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OBJECTIVE: To investigate the effect of 50 Hz 0.1 mT sinusoidal electromagnetic field at different time points on bone mineral density(BMD)and histomorphometry in rats. METHODS: Totally 50 6-week-old female SD rats were equally randomized into 5 groups: control group,45-minute group,90-minute group,180-minute group,and 270-minute group. Except for the control group,the other four groups were given magnetic intervention in the 50-Hz 0.1-mT sinusoidal electromagnetic field for 45 minutes,90 minutes,180 minutes,or 270 minutes,respectively,on a daily basis. After 8 weeks,the total body BMD,femur BMD,and vertebral BMD were measured by dual-energy X-ray absorptiometry. The left tibia and the fifth lumbar vertebrae were separated for bone tissue static and dynamic analyses. RESULTS: Compared with control group,the 90-minute group and the 180-minute group had significantly different total body BMD(P<0.01,P<0.05),while no such significant difference was seen in the 45-minute group and 270-minute group (P>0.05). The femur,vertebral BMD,serum biochemical markers,and the static parameters of the fifth lumbar vertebrae tissue showed significant differences in the 90-minute group,180-minute group,and 270-minute group(P<0.01),but not in the 45-minute group (P>0.05). As shown by double fluorescent labeling,the distance was sorted in an order of 90-minute group>180-minutes group>270-minute group>45-minutes group>control group. CONCLUSION: The 50-Hz 0.1-mT sinusoidal electromagnetic field can effectively increase bone mineral density and improve bone morphology;however,the intervention effectiveness differs at different time points,with the best effectiveness seen at 90 minutes.
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Densidad Ósea , Campos Electromagnéticos , Absorciometría de Fotón , Animales , Huesos , Femenino , Fémur , Vértebras Lumbares , Ratas , Ratas Sprague-Dawley , TibiaRESUMEN
The activated sludge process plays a crucial role in modern wastewater treatment plants. During the treatment of daily sewage, a large amount of residual sludge is generated, which, if improperly managed, can pose burdens on the environment and human health. Additionally, the highly hydrated colloidal structure of biopolymers limits the rate and degree of dewatering, making mechanical dewatering challenging. This study investigates the impact and mechanism of microwave irradiation (MW) in conjunction with peracetic acid (PAA) on the dewatering efficiency of sludge. Sludge dewatering effectiveness was assessed through capillary suction time (CST) and specific resistance to filtration (SRF). Examination of the impact of MW-PAA treatment on sludge dewatering performance involved assessing the levels of extracellular polymeric substances (EPS), employing three-dimensional excitation-emission matrix (3D-EEM), Fourier transform-infrared spectroscopy (FT-IR), and scanning electron microscopy. Findings reveal that optimal dewatering performance, with respective reductions of 91.22% for SRF and 84.22% for CST, was attained under the following conditions: microwave power of 600 W, reaction time of 120 s, and PAA dosage of 0.25 g/g MLSS. Additionally, alterations in both sludge EPS composition and floc morphology pre- and post-MW-PAA treatment underwent examination. The findings demonstrate that microwaves additionally boost the breakdown of PAA into â¢OH radicals, suggesting a synergistic effect upon combining MW-PAA treatment. These pertinent research findings offer insights into employing MW-PAA technology for residual sludge treatment.
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Microondas , Ácido Peracético , Aguas del Alcantarillado , Eliminación de Residuos Líquidos , Aguas del Alcantarillado/química , Ácido Peracético/química , Eliminación de Residuos Líquidos/métodos , Aguas Residuales/química , Espectroscopía Infrarroja por Transformada de FourierRESUMEN
Amyloid ß protein (Aß) is closely involved in the pathogenesis of Alzheimer's disease (AD), and one of the main strategies for AD treatment is antagonizing the neurotoxicity of Aß or even clearing the Aß deposited in the brain. The present study was aimed to observe the effects of intrahippocampal injection of Aß31â35 on the spatial learning and memory of rats by using Morris water maze technique, and explore the neuroprotective effects and possible mechanism of [Gly14]-humanin (HNG) against Aß-induced deficits in learning behavior. The results showed that bilateral intrahippocampal injection of 2.0 nmol Aß31â35 significantly increased the mean traveled distance of rats in searching for the hidden underwater platform and decreased the distance percentage in the target quadrant in probe test after withdrawal of platform, whereas pretreatment with HNG (0.2 nmol and 2.0 nmol) suppressed Aß31â35-induced increase in the traveled distance and decrease in swimming distance percentage. Application of Genistein (40 nmol), a specific tyrosine kinase inhibitor, almost completely blocked the antagonistic effects of HNG against Aß31â35. These results indicate that HNG can dose-dependently prevent against Aß31â35-induced impairment in spatial learning and memory of rats, and the neuroprotective effects of HNG might involve the activation of endogenous tyrosine kinase pathway, suggesting that up-regulation of the tyrosine kinase signaling by using HNG might be of great significance for the improvement of cognitive function in AD.
