强化生物除磷系统中主要菌群的富集和培养

以SBR反应器为载体,接种具有除磷功能的活性污泥后分别富集了强化生物除磷(EBPR)系统中的2个主要微生物种群聚磷菌(PAO)和聚糖菌(GAO).以P/C和碳源种类这2个关键因素作为选择性条件控制富集的方向.高P/C下以乙酸丙酸交替富集Accumulibacter;在低P/C下以乙酸富集Competibacter,以丙酸富集α-GAO.在适当pH、温度、好氧段DO、进水负荷等条件下,富集这3类微生物取得了成功,富集结果是Accumulibacter占80%, 系统对PO3-4-P的去除率可达98%以上,Competibacter占90%,α-GAO也占有非常大的比例.此外一些细节如配水灭菌、配水充分溶解等因素也能决定富集的成败.     

厌氧-低氧序批式反应器处理投加不同比例发酵液城市污水的试验研究

本文的研究重点是比较以城市污水为碳源的SBR-A及以化学合成的乙酸钠和以剩余污泥发酵产生的短链脂肪酸(简称发酵液)分别作为城市污水的补充碳源的SBR-B和SBR-C三个系统中的除磷脱氮效果和特性。     

厌氧-低氧序批式反应器处理投加不同比例

本文的研究重点是比较以城市污水为碳源的SBR-A及以化学合成的乙酸钠和以剩余污泥发酵产生的短链脂肪酸(简称发酵液)分别作为城市污水的补充碳源的SBR-B和SBR-C三个系统中的除磷脱氮效果和特性.     

DOPO-PHBA反应型阻燃剂的合成及其与TGIC复配体系对环氧树脂性能的影响

以9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物（DOPO）和对羟基苯甲醛（PHBA）为主要原料,合成了一种新型的反应型阻燃剂DOPO-PHBA,利用FTIR和核磁共振谱（¹H-NMR、³¹P-NMR）对其分子结构和组成进行了分析表征。将DOPO-PHBA与异氰尿酸三缩水甘油酯（TGIC）复配用于制备DOPO-PHBA-TGIC/环氧树脂（EP）复合材料,通过极限氧指数（LOI）、动态热机械测试（DMA）和TGA分别对DOPO-PHBA-TGIC/EP复合材料的阻燃性能和热性能进行了研究。结果表明：成功制备了DOPO-PHBA,且DOPO-PHBA-TGIC复配型阻燃剂能显著改善EP的阻燃性能,当体系磷元素的质量分数为0.6wt%时,氧指数（LOI）由24%提高至32.5%;此外不同磷含量的DOPO-PHBA-TGIC/EP复合材料的玻璃化转变温度（T_g）均保持在200℃以上并且在800℃时的残炭量不断提高,其初始分解温度和最大热失重速率均有所下降;燃烧后残炭的红外分析表明,该体系满足凝聚相阻燃机制,且DOPO-PHBA-TGIC的加入不会削弱EP的力学性能。     

室温交联型氟代烷氧基取代聚磷腈的研究

以2,2,2-三氟乙醇钠,2,2,3,3,4,4,5,5-八氟戊醇钠和4-甲醛基苯酚钠为亲核试剂与聚二氯磷腈进行取代反应,后经硼氢化钠将醛基还原,得到了一种含有羟基的氟代烷氧基取代聚磷腈。以异佛尔酮二异氰酸酯为交联剂,三乙胺为催化剂,可以将制得的氟代烷氧基取代聚磷腈在室温下交联。通过核磁共振(31P NMR,1H-NMR)和红外光谱(IR)对该氟代烷氧基取代聚磷腈的结构进行了表征,并对其交联前后的力学性能和热性能进行了分析,发现该氟代烷氧基取代聚磷腈具有拉伸强度高、玻璃化转变温度低、热稳定性好等优点。     

