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1.
Curr Microbiol ; 81(10): 335, 2024 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-39215822

RESUMEN

Sb-resistant strains can detoxify antimony through metabolic mechanisms such as oxidation and affect the migration, transformation, and ultimate fate of antimony in the environment. In this study, a strain of Sb-resistant fungi, Rhodotorula glutinis sp. Strain J5, was isolated from Xikuangshan mine and its growth characteristics, gene expression differences, and functional annotation under Sb(III) stress were further investigated to reveal the mechanism of resistance to Sb(III). We identified strain J5 as belonging to the Rhodotorula glutinis species optimally growing at pH 5.0 and at 28 °C of temperature. According to gene annotation and differential expression, the resistance mechanism of Strain J5 includes: reducing the endocytosis of antimony by aquaporin AQP8 and transmembrane transporter pst, enhancing the efflux of Sb(III) by the gene expression of acr2, acr3 and ABC, improving the oxidation of Sb(III) by iron-sulfur protein and Superoxide dismutase (SOD), glutathione (GSH) and cysteine (Cys) chelation, methylation of methyltransferase and N-methyltransferase, accelerating cell damage repair and EPS synthesis and other biochemical reaction mechanisms. FT-IR analysis shows that the -OH, -COOH, -NH, -PO, C-O, and other active groups of Strain J5 can be complexed with Sb(III), resulting in chemical adsorption. Strain J5 displays significant resistance to Sb(III) with the MIC of 1300 mg/L, playing a crucial role in the global biochemical transformation of antimony and its potential application in soil microbial remediation.


Asunto(s)
Antimonio , Rhodotorula , Rhodotorula/genética , Rhodotorula/efectos de los fármacos , Rhodotorula/metabolismo , Rhodotorula/aislamiento & purificación , Antimonio/farmacología , Farmacorresistencia Fúngica/genética , Minería , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo
2.
J Environ Manage ; 365: 121610, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38955048

RESUMEN

Effective elimination of heavy metals from complex wastewater is of great significance for industrial wastewater treatment. Herein, bimetallic adsorbent Fe3O4-CeO2 was prepared, and H2O2 was added to enhance Sb(V) adsorption by Fe3O4-CeO2 in complex wastewater of Sb(V) and aniline aerofloat (AAF) for the first time. Fe3O4-CeO2 showed good adsorption performance and could be rapidly separated by external magnetic field. After five adsorption/desorption cycles, Fe3O4-CeO2 still maintained good stability. The maximum adsorption capacities of Fe3O4-CeO2 in single Sb(V), AAF + Sb(V), and H2O2+AAF + Sb(V) systems were 77.33, 70.14, and 80.59 mg/g, respectively. Coexisting AAF inhibited Sb(V) adsorption. Conversely, additional H2O2 promoted Sb(V) removal in AAF + Sb(V) binary system, and made the adsorption capacity of Fe3O4-CeO2 increase by 14.90%. H2O2 could not only accelerate the reaction rate, but also reduce the optimal amount of adsorbent from 2.0 g/L to 1.2 g/L. Meanwhile, coexisting anions had little effect on Sb(V) removal by Fe3O4-CeO2+H2O2 process. The adsorption behaviors of Sb(V) in three systems were better depicted by pseudo-second-order kinetics, implying that the chemisorption was dominant. The complexation of AAF with Sb(V) hindered the adsorption of Sb(V) by Fe3O4-CeO2. The complex Sb(V) was oxidized and decomposed into free state by hydroxyl radicals produced in Fe3O4-CeO2+H2O2 process. Then the free Sb(V) was adsorbed by Fe3O4-CeO2 mostly through outer-sphere complexation. This work provides a new tactic for the treatment of heavy metal-organics complex wastewater.


