen, L ] C;[Zhu, MS ] J;Jinan Univ, Sch Environm, Guangdong Key Lab Environm Pollut & Hlth, Guangzhou 511443, Peoples R China.;Chinese Peoples Liberat Army Gen Hosp, Med Ctr 1, Dept Gen Practice, Beijing 100853, Peoples R China.
关键词：
advanced oxidation process;persulfate;reactive oxygen species;single atom catalysts;substance
摘要：
In this review, SACs with different metal species and substrates are summarized to investigate the metal−support interaction effects on the persulfate oxidation reaction for water treatments. Abstract With maximum utilization of active metal sites, more and more researchers have reported using single atom catalysts (SACs) to activate persulfate (PS) for organic pollutants removal. In SACs, single metal atoms (Fe, Co, Cu, Mn, etc.) and different substrates (porous carbon, biochar, graphene oxide, carbon nitride, MOF, MoS2, and others) are the basic structural. Metal single atoms, substances, and connected chemical bonds all have a great influence on the electronic structures that directly affect the activation process of PS and degradation efficiency to organic pollutants. However, there are few relevant reviews about the interaction between metal single atoms and substances during PS activation process. In this review, the SACs with different metal species and substrates are summarized to investigate the metal−support interaction and evaluate their effects on PS oxidation reaction process. Furthermore, how metal atoms and substrates affect the reactive species and degradation pathways are also discussed. Finally, the challenges and prospects of SACs in PS‐AOPs are proposed.
摘要：
Improving the adsorption performance of wetland fillers is of great significance for enhancing pollutant removal in constructed wetlands. Currently, limited by complex preparation processes and high costs, large numbers of high adsorption fillers studied in lab are difficult to be applied in practical engineering. In this study, a newly low-cost and efficient phosphorus removal composite wetland filler (CFB) is prepared by using industrial and agriculture waste (steel slag and oyster shells) and natural ore (volcanic rock) as raw materials. The results show that phosphorus removal efficiency was largely enhanced by synergistic effects of steel slag, oyster shells, and volcanic rock, and it was mainly influenced by the proportion of each component of CFB. Based on the fitting of the classical isothermal equation, the adsorption capacity of CFB is 18.339 mg/g. The adsorption of phosphorus by CFB is endothermic and spontaneous, and there are heterogeneous surfaces and multi-layer adsorption processes, as well as pH value and temperature, are free from the influence on CFB phosphorus removal. During the practical wastewater application experiments, the phosphorus removal rate of the CFB-filled constructed wetland apparatus (CW-A) can reach 94.89% and is free from the influence on the removal of other pollutants (COD, TN, and NH(3)-N) by the system. Overall, the prepared CFB is of excellent decontamination effect, an extremely simple preparation process, low cost, and sound practical engineering application potential, providing new ideas and approaches for enhancing the phosphorus removal capacity and waste resource utilization of constructed wetland systems.
期刊：
Science of The Total Environment,2024年922:171245 ISSN：0048-9697
通讯作者：
Hang Zhou
作者机构：
[Liao, Bohan; Zeng, Peng; Liao, Ye; Liu, Jiawei; Gu, Jiaofeng; Ni, Li; Zhou, Hang] College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China;[Zeng, Peng] Hunan Engineering and Technology Research Center for Soil Pollution Remediation and Carbon Sequestration, Changsha 410004, China. Electronic address: zengzengpp@foxmail.com;[Zhou, Hang] Hunan Engineering and Technology Research Center for Soil Pollution Remediation and Carbon Sequestration, Changsha 410004, China. Electronic address: zhouhang4607@163.com;[Wang, Yun] College of Life and Environmental Science, Hunan University of Arts and Science, Changde 415000, China;[Liao, Bohan; Gu, Jiaofeng] Hunan Engineering and Technology Research Center for Soil Pollution Remediation and Carbon Sequestration, Changsha 410004, China
通讯机构：
[Hang Zhou] C;College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China<&wdkj&>Hunan Engineering and Technology Research Center for Soil Pollution Remediation and Carbon Sequestration, Changsha 410004, China
关键词：
Cd and As pollution soil;Compound passivator coupled with foliar spraying and soil applying Si fertilizer;Health risk evaluation;Rice
摘要：