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Péptidos beta-Amiloides/efectos adversos , Memoria/efectos de los fármacos , Fragmentos de Péptidos/efectos adversos , Péptidos/farmacología , Aprendizaje Espacial/efectos de los fármacos , Enfermedad de Alzheimer/fisiopatología , Péptidos beta-Amiloides/antagonistas & inhibidores , Animales , Encéfalo/efectos de los fármacos , Genisteína/farmacología , Fármacos Neuroprotectores/farmacología , Fragmentos de Péptidos/antagonistas & inhibidores , RatasRESUMEN
The high density of senile plaques with amyloid beta protein (Aß) and the loss of cholinergic neurons in the brain are the dominated pathological characteristics of Alzheimer's disease (AD). However, the active center of Aß, especially the cholinergic mechanism underlying the Aß neurotoxicity, is mostly unknown. This study examined the effects of different Aß fragments on hippocampal long-term potentiation (LTP) and investigated its probable α7 nicotinic acetylcholine receptors (nAChRs) mechanism. The results show that: (1) intracerebroventicular injection of Aß25-35 or Aß31-35 significantly and similarly suppressed hippocampal LTP in CA1 region in rats; (2) choline, a selective α7 nAChR agonist, did not affect the LTP induction but enhanced LTP suppression induced by Aß31-35; and (3) methyllycaconitine, a specific α7 nAChR antagonist, slightly suppressed hippocamal LTP but effectively prevented against Aß31-35-induced LTP depression in the presence of Aß31-35. These results indicate that: (1) the amino acid sequence 31-35 of the Aß peptide might be a shorter active sequence in the full length molecule; (2) α7 nAChRs are required for the Aß-induced suppression of hippocampal LTP. Thus, this study not only provides a new insight into the mechanism by which Aß impairs synaptic plasticity but also strongly suggests that sequence 31-35 in Aß molecule and α7 nAChRs in the brain might be potential therapeutic targets for the treatment of AD.
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Péptidos beta-Amiloides/administración & dosificación , Región CA1 Hipocampal/fisiología , Depresión Sináptica a Largo Plazo/fisiología , Inhibición Neural/fisiología , Fragmentos de Péptidos/administración & dosificación , Receptores Nicotínicos/fisiología , Animales , Inyecciones Intraventriculares , Potenciación a Largo Plazo/fisiología , Masculino , Ratas , Ratas Sprague-Dawley , Receptor Nicotínico de Acetilcolina alfa 7RESUMEN
The asymmetric unit of the title compound, C(20)H(18)N(4)S(4), contains one half-mol-ecule situated on a twofold rotation axis, in which the thia-diazole and phenyl rings are twisted by 7.2â (3)°. In the crystal, weak inter-molecular C-Hâ¯π inter-actions link the mol-ecules into layers parallel to (103).
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Herein, a novel innovative lipid co-extraction strategy using the biodiesel-producing microalga Chlorella pyrenoidosa and planktonic cladoceran Daphnia was proposed. Co-extraction occurred as Daphnia ingested and digested microalgal cells in a pre-treatment process; thereafter, lipids from these organisms were extracted. Composition of fatty acids from C. pyrenoidosa and Daphnia were appropriate as potential biodiesel feedstocks. Daphnia had different absorption and conversion capacities of various fatty acids from C. pyrenoidosa, which showed potential for improving biodiesel characteristics. Linoleic acid (LA, C18:2n-6) and alpha-linolenic acid (ALA, C18:3n-3) were absorbed significantly into the body of Daphnia. The optimal lipid extraction and fatty acid methyl esters (FAMEs) recovery rates were up to 41.08% and 12.35%, respectively, which were greater than that of the traditional lipid extraction method due to the rich oil content of Daphnia. Overall, this lipid co-extraction process serves a potential Daphnia utilization as an economical, green, low-energy way for microalgae biodiesel production.
