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关键词： 生物反应器   增殖培养   蓝莓  

摘要： 以蓝莓第3代健壮无根组培苗为试材,采用3种不同生物反应器(摇摆式、气雾式和双瓶式)进行增殖培养,对蓝莓组培苗的生理生化指标进行了比较分析,以期选择出最佳的增殖培养生物反应器和培养方法。结果表明:新型生物反应器极显著提高了增殖系数,是对照的2.0~2.5倍,增殖效率综合分析,气雾式优于摇摆式优于双瓶式;新型生物反应器培养的增殖苗各项生长指标均极显著优于对照,生长指标综合最优的是双瓶式培养;新型生物反应器能显著降低增殖苗的褐化程度。

关键词： Bioleaching   Copper concentrate   Continuous stirred tank reactor (CSTR)   Thermophilic bacteria   Particle size distribution (PSD)  

摘要： The objective of the present research was to use two different bacterial cultures in continuous tank bioleaching circuits and to use this knowledge for mathematical modeling of the chalcopyrite bioleaching kinetic. Using three different particle size distributions (PSD) with the indices (d(80)) of 45, 32 and 16 mu m of a chalcopyrite concentrate from the main Iranian copper processing plant and two types of bacteria, one and two-step continuous tests were performed in stirred tanks. In the first phase, tests were performed at 50 +/- 2 degrees C using moderate thermophilic bacteria. The second part consisted of two-step continuous tests at 50 +/- 2 degrees C using moderate thermophilic bacteria in the first reactor and extremely thermophilic bacteria at 65 +/- 2 degrees C in the second reactor. The results of one-step continuous tests indicated that the highest rate of copper dissolution (5.21 g/***) resulted from test using feed with d(80) = 16 mu m The Field Emission Scanning Electron Microscopy (FE-SEM) analysis of bioleaching residue indicated that the surface of particles was mostly covered with secondary layers. The Energy-dispersive X-ray spectroscopy (EDS) analysis of the formed layer revealed high concentrations of iron, sulfur and a certain amount of potassium. The results of two-step tests showed that under the specified conditions of this study, about 95% of copper was leached and transferred to solution. The analysis of FE-SEM and EDS residue indicated that the particle surface activity at this stage was higher than that of a single-step system probably due to the high temperature of the reaction medium (50 degrees C for the first reactor and 65 degrees C for the second reactor) and the presence of Oxidation-Reduction Potential (ORP) of solution in the range between 360 and 480 mV, Ag/AgCl. The results of the mathematical modeling for predicting the PSD of existing particles in the one -step reactor indicated that the maximum rate of size reduction kin

关键词： 草莓   立体栽培   钙肥   产量   养分  

摘要： 对不同浓度钙肥条件下草莓生长、产量、品质情况进行了研究。结果表明,立体栽培草莓叶面喷施钙肥能够提高叶片SPAD值,叶面喷施Ca^2+0.15%浓度能显著提高草莓产量,叶面喷施Ca^2+0.1%浓度对提高草莓贮藏性、提高可溶性固形物含量和果实钙含量效果最佳。立体基质栽培草莓可选择糖醇螯合型钙,进行叶面喷施。

关键词： 膜生物反应器   中空填料   膜污染   污泥增殖   生物相  

摘要： 本文主要是研究增设中空填料型膜生物反应器中污泥增殖情况,探索膜生物反应器中实现污泥零增殖的条件与方法,以减缓因污泥增殖带来的膜污染。研究发现,在污泥浓度约为4500 mg/L,进水COD约为350 mg/L,DO维持在3.5mg/L时,中空填料内空容积与反应器有效容积之比约为1∶25000时,反应器中的污泥浓度基本能维持在同一水平。同时反应器去除有机物的效果良好:出水COD<38 mg/L,平均去除率在90%以上,出水氨氮小于5.4 mg/L,去除率为70%~100%,出水除总磷外,均达到生活杂用水标准。

关键词： Polyvinylidene fluoride   Fluidized media   Anaerobic fluidized bed membrane bioreactor   Energy   Membrane fouling  

