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Advanced oxidation techniques are efficient processes to dispose of organic contaminants in industrial wastewater with low secondary pollution. The solution plasma technique was featured as an advanced oxidation technique with low secondary pollution and high efficiency. However, the solution plasma technique reported previously could only treat wastewater of less than 200 mL owing to the limited plasma generated by only one pair of electrodes. In this work, multiple pairs of electrodes were installed at the bottom of the reaction vessel to generate plasma for decomposing methylene blue trihydrate (MB) and methyl orange (MO) solutions with a batch amount of 18 L/batch. The solution plasma technique was compared with direct ozonation in decomposition of MB and MO wastewater. A surprising phenomenon is that MO was more readily decomposed than MB by using direct ozonation, whereas the removal of MO was too low, and MB was more readily decomposed than MO by using the solution plasma technique.
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Resíduos Industriais/análise , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/química , Ozônio , Purificação da Água/métodosRESUMO
BACKGROUND: Coronavirus disease 2019 (COVID-19) has spread rapidly to multiple countries through its infectious agent severe acute respiratory syndrome coronavirus 2. The severity, atypical clinical presentation, and lack of specific anti-viral treatments have posed a challenge for the diagnosis and treatment of COVID-19. Understanding the epidemiological and clinical characteristics of COVID-19 cases in different geographical areas is essential to improve the prognosis of COVID-19 patients and slow the spread of the disease. AIM: To investigate the epidemiological and clinical characteristics and main therapeutic strategy for confirmed COVID-19 patients hospitalized in Liaoning Province, China. METHODS: Adult patients (n = 65) with confirmed COVID-19 were enrolled in this retrospective study from January 20 to February 29, 2020 in Liaoning Province, China. Pharyngeal swabs and sputum specimens were collected from the patients for the detection of severe acute respiratory syndrome coronavirus 2 nucleic acid. Patient demographic information and clinical data were collected from the medical records. Based on the severity of COVID-19, the patients were divided into nonsevere and severe groups. All patients were followed until March 20, 2020. RESULTS: The mean age of 65 COVID-19 patients was 45.5 ± 14.4 years, 56.9% were men, and 24.6% were severe cases. During the 14 d before symptom onset, 25 (38.5%) patients lived or stayed in Wuhan, whereas 8 (12.3%) had no clear history of exposure. Twenty-nine (44.6%) patients had at least one comorbidity; hypertension and diabetes were the most common comorbidities. Compared with nonsevere patients, severe patients had significantly lower lymphocyte counts [median value 1.3 × 109/L (interquartile range 0.9-1.95) vs 0.82 × 109/L (0.44-1.08), P < 0.001], elevated levels of lactate dehydrogenase [450 U/L (386-476) vs 707 U/L (592-980), P < 0.001] and C-reactive protein [6.1 mg/L (1.5-7.2) vs 52 mg/L (12.7-100.8), P < 0.001], and a prolonged median duration of viral shedding [19.5 d (16-21) vs 23.5 d (19.6-30.3), P = 0.001]. The overall median viral shedding time was 19.5 d, and the longest was 53 d. Severe patients were more frequently treated with lopinavir/ritonavir, antibiotics, glucocorticoid therapy, immunoglobulin, thymosin, and oxygen support. All patients were discharged following treatment in quarantine. CONCLUSION: Our findings may facilitate the identification of severe cases and inform clinical treatment and quarantine decisions regarding COVID-19.