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Grafted plant is a chimeric organism formed by the connection of scion and rootstock through stems, so stem growth and development become one of the important factors to affect grafted plant state. However, information regarding the molecular responses of stems secondary growth after grafting is limited. A grafted Rosa plant, with R. rugosa 'Rosea' as the scion (Rr_scion) grafted onto R. multiflora 'Innermis' as the stock (Rm_stock), has been shown to significantly improve stem thickness. To elucidate the molecular mechanisms of stem secondary growth in grafted plant, a genome-wide transcription analysis was performed using an RNA sequence (RNA-seq) method between the scion and rootstock. Comparing ungrafted R. rugosa 'Rosea' (Rr) and R. multiflora 'Innermis' (Rm) plants, there were much more differentially expressed genes (DEGs) identified in Rr_scion (6887) than Rm_stock (229). Functional annotations revealed that DEGs in Rr_scion are involved in two Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways: the phenylpropanoid biosynthesis metabolism and plant hormone signal transduction, whereas DEGs in Rm_stock were associated with starch and sucrose metabolism pathway. Moreover, different kinds of signal transduction-related DEGs, e.g., receptor-like serine/threonine protein kinases (RLKs), transcription factor (TF), and transporters, were identified and could affect the stem secondary growth of both the scion and rootstock. This work provided new information regarding the underlying molecular mechanism between scion and rootstock after grafting.
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Quimera/genética , Rosa/crecimiento & desarrollo , Rosa/genética , Quimera/metabolismo , Perfilación de la Expresión Génica/métodos , Regulación de la Expresión Génica de las Plantas/genética , Hojas de la Planta/crecimiento & desarrollo , Raíces de Plantas/genética , Raíces de Plantas/crecimiento & desarrollo , Tallos de la Planta/crecimiento & desarrollo , Transcriptoma/genéticaRESUMEN
OBJECTIVE: To study effects of 50 Hz 1.8 mT sinusoidal electromagnetic fields (SEMFs) on bone mineral density (BMD) in SD rats. METHODS: Thirty SD rats weighted(110±10) and aged 1 month were randomly divided into control group and electromagnetic field group, 15 in each group. Normal control group of 50 Hz 0 mT density and sinusoidal electromagnetic field group of 50 Hz 1.8 mT were performed respectively with 1.5 h/d and weighted weight once a week, and observed food-intake. Rats were anesthesia by intraperitoneal injection and dual energy X-ray absorptiometry were used to detect bone density of whole body, and detected bone density of femur and vertebral body. Osteocalcin and tartrate-resistant acid phosphatase 5b were detected by ELSA; weighted liver, kidney and uterus to calculate purtenance index, then detected pathologic results by HE. RESULTS: Compared with control group, there was no significant change in weight every week, food-intake every day; no obvious change of bone density of whole body at 2 and 4 weeks, however bone density of whole body, bone density of excised femur and vertebra were increased at 6 weeks. Expression of OC was increased, and TRACP 5b expression was decreased. No change of HE has been observed in liver, kidney and uterus and organic index. CONCLUSIONS: 50 Hz 1.8 mT sinusoidal electromagnetic fields could improve bone formation to decrease relevant factors of bone absorbs, to improve peak bone density of young rats, in further provide a basis for clinical research electromagnetic fields preventing osteoporosis foundation.
