Taste and odor compounds(T&Os),which is often associated with plankton in water sources,pose significant challenges to water quality in the world.Identifying the potential producers and understanding the driving f...Taste and odor compounds(T&Os),which is often associated with plankton in water sources,pose significant challenges to water quality in the world.Identifying the potential producers and understanding the driving factors are critical for effective treatment.While most studies focused on outbreak of T&Os linked with summer cyanobacterial blooms,questions remain about the mechanisms and environmental factors driving spring outbreaks when cyanobacteria are typically in low abundance.Therefore,changes in the concentrations of T&Os,i.e.,2-methylisoborneol(2-MIB)and three others,in relation to the phytoplankton community,the physico-chemical and hydrological conditions in a mesotrophic reservoir surrounded by hills in East China were investigated from March to June 2023.Results show that 2-MIB was the main T&O during the spring outbreak of phytoplankton,and peaked at 96.10 ng/L,which is nearly 10 times of its odor threshold concentration(OTC)of 10 ng/L.The filamentous cyanobacterium Pseudanabaena sp.was identified as the primary producer of 2-MIB,and the cell concentration of 4000 cells/mL of Pseudanabaena sp.could potentially result in 10 ng/L of 2-MIB in this reservoir.The abundance of Pseudanabaena sp.and 2-MIB were correlated significantly with turbidity,suggesting that a lower light environment might be critical to promote the dominance of Pseudanabaena sp.and the subsequent production of 2-MIB.Moreover,the combination of consistently decreased water level,moderate water stratification,optimal water temperature ranging~14-23℃,the increase of the chemical oxygen demand using permanganate as an oxidant(CODMn)and total nitrogen(TN)concentration were likely to drive the accumulation and outbreak of 2-MIB.The hydrodynamic disturbance(i.e.,a sudden rapid flow of water)triggered the abrupt disappearance of both Pseudanabaena sp.and 2-MIB.This study suggests that proliferation of Pseudanabaena sp.in spring is important in contributing to 2-MIB outbreak,and flushing may be an effective approach to mitigate T&O issues in water sources.展开更多
2-Methylisoborneol(2-MIB) is a cyanobacterial metabolite that is responsible for many taste and odor(T&O) complaints related to the aesthetics of drinking water and poses a problem for water authorities because it...2-Methylisoborneol(2-MIB) is a cyanobacterial metabolite that is responsible for many taste and odor(T&O) complaints related to the aesthetics of drinking water and poses a problem for water authorities because it is recalcitrant during conventional water treatment. A numerical model was developed to simulate 2-MIB in the Qingcaosha Reservoir, an estuarine drinking water resource in the Changjiang estuary with known 2-MIB episodes. The objective of this study was to numerically simulate the generation and release processes of 2-MIB in the reservoir and to provide useful information for better management of drinking water resources experiencing T&O problems caused by cyanobacteria. The simulation results from 2009 to 2013 showed that the simulated 2-MIB concentrations corresponded well to the observational data. 2-MIB was released mainly during periods of low dissolved oxygen(DO) levels with an adequate potential sediment source. The temporal and spatial variations in nutrients, chlorophyll-a(Chl-a), Cyanophyta and 2-MIB were presented and analyzed during 2009 to 2013. According to the study results, high-concentration areas and peak levels of 2-MIB can be controlled by inhibiting algal growth and increasing oxygen levels in the water, which can be achieved via adequate water exchange and oxygen exposure in the reservoir, respectively.展开更多
