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1.
Environ Sci Pollut Res Int ; 31(5): 7959-7976, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38175505

RESUMO

Sulfur-containing gases are main sources of landfill odors, which has become a big issue for pollution to environment and human health. Biocover is promising for treating landfill odors, with advantages of durability and environmental friendliness. In this study, charcoal sludge compost was utilized as the main effective component of a novel alternative landfill cover and the in situ control of sulfur-containing odors from municipal solid waste landfilling process was simulated under nine different operating conditions. Results showed that five sulfur-containing odors (hydrogen sulfide, H2S; methyl mercaptan, CH3SH; dimethyl sulfide, CH3SCH3; ethylmercaptan, CH3CH2SH; carbon disulfide, CS2) were monitored and removed by the biocover, with the highest removal efficiencies of 77.18% for H2S, 87.36% for CH3SH, and 92.19% for CH3SCH3 in reactor 8#, and 95.94% for CH3CH2SH and 94.44% for CS2 in reactor 3#. The orthogonal experiment showed that the factors influencing the removal efficiencies of sulfur-containing odors were ranked from high to low as follows: temperature > weight ratio > humidity content. The combination of parameters of 20% weight ratio, 25°C temperature, and 30% water content was more recommended based on the consideration of the removal efficiencies and economic benefits. The mechanisms of sulfur conversion inside biocover were analyzed. Most organic sulfur was firstly degraded to reduced sulfides or element sulfur, and then oxidized to sulfate which could be stable in the layer as the final state. In this process, sulfur-oxidizing bacteria play a great role, and the distribution of them in reactor 1#, 5#, and 8# was specifically monitored. Bradyrhizobiaceae and Rhodospirillaceae were the dominant species which can utilize sulfide as substance to produce sulfate and element sulfur, respectively. Based on the results of OUTs, the biodiversity of these sulfur-oxidizing bacteria, these microorganisms, was demonstrated to be affected by the different parameters. These results indicate that the novel alternative landfill cover modified with bamboo charcoal compost is effective in removing sulfur odors from landfills. Meanwhile, the findings have direct implications for addressing landfill odor problems through parameter adjustment.


Assuntos
Sulfeto de Hidrogênio , Odorantes , Humanos , Carvão Vegetal/metabolismo , Sulfeto de Hidrogênio/metabolismo , Enxofre/metabolismo , Instalações de Eliminação de Resíduos , Óxidos de Enxofre , Bactérias/metabolismo , Sulfatos/metabolismo
2.
Medicine (Baltimore) ; 103(2): e36518, 2024 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-38215105

RESUMO

To explore Helicobacter pylori (Hp) infection status and its relationship with lifestyle habits and dietary factors in patients with chronic atrophic gastritis. Six hundred thirty-eight patients with chronic atrophic gastritis, who were admitted to our hospital from March 2021 to April 2023, were selected for the study. All patients underwent the 13C urea breath test. The relationship between the detection rate of Hp infection and the clinical characteristics, lifestyle habits, and dietary factors of the patients was analyzed. Among the 638 patients with chronic atrophic gastritis, 531 patients were tested positive for Hp infection, the positive rate for Hp infection was approximately 83.23%. Analyzing the clinical characteristics of the patients, it was found that age, family history of gastric cancer, degree of chronic inflammation, degree of glandular atrophy, presence of low-grade dysplasia, and intestinal metaplasia all have an impact on the positive detection rate of patients (P < .05). Analyzing the patients' lifestyle habits, it was found that BMI, smoking history, alcohol consumption, preference for spicy food, dining location, consumption of pickled foods, frequent consumption of grilled/barbecued foods, preference for strong tea, consumption of sweets, and work-related stress had an impact on the positive rate of Hp infection in patients (P < .05). The discovery showed that the levels of total protein, albumin, hemoglobin, cholesterol, and the intake of livestock and poultry meat, seafood, dairy products, vegetables, fruits, and fats have an impact on the positivity rate of Hp infection in patients (P < .05). A multiple logistic regression analysis was performed, and it was found that patients' age, family history of gastric cancer, degree of chronic inflammation, degree of glandular atrophy, presence of low-grade dysplasia, presence of wasting or obesity, history of alcohol consumption, preference for spicy food, dining location, frequent consumption of strong tea, high work pressure, high intake of fish and seafood, low intake of dairy products, low intake of vegetables, low intake of fruits, and low intake of fats all had an impact on the occurrence of Hp infection in patients (P < .05). There is a certain correlation between patients' lifestyle habits, dietary factors, and clinical characteristics with the occurrence of Hp infection. These factors can assist in the prevention of Hp infection.


