Hydrological and rainfall patterns of Simuliumbreeding sites at Ugbem and Ukwepeyiere communities in Biase Local Government Area of Cross River State, Nigeria

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Vietnam's success story against COVID-19

Vietnam's close proximity to China where the COVID-19 outbreak started made it one of the countries expected to have widespread transmission of the virus. However, the country opposed this expectation and attained low spread of COVID-19 infection due to its proactive approaches in containing the disease. As of March 11, 2021, Vietnam has a total of 2529 confirmed cases, equivalent to 26 cases per one million population-compared to the global rate of 15,223 cases. The low-cost model approach used by Vietnam in dealing with previous public health issues, tackle the importance of a strategic public health system, good governance, and citizen cooperation in the fight against COVID 19 pandemic. This paper aims to analyze Vietnam's achievement in its early and continued success in combating COVID-19 by taking into account various aspects of its health system and experience on outbreaks that have previously occurred and how these can be applied to current COVID-19 responses

Preliminary study on optimization of pH, oxidant and catalyst dose for high COD content: solar parabolic trough collector

<p>Abstract</p> <p>In the present study, solar photocatalytic oxidation has been investigated through laboratory experiments as an alternative to conventional secondary treatment for the organic content reduction of high COD wastewater. Experiments have been performed on synthetic high COD wastewater for solar photocatalytic oxidation using a parabolic trough reactor. Parameters affecting the oxidation of organics have been investigated.</p> <p>The experimental design followed the sequence of dark adsorption studies of organics, followed by photolytic studies (in absence of catalyst) and finally photocatalytic studies in presence and absence of additional oxidant (H₂O₂). All the experimental studies have been performed at pH values of 2, 4, 6,8,10 and the initial pH value of the wastewater (normal pH). For photocatalytic studies, TiO₂ has been used as a photocatalyst. Optimization of catalyst dose, pH and H₂O₂ concentration has been done. Maximum reduction of organic content was observed at the normal pH value of the wastewater (pH = 6.8). The reaction rate was significantly enhanced in presence of hydrogen peroxide. The optimum pH other than the Normal was in the alkaline range. Acidic pH was not found to be favourable for organic content reduction. pH was found to be a dominant factor affecting reaction rate even in presence of H₂O₂ as an additional oxidant. Also, the solar detoxification process was effective in treating a waste with a COD level of more than 7500 mg/L, which is a otherwise a difficult waste to treat. It can therefore be used as a treatment step in the high organic wastewater treatment during the primary stage also as it effectively reduces the COD content by 86%.</p