Pilot plant studies on 2-methylisoborneol(2-MIB)removal in drinking water by biological activated carbon-sand filter(BACSF)were conducted in this paper.The biological activated carbon was chosen from a BAC filter of a...Pilot plant studies on 2-methylisoborneol(2-MIB)removal in drinking water by biological activated carbon-sand filter(BACSF)were conducted in this paper.The biological activated carbon was chosen from a BAC filter of an advanced treatment plant which has operated for 1 year.The results showed that the BACSF worked effectively when high concentrations of MIB in raw water especially in summer season.Most of the MIB was removed within 450 mm of the top packed media and the removal rate was 75.24%.The biomass on the surface of activated carbon increased to 103 nmolP/g carbon in August.In addition to MIB,turbidity,UV254 and DOC consumption value are also effectively removed by BACSF.The micro flocculation in combination with BACSF enhanced filtration test provided the evidence that the micro-flocculation made the contaminant in water forming the colloidal matter and it improved the BACSF removal ability of MIB.The optimum PACl dosage was 0.2 mg/L and the PACl contact time was 2-4 min.展开更多
芝麻是八大类食物过敏原之一,快速准确识别芝麻过敏原对预防其过敏有重要意义。核酸适配体可以高效识别靶标过敏原,在过敏原检测中有良好的应用前景。为了获得芝麻主要过敏原Ses i 2的特异性核酸适体,本研究以Ses i 2为靶标,通过磁珠筛...芝麻是八大类食物过敏原之一,快速准确识别芝麻过敏原对预防其过敏有重要意义。核酸适配体可以高效识别靶标过敏原,在过敏原检测中有良好的应用前景。为了获得芝麻主要过敏原Ses i 2的特异性核酸适体,本研究以Ses i 2为靶标,通过磁珠筛选法(磁珠-SELEX)开展10轮筛选,经由高通量测序获得6条候补序列(S1~S6),并进行家族性、同源性分析及二级结构预测。结果表明,6条候选核酸适体的重复率可达46.38%,其自由能在-9.02到-2.47 kcal·moL^(-1)之间,根据自由能能量稳定原则,S1和S5吉布斯自由能最低最稳定,分别为-6.70和-9.02 kcal·moL^(-1)。利用ELISA试验进行亲和力测试,结果表明核酸适体S1和S2的亲和能力较强,S1:KD=67.02 nmol·L^(-1),R2=0.925 8,S2:KD=97.65 nmol·L^(-1),R2=0.795 1。核酸适体S1与过敏原Ses i 2的结合力和其他过敏原蛋白相比有显著差异,可视为具有特异性。本研究最终获得一条兼具良好亲和力和特异性的核酸适体S1,为芝麻过敏原快速检测提供了技术支撑。展开更多
基金Supported by the National Natural Science Foundation of China(Nos.42271080,U2340209)the Science and Technology Planning Project of NIGLAS(Nos.NIGLAS2022GS03,NIGLAS2022TJ08)。
文摘Taste and odor compounds(T&Os),which is often associated with plankton in water sources,pose significant challenges to water quality in the world.Identifying the potential producers and understanding the driving factors are critical for effective treatment.While most studies focused on outbreak of T&Os linked with summer cyanobacterial blooms,questions remain about the mechanisms and environmental factors driving spring outbreaks when cyanobacteria are typically in low abundance.Therefore,changes in the concentrations of T&Os,i.e.,2-methylisoborneol(2-MIB)and three others,in relation to the phytoplankton community,the physico-chemical and hydrological conditions in a mesotrophic reservoir surrounded by hills in East China were investigated from March to June 2023.Results show that 2-MIB was the main T&O during the spring outbreak of phytoplankton,and peaked at 96.10 ng/L,which is nearly 10 times of its odor threshold concentration(OTC)of 10 ng/L.The filamentous cyanobacterium Pseudanabaena sp.was identified as the primary producer of 2-MIB,and the cell concentration of 4000 cells/mL of Pseudanabaena sp.could potentially result in 10 ng/L of 2-MIB in this reservoir.The abundance of Pseudanabaena sp.and 2-MIB were correlated significantly with turbidity,suggesting that a lower light environment might be critical to promote the dominance of Pseudanabaena sp.and the subsequent production of 2-MIB.Moreover,the combination of consistently decreased water level,moderate water stratification,optimal water temperature ranging~14-23℃,the increase of the chemical oxygen demand using permanganate as an oxidant(CODMn)and total nitrogen(TN)concentration were likely to drive the accumulation and outbreak of 2-MIB.The hydrodynamic disturbance(i.e.,a sudden rapid flow of water)triggered the abrupt disappearance of both Pseudanabaena sp.and 2-MIB.This study suggests that proliferation of Pseudanabaena sp.in spring is important in contributing to 2-MIB outbreak,and flushing may be an effective approach to mitigate T&O issues in water sources.