Assuntos
Gastrite Atrófica , Infecções por Helicobacter , Helicobacter pylori , Neoplasias Gástricas , Humanos , Gastrite Atrófica/epidemiologia , Gastrite Atrófica/tratamento farmacológico , Infecções por Helicobacter/tratamento farmacológico , Neoplasias Gástricas/patologia , Estudos Retrospectivos , Inflamação/patologia , Ingestão de Alimentos , Atrofia , Hábitos , Chá , Mucosa Gástrica/patologia
3.
Ecotoxicol Environ Saf ; 262: 115166, 2023 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-37348213

RESUMO

The widespread heavy metal contamination of agricultural soils poses an enormous challenge to food safety. To evaluate the Cd immobilization potential of vermicompost combined with modified shell powder (VMSP) on Cd-contaminated soil, batch adsorption tests and field experiments were conducted. First, the Cd2+ removal characteristics and adsorption mechanisms of vermicompost (V), vermicompost combined with shell powder (VSP), and VMSP in an aqueous solution were investigated by batch tests. Then, 3 kg·m2 V, VSP, and VMSP doses were applied to Cd-contaminated farmland soils as soil amendments to plant green garlic (Allium sativum L.) and investigate their Cd immobilization effects in Cd-contaminated soils. Batch adsorption tests showed that VMSP was most effective for Cd2+ removal, with adsorption rates as high as 85.7-99.79% and desorption rates of approximately 1.25-1.34%. Combining further characterization analysis of VMSP, it was demonstrated that the adsorption mechanism of Cd2+ was monolayer chemisorption, mainly involving the complexation reaction of Cd2+ with organic functional groups and the precipitation reaction of Cd2+ with mineral elements. The field experiment showed that adding V, VSP, and VMSP effectively inhibited the enrichment of Cd in green garlic, and the Cd content was reduced by 42.18%, 46.88%, and 68.75%, respectively. However, only the Cd content of green garlic treated with VMSP was lower than the national standard for food safety in China (Cd≤ 0.2 mg·kg-1). V, VSP, and VMSP additions improved soil fertility and reduced Cd bioavailability in the soil by 15.5%, 18.9%, and 36.3%, respectively. In addition, V, VSP, and VMSP addition increased bacterial diversity and improved bacterial communities and functions in the soil by improving basic soil properties and reducing Cd-related toxicity. The results indicated that VMSP is a promising amendment for Cd immobilization in Cd-contaminated farmland soils.

4.
Environ Sci Pollut Res Int ; 30(4): 8998-9010, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35648348

RESUMO

A large amount of kitchen waste is produced all over the world. Biochemical disposal is an effective method for the reduction and safe utilization of kitchen waste. However, high salinity, low maturity and poor biocompatibility were encountered when utilizing the biochemical residue of kitchen waste (BRKW) as a kind of soil amendment. To reduce the high salinity, accelerate the maturity and improve the biocompatibility in the BRKW, this study used the BRKW as the main feedstock for earthworms after hydrolyzed polymaleic anhydride (HPMA) was added and focused on revealing the effect of HPMA addition combined with the vermicomposting process on the growth of earthworms and on the basic physicochemical properties and the microbial diversity of the derived vermicompost. The results showed that HPMA addition can promote earthworm growth and reproduction. The pH, electric conductivity, organic matter content, C/N and NH4+-N/NO3--N were decreased in the final vermicompost, while total nitrogen, total phosphorus and total potassium contents, and the seed germination index were increased. Scanning electron microscopy analysis showed that there was more disintegration in the final vermicompost. Meanwhile, adding the HPMA also helped to decrease the total number of fungi while increasing the populations of nitrogen-fixing bacteria, phosphorus-solubilizing bacteria and potassium-solubilizing bacteria as well as amount of total bacteria and actinomycetes. The vermicomposting process increased the bacterial phyla that promote the degradation of OM, such as Actinobacteria, Firmicutes and Acidobacteria, decreased the pathogenic Enterobacter and increased the bacterial genera that promote the maturity and quality, such as Cellvibrio and Pseudomonas. Thus, HPMA addition combined with vermicomposting can promote the growth of beneficial bacteria that promote the degradation of lignocelluloses and accelerate maturity while inhibiting some potential bacterial pathogens, which helps guarantee the safety of vermicomposting products from BRKW. Hence, employing HPMA to promote BRKW vermicomposting can possibly reduce salt content and improve the maturity and biocompatibility of the final vermicompost. This approach may help realize the safe utilization of BRKW and further promote the biochemical disposal of kitchen waste.