摘要： New attempts using polymeric media with a tubular shape consisting of polyvinylidene fluoride (PVDF) were made as fluidized agent for anaerobic fluidized bed membrane bioreactor (AFMBR) in wastewater treatment. The AFMBR added with PVDF media was operated at room temperature and hydraulic retention time (HRT) from 4 to 16 h to investigate membrane fouling, organic removal efficiency, and microbial structure. Results showed that the PVDF media reduced membrane fouling effectively due to their scouring actions to clean the membrane. Transmembrane pressure (TMP) was maintained less than 0.1 bar during the operational period. More than 90% of chemical oxygen demand (COD) removal was achieved, yielding 10 mg/L of COD in membrane permeate. The energy required to operate the AFMBR using PVDF media was only 1.09×10⁻² kWh/m³. The electrical energy produced by AFMBR was 0.246 kWh/m³, which is much higher than that required for system operation. Microbial community analysis based on 16S rRNA gene sequencing showed that the microbial community on PVDF biofilm was distinct from that in the suspended microbes. Importantly, it was found that dominant propionate-catabolizing bacteria on PVDF media include Desulfobulbus and syntroph Syntrophobacter while the key methanogenic player shifted from hydrogenotrophic Methanolinea to acetoclastic Methanothrix during the operation.

关键词： Biofilm MBR with pre-anoxic tank   Membrane fouling   Extracellular polymeric substances   Biofouling   Saline wastewater  

摘要： This study compared the membrane fouling mitigation in two novel types of biofilm membrane bioreactor coupled with a pre-anoxic tank (BF-AO-MBR)-namely a fixed biofilm membrane bioreactor (FB-MBR) with fiber bundle bio-carriers and a moving-bed biofilm membrane bioreactor (MB-MBR) with suspended bio-carriers-relative to an anoxic/oxic MBR (AO-MBR), at salinities ranging from zero to 60 g/L. The results showed that the FB-MBR mitigated membrane fouling to a greater degree than the MB-MBR and AO-MBR. During operation, the FB-MBR exhibited the lowest fouling development, with three membrane filtration cycles, while the AO-MBR and MB-MBR had 22 and nine cycles, respectively. The key fouling factor in all reactors was cake layer resistance (R-C), which contributed to 89.61, 62.20, and 83.17% of the total fouling resistance (R-T) in AO-MBR, FB-MBR and MB-MBR, respectively. Additionally, in the FB-MBR, the pore blocking resistance (30.07%) was also an important cause of fouling. Fiber bundle bio-carriers and suspended bio-carriers reduced the R-T by 37.68% and 21.24% (mainly the R-C) compared to that of AO-MBR. Furthermore, FB-MBR and MB-MBR caused a decrease of suspended biomass (80.14 and 15.90%, respectively), and the latter exhibited a higher sludge particle size than AO-MBR, possibly resulting in the cake layer decline. The studied BF-AO-MBRs further alleviated the fouling propensity by reducing the amount of soluble microbial product (SMP) and extracellular polymeric substances (EPS) under all salinity levels, especially the FB-MBR. Among the protein components, the amounts of tryptophan protein-like substance and aromatic protein-like substance were significantly lower in the FB-MBR compared to the AO-MBR and MB-MBR. Additionally, at 60 g/L salinity, the structure of the microbial community in the FB-MBR had a lower abundance of Bacteroidetes and more biomacromolecule degraders, which may have contributed to the moderation of membrane fouling. (C) 2020 Elsevier B.V.

关键词： 草莓   沼液   叶绿素荧光参数   日变化   环境因子  

摘要： 以基质栽培"红颜"草莓为试材,以沼液与山崎配方不同浓度(体积比2∶3、1∶1、3∶2)混合液为营养液,测定了不同营养液下生长的草莓叶绿素荧光参数的日变化,分析了各参数与环境因子的关系,以期确定适宜草莓生长的最佳沼液营养液配比。结果表明:草莓叶片PSⅡ的实际光化学量子效率ΦPSⅡ、激发能的捕获效率Fv′/Fm′和光化学淬灭系数qP的日变化均呈先降低后升高的趋势,13:00时达最低值。相对电子传递速率ETR在第1茬果实转红期的日变化呈先升高后降低的趋势,13:00时达最高峰;在第3茬果实完熟期则表现为双峰,峰值分别出现在11:00和15:00,上午峰值稍大于下午。叶片的ΦPSⅡ、Fv′/Fm′和qP在第1茬果实转红期的日均值高于第3茬果实完熟期,但ETR在2个时期内日均值相差不大。沼液浓度影响草莓叶绿素荧光参数的大小。沼液母液∶山崎配方为2∶3时提高了叶片的ΦPSⅡ、Fv′/Fm′、qP和ETR值;沼液母液∶山崎配方为3∶2降低了叶片的ΦPSⅡ、Fv′/Fm′、qP和ETR值;而沼液母液∶山崎配方为1∶1时,除第3茬果实完熟期的ETR值稍大于对照外,其它各参数均与纯山崎配方作为营养液时无显著差异。综合考虑植株生长和生产成本,可将沼液∶山崎配方为1∶1作为草莓基质栽培中营养液的适宜浓度。