Cadmium (Cd) and arsenic (As) are precedence-controlled contaminants in paddy soils, that can easily accumulate in rice grains. Limestone and sepiolite (LS) compound passivator can obviously reduce Cd uptake in rice, whereas Si fertilizer can effectively decrease rice As uptake. Here, the synergistic effects of the LS compound passivator coupled with Si fertilizer (LSCS) on the soil pH and availability of Si, Cd, and As, as well as rice grain Cd and As accumulation and its health risk were studied based on a 3-year consecutive field experiment. The results showed that the LSCS performed the best in terms of synchronously decreasing soil Cd and As availability and rice Cd and As uptake. In the LSCS treatments, soil pH gradually decreased with the rice-planting season, while soil available Cd and As contents gradually increased, suggesting that the influence of LSCS on Cd and As availability gradually weakened with rice cultivation. Nonetheless, the contents of Cd and inorganic As (i-As) in rice grains treated with LSCS were slightly affected by cultivation but were significantly lower than the single treatments of LS compound passivator or Si fertilizer. According to the Cd and As limit standards in food (GB2762-2022), the Cd and i-As content in rice grains can be lowered below the standard by using the 4500kg/hm(2) LS compound passivator coupled with 90kg/hm(2) Si fertilizer in soil and spraying 0.4g/L Si fertilizer on rice leaves for at least three years. Furthermore, health risk evaluation revealed that LSCS treatments significantly reduced the estimated daily intake, annual excess lifetime cancer risk, and hazard quotient of Cd and i-As in rice grains. These findings suggest that LSCS could be a viable approach for reducing Cd and As accumulation in rice grains and lowering the potential health risks associated with rice.
摘要：
Antimicrobial resistance is a global health security issue of widespread concern. Recent studies have unveiled the potential contribution of non-antibiotics to the emergence of antimicrobial resistance. This study investigated the effect of carbamazepine, a non-antibiotic pharmaceutical, on the fate of antibiotic resistance genes (ARGs) during anaerobic digestion. The results, as revealed by both metagenomic sequencing and absolute quantification, demonstrated that carbamazepine induced the enrichment of ARGs and increased the abundance of ARGs hosts by 1.2-2.1 times. Carbamazepine facilitated microbial aggregation and intercellular communication by upregulating functional genes associated with two-component systems, quorum sensing and type IV secretion systems, thereby increasing the frequency of ARGs conjugation. Furthermore, carbamazepine induced the acquisition of ARGs by pathogens and elevated the overall pathogenic abundance. This study revealed the mechanisms of microbial self-regulation and ARGs transmission under carbamazepine stress, highlighting the potential health risks posed by non-antibiotic pharmaceuticals during the safe disposal of sludge.
摘要：
Bacteria colonized on solid electrode developing electroactive biofilm (EAB) has been shown to promote the contaminants biodegradation. Regulating electrode potential can improve the stability of extracellular electron transfer (EET), but how the electrode potential regulating the extracellular polymer secretion and the tetracycline (TC) removal has not been fully studied. Here, EAB cultured at 0 V was used to study the degradation mechanism of TC at different electrode potentials. Results showed that −0.1 V was the optimized electrode potential for TC biodegradation compared with 0.1 V, 0 V and −0.3 V, which was 28 % higher than that without electric field. Stimulation of electric field can retain proper extracellular polymer (EPS) to relieve the poison of TC, while excessive extracellular polysaccharide (PS) at 0 V have hindered the contact between microorganisms and TC, thus limited electron transfer and reduced the TC biodegradation efficiency. Excessively negative potential (−0.3 V) will restrict the electron transfer which was not conducive to the biodegradation of organic pollutants. Microbial community analysis revealed that TC addition have refreshed the EAB structure, Dokdonella and Norank_f_Rikenellaceae replaced Geobacter as the dominant species in EAB to promote TC biodegradation. The variation of metabolic pathway was suggested that the up-regulation of pyruvate metabolism and ubiquinone synthesis at −0.1 V have promoted the TC removal. This study has provided theoretical support for the electrode potential regulating the extracellular polymer secretion and promoting the pollution bioremediation.