Asunto(s)
Peróxido de Hidrógeno , Aguas Residuales , Aguas Residuales/química , Peróxido de Hidrógeno/química , Adsorción , Contaminantes Químicos del Agua/química , Compuestos de Anilina/química , Cerio/química
3.
Chemosphere ; 349: 140914, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38092173

RESUMEN

Magnetically modified carbon-based adsorbent (BC@γ-Fe2O3) was prepared through facile route using activated sludge biomass and evaluated for the simultaneous removal of Sb(III) and Pb(II). BC@γ-Fe2O3 exhibited outstanding Sb(III) and Pb(II) adsorption capacity when 200 mg of adsorbent was employed at pH 5.0 for 240 min, with the removal efficiency higher than 90%. The experiments demonstrated the excellent reusability and the potent anti-interference properties of the prepared absorbent. Freundlich and pseudo-second-order kinetic were prior to describe the adsorption process. The adsorption of Sb(III) and Pb(II) onto BC@γ-Fe2O3 was spontaneous and endothermic. BC@γ-Fe2O3 with high specific surface area revealed the exceptional competence to absorb Sb(III) and Pb(II) through pore filling, electrostatic adsorption and complexation. The adsorption mechanisms of Sb(III) and Pb(II) showed similarities with slight disparities. The removal of Sb(III) involved the Fe-O-Sb bond and π-π bond, while the adsorption of Pb(II) was closely related to ion exchange. Moreover, Sb(III) was oxidized to Sb(V) in a minor part during adsorption. The Fe-O-Cl active sites on BC allowed for the binding of γ-Fe2O3, guaranteeing the abundant adsorption sites and stability. BC@γ-Fe2O3 provides an efficient and green insight into the simultaneous removal of complex heavy metals with promising application in wastewater treatment.


Asunto(s)
Aguas Residuales , Contaminantes Químicos del Agua , Aguas del Alcantarillado , Adsorción , Plomo , Contaminantes Químicos del Agua/análisis , Carbón Orgánico/química , Cinética , Fenómenos Magnéticos
4.
Chemosphere ; 326: 138481, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-36958501

RESUMEN

The conventional zero-valent iron/peracetic acid (ZVI/PAA) system is severely limited owing to the passivation of ZVI and the low recovery of Fe2+. In this study, a reducing agent, vitamin C (H2A), was used for the first time to enhance the ZVI/PAA system as a way to improve its degradation performance. Under optimal conditions, the removal efficiency of the H2A/ZVI/PAA system was 82.9%, while that of the H2A/PAA and ZVI/PAA systems were only 19.0% and 25.6%. Free radical quenching and electron paramagnetic experiments (EPR) confirmed that CH3C(O)O•, •OH and CH3C(O)OO• were the major active species for acid orange 7 (AO7) degradation with contributions of 9.7%, 75% and 14.4%, respectively. The degradation mechanism was proposed through UV-vis full-wavelength scanning and chemical oxygen demand (COD) experiments. The removal of AO7 was not affected in the presence of Cl-, SO42- and HCO3-, while inhibition occurred with humic acid. ZVI exhibited excellent catalytic properties and stability, and the removal efficiency of AO7 exceeded 70% after three cycles. Additionally, the H2A/ZVI/PAA system showed good ability to remove AO7 in well water, lake water, river water and reservoir water, and the elimination efficiency of MO, DCF and ACE also exceeded 70%. Overall, this study contributes new cognition for enhancing the ZVI/PAA system to degrade contaminants, which is expected to achieve a cleaner water environment.


Asunto(s)
Hierro , Contaminantes Químicos del Agua , Hierro/química , Ácido Ascórbico , Ácido Peracético , Contaminantes Químicos del Agua/química , Vitaminas , Oxidación-Reducción
5.
Sensors (Basel) ; 22(19)2022 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-36236587

RESUMEN

Smart grids are being expanded in scale with the increasing complexity of the equipment. Edge computing is gradually replacing conventional cloud computing due to its low latency, low power consumption, and high reliability. The CORDIC algorithm has the characteristics of high-speed real-time processing and is very suitable for hardware accelerators in edge computing devices. The iterative calculation method of the CORDIC algorithm yet leads to problems such as complex structure and high consumption of hardware resource. In this paper, we propose an RDP-CORDIC algorithm which pre-computes all micro-rotation directions and transforms the conventional single-stage iterative structure into a three-stage and multi-stage combined iterative structure, thereby enabling it to solve the problems of the conventional CORDIC algorithm with many iterations and high consumption. An accuracy compensation algorithm for the direction prediction constant is also proposed to solve the problem of high ROM consumption in the high precision implementation of the RDP-CORDIC algorithm. The experimental results showed that the RDP-CORDIC algorithm had faster computation speed and lower resource consumption with higher guaranteed accuracy than other CORDIC algorithms. Therefore, the RDP-CORDIC algorithm proposed in this paper may effectively increase computation performance while reducing the power and resource consumption of edge computing devices in smart grid systems.