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Densidad Ósea , Huesos/fisiología , Campos Electromagnéticos , Osteogénesis , Animales , Femenino , Distribución Aleatoria , Ratas , Ratas Sprague-DawleyRESUMEN
Pulsed electromagnetic fields (PEMFs) have been considered as a potential candidate for the prevention and treatment of osteoporosis, however, the mechanism of its action is still elusive. We have previously reported that 50Hz 0.6mT PEMFs stimulate osteoblastic differentiation and mineralization in a primary cilium- dependent manner, but did not know the reason. In the current study, we found that the PEMFs promoted osteogenic differentiation and maturation of rat calvarial osteoblasts (ROBs) by activating bone morphogenetic protein BMP-Smad1/5/8 signaling on the condition that primary cilia were normal. Further studies revealed that BMPRII, the primary binding receptor of BMP ligand, was readily and strongly upregulated by PEMF treatment and localized at the bases of primary cilia. Abrogation of primary cilia with small interfering RNA sequence targeting IFT88 abolished the PEMF-induced upregulation of BMPRII and its ciliary localization. Knockdown of BMPRII expression level with RNA interference had no effects on primary cilia but significantly decreased the promoting effect of PEMFs on osteoblastic differentiation and maturation. These results indicated that PEMFs stimulate osteogenic differentiation and maturation of osteoblast by primary cilium-mediated upregulation of BMPRII expression and subsequently activation of BMP-Smad1/5/8 signaling, and that BMPRII is the key component linking primary cilium and BMP-Smad1/5/8 pathway. This study has thus revealed the molecular mechanism for the osteogenic effect of PEMFs.
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Receptores de Proteínas Morfogenéticas Óseas de Tipo II/metabolismo , Diferenciación Celular , Cilios/metabolismo , Campos Electromagnéticos , Osteoblastos/citología , Osteoblastos/metabolismo , Osteogénesis , Regulación hacia Arriba , Animales , Animales Recién Nacidos , Proteína Morfogenética Ósea 2/metabolismo , Receptores de Proteínas Morfogenéticas Óseas de Tipo 1/metabolismo , Calcificación Fisiológica/efectos de los fármacos , Proteínas Portadoras/farmacología , Diferenciación Celular/efectos de los fármacos , Silenciador del Gen/efectos de los fármacos , Humanos , Osteoblastos/efectos de los fármacos , Osteogénesis/efectos de los fármacos , Pirazoles/farmacología , Pirimidinas/farmacología , ARN Interferente Pequeño/metabolismo , Ratas Wistar , Transducción de Señal/efectos de los fármacos , Proteínas Smad/metabolismo , Proteínas Supresoras de Tumor/metabolismo , Regulación hacia Arriba/efectos de los fármacosRESUMEN
Although the neurotoxicity of amyloid ß (Aß) protein in Alzheimer's disease (AD) has been reported widely, the exact molecular mechanism underlying the Aß-induced synaptic dysfunction and memory impairment remains largely unclear. Growing evidence indicates that wingless-type (Wnt) signaling plays an important role in neuronal development, synapse formation and synaptic plasticity. In the present study, we investigated the neuroprotective action of Wnt-5a against the synaptic damage and memory deficit induced by Aß25-35 by using in vivo electrophysiological recording and Morris water maze (MWM) test. We found that intracerebroventricular (i.c.v.) injection of Aß25-35 alone did not affect the baseline field excitatory postsynaptic potentials (fEPSPs) and the paired-pulse facilitation (PPF) in the hippocampal CA1 region of rats, but significantly suppressed high frequency stimulation (HFS) induced long-term potentiation (LTP); pretreatment with Wnt-5a prevented the Aß25-35-induced suppression of hippocampal LTP in a dose-dependent manner; soluble Frizzled-related protein (sFRP), a specific Wnt antagonist, effectively attenuated the protective effects of Wnt-5a. In MWM test, Aß25-35 alone significantly disrupted spatial learning and memory ability of rats, while pretreatment with Wnt-5a effectively prevented the impairments induced by Aß25-35. These results in the present study demonstrated for the first time the neuroprotective effects of Wnt-5a against Aß-induced in vivo synaptic plasticity impairment and memory disorder, suggesting that Wnt signaling pathway is one of the important targets of Aß neurotoxicity and Wnt-5a might be used as one of the putative candidates for the therapeutic intervention of AD.