Assuntos
Oligoquetos , Animais , Oligoquetos/metabolismo , Solo/química , Bactérias , Fósforo/metabolismo , Esterco
5.
Environ Sci Pollut Res Int ; 29(47): 70635-70657, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35997884

RESUMO

Cyanobacterial bloom is by far one of the most common water quality hazards. As cyanobacteria are rich in nitrogen, phosphorus, and other organic matter, the potential for beneficial use of cyanobacteria is promising. Aerobic composting is currently a hot topic of research in cyanobacteria treatment, which can effectively achieve reduction, recycling, and removal of the harmful impact of cyanobacteria. In this review, the characteristics of cyanobacteria in aerobic composting processes, the effects of physical, chemical, and biological factors on the composting process, and the degradation of microcystic toxins were systematically discussed and summarized. This review epitomizes the large quantities of research data collected by many scholars around the world to address the characteristics of "one low and five highs" in the aerobic cyanobacterial composting process. The composting techniques developed are effective and easy to adopt in the real world, such as adjusting the substrate C/N ratio and moisture content and use of chemical and biological additives to achieve reduction, recycling, and detoxication of the cyanobacterial wastes. The aim of this comprehensive review is to provide theoretical guidance and reference for further development and application of aerobic cyanobacteria composting technology.


Assuntos
Compostagem , Cianobactérias , Fatores Biológicos , Toxinas de Cianobactérias , Nitrogênio/análise , Fósforo , Solo/química
6.
J Laparoendosc Adv Surg Tech A ; 32(2): 158-164, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33651638

RESUMO

Objective: To investigate the efficacy and safety of cold snare endoscopic mucosal resection (CS-EMR) and hot snare endoscopic mucosal resection (HS-EMR) for colorectal polyps with diameters of 6-9 mm. Methods: Retrospective analysis was performed on the clinical data of 485 patients with colorectal polyps (6-9 mm in size) who were treated with CS-EMR or HS-EMR in the endoscopy center of Hangzhou Third People's Hospital from January 2017 to December 2019. Colorectal polyps were lifted by submucosal injection of normal saline. The CS-EMR group used a cold snare to remove the lifting polyps, while the HS-EMR group used a hot snare. Propensity score matching analysis with 1:1 matching and the nearest neighbor matching method were performed to ensure well-balanced characteristics of the CS-EMR and HS-EMR groups. Matching factors included age, gender, body mass index, blood routine, coagulation indicators, polyp site, size, number, and morphology. This resulted in a balanced cohort of 128 patients per group. Polyp recovery, complications, clipping for disclosure, and length of hospital stay were compared after matching. t-Tests, χ2 tests, McNemar's tests, and Fisher's exact test were used for comparison between the two groups before and after matching. Results: There were no differences between the two groups of intraoperative and postoperative bleeding (P > .05), but the CS-EMR clipping rate was lower than the HS-EMR group (P < .01). There was a higher incidence of post-polypectomy syndrome (PPS) (P = .03) and longer hospital stays (P < .01) in the HS-EMR group than the CS-EMR group. Conclusions: Compared with HS-EMR, CS-EMR is more convenient to operate, with a low incidence of PPS, clipping rates, and short hospital stays. It is a safe and effective removal method for 6-9 mm colorectal polyps.