双基协同阻燃环氧树脂HPCTP-DOPS/EP的性能研究

单一的磷杂菲、磷腈类阻燃剂的阻燃效果有限,为了改善9,10-二氢-9-氧杂-10-磷杂菲-10-硫化物(DOPS)对环氧树脂(EP)的阻燃效果,将DOPS和六苯氧基环三磷腈(HPCTP)复配应用于EP。在总含P量为1.2wt%时,通过调整磷杂菲和磷腈阻燃剂中含P量的比例,将DOPS和HPCTP复配添加到EP中,制备EP复合材料。利用极限氧指数(LOI)、垂直燃烧(UL-94)、热重(TG)、锥形量热(CONE)、扫描电镜-能量色散X射线谱(SEM-EDS)、热重-红外光谱联用(TG-IR)等测试手段研究不同比例的磷杂菲和磷腈基团对EP热稳定性和阻燃性能的影响,探究双基协同阻燃规律和机制。研究结果表明：P、S元素之间存在协同阻燃作用,当总含P量为1.2wt%时,复合体系中随着含S量的增加,HPCTP-DOPS/EP的LOI值和UL-94等级逐渐升高,当HPCTP和DOPS中的含P量比为0.2∶1时,HPCTP-DOPS/EP的LOI值为30.4%,达到UL-94 V-0级,总热释放量(THR)和热释放速率峰值(PHRR)显著降低,燃烧后形成了更加致密、稳定的膨胀炭层,优于两种阻燃剂单独使...     

模糊控制强化生物除磷SBR系统的除磷过程

采用在线ORP和pH仪对两个平行的强化生物除磷(EBPR)SBR反应系统的厌氧放磷、缺氧吸磷和好氧吸磷过程进行监测。针对聚糖菌(GAO)和聚磷菌(PAO)的竞争和影响PAO和反硝化聚磷菌(DPAO)的各种因素,验证了以氧化还原电位(ORP)和pH作为除磷过程模糊控制参数的可行性和有效性。在此基础上,确立了厌氧／好氧(A／O)SBR系统和厌氧／缺氧(A2)SBR系统除磷过程的模糊控制策略。对ORP和pH的在线检测不仅可以模糊控制厌氧放磷、缺氧吸磷和好氧吸磷过程所需时间,节约能源优化处理效果,而且可以指示系统运行效果和功能微生物种群的竞争行为。     

含羧基官能团杂多酸盐的制备及其性能测试

设计合成氯化1-(2-丙酸基)吡啶离子液体([2-CA-PY]Cl),并通过离子交换法合成一组新型的含有羧基官能团的杂多酸盐,使用1H-NMR、IR以及XRD对合成的离子液体和杂多酸盐结构进行表征;同时,测定此类杂多酸盐的酸度及其热稳定性。结果表明:在250℃左右,合成的杂多酸盐具有较好的热稳定性;当物质量浓度为5×10-5mol/L时,此类杂多酸盐都具有较强的酸度,其中1-(2-丙酸基)吡啶磷钨酸盐的酸度最高;可以作为此类杂多酸盐酸催化性能的理论依据。     

含碳硼烷的磷-氮烯聚合物

美国NASA所属Ames研究中心开发了含碳硼烷(Carborane)的磷-氮烯类聚合物(Phosphazene Po1ymer),该研究中心发现在磷-氮烯聚合物中添加碳硼烷化合物能提高聚合物的耐热性。苯羰基-五氯环三磷-氮烯的热聚合反应产物同三氟乙氧基钠反应,置换出氯原子,生成碳硼烷取代的聚磷-氮烯聚合物。这种新型聚合物具有高的炭得率,并有耐水解性。有机磷-氮烯聚合物具有良好的综合性     

高效液相色谱法同时测定糕点中双乙酸钠、丙酸钠(钙)含量

本方法采用了高效液相色谱法同时对糕点中的双乙酸钠,丙酸钠(钙)含量进行测定。样品中的双乙酸钠和丙酸钠(钙)经酸化后,转化为乙酸和丙酸,经超声波水浴提取后,调节PH值至酸性,经高效液相色谱测定,外标法定量。双乙酸钠和丙酸钠(钙)标准曲线的线性回归系数均在0.999以上。回收率为:91-107%。本方法具有快速,灵敏,高效的特点。     

Simultaneous nitrification-denitrification and phosphorus removal in a fixed bed sequencing batch reactor (FBSBR)

