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关键词： AnMBR   脱氮滤池   氮脱除路径   污水处理  

摘要： 为解决AnMBR(厌氧膜生物反应器)出水NH_4^+脱除的问题,提出利用AnMBR出水中残余CODCr、溶解性CH4以及低价态硫元素,通过构建缺氧滤池和好氧滤池进行生物异养和硫自养脱氮的方法,进一步削减AnMBR出水CODCr、去除溶解性CH4、同时同步生物脱氮.结果表明:①缺氧滤池与好氧滤池经过120 d单独驯化与33 d串联驯化后,在HRT(hydraulic retention time,水力停留时间)为6 h、进水为实际AnMBR出水的工况条件下,出水ρ(TN)为17. 93 mg/L,去除率为52. 7%;出水ρ(NH_4^+-N)为2. 78 mg/L,去除率为92. 3%,达到GB 18918—2002《城镇污水处理厂污染物排放标准》一级B标准.在HRT为8 h工况条件下,出水ρ(TN)为14. 60 mg/L,去除率为59. 0%;出水ρ(NH_4^+-N)为2. 22 mg/L,去除率为93. 7%,达到GB 18918—2002一级A标准.②脱氮滤池中氮脱除路径主要包括残余CODCr异养反硝化、溶解性CH4异养反硝化和硫自养反硝化,并通过物料衡算评价了三者对于氮脱除的贡献,在HRT为6 h的工况条件下,脱氮滤池脱氮过程中残余CODCr异养反硝化、溶解性CH4异养反硝化和硫自养反硝化三者占比分别为54. 1%、24. 3%和21. 5%;在HRT为8 h的工况条件下,脱氮滤池脱氮过程中3种途径占比分别为70. 4%、13. 8%和15. 8%.研究显示,脱氮滤池可以实现对AnMBR出水的低耗生物脱氮以及整体水质的达标排放.

关键词： 正渗透膜生物反应器   溶质反渗   微生物群落   菌群丰度  

摘要： 以氯化钠为驱动溶质,采用正渗透膜生物反应器(forward osmosis membrane bioreactor,FOMBR)处理生活污水,考察其在运行过程中溶质反渗对系统内微生物群落造成的影响。稳定运行状态下的第7、14、20天的混合液污泥样品分别称为A1、A2、A3,并对微生物群落物种丰度、群落结构、聚类等进行了分析。结果表明:正渗透膜生物反应器运行20 d内水通量从9.5 L/(m^2·h)下降到8.17 L/(m^2·h),反向盐通量从29.52 g/(m^2·h)增加到35.06 g/(m^2·h)。整个运行过程中溶质反渗对微生物群落结构的变化有着一定的影响,3个样品共产生1496个OTUs,各样品间共享的OTUs不尽相同;溶质反渗对3种样品的微生物群落多样性、菌群丰度等影响较小。PCA分析中A2和A3两个样品距离更近,组成更相似,热图聚类分析再次验证A2与A3相似性更高;3个样品斜率较小且非常接近,并且A1和A3两个样品所含物种的丰富程度和均匀程度几乎一样;3个样品的活性污泥群落结构在门、纲、目分类水平上均具有较高的多样性,各分类水平上的菌群丰度存在一定的差异。

关键词： 网纹甜瓜   裂果   品质   营养液浓度  

摘要： 为了研究营养液浓度对海南冬春季椰糠基质培养网纹甜瓜生长、裂果和品质的影响,用1.0S、1.5S、2.0S、2.5S、3.0S、3.5S、4.0S浓度的营养液对网纹甜瓜进行滴灌处理。结果表明,适当提高营养液浓度能不同程度地促进网纹甜瓜的植株生长,增强果实抗裂性并提高果实品质,1.5S^3.5S之间的5个处理主蔓生长最快;3.5S和4.0S处理降低裂果的效果最为显著,其次是1.5S和2.0S处理;结果率和果皮厚度都以1.5S和2.0S处理最高;果形指数以1.5S最高,与3.0S、3.5S、4.0S处理差异不显著;营养液浓度对坐果节位无显著影响;提高营养液浓度可以不同程度地提高网纹甜瓜的茎粗;从采收时的单瓜质量来看,以1.5S、2.0S、2.5S处理的单瓜质量最大,且显著高于其他处理;甜瓜品质指标来看,以1.5S处理的表现最优,2.0S处理的次之。综合甜瓜植株生长、坐果、裂果和产量、品质等因素,在海南冬春季节,设施椰糠基质培养网纹甜瓜在海南冬春季节适宜的营养液浓度为本试验所用标准营养液浓度的1.5倍。

关键词： Stormwater treatment   Woodchip bioreactor   Biochar   Nitrate   Trace organic contaminants   Metals  