Assuntos
Pólipos do Colo , Ressecção Endoscópica de Mucosa , Pólipos do Colo/cirurgia , Colonoscopia , Humanos , Pontuação de Propensão , Estudos Retrospectivos
7.
Waste Manag Res ; 40(6): 736-744, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34334056

RESUMO

Aiming to reveal the humification process of organic waste and its contribution to the heavy metal behaviour affected by earthworm activity, it was studied about the variation of humic acid (HA) and heavy metal behaviour during vermicomposting of the mixed pig manure and 13C-labelled rice straw. The results showed that earthworms could well adapt to the culturing environment and feed organic matter for its growth and reproduction, the vermicomposting process increased the content of humic substances (HS), HA, and fulvic acid (FA) in substrate residues, but led to less transformation of HA into FA. The elemental, ultraviolet absorption spectroscopy, Fourier transform infrared (FTIR) and fluorescence excitation-emission matrix (EEM) analysis indicated that vermicomposting led to more aromatic structures and much higher humification degree in HA, whereas less protein, FA-like substances and plastein in HA. Vermicomposting could enhance the total Cu content and decrease Cu/Zn bioavailability in the substrate residues, and vermicomposting especially can help stabilize Cu in the substrate residues by forming more complexed HA-Cu.


Assuntos
Metais Pesados , Oligoquetos , Oryza , Animais , Substâncias Húmicas/análise , Esterco , Oligoquetos/metabolismo , Suínos
8.
Ecotoxicol Environ Saf ; 215: 112163, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33756288

RESUMO

Cadmium (Cd) contamination has become serious in soil and in situ stabilization technology has been widely used for heavy metal remediation. A field study was conducted to determine the effect of amendments with the doses of 3 kg/m2, including single vermicompost (A1), a 95% vermicompost mixed with 5% shell powder composite (A2) and a 95% vermicompost mixed with 5% modified shell powder composite (A3), on the Cd bioavailability, enzyme activity and bacterial community in soil, and the experiment was conducted with lettuce (Lactuca sativa L.) grown in a Cd-contaminated farmland soil. The results showed that the application of amendments increased the pH, cation exchange capacity (CEC), organic matter (OM), available nutrients, catalase (S-CAT), invertase (S-SC) and urease (S-UE) activities in soil, while significantly reduced the Cd bioavailability with the lowest Cd bioavailability being observed in the soil with A3 application. The soil bacterial richness and diversity increased after amendments application, and the bacterial community was characterized by an increase in metal-tolerant bacteria but a decrease in Proteobacteria, Acidobacteria and Gemmatimonadetes. In addition, the application of amendments significantly improved the growth of lettuce (Lactuca sativa L.) and inhibited Cd accumulation in its edible parts, especially, the Cd content in lettuce (Lactuca sativa L.) grown in soil with A3 application was below the limit of the National Food Safety Standard of China (maximum level ≤ 0.2 mg/kg). Thus, composite amendment obtained from vermicompost mixed with modified shell powder can be used as potential remediation material in Cd-contaminated soil. CAPSULE: Composite amendment obtained from vermicompost and modified shell powder had good effects on remediation of Cd-contaminated soil.


Assuntos
Cádmio/análise , Microbiologia do Solo , Poluentes do Solo/análise , Acidobacteria , Bactérias , Disponibilidade Biológica , China , Poluição Ambiental , Fazendas , Lactuca , Metais Pesados , Pós , Proteobactérias , Solo/química , Urease
9.
Clin Cosmet Investig Dermatol ; 14: 129-136, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33584099

RESUMO

OBJECTIVE: To investigate the role of Helicobacter pylori (HP) eradication in chronic spontaneous urticaria (CSU) treatment. METHODS: Retrospective analysis was performed on the clinical data of 522 patients with CSU who underwent a HP breath test in Hangzhou Third People's Hospital between January 2018 and December 2019. The CSU-HP(+) group consisted of patients with CSU and HP infection, who were treated with antihistamines combined with HP eradication therapy. The CSU-HP(-) group consisted of patients with CSU alone, who were treated with antihistamines. Propensity score matching (PSM) analysis, using the nearest neighbor matching method on a 1:1 basis, was performed to ensure the characteristics of the CSU-HP(+) and CSU-HP(-) groups were similar. Factors, including age, gender, white blood cells, red blood cells, platelets, alanine transaminase, creatinine, immunoglobulin E, and pre-treatment urticaria activity score (UAS), were matched to obtain a balanced cohort of patients in each group. Therapeutic effects were compared after matching. t-tests, Χ 2 test, and McNemar's test were used for comparison between the two groups before and after matching. RESULTS: Patients in the CSU-HP(+) group reported significantly more gastrointestinal symptoms than those in the CSU-HP(-) group. UAS scores in the second week of treatment were significantly different between the two groups. After 3 months, the recurrence rate in the CSU-HP(+) group was lower than in the CSU-HP(-) group. CONCLUSION: Eradication of HP infection in patients with CSU helps relieve gastrointestinal symptoms, improves the therapeutic effect of CSU within 2 weeks, and reduces the recurrence rate 3 months after treatment.