摘要：
Metal-based materials are widely regarded as promising catalysts for activating peroxymonosulfate (PMS) to remove refractory organic contaminants with high efficiency. In our study, Ni-Fe layered double hydroxide (LDH)-biochar (BC) composite-induced PMS-based advanced oxidation process (AOP) was utilized to elucidate the degradation of tetracycline hydrochloride (TCH). In Ni-Fe LDH-BC/PMS system, more than 99% TCH (45 mu M) could be removed effectively at low doses of oxidant (PMS, 0.10 mM) and catalyst (Ni-Fe LDH-BC, 0.10 g/L) addition within 80 min. Besides, the Ni-Fe LDH-BC/PMS system showed high resistance to some inorganic anions, and the Ni-Fe LDH-BC composite possessed excellent reusability in the degradation of TCH (>99% in four cyclic experiments). The reaction mechanisms were investigated via electron paramagnetic resonance detection, chemical quenching tests, probe experiments, and electrochemical measurements. These results indicated that the electron-shuttle mechanism played the dominant role in the removal of TCH. It is worth noting that determination of PMS concentration can reflect the reliability of quenching experiments. In the Ni-Fe LDH-BC composite, BC could not only improve the dispersion of Ni-Fe LDH, but also increase the conductivity of Ni-Fe LDH. Overall, a successful modification strategy was proposed in our study to improve the catalytic property of Ni-Fe LDH, and reaction mechanisms of TCH degradation were discussed deeply and comprehensively.
摘要：
Single-atom catalysts have wide application prospects in peroxydisulfate (PDS)-based advanced oxidation process to degrade organic pollutants, but its catalytic performance is limited due to its cost, Metal-N coordination number, and single-atom loading amount. Herein, a novel nitrogen doped algal-based carbon confined singleatom copper catalyst (Cu-N/C-SAC((S))) was synthesized using molten salt assisted pyrolysis and coupling with PDS to degrade tetracycline (TC). AC-HAADF-STEM and XAFS analysis proved that single atom Cu was loaded (Content 1.9 %) successfully and coordinated with two N and two C. XPS and XANES spectra analysis suggested that Cu atoms mainly existed in a positive divalent state in Cu-N/C-SAC(S). When the catalyst dosage of Cu-N/CSAC((S)) was 0.1 g/L, TC was almost completely removed. Moreover, Cu-N/C-SAC(S) had a broad pH adaptation range and strong ability against interference. Singlet oxygen (O-1(2)), superoxide radicals (center dot O-2(-)), and electron transfer had an important contribution for TC removal. DFT calculations confirmed that the activation process of Cu-N/C-SAC((S)) producing SO4 center dot- was easier than the nitrogen doped blue-green algal-based carbon (N-BGAC). In addition, Cu-N/C-SAC((S)) possessed good recyclability and stability. The main degradation pathways of TC were analyzed, and the toxicity of the intermediates was calculated. This study provides a new solution strategy for the resource utilization of waste biomass, and provides technical support and theoretical guidance for the efficient application of single-atom catalysts in organic wastewater.
作者机构：
[Yufei Wu; Kelin Li; Xiaohua Fu] College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha, Hunan, 410004, China
通讯机构：
[Yufei Wu] C;College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha, Hunan, 410004, China
关键词：
Data envelopment analysis;Zero-sum game;Quality function deployment;Carbon emissions;Carbon reduction;Allowance allocation
摘要：
As the global economic environment changes, the concept of green and sustainable development has become the international community’s consensus. As a participant in the worldwide emission reduction plan, China is also under great pressure to reduce carbon emissions. As an example, this study constructs an optimal scheme for regional carbon emission allowance allocation in Hunan Province, China. We first forecast the total carbon emissions in 2030 for each city, state, and major industry in Hunan Province through a scenario and then innovatively use the mass function allocation theory in marketing to sort out the logical ideas of the optimization model. More importantly, we combine the zero-sum game theory to build the zero-sum game-data envelopment analysis model to continuously reallocate the carbon emission allowances of each city and state and major industries in Hunan Province until the optimal allocation scheme is reached. From the perspective of each city and state, the initial carbon emission efficiency level of fourteen cities in Hunan is high, but there are still some differences. From the perspective of industries, the initial efficiency of carbon emission of six major industries in Hunan is lower, and the difference in efficiency values is evident.