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Péptidos beta-Amiloides/toxicidad , Potenciación a Largo Plazo/efectos de los fármacos , Trastornos de la Memoria/inducido químicamente , Trastornos de la Memoria/tratamiento farmacológico , Fragmentos de Péptidos/toxicidad , Memoria Espacial/efectos de los fármacos , Proteínas Wnt/uso terapéutico , Análisis de Varianza , Animales , Relación Dosis-Respuesta a Droga , Estimulación Eléctrica , Reacción de Fuga/efectos de los fármacos , Glicoproteínas/uso terapéutico , Hipocampo/efectos de los fármacos , Péptidos y Proteínas de Señalización Intracelular , Potenciación a Largo Plazo/fisiología , Masculino , Aprendizaje por Laberinto/efectos de los fármacos , Ratas , Ratas Wistar , Tiempo de Reacción/efectos de los fármacos , Proteína Wnt-5aRESUMEN
OBJECTIVE: To investigate the effects of different-intensity sinusoidal electromagnetic fields (SEMFs) on bone mineral density (BMD) and histomorphometry in SD rats. METHODS: Thirty female SD rats were randomly divided into three groups: group A (a control group), group B (0.1 mT group) and group C (0.6 mT group). The rats in group B and C were exposed to 50 Hz SEMFs 3 hours each day. However,the magnetic intensity was different between group B and group C:0.1 mT for group B and 0.6 mT for group C. After 8 weeks, all the animals were killed. Changes of BMD and histomorphometric properties were observed. RESULTS: Compared with group A, the BMD of whole body, femur and vertebrae of rats in group B increased significantly; the area percentage, number and width of bone trabeculae in vertebrae and femur of rats in group B were larger than those of group A; but the resolution of bone trabeculae of rats in group B was lower than that of group A. The trabecular number in group C rats were significantly decreased, compared with that in group A rats. The outcome of double fluorescence labeling in group B was found to be significantly different with that in group A. But the difference between rats in group A and C was not significant. CONCLUSION: This study demonstrates that 50 Hz 0.1 mT SEMFs can increase BMD, improve bone tissue microstructure and, promote bone formation.
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Densidad Ósea/efectos de la radiación , Campos Electromagnéticos , Vértebras Lumbares/efectos de la radiación , Tibia/efectos de la radiación , Animales , Femenino , Vértebras Lumbares/patología , Osteogénesis/efectos de la radiación , Ratas , Ratas Sprague-Dawley , Tibia/patologíaRESUMEN
The removal efficiency of Prometon degraded by O3/H2O2 advanced oxidation process (AOP) was represented by the pseudo-first-rate order to discuss the effect of n(H2O2)/n(O3), pH, water quality and HCO-. The organic products were characterized by GC/MS and LC/MS and NO3- produced during degradation was determined by IC, on the basis of which the degradation path of Prometon was also investigated. The result indicated that when concentration of Prometon was 2 mg x L(-1), dosage of ozone was 13 mg x L(-1), the reactive temperature was 25 degrees C, the optimal condition of degradation was as follows, n(H2O2)/n (O3 ) = 0.7, pH 7-8; The micro inorganic and organic substances in tap water promoted the removal rate of the Prometon comparing to that in pure water, and HCO3- showed inhibition effect on degradation. The results of GC/MS and LC/MS suggested that the triazine ring of Prometon was not destroyed during the AOP, the two isopropyl of triazine ring were disengaged firstly, and the NO3- detected by IC might be the oxidation product of the amido of the triazine ring.
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Peróxido de Hidrógeno/química , Ozono/química , Triazinas/aislamiento & purificación , Contaminantes Químicos del Agua/aislamiento & purificación , Purificación del Agua/métodos , Herbicidas/aislamiento & purificación , Oxidación-Reducción , Abastecimiento de AguaRESUMEN
An atrazine-degrading bacterial strain named L-6 was isolated from the sludge mixture of the sewage treatment plant by cultivating in raw water with limited nutrition and aeration and was domesticated steadily using SBR (Sequencing Batch Reactor) for two months. The degradation rate of atrazine in inorganic liquid culture medium with atrazine as the sole source of nitrogen could reach 89.2% after 96 hours. The cells showed shape of long rod under scanning electron microscope. After extraction of genomic DNA and PCR amplification, the 16S rRNA gene sequences were used for homology analysis and construction of phylogenetic trees. The results suggested that the 16S rRNA gene sequence of L-6 had up to 99% homology with those of many strains of Pseudomonas strains in GenBank database. With physiological and biochemical reactions, the strain L-6 was identified as Pseudomonas sp. Carbon use test indicated that L-6 can utilize glucose, fructose and citric acid sodium as carbon sources, but could not use sucrose, lactose or starch. The optimum degradation conditions were optimized as following:temperature 30 degrees C, initial pH 7-9.
