采用厌氧反应器接种厌氧氨氧化污泥,研究了脱氮效能提高过程中颗粒污泥的沉淀性能及不同策略对增强颗粒污泥沉淀性的影响。结果表明:当反应器氮去除速率达到3.2 kg m-3 d-1时,产气量的增加使得颗粒污泥出现大量流失。采用"粉碎-回...采用厌氧反应器接种厌氧氨氧化污泥,研究了脱氮效能提高过程中颗粒污泥的沉淀性能及不同策略对增强颗粒污泥沉淀性的影响。结果表明:当反应器氮去除速率达到3.2 kg m-3 d-1时,产气量的增加使得颗粒污泥出现大量流失。采用"粉碎-回流-重新形成颗粒污泥"方式不能完全有效地改善颗粒污泥的沉降性能。通过对反应器内和流失的污泥进行测定发现,相同粒径的反应器内颗粒污泥的MLVSS/MLSS值要明显低于流失的颗粒污泥。通过CaSO4颗粒投加,回流的流失污泥会以CaSO4作为颗粒污泥的核。经过48 d的培养,污泥的沉降性能得到良好的改善,反应器氮去除速率从5.23 kg m-3 d-1上升到9.2 kg m-3 d-1。同时该研究还发现当进水总氮浓度达到1320 mg L-1时,厌氧氨氧化颗粒污泥活性并未受到影响,说明厌氧氨氧化颗粒污泥对进水基质浓度具有较强的耐受性。展开更多
Background:The aim of this review is to summarize the current evidence regarding small airway disease in asthma,focusing on recent advances in small airway pathophysiology,assessment and therapeutic implications.Metho...Background:The aim of this review is to summarize the current evidence regarding small airway disease in asthma,focusing on recent advances in small airway pathophysiology,assessment and therapeutic implications.Methods:A search in Medline was performed,using the keywords“small airways”,“asthma”,“oscillometry”,“nitrogen washout”and“imaging”.Our review was based on studies from adult asthmatic patients,although evidence from pediatric populations is also discussed.Results:In asthma,inflammation in small airways,increased mucus production and airway wall remodelling are the main pathogenetic mechanisms of small airway disease.Small airway dysfunction is a key component of asthma pathophysiology,leading to increased small airway resistance and airway closure,with subsequent ventilation inhomogeneities,hyperresponsiveness and airflow limitation.Classic tests of lung function,such as spirometry and body plethysmography are insensitive to detect small airway disease,providing only indirect measurements.As discussed in our review,both functional and imaging techniques that are more specific for small airways,such as oscillometry and the multiple breath nitrogen washout have delineated the role of small airways in asthma.Small airways disease is prevalent across all asthma disease stages and especially in severe disease,correlating with important clinical outcomes,such as asthma control and exacerbation frequency.Moreover,markers of small airways dysfunction have been used to guide asthma treatment and monitor response to therapy.Conclusions:Assessment of small airway disease provides unique information for asthma diagnosis and monitor-ing,with potential therapeutic implications.展开更多
文摘采用厌氧反应器接种厌氧氨氧化污泥,研究了脱氮效能提高过程中颗粒污泥的沉淀性能及不同策略对增强颗粒污泥沉淀性的影响。结果表明:当反应器氮去除速率达到3.2 kg m-3 d-1时,产气量的增加使得颗粒污泥出现大量流失。采用"粉碎-回流-重新形成颗粒污泥"方式不能完全有效地改善颗粒污泥的沉降性能。通过对反应器内和流失的污泥进行测定发现,相同粒径的反应器内颗粒污泥的MLVSS/MLSS值要明显低于流失的颗粒污泥。通过CaSO4颗粒投加,回流的流失污泥会以CaSO4作为颗粒污泥的核。经过48 d的培养,污泥的沉降性能得到良好的改善,反应器氮去除速率从5.23 kg m-3 d-1上升到9.2 kg m-3 d-1。同时该研究还发现当进水总氮浓度达到1320 mg L-1时,厌氧氨氧化颗粒污泥活性并未受到影响,说明厌氧氨氧化颗粒污泥对进水基质浓度具有较强的耐受性。
基金DT is a recipient of a Long-Term Research Fellowship from the Eu-ropean Respiratory Society.
文摘Background:The aim of this review is to summarize the current evidence regarding small airway disease in asthma,focusing on recent advances in small airway pathophysiology,assessment and therapeutic implications.Methods:A search in Medline was performed,using the keywords“small airways”,“asthma”,“oscillometry”,“nitrogen washout”and“imaging”.Our review was based on studies from adult asthmatic patients,although evidence from pediatric populations is also discussed.Results:In asthma,inflammation in small airways,increased mucus production and airway wall remodelling are the main pathogenetic mechanisms of small airway disease.Small airway dysfunction is a key component of asthma pathophysiology,leading to increased small airway resistance and airway closure,with subsequent ventilation inhomogeneities,hyperresponsiveness and airflow limitation.Classic tests of lung function,such as spirometry and body plethysmography are insensitive to detect small airway disease,providing only indirect measurements.As discussed in our review,both functional and imaging techniques that are more specific for small airways,such as oscillometry and the multiple breath nitrogen washout have delineated the role of small airways in asthma.Small airways disease is prevalent across all asthma disease stages and especially in severe disease,correlating with important clinical outcomes,such as asthma control and exacerbation frequency.Moreover,markers of small airways dysfunction have been used to guide asthma treatment and monitor response to therapy.Conclusions:Assessment of small airway disease provides unique information for asthma diagnosis and monitor-ing,with potential therapeutic implications.