10.
Front Chem ; 8: 467, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32754572

RESUMO

A binary hybrid system comprising a hypervalent iodine(III) reagent and BF3•OEt2 Lewis acid was found to be effective for the diastereoselective α-acetoxylation of cyclic ketones. In this hybrid system, BF3•OEt2 Lewis acid allowed the activation of the hypervalent iodine(III) reagent and cyclic ketones for smooth α-acetoxylation reaction, achieving high diastereoselectivity. This hypervalent iodine-mediated α-acetoxylation of the cyclic ketone reaction plausibly undergoes an SN2 substitution mechanism via an α-C-bound hypervalent iodine intermediate. The diastereoselectivity of the reaction mainly originates from thermodynamic control.

11.
Front Physiol ; 11: 316, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32351401

RESUMO

Hazardous anatoxin-a (ANTX-a) is produced by freshwater algal blooms worldwide, which greatly increases the risk of consumer exposure. Although ANTX-a shows widespread neurotoxicity in aquatic animals, little is known about its mechanism of action and biotransformation in biological systems, especially in immunobiological models. In this study, transmission electron microscopy results showed that ANTX-a can destroy lymphocytes of Carassius auratus in vitro by inducing cytoplasmic concentration, vacuolation, and swollen mitochondria. DNA fragmentations clearly showed a ladder pattern in agarose gel electrophoresis, which demonstrated that the apoptosis of fish lymphocytes was caused by exposure to ANTX-a. Flow cytometry results showed that the apoptotic percentage of fish lymphocytes exposed to 0.01, 0.1, 1, and 10 mg/L of ANTX-a for 12 h reached 18.89, 22.89, 39.23, and 35.58%, respectively. ANTX-a exposure induced a significant increase in reactive oxygen species (ROS) and malonaldehyde (MDA) in lymphocytes. The activities of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx), and the glutathione (GSH) content of the 0.01 mg/L ANTX-a-treated group decreased significantly by about 41, 46, 67, and 54% compared with that of the control group (p < 0.01), respectively. Although these observations were dose-dependent, these results suggested that ANTX-a can induce lymphocyte apoptosis via intracellular oxidative stress and destroy the antioxidant system after a short exposure time of only 12 h. Besides neurotoxicity, ANTX-a may also be toxic to the immune system of fish, even when the fish are exposed to environmentally relevant concentrations, which clearly demonstrated that the potential health risks induced by ANTX-a in aquatic organisms requires attention.

12.
Sci Total Environ ; 716: 137108, 2020 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-32059306

RESUMO

Waste emissions have increased the amount of water and soil contaminated with heavy metals such as Pb. To broaden the methods for the recycling and environmental usage of cow manure (CM) and its vermicompost (CV), CM, CV, and their derived biochars produced by the pyrolysis of CM or CV at 350 and 700 °C were used as adsorbents for Pb2+ removal in this batch adsorption experiment to reveal their different Pb2+ removal efficiencies and the underlying mechanisms. The batch experiment results revealed that all adsorbents rapidly removed Pb2+ within 30 min. A pH between 2.0 and 6.0 positively affected Pb2+ removal by CM and its biochar, whereas that by CV and its biochar was only positively affected by pH between 2.0 and 3.0. CV-derived biochar was more effective in the removal of Pb2+ than the other absorbents, with the maximum adsorption capacities (Qm) fitted from the Langmuir model reaching approximately 230.0 mg·g-1 and the desorption rate (DR) being approximately 0.00-0.02%. Material physiochemical characterization, including X-ray diffraction analysis, showed that high pH, high ash content, rich mineral content, and high mineral contents might have been the main reasons for more effective removal of Pb2+ from aqueous solutions by CV-derived biochar. Fourier-transform infrared analysis indicated that surface functional groups such as -OH, CO, -COO-, and C-O; original and newly produced carbonate; and phosphate in CV also led to more effective Pb2+ removal efficiency from aqueous solution via surface functional group binding. Thus, pyrolyzing CVs may be used to produce biochar as a cost-effective adsorbent for heavy metal remediation in soil and water in the future.