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Atrazina/aislamiento & purificación , Pseudomonas/aislamiento & purificación , Pseudomonas/metabolismo , Atrazina/metabolismo , Biodegradación Ambiental , Reactores Biológicos/microbiología , Herbicidas/aislamiento & purificación , Herbicidas/metabolismo , Pseudomonas/genética , ARN Ribosómico 16S/genéticaRESUMEN
Effect of dosing powder activated carbon (PAC) on the characteristics of the sludge mixed liquor in membrane bioreactor (MBR) was investigated by parallel tests. And the reason that PAC mitigated membrane fouling was also explored. The results showed that PAC could decrease mixture viscosity and increase sludge particle size, which led to less trans-membrane pressure developing. Extracellular polymer substances (EPS) content, sludge specific resistance and cake layer resistance (R(c)) had a good correlation. Adding PAC could decrease EPS concentration, sludge specific resistance and then slow down the increase of R(c), which mitigated membrane fouling. Membrane pore blocking resistance (R(p)) increased exponentially with increasing of the soluble microbial products (SMP) concentration in the supernatant. Dosing PAC reduced the SMP concentration and slowed down the growth rate of R(p), which was helpful to mitigating membrane fouling. R(c) and R(p) increased along with the operation of MBRs and R(c)/R(f) (26.32% -63.16%) was always greater than R(p)/R(f) (7.89% -35.32%) which suggested the R(c) was the main factor in membrane fouling. Moreover, it was also found that controlling of dosing PAC on R(c) was better than it on R(p).
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Reactores Biológicos , Carbón Orgánico/química , Membranas Artificiales , Aguas del Alcantarillado/química , Eliminación de Residuos Líquidos/métodos , Adsorción , Análisis de Falla de Equipo , Filtración/instrumentación , Filtración/métodos , Eliminación de Residuos Líquidos/instrumentaciónRESUMEN
The two-chamber microbial fuel cells (MFCs) were constructed with excess sludge as the anodic substrate and CuSO4 solution as the catholyte. The start up method, degradation of the anodic sludge, removal of the Cu2+ and products on cathode were investigated in the study. The results of batch experiments showed that Cu2+ can be used as cathodic electron acceptors, e. g. a stable voltage output of 0.478 V and a maximum power density of 536 mW/m3 were obtained at external resistance of 1 000 omega and Cu2+ concentration of 6 400 mg/L. The Cu2+ contained in wastewater could be removed effectively by the MFC process, e. g. 97.8% of Cu2+ was removed in a MFC reactor at the end of 288 h with initial Cu2+ concentration of 1 000 mg/L and external resistance of 0 omega. The cathodic products depended on cathodic reducibility, most of Cu2+ was deposited as Cu2O and a small part as Cu4 (OH), 6SO4 with lower cathodic reducibility, metal copper deposited on the cathode with higher cathodic reducibility. Using excess sludge as anodic substrate could support the MFCs for long-term operation. The acclimation stage of the exoelectrogenic bacteria on the anode had an impact on MFC performance and cathodic reduction of Cu2+, and the stability of exoelectrogenic biofilm on anode could be determined by monitoring the anode potential. The MFC with excess sludge as anodic substrate can degrade organic matter in sludge and accomplish Cu(2+) -containing wastewater treatment and copper recovery simultaneously.