Biological nutrient removal (BNR) was investigated in a fixed bed sequencing batch reactor (FBSBR) in which instead of activated sludge polypropylene carriers were used. The FBSBR performance on carbon and nitrogen removal at different loading rates was significant. COD, TN, and phosphorus removal efficiencies were at range of 90-96%, 60-88%, and 76-90% respectively while these values at SBR reactor were 85-95%, 38-60%, and 20-79% respectively. These results show that the simultaneous nitrification-denitrification (SND) is significantly higher than conventional SBR reactor. The higher total phosphorus (TP) removal in FBSBR correlates with oxygen gradient in biofilm layer. The influence of fixed media on biomass production yield was assessed by monitoring the MLSS concentrations versus COD removal for both reactors and results revealed that the sludge production yield (Y(obs)) is significantly less in FBSBR reactors compared with SBR reactor. The FBSBR was more efficient in SND and phosphorus removal. Moreover, it produced less excess sludge but higher in nutrient content and stabilization ratio (less VSS/TSS ratio).     

基于OpenCL的流式应用程序在MPSoC上的动态并行度伸缩调度

分析了嵌入式系统应用程序的复杂化和多样化趋势,面向嵌入式系统常见的流式应用程序,提出了基于开放运算语言(OpenCL)的统一编程框架,并在此框架的基础上设计一个运行时系统,在应用程序可用计算资源发生变化的场景下,该系统可在线调整应用程序的并行度,并进行动态调度。实验结果显示,与已有的Flextream动态调度系统相比,该调度系统在性能上最高可以提场17%,在动态调度的时间开销上最多可以降低7%。     

蓖麻油基阻燃增塑剂的合成及在聚氯乙烯中的应用

为了进一步利用可再生资源为原料合成环保增塑剂,文中以蓖麻油和自制的含磷阻燃剂为原料合成了一种含磷阻燃增塑剂,再将其环氧化得到蓖麻油基含磷阻燃增塑剂(P-ECO)。采用傅里叶变换红外光谱、核磁共振氢谱和核磁共振磷谱对产物的结构进行表征。将其与聚氯乙烯(PVC)热塑共混成型,通过动态力学性能、拉伸性能测试、热重评价了蓖麻油基含磷增塑剂应用于PVC的增塑效果;随着P-ECO含量的增加,体系的Tg从41℃下降到9℃,拉伸强度随之下降到10.17 MPa,而断裂伸长率由146.22%增加到197.31%。通过测试极限氧指数、锥形量热仪测试其阻燃性能,氧指数达到28.1%,热释放速率最高为280.46kW/m2。     

Modelling Cr(VI) removal by a combined carbon-activated sludge system

The combined carbon-activated sludge process has been proposed as an alternative to protect the biomass against toxic substances in wastewaters; however, the information about the effect of powdered-activated carbon (PAC) addition in activated sludge reactors for the treatment of wastewaters containing Cr(VI) is limited. The objectives of the present study were: (a) to evaluate the removal of hexavalent chromium by (i) activated sludge microorganisms in aerobic batch reactors, (ii) powdered-activated carbon, and (iii) the combined action of powdered-activated carbon and biomass; (b) to propose mathematical models that interpret the experimental results. Different Cr(VI) removal systems were tested: (S1) biomass (activated sludge), (S2) PAC, and (S3) the combined activated carbon-biomass system. A Monod-based mathematical model was used to describe the kinetics of Cr(VI) removal in the system S1. A first-order kinetics with respect to Cr(VI) and PAC respectively, was proposed to model the removal of Cr(VI) in the system S2. Cr(VI) removal in the combined carbon-biomass system (S3) was faster than both Cr(VI) removal using PAC or activated sludge individually. Results showed that the removal of Cr(VI) using the activated carbon-biomass system (S3) was adequately described by combining the kinetic equations proposed for the systems S1 and S2.     

Biodegradation of total organic carbons (TOC) in Jordanian petroleum sludge

Biodegradation is cost-effective, environmentally friendly treatment for oily contaminated sites by the use of microorganisms. In this study, laboratory experiments were conducted to establish the performance of bacterial isolates in degradation of organic compounds contained in oily sludge from the Jordanian Oil Refinery plant. As a result of the laboratory screening, three natural bacterial consortia capable of degrading total organic carbons (TOC) were prepared from isolates enriched from the oil sludge. Experiments were conducted in Erlenmeyer flasks under aerobic conditions, with TOC removal percentage varied from 0.3 to 28% depending on consortia type and concentration. Consortia 7B and 13B exhibited the highest TOC removal percentage of 28 and 22%, respectively, before nutrient addition. TOC removal rate was enhanced after addition of nutrients to incubated flasks. The highest TOC reduction (43%) was estimated after addition of combination of nitrogen, phosphorus and sulphur to consortia 7B.