Assuntos
Esterco , Adsorção , Animais , Bovinos , Carvão Vegetal , Feminino , Chumbo
14.
Bioresour Technol ; 293: 122096, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31493731

RESUMO

The microbial community characteristics, functional and antibiotic resistance genes (ARGs), anammox performance under individual and combined oxytetracycline (OTC) and sulfamethoxazole (SMX) were tested under environmentally relevant levels. The results showed that anammox performance was inhibited when the OTC or SMX concentration increased from 0.5 to 1.0 mg L-1. The absolute abundance of tetX in OTC (3.03 × 106 copies mg-1), SMX (2.80 × 106 copies mg-1) and OTC + SMX (2.03 × 106 copies mg-1) was the highest and one more order of magnitude higher than that of tetG, tetM, intI1, or sul2. The anammox performance in the presence of OTC or SMX was lower than that sum of their independent effects. The enrichment of sludge resistomes with prolonged exposure time and increasing OTC and SMX doses might be due to succession of bacterial hosts and potential elevation of ARGs by horizontal transfer.


Assuntos
Microbiota , Oxitetraciclina , Antibacterianos , Resistência Microbiana a Medicamentos , Genes Bacterianos , Sulfametoxazol
15.
Chemosphere ; 233: 625-632, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31195266

RESUMO

The response of anaerobic ammonium oxidation (anammox) process and granular sludge in the upflow anaerobic sludge blanket reactor was analyzed under long-term exposure to MnO2 nanoparticles (NPs) (1-200 mg L-1). The addition of 200 mg L-1 MnO2 NPs had a significantly positive effect on nitrogen removal and this system exhibited excellent performance, with a total nitrogen removal efficiency of 93.1%. Moreover, the specific anammox activity enhanced with increasing concentrations of MnO2 NPs up to the maximum value of 657.3 ±â€¯9.3 mg TN g-1 VSS d-1 under MnO2 NPs concentration of 200 mg L-1. This value was approximately 1.6-fold higher than that of the reactor in the absence of MnO2 NPs. The extracellular polymeric substances and settling velocity were both increased with MnO2 NPs addition. Meanwhile, the high-throughput sequencing results revealed that MnO2 NPs increased the relative abundance of dominant bacteria (Candidatus Kuenenia) from 17.3% at the absence of MnO2 NPs to 23.9% at 200 mg L-1 MnO2 NPs, which resulted in a higher efficiency of biological nitrogen removal on the anammox system. These results indicated that MnO2 NPs enhanced nitrogen removal performance of anammox process.


Assuntos
Reatores Biológicos/microbiologia , Microbiota , Nanopartículas/toxicidade , Óxidos/toxicidade , Anaerobiose , Bactérias , Compostos de Manganês , Nitrogênio , Oxirredução , Esgotos/microbiologia
16.
Environ Pollut ; 251: 166-174, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31078088

RESUMO

The increasing release of engineered nanoparticles (NPs) from consumer products has raised great concerns about their impacts on biological wastewater treatment. In this study, the widely-used ZnO NP was selected as a model NP to investigate its impact on high-rate denitrifying granular sludge in terms of sludge properties and community structure. A hormesis effect was observed during short-term exposure, in which the specific denitrification activity (SDA) was stimulated by 10% at 1 mg L-1 ZnO NPs, but inhibited by 23% at 5.0 mg L-1 ZnO NPs. When continuously exposed to 2.5 mg L-1 ZnO NPs, the nitrogen removal capacity of the denitrification reactor was nearly deprived within 15 days, and the relative abundance of the dominant denitrifying bacterium (Castellaniella) was decreased from 51.0 to 8.0%. Meanwhile, the dehydrogenase activity (DHA) and the content of extracellular polymeric substance (EPS) significantly decreased to 22.3 and 61.1%, respectively. Nevertheless, the presence of phosphate substantially weakened the adverse effects of ZnO NPs on the SDA, EPS, DHA and the relative abundance of functional genes even exposed to 6.25 mg L-1 ZnO NPs, which was associated with the fact that the level of Zn(II) released from ZnO NPs was significantly reduced in the presence of phosphate. Therefore, the toxicity of ZnO NPs may be mainly attributed to the release of toxic Zn(II) and could be attenuated in the presence of phosphate. Overall, this study provided further reference and meaningful insights into the impact of engineered NPs on biological wastewater treatment.