摘要： Stormwater is increasingly being valued as a freshwater resource in arid regions and can provide opportunities for beneficial reuse via aquifer recharge if adequate pollutant removal can be achieved. We envision a multi-unit operation approach to capture, treat, and recharge (CTR) stormwater using low energy, cost-effective technologies appropriate for larger magnitude, less frequent events. Herein, we tested nutrient, metal, and trace organic contaminant removal of a pilot-scale CTR system in the laboratory using biochar-amended woodchip bioreactors following eight months of aging under field conditions with exposure to real stormwater. Replicate columns with woodchips and biochar (33% by weight), woodchips and straw, or woodchips only were operated with continuous, saturated flow for eight months using water from a watershed that drained an urban area consisting of residential housing and parks in Sonoma, California. After aging, columns were challenged for five months by continuous exposure to synthetic stormwater amended with 50 mu g L-1 of six trace organic contaminants (i.e., fipronil, diuron, 1H-benzotriazole, atrazine, 2,4-D, and TCEP) and five metals (Cd, Cu, Ni, Pb, Zn) frequently detected in stormwater in order to replicate the treatment unit operation of a CTR system. Throughout the eight-month aging and five-month challenge experiment, nitrate concentrations were below the detection limit after treatment (i.e., <0.05 mg N L-1). The removal efficiencies for metals in all treatments were >80% for Ni, Cu, Cd, and Pb. For Zn, about 50% removal occurred in the woodchip-biochar systems while the other systems achieved about 20% removal. No breakthrough of the trace organic compounds was observed in any biochar-containing columns. Woodchip columns without biochar removed approximately 99% of influent atrazine and 90% of influent fipronil, but exhibited relatively rapid breakthrough of TCEP, 2,4-D, 1H-benzotriazole, and diuron. The addition of straw to the wood

关键词： IBR生物反应器   激波传质器  

摘要： 目前,集镇面积不断扩大,人口急剧增加。城镇的污水治理问题急需解决,本文结合鸭池镇的污水处理工程,介绍了一种除磷脱氮效果比较好的IBR生物反应器。它具有节省基建投资,处理能耗低,建设投资低、运行费用低、管理要求低、占地面积少等特点。对城镇污水处理项目具有一定的参考意义。

关键词： 多西环素   碱烧伤   角膜   转化生长因子-β1   基质金属蛋白酶-9  

摘要： 目的探讨不同浓度多西环素对碱烧伤大鼠角膜中转化生长因子β1(transforming growth factor-β1,TGF-β1)和基质金属蛋白酶-9(matrix metalloproteinase-9,MMP-9)表达的影响及其调节作用。方法 SD大鼠右眼制备成角膜碱烧伤模型,随机分为对照组、0.5 g·L^(-1)多西环素组和1.0 g·L^(-1)多西环素组,每组15只。3组分别于造模后每天给予20μL眼液溶媒、0.5 g·L^(-1)多西环素、1.0 g·L^(-1)多西环素滴眼至观察期末。于碱烧伤后第3天、第7天、第14天对角膜混浊程度进行评分,并行RT-PCR和ELISA检测角膜组织中TGF-β1、MMP-9 mRNA和蛋白的表达情况。结果与对照组相比,碱烧伤后第7天、第14天,0.5 g·L^(-1)多西环素组[(2.80±0.45)分、(2.20±0.45)分]和1.0 g·L^(-1)多西环素组[(2.00±0.00)分、(0.60±0.55)分]角膜混浊程度评分降低,且1.0 g·L^(-1)多西环素组更低,差异均有统计学意义(均为P<0.05)。碱烧伤后第3天、第7天、第14天,0.5 g·L^(-1)多西环素组、1.0 g·L^(-1)多西环素组TGF-β1 mRNA及蛋白表达量均较对照组低,且1.0 g·L^(-1)多西环素组表达更低,差异均有统计学意义(均为P<0.05)。碱烧伤后第3天、第7天,0.5 g·L^(-1)多西环素组、1.0 g·L^(-1)多西环素组MMP-9 mRNA及蛋白表达均较对照组低,且1.0 g·L^(-1)多西环素组表达更低,差异均有统计学意义(均为P<0.05)。结论多西环素可下调碱烧伤大鼠角膜中TGF-β1和MMP-9的表达,促进角膜愈合,并呈一定程度的剂量依赖性。

关键词： Electrochemical membrane bioreactor   Biofouling   Microbial electrolysis cell   Specific cathode surface area   Hydrogen gas scouring  