A significant variation (P < 0.005) was obser0ved between the effect of consortia type and concentration on TOC% reduction. No significant variation was observed between incubation at 10 and 18 days in TOC% reduction. This is the first report concerning biological treatment of TOC by bacteria isolated from the oil refinery plants, where it lays the ground for full integrated studies recommended for the degradation of organic compounds that assist in solving sludge problems.     

Transformation of phosphorus in intermittent aerated biofilter under aerobic continuous feeding with long backwashing intervals

A combined fixed-film system composed of anaerobic biofilter, aerobic biofilter, and intermittent aerated biofilter (IABF) is developed for enhanced biological phosphorus removal (EBPR) treating domestic wastewater. This work presents details on the performance of IABF under aerobic condition, where phosphorus-accumulating organisms are accumulated. Analysis on distribution of phosphorus in both the bulk and the biofilm indicates that the PAOs-rich biofilm is characterized by a high activity, a strong P capacity, and a good adaptability of fluctuations in aerobic continuous loading. An innovative means for P removal slows down accumulation of P in biofilm. As a result, removal of P-rich biomass is no longer a key limitation of EBPR performance in the biofilm system. Long backwashing interval is practicable in IABF under aerobic continuous feeding regime.     

Thermal–hydraulic passive system reliability-based design approach

In order to enhance the safety of new advanced reactors, optimization of the design of the implemented passive systems is required. Therefore, a reliability-based approach to the design of a thermal–hydraulic passive system is being considered, and a limit state function (LSF)-based approach elicited from mechanical reliability is developed. The concept of functional failure, i.e., the possibility that the load will exceed the capacity in a reliability physics framework, in terms of performance parameter is introduced here for the reliability evaluation of a natural circulation passive system, designed for decay heat removal of innovative light water reactors. Water flow rate circulating through the system is selected as passive system performance characteristic parameter and the related limit state or performance function is defined. The probability of failure of the system is assessed in terms of safety margin, corresponding to the LSF. Results help the designer to determine the allowable limits or set the safety margin for the system operation parameters, to meet the safety and reliability requirements.     

低分子量HTPB聚氨酯弹性体的制备及其性能

为改善高固含量高聚物黏结炸药(PBX)和丁羟推进剂的工艺性能,以低分子量的端羟基聚丁二烯(HTPB)、异佛尔酮二异氰酸酯(IPDI)为主要原料,选用一缩二乙二醇(DEG)为扩链剂,采用二步法制备了聚氨酯弹性体。研究了催化剂用量对浆料黏度的影响,固化参数R及扩链剂用量对HTPB聚氨酯弹性体力学性能的影响。试验结果表明,当催化剂质量分数为0.004%时,适用期可达5 h;R值为1.1,DEG羟基含量占反应总羟基量的60%时,聚氨酯弹性体力学性能较好,拉伸强度达7.60 MPa,断裂伸长率达540.21%。动态力学分析(DMA)测试结果显示,低分子量HTPB聚氨酯弹性体有两个明显的玻璃化转变温度,说明样品存在明显的微相分离结构。     

偏振模色散对NRZ码和RZ码的40Gbit/s系统性能影响的仿真分析

偏振模色散(PMD)是进一步提高现有光纤通信系统单信道速率必须克服的障碍之一。本文基于已铺设光纤的典型值,针对偏振模色散对采用NRZ码和RZ码的40Gbit／s光纤通信系统的性能影响进行了分析与仿真。结果表明,考虑PMD的影响时,采用RZ码的系统并不一定比采用NRZ码的系统的传输性能好,而在占空比[0,1]之间存在一个最佳值,此时,高速系统受偏振模色散的影响最小。这对于研究、设计高速光纤通信系统时选择合适的码型和RZ码的占空比,具有重要的参考意义。