Assuntos
Fosfatos/química , Eliminação de Resíduos Líquidos , Poluentes Químicos da Água/toxicidade , Óxido de Zinco/toxicidade , Bactérias , Desnitrificação , Matriz Extracelular de Substâncias Poliméricas , Nanopartículas/toxicidade , Nitrogênio/análise , Esgotos/química , Águas Residuárias
17.
Waste Manag ; 87: 679-690, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31109570

RESUMO

Odor problem has become a growing concern for municipal solid waste (MSW) operators and communities located close to landfill sites. In this study, nine laboratory-scale landfill reactors were used to simulate in-situ odor control by a novel landfill cover material consisting of biochar-added sludge compost under various operating parameters. Characterization of odor removal and microbial community in the cover layer under various operating parameters was conducted using gas chromatograph-mass spectrometry and 454 high-throughput pyrosequencing, respectively. Results showed that H2S (76.9-86.0%) and volatile organic sulfur compounds (VOSCs) (12.3-21.7%) were dominant according to their theoretical generated odor concentrations. The total odor REs calculated using the theoretical odor concentrations in the landfill reactors were different than using the measured odor values, which were ranked from high to low as: R6 > R5 > R7 > R4 > R8 > R9 > R3 > R2 > R1, showing the largest discrepancy of 25.3%. The optimum combination of operating parameters based on the theoretical odor concentration was different with that based on the measured odor concentrations. Moreover, although Firmicutes (12.21-91.48%), Proteobacteria (3.55-51.03%), and Actinobacteria (4.01-47.39%) were in general the three major bacterial phyla found in the landfill covers, the detailed bacterial communities in the cover materials of the simulated reactors varied with various operating parameters. Alicyclobacillus and Tuberibacillus showed positive correlations with the removal efficiencies (REs) of chlorinated compounds, H2S, aromatic compounds, volatile organic sulfur compounds (VOSCs), and organic acids. The correlations of Rhodanobacter, Gemmatimonas, Flavisolibacter and Sphingomonas were strongly positive with ammonia RE and relatively positive with REs of organic acids, VOSCs, and aromatic compounds. These findings are instrumental in understanding the relationship between the structure of microbial communities and odor removal performances, and in developing techniques for in-situ odor control at landfills.


Assuntos
Compostagem , Microbiota , Eliminação de Resíduos , Carvão Vegetal , Odorantes , Esgotos , Instalações de Eliminação de Resíduos
18.
Environ Sci Pollut Res Int ; 26(12): 11756-11766, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30815814

RESUMO

Ammonia emission during composting results in anthropogenic odor nuisance and reduces the agronomic value of the compost due to the loss of nitrogen. Adjusting the operating parameters during composting is an emerging in situ odor control technique that is cheap and highly efficient. The effects of in situ NH3 emission control were investigated in this study by simultaneously adjusting key operating parameters (such as C/N ratio, aeration rate, and moisture content) during the composting processes (C1-C9). Results showed that the average NH3 emission concentrations for different treatments were in the order of C1 > C4 > C2 > C5 > C3 > C6 > C7 > C8 > C9. The total content of NH3 emission (21.02 g/kg) in C9 (C/N ratio = 35, aeration rate = 15 L/min, and moisture content = 60%) was much lower than that (65.95 g/kg) in C1 (C/N ratio = 15, aeration rate = 5 L/min, and moisture content = 60%). The nitrogen loss ratio was 27.36% for C1, while 16.15% for C9. The microbial diversity and abundance in C9 and C1 were compared using high-throughput sequencing. The relationship between NH3 emission, operating parameters, and the related functional microbial communities was also investigated. Results revealed that Nitrosospira, Nitrosomonas, Nitrobacter, Pseudomonas, Methanosaeta, Rhodobacter, Paracoccus, and Sphingobacterium were negatively related to NH3 emission. According to the above results, the optimal values for different operating parameters for the in situ NH3 control during kitchen waste composting were, respectively, moisture content of 70%, C/N ratio of 35, and aeration rate of 15 L/min, with the order of effectiveness from high to low being aeration rate > C/N > moisture. This information could be used as a valuable reference for the in situ NH3 emission control during kitchen waste composting.