6.
Bioresour Technol ; 351: 126977, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35276376

RESUMEN

Biological nutrients removal performance affected by starvation stress was investigated via the addition of pre-anoxic stage to SBR. COD removal efficiency maintained at around 90% regardless of the starvation stress. Starvation stress presented significant impact on nitrogen and phosphorus removal, with noticeable reduction of TN removal and remarkable deterioration of TP removal as prolonging the pre-anoxic time, which was mainly attributed to the integrative effect of carbon source competition, depression of denitrification and invalid P release as well as the variation of microbial community. It was notable that starvation stress exerted distinct evolution on microbial community. The improvement in relative abundance of the certain genera relating to denitrification was the main reason for the partial recovery of nitrogen removal after eliminating stress starvation. The promotion of P uptake capacity accompanied with the relief of invalid P release and the enriched DPAOs accounted for the complete recovery of phosphorus removal.


Asunto(s)
Desnitrificación , Eliminación de Residuos Líquidos , Reactores Biológicos , Nitrógeno/análisis , Nutrientes , Fósforo , Aguas del Alcantarillado
7.
Curr Microbiol ; 77(9): 2071-2083, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32474703

RESUMEN

How to effectively remove excess Sb(III) in the water environment by biosorption is receiving close attention in the international scientific community. To obtain the maximum biosorption efficiency, response surface methodology (RSM) was employed to optimize a total of 13 factors for biosorption of Sb(III) onto living Rhodotorula mucilaginosa DJHN070401. The mechanism of biosorption and bioaccumulation was also studied. The results showed that biosorption reached 56.83% under the optimum conditions. Besides, pH, Fe2+, and temperature are significant influencing factors, and control of Ca2+ and Fe2+ has a beneficial impact on Sb(III) biosorption. The characterization explained that physical adsorption occurred readily on the loose and porous surface of DJHN070401 where carboxyl, amidogen, phosphate group, and polysaccharide C-O functional groups facilitated absorption by complexation with Sb(III), accompanied by ion exchange of Na+, Ca2+ ions with Sb(III). It was also noted that the living cell not only improved the removal efficiency in the presence of metabolic inhibitors but also prevented intracellular Sb(III) being re-released into the environment. The results of this study underpin improved and efficient methodology for biosorption of Sb(III) from wastewater.


Asunto(s)
Contaminantes Químicos del Agua , Adsorción , Concentración de Iones de Hidrógeno , Cinética , Rhodotorula , Aguas Residuales , Contaminantes Químicos del Agua/análisis
8.
Sci Rep ; 9(1): 13021, 2019 09 10.
Artículo en Inglés | MEDLINE | ID: mdl-31506559

RESUMEN

A novel adsorbent (Fe3O4/HCO) was prepared via co-precipitation from a mix of ferriferrous oxide and a Ce-rich waste industrial sludge recovered from an optical polishing activity. The effect of system parameters including reaction time, pH, dose, temperature as well as initial concentration on the adsorption of Sb(III) were investigated by sequential batch tests. The Sb(III)/Fe3O4/HCO system quickly reached adsorption equilibrium within 2 h, was effective over a wide pH (3-7) and demonstrated excellent removal at a 60 mg/L Sb(III) concentration. Three isothermal adsorption models were assessed to describe the equilibrium data for Sb(III) with Fe3O4/HCO. Compared to the Freundlich and dubinin-radushkevich, the Langmuir isotherm model showed the best fit, with a maximum adsorption capacity of 22.853 mg/g, which exceeds many comparable absorbents. Four kinetic models, Pseudo-first-order, Pseudo-second-order, Elovich and Intra-particle, were used to fit the adsorption process. The analysis showed that the mechanism was pseudo-second-order and chemical adsorption played a dominant role in the adsorption of Sb(III) by Fe3O4/HCO (correlation coefficient R2 = 0.993). Thermodynamic calculations suggest that adsorption of Sb(III) ions was endothermic, spontaneous and a thermodynamically feasible process. The mechanism of the adsorption of Sb(III) on Fe3O4/HCO could be described by the synergistic adsorption of Sb (III) on Fe3O4, FeCe2O4 and hydrous ceric oxide. The Fe3O4/HCO sorbent appears to be an efficient and environment-friendly material for the removal of Sb(III) from wastewater.