摘要： The effect of specific cathode surface area (SCSA;2, 4 and 8 m(2)/m(3)) on biogas production and biofouling control was investigated in anaerobic electrochemical membrane bioreactors (AnEMBRs). Nickel-based hollow fibers were used as both a cathode for hydrogen evolution and a membrane for the filtration of treated water. Varying the SCSA was found to influence the current density, biogas quantity and composition, and trans-membrane pressure (TMP). In situ gas generation was monitored using a high-speed camera;where the 8 m(2)/m(3) AnEMBRs were found to mainly evolve smaller sized bubbles (45-114 mu m) compared to the 2 and 4 m(2)/m(3) AnEMBRs. This correlated with the lowest TMP (0.37 bars) compared to the other reactors (4 m(2)/m(3), 0.76 bars;2 m(2)/m(3), 1.18 bars). The cathodic microbial community varied with SCSA, with Acetobacterium dominating at a relative abundance that reached 62% (4 m(2)/m(3)), while hydrogenotrophic methanogens (represented by Methanocorpusculum) comprised up to 2.5% of the total community. This community variability apparently influenced both the hydrogen (Q(H2)) and methane (Q(CH4)) production rates, reaching a maximum Q(H2) of 0.416 m(3)/m(3)/day (SCSA 8 m(2)/m(3)). Overall, this study discloses the cumulative effect of Q(H2), Q(CH4), bubble distribution and frequency on biofouling with SCSA variation in AnEMBRs, demonstrating that with higher SCSA the in situ gas scouring effect is more pronounced leading to a lower fouling propensity.

关键词： Glucan   Glucose   Biofuels   Autohydrolysis   Severity factor   Biorefinery  

摘要： One of the major challenges in biofuels production from lignocellulosic biomass is the generation of high glucose titers from cellulose in the enzymatic hydrolysis stage of pretreated biomass to guarantee a cost-effective process. Therefore, the enzymatic saccharification on cellulose at high solid loading is an alternative. In this work, the agave bagasse was hydrothermally pretreated and optimized at 194 degrees C/30 min, obtaining a pretreated solid rich in cellulose content (> 46.46%), and subjected to enzymatic hydrolysis at high solid levels. A horizontal bioreactor was designed for enzyme saccharification at high solid loadings [25% (w/v)]. The bioreactor improved mixing efficiency, with cellulose conversions up to 98% (195.6 g/L at 72 h). Moreover, mathematical modeling of cellulase deactivation demonstrated that cellulases lose most of their initial activity in the first hours of the reaction. Also, cellulose was characterized by X-ray diffraction, and the pretreated solids were visualized using scanning electron microscopy.

关键词： Bisphenol A   Biodegradation   Mineralization   Enzyme   Peroxidase  

摘要： The present study focused on the enhanced biodegradation and mineralization of bisphenol A (BPA) as a toxic endocrine disrupting compound using peroxidase-mediated bioprocess under H2O2-infusion. The complete biodegradation of 100 mg/L BPA was achieved within 54 h reaction time at the optimum H2O2:BPA molar ratio of 10. BPA concentrations up to 100 mg/L had no inhibitory effect on the bacterial biomass at which a dehydrogenase activity of 9.1 mu g TF/g(bi)(omass) and a peroxidase activity of 1.4 U/mL was obtained. The increase in biomass concentration from 90 to 450 mg/L improved the BPA biodegradation from 70.3% to 97.8% and its mineralization from 11.5% to 71.2% at the reaction time of 36 h. The highest BPA biodegradation rate was found to be 10.8 mg BPA/g(biomass). h. Accordingly, infusing H2O2 into the bioreactor stimulated the bacteria to produce peroxidase and allowed peroxidase-mediated enhanced biodegradation of BPA. (C) 2019 Elsevier Ltd. All rights reserved.

关键词： Suspended TiO2 nanoparticles   Activated sludge floc properties   Membrane bioreactor   Extracellular polymeric substances (EPS)  

摘要： With the rapid development and application of consumer products containing nanoparticles (NPs), especially titanium dioxide (TiO2) NPs, the potential effects of suspended NPs on wastewater treatment has been a concern over the recent years. This study investigated the potential effects of suspended TiO2 NPs on activated sludge flocculation properties in a membrane bioreactor (MBR). Results showed that suspended TiO2 NPs inhibited the viability of activated sludge flocs, and led to bacterial protein secretion for bacterial protection, causing an overall protein increase of soluble microbial products. Suspended TiO2 NPs also destabilized the activated sludge floc structure and reduced flocculation capacity of flocs, causing an over production of organic matter and resulting in a floc size decrease of over 50%. Suspended TiO2 NPs also caused a change in the phylogenetic distribution of bacterial community. Whereby, the dominant species in activated sludge was replaced from Comamonadaceae to Thiotrichaceae in 50 mg/L suspended TiO2 NPs. (C) 2019 Elsevier Ltd. All rights reserved.