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BACKGROUND: Pneumonia of uncertain cause has been reported in Wuhan, China since the beginning of early December 2019. In early January 2020, a novel strain of ß-coronavirus was identified by the Chinese Center for Disease Control and Prevention from the pharyngeal swab specimens of patients, which was recently named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). There is evidence of human-to-human transmission and familial cluster outbreak of SARS-CoV-2 infection. The World Health Organization(WHO) recently declared the SARS-CoV-2 epidemic a global health emergency. As of February 17, 2020, 71329 laboratory-confirmed cases (in 25 countries, including the United States and Germany) have been reported globally. Other than its rapid transmission, the epidemiological and clinical characteristics of coronavirus disease 2019 (COVID-19) remain unclear. In December 2019, coronavirus disease (named COVID-19 by the WHO) associated with the SARS-CoV-2 emerged in Wuhan, China and spread quickly across the country. AIM: To analyze the epidemiological and clinical characteristics of confirmed cases of this disease in Liaoning province, a Chinese region about 1800 km north of Wuhan. METHODS: The clinical data of 56 laboratory-confirmed COVID-19 cases due to 2019-nCoV infection were analyzed. The cases originated from eight cities in Liaoning province. RESULTS: The median age of the patients was 45 years, and 57.1% of them were male. No patient had been in direct contact with wild animals. Among them, 23 patients (41.1%) had resided in or traveled to Wuhan, 27 cases (48.2%) had been in contact with confirmed COVID-19 patients, 5 cases (8.9%) had been in contact with confirmed patients with a contact history to COVID-19 patients, and 1 case (1.8%) had no apparent history of exposure. Fever (75.0%) and cough (60.7%) were the most common symptoms. The typical manifestations in lung computed tomography (CT) included ground-glass opacity and patchy shadows, with 67.8% of them being bilateral. Among the patients in the cohort, 78.6% showed reduction in their lymphocyte counts, 57.1% showed increases in their C-reactive protein levels, and 50.0% showed decreases in their blood albumin levels. Eleven patients (19.6%) were admitted to intensive care unit, 2 patients (3.5%) progressed to acute respiratory distress syndrome, 4 patients (7.1%) were equipped with non-invasive mechanical ventilation, and 1 patient (1.8) received extracorporeal membrane oxygenation support. There were 5 mild cases (5/56, 8.9%), 40 moderate cases (40/56, 71.4%), 10 severe cases (10/56, 17.9%), and 1 critical case (1/56, 1.8%). No deaths were reported. CONCLUSION: SARS-CoV-2 can be transmitted among humans. Most COVID-19 patients show symptoms of fever, cough, lymphocyte reduction, and typical lung CT manifestations. Most are moderate cases. The seriousness of the disease (as indicated by blood oxygen saturation, respiratory rate, oxygenation index, blood lymphocyte count, and lesions shown in lung CT) is related to history of living in or traveling to Wuhan, underlying diseases, admittance to intensive care unit, and mechanical ventilation.
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Heavy metals are one of the important factors that affect the final disposal of sewage sludge. In this paper, the metal mobility and bioavailability of heavy metals in sewage sludge were studied by using Community Bureau of Reference (BCR) sequential extraction procedure to get more information for the reasonable disposal of sludge. Sewage sludge was collected from five municipal wastewater treatment plants and three industrial wastewater treatment plants. The sludge was examined for and the total concentrations and different chemical fractions of Cd, Cr, Pb, Cu, Ni and Zn. The total metal concentrations of heavy metals in sludge varied greatly. The contents of Zn and Cu were the highest, followed by then Cr, Ni and Pb and the content of Cd was the least. There was no significant difference in total metal concentration between municipal and industrial wastewater treatment plants. Fractions extracted by the BCR sequential procedure were acid soluble/exchangeable, reducible and oxidizable fraction. Sludge pH was found to have profound effect on the chemical fractions of heavy metals. Acidic sludges (Xiamen and Jinlin Petrochemical Group Co., wastewater treatment plant) had higher proportion of the acid soluble/exchangeable fractions than in neutral sludge. In neutral sludges, Pb and Cr were principally distributed in between the oxidizable fraction and the residual fraction; Cu was in the oxidizable fraction; Cd mainly in the residual fraction in municipal wastewater treatment plants and had high percentage of acid soluble/exchangeable and reducible fractions in industrial wastewater treatment plants; Ni and Zn had higher percentage in the acid soluble/exchangeable and the oxidizable fraction.