9.
Chemosphere ; 237: 124509, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31400741

RESUMEN

A novel system combined with photocatalytic fuel cell and electrochemical system assisted by reverse electrodialysis (PREC) is proposed for H2O2 production and electricity generation. Results demonstrated the H2O2 concentration increased gradually with time and reached around 940 mg/L at 24 h. The optimum air flow rate was 15 L/min. The current efficiency was 31.3%. The maximum short-circuit current density, maximum open-circuit voltage and maximum power density were 0.95 mA/cm2, 1.52 V and 68 W/m2. The salinity-driven potential, created with the five pairs of the HC and LC cells in the PREC, was calculated to be 0.72 V. Additionally, the energy efficiency (ηE) was 40.5%. The integrated system is confirmed to be serviced as an efficient technology for H2O2 electro-genneration and salinity-gradient energy utilization simultaneously.


Asunto(s)
Fuentes de Energía Bioeléctrica , Peróxido de Hidrógeno/química , Electricidad , Electrodos , Salinidad
10.
Angew Chem Int Ed Engl ; 58(35): 12154-12158, 2019 08 26.
Artículo en Inglés | MEDLINE | ID: mdl-31245892

RESUMEN

The synthesis of renewable jet fuel from lignocellulosic platform compounds has drawn a lot of attention in recent years. So far, most work has concentrated on the production of conventional jet fuels. JP-10 is an advanced jet fuel currently obtained from fossil energy. Due to its excellent properties, JP-10 has been widely used in military aircraft. However, the high price and low availability limit its application in civil aviation. Here, we report a new strategy for the synthesis of bio-JP-10 fuel from furfuryl alcohol that is produced on an industrial scale from agricultural and forestry residues. Under the optimized conditions, bio-JP-10 fuel was produced with high overall carbon yields (≈65 %). A preliminary economic analysis indicates that the price of bio-JP-10 fuel can be greatly decreased from ≈7091 US$/ton (by fossil route) to less than 5600 US$/ton using our new strategy. This work makes the practical application of bio-JP-10 fuel forseeable.

11.
Bioresour Technol ; 271: 332-339, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30292132

RESUMEN

A membrane electro-bioreactor (MEBR) embracing biological treatment, electrokinetic phenomena and membrane filtration was established by applying intermittent direct current (DC) to MBR. MEBR exhibited significant improvement of treatment performance and reduction of membrane fouling. COD and total phenols removal efficiencies increased to 83.53% and 93.28% at an exposure mode of 24'-OFF/6'-ON, compared to 71.24% and 82.43% in MBR. Trans-membrane pressure increment rate declined dramatically in MEBR, which was mainly attributed to the increase of sludge floc size and decrease of zeta potential, soluble microbial products and specific resistance to filtration, resulted from electrokinetic effects such as electrocoagulation, electrophoresis, electroosmosis and electromigration of ions. It was notable that DC exposure exerted distinct evolution on microbial community, with the improvement of microbial community richness and diversity. The relative abundances of functional genera were promoted noticeably in MEBR. An interactive relevance existed among microbial community structure, mixed liquor properties and operational parameters.


Asunto(s)
Reactores Biológicos , Carbón Mineral , Aguas Residuales/química , Industria Química , Electricidad , Filtración/métodos , Fenoles/química , Aguas del Alcantarillado , Eliminación de Residuos Líquidos/instrumentación , Eliminación de Residuos Líquidos/métodos
12.
Water Sci Technol ; 76(9-10): 2350-2356, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29144293

RESUMEN

A novel type of catalytic particle electrode (SAC-Fe) was developed from sewage sludge and iron sludge via a facile method. The catalytic particle electrodes (CPEs) were also supposed to be heterogeneous catalyst for electro-Fenton (EF). The CPEs were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). SAC-Fe showed superior porous structure and higher adsorption capacity and catalytic activity than Fe3O4 magnetic nanoparticles. Catechol and total organic carbon (TOC) removal efficiency can reach 96.7% and 88.3% after three-dimensional (3D) EF with SAC-Fe as CPEs. A possible mechanism was deduced based on adsorption tests and radicals detection. Meanwhile, the stability and reusability of the CPEs were evaluated.