摘要：
It is important to reduce Cd and As content in brown rice in contaminated paddy soils. We conducted research on the effects of rice husk ash (RHA) on the Cd and As in the rhizosphere microenvironment (soil, porewater, and iron plaque) and measured the Cd, As, and Si content in rice plants. The main elements in RHA were Si (29.64%) and O (69.17%), which had the maximum adsorption capacity for Cd was 42.49 mg/kg and for As was 18.62 mg/kg. Soil pH and available Si content increased, while soil available Cd and As decreased following application of 0.5%-2% RHA. RHA promote the transformation of Cd to insoluble fraction, while As was transformed from a poorly soluble form to a more active one. RHA reduced Cd content and increased Si content in porewater, and reduced As only at the later rice growth stages. RHA increased the amount of iron plaque, thereby decreasing the Cd content in iron plaque, while increased the As content in it. Cd and inorganic As content in brown rice were decreased, to 0.31 mg/kg and 0.18 mg/kg, respectively. The decrease of Cd in brown rice was due to the decrease of Cd mobility in soil, thereby reducing root accumulation, while the decrease of As in brown rice was affected by the transport from roots to stems. Therefore, RHA can be considered as a safe and efficient in-situ remediation amendment for Cd and As co-contaminated paddy soil.(c) 2023 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V.
期刊：
Science of The Total Environment,2024年906:167219 ISSN：0048-9697
通讯作者：
Wang, Ping;Zhu, J
作者机构：
[Zhou, Tao; Sun, Jikang; Xing, Qinqin] Cent South Univ Forestry & Technol, Coll Life Sci & Technol, 498 South Shaoshan Rd, Changsha 410004, Hunan, Peoples R China.;[Wang, Ping; Zhu, Jian; Zhu, J] Cent South Univ Forestry & Technol, Coll Environm Sci & Engn, 498 South Shaoshan Rd, Changsha 410004, Peoples R China.;[Liu, Zhiming] Eastern New Mexico Univ, Dept Biol, Portales, NM 88130 USA.
通讯机构：
[Wang, P; Zhu, J ] C;Cent South Univ Forestry & Technol, Coll Environm Sci & Engn, 498 South Shaoshan Rd, Changsha 410004, Peoples R China.
关键词：
Cd stress;Koelreuteria paniculata;KpMIPS;Resistance
摘要：
Cadmium (Cd) pollution in soil is an important factor endangering plant growth and harming human health through food chains. Koelreuteria paniculata is an important woody plant for ecological restoration of Cd-contaminated soils. In this study, KpMIPS gene of K. paniculata was cloned, and the expressed protein (60kDa) had 1-phosphate synthase activity. The results showed that KpMIPS significantly promoted root development of K. paniculata and Arabidopsis thaliana, reduced damage to the roots of Arabidopsis thaliana caused by Cd, and decreased transfer of Cd to the aboveground parts of K. paniculata and Arabidopsis thaliana . In the K. paniculata plants overexpressing KpMIPS integrity of the root cells was maintained and the content of pectin and phytic acid was significantly increased. Overexpression of KpMIPS increased the Cd accumulation in the roots and decreased the Cd content in the stems and leaves. Clearly, KpMIPS could regulate the contents of pectin and phytic acid in K. paniculata, thereby passivating Cd(2+) and enriching it in the root cell wall, reducing the transfer of free Cd(2+) to other parts of K. paniculata, and providing a positive regulatory effect on the Cd resistance of K. paniculata. The results of the study provide a technical introduction for the selection and genetic improvement of target genes regulating heavy metal resistance of plants in phytoremediation technology.
期刊：
Separation and Purification Technology,2024年341:126909 ISSN：1383-5866
通讯作者：
Huang, Chao;Wang, P
作者机构：
[Wang, Ping; Wei, Jie; Huang, Chao; Wu, Qingyu; Tian, Haoran; Wu, Qiuju; Xu, Haiyin; Sun, Chengyou] Cent South Univ Forestry & Technol, Coll Environm Sci & Engn, Changsha 410004, Peoples R China.;[Zhang, Ruimei] Cent South Univ Forestry & Technol, Coll Sci, Changsha 410004, Peoples R China.;[Liu, Zhiming] Eastern New Mexico Univ, Dept Biol, Portales, NM 88130 USA.
通讯机构：
[Wang, P ; Huang, C] C;Cent South Univ Forestry & Technol, Coll Environm Sci & Engn, Changsha 410004, Peoples R China.