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Fuentes de Energía Bioeléctrica , Cobre/aislamiento & purificación , Aguas del Alcantarillado/química , Eliminación de Residuos Líquidos/métodos , Electrodos , Microbiología Industrial , Especificidad por SustratoRESUMEN
In order to study the effect of O3 inactivating Giardia in water, different factors (CT value, pH, temperature, turbidity, organic content and inorganic ions) which might influence the inactivation were investigated by using fluorescence staining method. The results indicated that the whole process of O3 inactivating Giardia could be divided into two periods, the inactivated rate in log phase was significantly faster than it in the slow phase [k1 = (5.64 +/- 0.023) x 10(-1) mg x min, k2 = (2.72 +/- 0.002) x 10(-2) mg x min, k1 >> k2]. When the turbidity was 0.1 to 20. 0NTU, temperature was 5 to 35 degrees C, pH was 6.0 to 9.0, HA content was 0.5 to 10.0 mg/L, the turbidity was lower, the higher inactivating ratio could be received. With the increasing of temperature, the inactivating effect was decreased. The ability of O3 inactivating Giardia was stronger under acidic condition than it was in alkali circumstance. When the reaction system contained higher concentration of organics, the competition reaction might take place between Giardia and organics with O3, which might reduce inactivation ratio. The sequence of affecting disinfectant ability of O3 was NO3- > None > SO4(2-) > HCO3-, while inorganic cations (Ca2+, Mg2+ and Cu2+) promoted the inactive reaction to a certain extent. If the CT value of O3 was more than 15.0 min x mg/L, the ratio of inactivation could exceed 99.0% during disinfecting drinking water.
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Desinfectantes/farmacología , Giardia/efectos de los fármacos , Ozono/farmacología , Agua/parasitología , Animales , Giardia/crecimiento & desarrollo , Concentración de Iones de Hidrógeno , Temperatura , Abastecimiento de AguaRESUMEN
The endocrine disrupter Atrazine was oxidized by O3/H2O2 system and the products were analyzed to assess the degradation efficiency of Atrazine. When it's initial content was 2 mg/L and O3 dosage was 7.5 mg/L, Atrazine was removed about 27.2% after 5 minutes. Under the same condition, H2O2/O3 molar ratio was 0.75, Atrazine maximum removal rate reached 96.5%, which suggested that Atrazine could be degraded by O3/H2O2 system effectively. Ion Chromatography (IC) analysis showed that concentrations of chloride and nitrate ions were increasing along with the Atrazine content decreasing. Gas Chromatography-Mass spectrometry (GC-MS) and Liquid Chromatography-Mass spectrometry chromatograms (LC-MS) analyzing illuminated the existence of de-ethyl-atrazine, de-isopropyl-atrazine and de-chloro-atrazine, which indicated the Atrazine could not be destroyed completely by O3/H2O2 system. Consequently, it should be combined with GAC (Granular Activated Carbon) or other techniques while used as primary treatment unit or emergency measure.
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Atrazina/aislamiento & purificación , Peróxido de Hidrógeno/química , Ozono/química , Contaminantes Químicos del Agua/aislamiento & purificación , Purificación del Agua/métodos , Atrazina/química , Disruptores Endocrinos/química , Disruptores Endocrinos/aislamiento & purificación , Cromatografía de Gases y Espectrometría de Masas , Oxidación-Reducción , Contaminantes Químicos del Agua/químicaRESUMEN
The endocrine disrupter simazine was oxidized by O3/H2O2 and the reactive productions was analyzed by chromatography to assess the degradation efficiency of Simazine. The initial content of Simazine 2 mg/L was removed about 87.1% by O3H2O2 system when the O3 was dosed as 10.0 mg/L, the H2O2/O3 molar ratio was 0.70, the temperature was 26 degrees C and pH 7-8, which indicated Simazine could be conveniently removed by O3/H2O2 system in ordinary reactive condition. The simazine removal ratio in tap water was 10% more than it in purified water up to 86.9%. The removal of simazine was decreased when the content of humic acid (HA) was high, whereas it was increased while low content HA in water. Also, the removal efficiency was inhabited by hydrogen carbonate fairly. The deethyl-simazine (DES) was trapped by Gas Chromatography Mass Spectrum(GC-MS) which was also certificated by analyzing the Liquid Chromatography Mass Spectrum (LC-MS) of the products. The Ion Chromatography spectrum showed the existing of de-chloro-procedure and breakage of triazine ring. Which indicated the oxidizability of O3/H2O2 system was fairly strong.