Asunto(s)
Técnicas Electroquímicas/métodos , Hierro/química , Aguas del Alcantarillado/química , Contaminantes Químicos del Agua/química , Adsorción , Catálisis , Técnicas Electroquímicas/instrumentación , Electrodos , Difracción de Rayos X
13.
ChemSusChem ; 10(5): 819-824, 2017 03 09.
Artículo en Inglés | MEDLINE | ID: mdl-27863052

RESUMEN

A highly dispersed Au and Pt catalyst supported on WOx was developed for high performance in the selective hydrogenolysis of glycerol to 1,3-propanediol (1,3-PD) under very mild reaction conditions (81.4 % glycerol conversion, 51.6 % 1,3-PD selectivity at 413 K, 1 MPa H2 ). The highly dispersed Au decreased the original surface Lewis-acid sites on Pt/WOx but greatly increased its in situ generated Brønsted-acid sites with the assistance of H2 through the formation of frustrated Lewis pairs. These in situ formed and spatially separated pairs of H+ and H- function as the active sites in glycerol conversion to 1,3-PD.


Asunto(s)
Glicerol/química , Oro/química , Óxidos/química , Platino (Metal)/química , Glicoles de Propileno/química , Tungsteno/química , Catálisis , Hidrógeno/química , Especificidad por Sustrato , Temperatura
14.
Chemosphere ; 164: 14-24, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27573211

RESUMEN

Coupling of the Fe-C micro-electrolysis (IC-ME) into the up-flow anaerobic sludge blanket (UASB) was developed for enhanced Fischer-Tropsch wastewater treatment. The COD removal efficiency and methane production in R3 with IC-ME assisted both reached up to 80.6 ± 1.7% and 1.38 ± 0.11 L/L·d that higher than those values in R1 with GAC addition (63.0 ± 3.4% and 0.95 ± 0.09 L/L·d) and R2 with ZVI addition (74.5 ± 2.8% and 1.21 ± 0.09 L/L·d) under the optimum HRT (5 d). The Fe corrosion as electron donor reduced the ORP values and stimulated the activities of hydrogenotrophic methanogens to lower H2 partial pressure in R2 and R3. Additionally, Fe2+ as by-product of iron corrosion, its presence could effectively increase the percentage of protein content in tightly bound extracellular polymeric substances (TB-EPS) to promote better bioflocculation, increasing to 90.5 mg protein/g·VSS (R2) and 106.3 mg protein/g·VSS (R3) while this value in R1 was simply 56.6 mg protein/g·VSS. More importantly, compared with R1, the excess accumulation of propionic acid and butyric acid in system was avoided. The macroscopic galvanic cells around Fe-C micro-electrolysis carriers in R3, that larger than microscopic galvanic cells in R2, further accelerate to transfer the electrons from anodic Fe to cathodic carbon that enhance interspecies hydrogen transfer, making the decomposition of propionic acid and butyric acid more thermodynamically feasible, finally facilitate more methane production.


Asunto(s)
Carbono/química , Electrólisis/métodos , Hierro/química , Aguas del Alcantarillado/química , Aguas Residuales/análisis , Purificación del Agua/métodos , Anaerobiosis , Reactores Biológicos/microbiología , Catálisis , China , Hidrógeno/química , Metano/metabolismo , Oxidación-Reducción , Proyectos Piloto , Aguas Residuales/química
15.
Bioresour Technol ; 200: 103-10, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26476170

RESUMEN

The novel system of EBA (based on external circulation anaerobic (EC) process-biological enhanced (BE) process-anoxic/oxic (A/O) process) was applied to treat the British Gas/Lurgi coal gasification wastewater in Erdos, China. After a long time of commissioning, the EBA system represented a stable and highly efficient performance, particularly, the concentrations of COD, NH4(+)-N, total organic carbon, total nitrogen and volatile phenols in the final effluent reached 53, 0.3, 18, 106mg/L and not detected, respectively. Both the GC-MS and fluorescence excitation-emission matrix analyses revealed significant variations of organic compositions in the effluent of different process. The results of high-throughput sequencing represented the EBA system composed 34 main bacteria which were affiliated to 7 phyla. In addition, the canonical correspondence analysis indicated high coherence among community composition, wastewater characteristics and environmental variables, in which the pH, mixed liquid suspended solids and total phenols loading were the most three significant variables.