关键词：
Cr(VI);Carbon nanotubes;Nano zero-valent iron (nZVI);Shewanella oneidenis MR-1;Electron transfer
摘要：
Nano zero-valent iron (nZVI) has been widely employed for the elimination of heavy metals from wastewater. However, the practical application of nZVI is greatly limited due to its fast aggregation and surface passivation. In this study, a carbon nanotube-supported nZVI composite (nZVI@CNTs) was synthesized and coupled with Shewanella oneidensis MR -1 to enhance the removal of Cr(VI) from aqueous media. The results demonstrated that the coupling of nZVI@CNTs and MR -1 (nZVI@CNTs/MR-1) exhibited superior performance in eliminating Cr(VI) compared to using nZVI@CNTs or MR -1 alone. Electrochemical characterization demonstrated that CNTs acting as electron shuttles improve the electron transfer from MR -1 to nZVI, thus facilitating the passivation layer dissolution. XRD analysis proved that MR -1 can effectively promote the dissolution of the Fe(III) passivation layer with the existence of CNTs. FTIR and XPS analyses confirmed that CNTs contain many functional groups (such as C - C and C = O) related to extracellular electron transfer, thus promoting the electron transfer of MR -1 to nZVI. Three-dimensional excitation -emission matrix (3D-EEM) analysis showed that the extracellular polymeric substances (EPS) generated from MR -1 participated in the Cr(VI) elimination. The mechanism analysis demonstrated the Fe(II) dissolved from the nZVI passivation layer reduces Cr(VI) to Cr(III) and then removes it by co -precipitation, and the EPS secreted by MR -1 also participates in the Cr(VI) adsorption and reduction. Generally, the coupling of nZVI@CNTs and MR -1 successfully addresses the drawbacks of nZVI and demonstrates a remarkable ability to remove Cr(VI).
作者机构：
[Liu, Zili; Hu, Xinjiang; Tian, Haoran; Xu, Haiyin; Sun, Chengyou; Zhu, Jian] College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China;[Huang, Chao] College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China. Electronic address: huangchao@csuft.edu.cn;[Wang, Ping] College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China. Electronic address: pingwang@csuft.edu.cn;[Yin, Jinglin] College of Science, Central South University of Forestry and Technology, Changsha 410004, China;[Liu, Zhiming] Department of Biology, Eastern New Mexico University, Portales, NM 88130, USA. Electronic address: zhiming.liu@enmu.edu
通讯机构：
[Liu, Zhiming] D;[Huang, Chao; Wang, Ping] C;College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China. Electronic address:;Department of Biology, Eastern New Mexico University, Portales, NM 88130, USA. Electronic address: zhiming.
摘要：
Fly ash (FA) and eggshells (ES) are common solid wastes with significant potential for the recovery of phosphorus from water. This study focuses on synthesizing a low-cost and environmental-friendly phosphate adsorbent called eggshell-fly ash geopolymer composite (EFG) using eggshells instead of chemicals. The CaO obtained from the high-temperature pyrolysis of eggshells provides active sites for phosphate adsorption, and CO(2) serves as a pore-forming agent. The phosphate adsorption performance of EFG varied with the eggshell-fly ash ratios and achieved a maximum of 49.92 mg P/g at an eggshell-fly ash ratio of 40 %. The adsorption process was well described by the pseudo-second-order model and the Langmuir model. EFG also exhibited a good regeneration performance through six-cycle experiments and achieved the highest phosphate desorption at pH 4.0. The results of the column experiment showed that EFG can be used as a filter media for phosphorus removal in a real-scale application with low cost. Soil burial test indicated saturated EFG has a good phosphate slow-release performance (maintained for up to 60 days). Overall, EFG has demonstrated to be a promising adsorbent for phosphorus recovery.
摘要：
Microplastics (MPs), a new type of pollutant, have attracted much attention worldwide. MPs are often complexed with other pollutants such as heavy metals, resulting in combined toxicity to organisms in the environment. Studies on the combined toxicity of MPs and heavy metals have usually focused on the marine, while on the freshwater are lacking. In order to understand the combined toxic effects of MPs and heavy metals in the freshwater, five typical MPs (PVC, PE, PP, PS, PET) were selected to investigate the adsorption characteristics of MPs to Pb(2+) before and after the MPs aging by ultraviolet (UV) irradiation through static adsorption tests. The results showed that UV aging enhanced adsorption of Pb(2+) by MPs. It is noteworthy that MPs-PET had the highest adsorption capacity for Pb(2+), and the interaction between MPs-PET and Pb(2+) was the strongest. We specifically selected MPs-PET to study its combined toxicity with Pb(2+) to Chlorella pyrenoidosa. In the combined toxicity test, MPs-PET and Pb(2+) had significant toxic effects on Chlorella pyrenoidosa in the individual exposure, and the toxicity of individual Pb(2+) exposure was greater than that of individual MPs-PET exposure. In the combined exposure, when MPs-PET and Pb(2+) without adsorption (MPs-PET/Pb(2+)), MPs-PET and Pb(2+) had a synergistic effect, which would produce strong physical and chemical stress on Chlorella pyrenoidosa simultaneously, and the toxic effect was the most significant. After the adsorption of MPs-PET and Pb(2+) (MPs-PET@Pb(2+)), the concentration and activity of Pb(2+) decreased due to the adsorption and fixation of MPs-PET, and the chemical stress on Chlorella pyrenoidosa was reduced, but the physical stress of MPs-PET still existed and posed a serious threat to the survival of Chlorella pyrenoidosa. This study has provided a theoretical basis for further assessment of the potential environmental risks of MPs in combination with other pollutants such as heavy metals.
