Mechanisms of arsenate removal and membrane fouling in ferric based coprecipitation-low pressure membrane filtration systems

Ferric based coprecipitation-low pressure membrane filtration is a promising arsenic (As) removal method, however, membrane fouling mechanisms are not fully understood. In this study we investigated the effect of feed water composition and membrane pore size on arsenate [As(V)] removal and membrane fouling. We observed that As removal efficiency was independent of the membrane pore size because the size of the Fe(III) particles was larger than the pore size of the membranes, attributed to a high calcium concentration in the feed water. Arsenic coprecipitation with Fe(III) (oxyhydr)oxides rapidly reached equilibrium before membrane filtration, within 1 min. Therefore, As removal efficiency was not improved by increasing residence time before membrane filtration. The removal of As(V) was strongly dependent on feed water composition. A higher Fe(III) dose was required to reduce As(V) to sub-mu g/L levels for feed water containing higher concentration of oxyanions such as phosphate and silicate, and lower concentration of cations such as calcium. Cake-layer formation was observed to be the predominant membrane fouling mechanism

Hydroxychloroquine and chloroquine for treatment of COVID-19:Lacking evidence for effectivity

Op 3 maart 2020 verscheen het document ‘Medicamenteuze behandelopties bij patiënten met COVID-19 (infecties met SARS-CoV-2)’ op de website van de Stichting Werkgroep Antibioticabeleid (SWAB).Op basis van een 7-stapsanalyse van de literatuur werden hydroxychloroquine (HCQ) en chloroquine (CQ) aanvankelijk opgenomen in het SWAB-document als mogelijke medicamenteuze behandeling van klinisch opgenomen volwassen COVID-19-patiënten.In de afgelopen weken zijn echter de resultaten gepubliceerd van diverse onderzoeken naar de effectiviteit van de behandeling met HCQ en CQ bij patiënten met COVID-19.Op basis van die resultaten concluderen wij dat er onvoldoende bewijs is om HCQ en CQ te beschouwen als zinvolle behandeling van patiënten met COVID-19.Bij minstens 1 op de 10 COVID-19-patiënten die met HCQ of CQ behandeld worden treedt een klinisch relevante verlenging van de QTc-tijd op.Op 3 maart 2020 verscheen het document ‘Medicamenteuze behandelopties bij patiënten met COVID-19 (infecties met SARS-CoV-2)’ op de website van de Stichting Werkgroep Antibioticabeleid (SWAB).Op basis van een 7-stapsanalyse van de literatuur werden hydroxychloroquine (HCQ) en chloroquine (CQ) aanvankelijk opgenomen in het SWAB-document als mogelijke medicamenteuze behandeling van klinisch opgenomen volwassen COVID-19-patiënten.In de afgelopen weken zijn echter de resultaten gepubliceerd van diverse onderzoeken naar de effectiviteit van de behandeling met HCQ en CQ bij patiënten met COVID-19.Op basis van die resultaten concluderen wij dat er onvoldoende bewijs is om HCQ en CQ te beschouwen als zinvolle behandeling van patiënten met COVID-19.Bij minstens 1 op de 10 COVID-19-patiënten die met HCQ of CQ behandeld worden treedt een klinisch relevante verlenging van de QTc-tijd op

Mechanisms of arsenate removal and membrane fouling in ferric based coprecipitation–low pressure membrane filtration systems

Ferric based coprecipitation–low pressure membrane filtration is a promising arsenic (As) removal method, however, membrane fouling mechanisms are not fully understood. In this study we investigated the effect of feed water composition and membrane pore size on arsenate [As(V)] removal and membrane fouling. We observed that As removal efficiency was independent of the membrane pore size because the size of the Fe(III) particles was larger than the pore size of the membranes, attributed to a high calcium concentration in the feed water. Arsenic coprecipitation with Fe(III) (oxyhydr)oxides rapidly reached equilibrium before membrane filtration, within 1 min. Therefore, As removal efficiency was not improved by increasing residence time before membrane filtration. The removal of As(V) was strongly dependent on feed water composition. A higher Fe(III) dose was required to reduce As(V) to sub-µg/L levels for feed water containing higher concentration of oxyanions such as phosphate and silicate, and lower concentration of cations such as calcium. Cake-layer formation was observed to be the predominant membrane fouling mechanism.</p

The medicinal treatment of COVID-19:a brief update

Much has changed in the medical treatment of COVID-19 after the first patient with an infection with SARS-CoV-2 in the Netherlands was diagnosed in February 2020. On the basis of limited data, at first only off-label use of (hydroxy)chloroquine seemed to be a treatment option. However, now based on the findings of several randomized studies, other medicines have been included in the Dutch guidelines about the treatment of COVID-19. In this article, we will briefly discuss the current state of affairs with regard to the drugs (hydroxy) chloroquine, remdesivir and corticosteroids. Again, it appears that only well-executed randomized clinical trials can determine the status of various supposedly effective drugs.</p

Cardiovascular disease prevention in rural Nigeria in the context of a community based health insurance scheme: QUality Improvement Cardiovascular care Kwara-I (QUICK-I)

Background: Cardiovascular diseases (CVD) are a leading contributor to the burden of disease in low- and middle-income countries. Guidelines for CVD prevention care in low resource settings have been developed but little information is available on strategies to implement this care. A community health insurance program might be used to improve patients' access to care. The operational research project "QUality Improvement Cardiovascular care Kwara - I (QUICK-I)" aims to assess the feasibility of CVD prevention care in rural Nigeria, according to international guidelines, in the context of a community based health insurance scheme. Methods/Design. Design: prospective observational hospital based cohort study. Setting: a primary health care centre in rural Nigeria. Study population: 300 patients at risk for development of CVD (patients with hypertension, diabetes, renal disease or established CVD) who are enrolled in the Hygeia Community Health Plan. Measurements: demographic and socio- economic data, physical and laboratory examination, CVD risk profile including screening for target organ damage. Measurements will be done at 3 month intervals during 1 year. Direct and indirect costs of CVD prevention care will be estimated. Outcomes: 1) The adjusted cardiovascular quality of care indicator scores based on the "United Kingdom