Assuntos
Poluentes Atmosféricos/análise , Amônia/análise , Compostagem/métodos , Microbiota , Nitrogênio/análise , Solo
19.
Ecotoxicol Environ Saf ; 167: 29-35, 2019 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-30292973

RESUMO

Perfluorooctanoic acid (PFOA) is a perfluorinated compound that is widely distributed, is persistent in the environment, and has a low-level chronic exposure effect on human health. The aim of this study was to investigate the peroxisome proliferator activated receptors γ (PPARγ) and the sterol regulatory element-binding protein 2 (SREBP2) signaling pathways in regulating the lipid damage response to PFOA in the livers of amphibians. Male and female frogs (Rana nigromaculata) were exposed to 0, 0.01, 0.1, 0.5 and 1 mg/L PFOA. After treatment, we evaluated the pathological changes in the liver by Oil Red O, staining and examined the total cholesterol (T-CHO) and triglyceride (TG) contents. The mRNA expression levels of PPARγ, Fatty acid synthase (FAS), Acetyl-CoA carboxylase (ACC), Glycerol-3-phosphate acyltransferase (GPAT), SREBP2 and 3-hydroxy-3-methylglutaryl CoA (HMG-CoA) were measured by quantitative real-time polymerase chain reaction (qRT-PCR). The administration of PFOA caused marked lipid accumulation damage in the amphibian livers. The T-CHO contents were elevated significantly after PFOA treatment; these results show a dose-dependent manner in both sexes. The TG content showed a significant increase in male livers, while it was elevated significantly in female livers. The RT-PCR results showed that the mRNA expression levels of PPARγ, ACC, FAS, GPAT, SREBP2 and HMG-CoA were significantly dose-dependently increased in the PFOA-treated groups compared with those of the control group. Our results demonstrated that PFOA-induced lipid accumulation also affected the expression levels of genes FAS, ACC, GPAT and HMG-CoA in the PPARγ and SREBP2 signaling pathways in the liver. These finding will provide a scientific theoretical basis for the protection of Rana nigromaculata against PFOA effects.


Assuntos
Caprilatos/toxicidade , Fluorocarbonos/toxicidade , Metabolismo dos Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Ranidae/metabolismo , Acil Coenzima A/metabolismo , Animais , Colesterol/metabolismo , Relação Dose-Resposta a Droga , Ácido Graxo Sintases/genética , Ácido Graxo Sintases/metabolismo , Feminino , Fígado/metabolismo , Masculino , PPAR gama/genética , PPAR gama/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 2/genética , Proteína de Ligação a Elemento Regulador de Esterol 2/metabolismo , Triglicerídeos/metabolismo
20.
World J Clin Cases ; 6(9): 291-295, 2018 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-30211210

RESUMO

Acute pancreatitis is rarely associated with drugs. Acetaminophen overdose is a well-known cause of hepatic toxicity, but drug-induced pancreatitis is rarely reported, especially after mild overdose. A 32-year-old woman presented with nausea and vomiting for 12 h, but no abdominal pain following an overdose of eight Tylenol tablets containing acetaminophen (325 mg acetaminophen per tablet). Laboratory results on admission showed abnormal amylase and lipase levels but completely normal liver function. Magnetic resonance cholangiopancreatography revealed mild swelling of the pancreas without fluid collection around the pancreas. The patient complained of severe abdominal pain five days after admission when attempting to drink water and liquids. Eight days after admission, fluid around the pancreas was observed by computed tomography. The patient was subsequently diagnosed with acetaminophen-induced acute pancreatitis after exclusion of common causes. Routine treatment for pancreatitis and N-acetylcysteine were administered to prevent disease progression. The patient was discharged in good condition.

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