基金Supported by the National Key R&D Program of China(No.2017YFC0405400)the Shanghai Municipal Science and Technology Commission,China(Nos.12231201603,15YF1409900)the Hangzhou Science and Technology Guidance Project in 2016(No.20163501Y54)
文摘2-Methylisoborneol(2-MIB) is a cyanobacterial metabolite that is responsible for many taste and odor(T&O) complaints related to the aesthetics of drinking water and poses a problem for water authorities because it is recalcitrant during conventional water treatment. A numerical model was developed to simulate 2-MIB in the Qingcaosha Reservoir, an estuarine drinking water resource in the Changjiang estuary with known 2-MIB episodes. The objective of this study was to numerically simulate the generation and release processes of 2-MIB in the reservoir and to provide useful information for better management of drinking water resources experiencing T&O problems caused by cyanobacteria. The simulation results from 2009 to 2013 showed that the simulated 2-MIB concentrations corresponded well to the observational data. 2-MIB was released mainly during periods of low dissolved oxygen(DO) levels with an adequate potential sediment source. The temporal and spatial variations in nutrients, chlorophyll-a(Chl-a), Cyanophyta and 2-MIB were presented and analyzed during 2009 to 2013. According to the study results, high-concentration areas and peak levels of 2-MIB can be controlled by inhibiting algal growth and increasing oxygen levels in the water, which can be achieved via adequate water exchange and oxygen exposure in the reservoir, respectively.
基金Sponsored by the National Natural Science Foundation of China(Grant No.50678046)
文摘Pilot plant studies on 2-methylisoborneol(2-MIB)removal in drinking water by biological activated carbon-sand filter(BACSF)were conducted in this paper.The biological activated carbon was chosen from a BAC filter of an advanced treatment plant which has operated for 1 year.The results showed that the BACSF worked effectively when high concentrations of MIB in raw water especially in summer season.Most of the MIB was removed within 450 mm of the top packed media and the removal rate was 75.24%.The biomass on the surface of activated carbon increased to 103 nmolP/g carbon in August.In addition to MIB,turbidity,UV254 and DOC consumption value are also effectively removed by BACSF.The micro flocculation in combination with BACSF enhanced filtration test provided the evidence that the micro-flocculation made the contaminant in water forming the colloidal matter and it improved the BACSF removal ability of MIB.The optimum PACl dosage was 0.2 mg/L and the PACl contact time was 2-4 min.
文摘芝麻是八大类食物过敏原之一,快速准确识别芝麻过敏原对预防其过敏有重要意义。核酸适配体可以高效识别靶标过敏原,在过敏原检测中有良好的应用前景。为了获得芝麻主要过敏原Ses i 2的特异性核酸适体,本研究以Ses i 2为靶标,通过磁珠筛选法(磁珠-SELEX)开展10轮筛选,经由高通量测序获得6条候补序列(S1~S6),并进行家族性、同源性分析及二级结构预测。结果表明,6条候选核酸适体的重复率可达46.38%,其自由能在-9.02到-2.47 kcal·moL^(-1)之间,根据自由能能量稳定原则,S1和S5吉布斯自由能最低最稳定,分别为-6.70和-9.02 kcal·moL^(-1)。利用ELISA试验进行亲和力测试,结果表明核酸适体S1和S2的亲和能力较强,S1:KD=67.02 nmol·L^(-1),R2=0.925 8,S2:KD=97.65 nmol·L^(-1),R2=0.795 1。核酸适体S1与过敏原Ses i 2的结合力和其他过敏原蛋白相比有显著差异,可视为具有特异性。本研究最终获得一条兼具良好亲和力和特异性的核酸适体S1,为芝麻过敏原快速检测提供了技术支撑。