Asunto(s)
Eliminación de Residuos Líquidos/instrumentación , Eliminación de Residuos Líquidos/métodos , Contaminantes Químicos del Agua/aislamiento & purificación , Anaerobiosis , Bacterias/genética , Análisis de la Demanda Biológica de Oxígeno , Reactores Biológicos/microbiología , Carbono/metabolismo , China , Carbón Mineral , Fluorescencia , Cromatografía de Gases y Espectrometría de Masas , Consorcios Microbianos/genética , Consorcios Microbianos/fisiología , Nitratos/química , Nitratos/metabolismo , Nitrógeno/metabolismo , Fenoles/química , Fenoles/metabolismo , Aguas Residuales/química , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/metabolismo
16.
Bioresour Technol ; 198: 918-21, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26428576

RESUMEN

Laboratorial scale experiments were conducted to investigate a novel system three-dimensional catalytic electro-Fenton (3DCEF, catalyst of sewage sludge based activated carbon which loaded Fe3O4) integrating with membrane bioreactor (3DCEF-MBR) on advanced treatment of biologically pretreated coal gasification wastewater. The results indicated that 3DCEF-MBR represented high efficiencies in eliminating COD and total organic carbon, giving the maximum removal efficiencies of 80% and 75%, respectively. The integrated 3DCEF-MBR system significantly reduced the transmembrane pressure, giving 35% lower than conventional MBR after 30 days operation. The enhanced hydroxyl radical oxidation and bacteria self repair function were the mechanisms for 3DCEF-MBR performance. Therefore, the integrated 3DCEF-MBR was expected to be the promising technology for advanced treatment in engineering applications.


Asunto(s)
Reactores Biológicos , Carbón Mineral , Aguas Residuales , Purificación del Agua , Técnicas Electroquímicas , Membranas Artificiales , Aguas Residuales/análisis , Aguas Residuales/química
17.
Bioresour Technol ; 196: 721-5, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26227570

RESUMEN

A novel integrated process with three-dimensional electro-Fenton (3D EF) and biological activated carbon (BAC) was employed in advanced treatment of biologically pretreated Lurgi coal gasification wastewater. SAC-Fe (sludge deserved activated carbon from sewage and iron sludge) and SAC (sludge deserved activated carbon) were used in 3D EF as catalytic particle electrodes (CPEs) and in BAC as carriers respectively. Results indicated that 3D EF with SAC-Fe as CPEs represented excellent pollutants and COLOR removals as well as biodegradability improvement. The efficiency enhancement attributed to generating more H2O2 and OH. The integrated process exhibited efficient performance of COD, BOD5, total phenols, TOC, TN and COLOR removals at a much shorter retention time, with the corresponding concentrations in effluent of 31.18, 6.69, 4.29, 17.82, 13.88mg/L and <20 times, allowing discharge criteria to be met. The integrated system was efficient, cost-effective and ecological sustainable and could be a promising technology for engineering applications.


Asunto(s)
Carbón Orgánico/química , Carbón Mineral , Técnicas Electroquímicas/métodos , Residuos Industriales/análisis , Aguas Residuales/química , Purificación del Agua/métodos
18.
J Environ Sci (China) ; 33: 12-20, 2015 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-26141873