关键词： Biological sulfate reduction   CO bioconversion   Gas lift reactor   Iron nanoparticle   Artificial neural network   Wastewater treatment  

摘要： This study evaluated biodesulfuruization of sulfate containing wastewater using CO as the only carbon substrate in a gas lift bioreactor. The effect of hydraulic retention time (HRT), sulfate loading and CO loading rates on sulfate reduction and CO conversion was examined, and 72 h HRT proved to be best for achieving maximum sulfate reduction and CO utilization (97.2% and 88.9%, respectively). The CO utilization was nearly 80% at the beginning of the reactor operation, which reduced later due to increase in the inlet CO concentration in the third phase of bioreactor operation. Artificial neural network based model was successfully described to predict the performance of the system using Levenberg-Marquardt (LM) algorithm with twelve number of neurons. Steady state experimental values of sulfate reduction obtained using the gas lift bioreactor accurately matched well with the values predicted by the ANN model. Furthermore, addition of biologically synthesized iron nanoparticles using green tea extract significantly improved the bioreactor performance towards sulfate rich wastewater treatment with CO, particularly under high sulfate loading condition.

关键词： Seed germination   Landfill leachate   Activated sludge (AS)   Membrane bioreactor (MBR)  

摘要： This research comparatively investigates the effect of landfill leachate effluent of two biological treatment schemes on germination of Lactuca sativa and Vigna radiata. The treatment schemes are two-stage activated sludge (AS) and two-stage membrane bioreactor (MBR) systems with acclimatized seed sludge. The AS and MBR are operated under two concentrations of landfill leachate influent: moderate (condition 1) and elevated (condition 2). The results show that, under condition 1, the AS and MBR efficiently remove 80-96% of organic compounds and nutrients and 81-100% of harmful micropollutants. Under condition 2 with elevated influent concentration, MBR is more effective in biodegrading micropollutants than the AS system. The germination rate (GR) and germination seed index (GSI) of L. sativa and V. radiata germinated with AS and MBR effluent from condition 1 are 100% and 1.29-1.56. Under condition 2, the GR and GSI with AS effluent are reduced to 80% and 0.65-0.77, while those with MBR effluent are 100% and 1.27-1.38. Quantitative real-time polymerase chain reaction (qPCR) analysis indicates that the bacterial community in the MBR is more abundant than in the AS, especially ammonia oxidizing bacteria, Nitrobacter, and Nitrospira, which aid heterotrophic bacteria in biodegradation of micropollutants and promote the growth of heterotrophs. The bacterial abundance and community composition render the MBR scheme more operationally suitable for elevated landfill-leachate influent concentrations. By comparison, the MBR system is more effective in removal of micropollutants than the AS, as evidenced by higher GR and GSI. The technology also could potentially be applied to water reclamation. A lack of technological and financial resources in many developing countries nevertheless precludes the adoption of MBR despite higher pollutant removal efficiency. An alternative solution is the use of acclimatized seed sludge in AS system to enhance treatment efficiency, especially in

关键词： 医院废水   膜生物反应器   处理工艺  

摘要： 医院废水污染物包括残留药品和微生物污染两大类,膜生物反应器(MBR)技术与现有的废水处理系统相比,提供了一种更有效的去除医院废水中污染成分的工艺方法。MBR可以有效地节省消毒剂消耗(氯添加量可以降低到1毫克/升),缩短反应时间(大约1.5分钟),微生物灭活效果好。低剂量消毒剂和较少的消毒副产物(DBPs)对MBR出水具有较高的消毒效果出水COD<25 mg/l,氨氮<1.5 mg/L,浊度<3 ntu,对COD、NH^+4-N和浊度的去除率分别为80%、93%和83%。大肠杆菌去除率达98%以上。