摘要：
The coexistence of herbicide atrazine (ATZ) and the nanomaterial graphene oxide (GO) in natural water bodies will be an inevitable scenario due to their widespread application and consequent release into aquatic ecosystems. But the dissipation of ATZ with GO and the response of the microbial community to their combination are still not clear. Here, we investigated the dissipation dynamics and transformation of ATZ with and without GO in river water after 21-d incubation. In the presence of GO, ATZ residue significantly decreased by 11%-43%; the transformation of ATZ markedly increased by 11%-17% when ATZ concentrations were not above 1.0mg∙L(-1). The direct adsorption of ATZ on GO, mainly via π-π interactions, proton transfer and hydrogen bonding, contributed 54%-68% of the total increased ATZ dissipation by GO. ATZ and ATZ+GO exerted effects of similar magnitude on microbial OTU numbers with an increase of bacterial diversity. The coexisting GO increased the relative abundance of ATZ-degradation bacteria and Chitinophagales, thus improving ATZ transformation. This work indicated that the coexistence of GO at environmentally relevant concentrations can effectively reduce ATZ residues and promote the transformation of ATZ to degradation products in river water; nevertheless, the potential risk of GO acting as an ATZ carrier should be given more prominence.
摘要：
This work innovatively used cellulose nanofibers as a photocatalyst carrier, which could recycle nano-photocatalysts and minimize nanoparticle aggregation. The morphology, structures, chemical composition, optical-electronic properties and photocatalytic performance of amino-modified carbon quantum dots-ZnO/cellulose nanofiber (N-CQDs-ZnO/CNF: ZCH-2) hydrogel were characterized by SEM, TEM, BET, EDS, XRD, FTIR, UV-vis, XPS, PL and other techniques. The mechanism of Cr(VI) adsorption synergistic photoreduction by ZCH-2 was discussed in detail. The results showed that the prepared ZCH-2 had excellent removal performance for Cr(VI). After 120min of adsorption and 40min of photoreduction, the removal efficiency of Cr(VI) was 98.9%. Compared with ZnO/CNF hydrogel, the adsorption performance of ZCH-2 increased by 268% and the photoreduction performance increased by 116%. The adsorption of Cr(VI) by ZCH-2 was controlled by electrostatic attraction and chemical adsorption. The photoreduction kinetic constant of ZCH-2 was 0.106min(-1), which was 8.9 times that of ZnO/CNF hydrogel. The N-CQDs in ZCH-2 could form N-CQDs-metal complexes with Cr(VI), resulting in fluorescence quenching, so Cr(VI) could be visually identified by fluorescence changes. This study provides a new idea for the design and optimization of a new multifunctional hydrogel with efficient adsorption-photoreduction-fluorescence recognition.
摘要：
Characterized by irregular spatial and temporal variations of pollutant loading and complex occurrence mechanisms, agricultural nonpoint source pollution (ANPSP) has always been a great challenge in field restoration worldwide. Returning farmlands to wetlands (RFWs) as an ecological restoration mode among various constructed wetlands was selected to manage ANPSP in this study. Triarrhena lutarioriparia, Nelumbo nucifera and Zizania latifolia monocultures were designed and the water pollutants was monitored. N. nucifera and Z. latifolia could reach the highest TN (53.28%) and TP (53.22%) removal efficiency, respectively. By 16s high-throughput sequencing of rhizosphere bacteria, 45 functional species were the main contributors for efficient N and P removal, and 38 functional keystone taxa (FKT) were found with significant ecological niche roles and metabolic functions. To our knowledge, this is the first study to explore the microbial driving N and P removal mechanism in response to ANPSP treated by field scale RFWs.