RESUMEN

Sewage sludge from a biological wastewater treatment plant was converted into sewage sludge based activated carbon (SBAC) with ZnCl2 as activation agent, which was used as a support for ferric oxides to form a catalyst (FeOx/SBAC) by a simple impregnation method. The new material was then used to improve the performance of Fenton oxidation of real biologically pretreated coal gasification wastewater (CGW). The results indicated that the prepared FeOx/SBAC significantly enhanced the pollutant removal performance in the Fenton process, so that the treated wastewater was more biodegradable and less toxic. The best performance was obtained over a wide pH range from 2 to 7, temperature 30°C, 15 mg/L of H2O2 and 1g/L of catalyst, and the treated effluent concentrations of COD, total phenols, BOD5 and TOC all met the discharge limits in China. Meanwhile, on the basis of significant inhibition by a radical scavenger in the heterogeneous Fenton process as well as the evolution of FT-IR spectra of pollutant-saturated FeOx/BAC with and without H2O2, it was deduced that the catalytic activity was responsible for generating hydroxyl radicals, and a possible reaction pathway and interface mechanism were proposed. Moreover, FeOx/SBAC showed superior stability over five successive oxidation runs. Thus, heterogeneous Fenton oxidation of biologically pretreated CGW by FeOx/SBAC, with the advantages of being economical, efficient and sustainable, holds promise for engineering application.


Asunto(s)
Carbón Mineral/análisis , Residuos Industriales/análisis , Aguas Residuales/química , Biodegradación Ambiental , Reactores Biológicos , Carbono , Catálisis , Cloruros , Compuestos Férricos , Microscopía de Fuerza Atómica , Oxidación-Reducción , Aguas del Alcantarillado , Compuestos de Zinc
19.
Bioresour Technol ; 192: 507-13, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26081627

RESUMEN

A laboratory-scale external circulation anaerobic reactor (ECAR) was developed to treat actual coal gasification wastewater. The external circulation ratio (R) was selected as the main operating variable for analysis. From the results, with the hydraulic retention time of 50h, pH > 8.0 and R of 3, the COD, total phenols, volatile phenol and NH4(+)-N removal efficiencies were remarkably increased to 10 ± 2%, 22 ± 5%, 18 ± 1%, and -1 ± 2%, respectively. Besides, increasing R resulted in more transformation from bound extracellular polymeric substances (EPS) to free EPS in the liquid and the particle size distribution of anaerobic granular sludge accumulated in the middle size range of 1.0-2.5mm. Results showed the genus Saccharofermentans dominanted in the ECAR and the bacterial community shift was observed at different external circulation ratio, influencing the pollutants removal profoundly.


Asunto(s)
Bacterias Anaerobias/metabolismo , Reactores Biológicos/microbiología , Carbón Mineral , Gases/química , Reología/instrumentación , Purificación del Agua/instrumentación , Archaea , Diseño de Equipo , Análisis de Falla de Equipo , Aguas Residuales/microbiología , Contaminantes Químicos del Agua/aislamiento & purificación , Contaminantes Químicos del Agua/metabolismo
20.
Bioresour Technol ; 189: 426-429, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25936898

RESUMEN

Laboratorial scale experiments were conducted to investigate a novel system integrating catalytic ultrasound oxidation (CUO) with membrane bioreactor (CUO-MBR) on advanced treatment of biologically pretreated coal gasification wastewater. Results indicated that CUO with catalyst of FeOx/SBAC (sewage sludge based activated carbon (SBAC) which loaded Fe oxides) represented high efficiencies in eliminating TOC as well as improving the biodegradability. The integrated CUO-MBR system with low energy intensity and high frequency was more effective in eliminating COD, BOD5, TOC and reducing transmembrane pressure than either conventional MBR or ultrasound oxidation integrated MBR. The enhanced hydroxyl radical oxidation, facilitation of substrate diffusion and improvement of cell enzyme secretion were the mechanisms for CUO-MBR performance. Therefore, the integrated CUO-MBR was the promising technology for advanced treatment in engineering applications.


Asunto(s)
Reactores Biológicos , Carbón Mineral , Gases/química , Ultrasonido/instrumentación , Eliminación de Residuos Líquidos/instrumentación , Eliminación de Residuos Líquidos/métodos , Aguas Residuales/química , Biodegradación Ambiental , Análisis de la Demanda Biológica de Oxígeno , Carbono/aislamiento & purificación , Catálisis , Carbón Orgánico/química , Membranas Artificiales , Oxidación-Reducción , Aguas del Alcantarillado/química , Factores de Tiempo
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