两级常温厌氧—好氧—固定化微生物组合工艺处理酿酒废水

酿酒废水是一种典型的高氨氮浓度的有机废水.采用两级常温厌氧-好氧-固定化微生物组合工艺对酿酒废水进行中试研究,重点考察了各级工艺对有机物和氨氮的去除效果,并且对影响系统稳定运行的主要因素进行分析.试验结果表明,稳定运行状态下,一级厌氧膨胀颗粒污泥床(EGSB)反应器对有机物去除率可达到70%～90%,处理效果受环境温度影响较大;二级EGSB反应器可以同时去除有机物和氮氧化物;三级好氧接触氧化反应器对有机物的去除率可达到70%,氨氮去除率维持在50%;包埋硝化菌流化床反应器最终能有效地去除水中的氨氮,出水氨氮质量浓度低于15 mg/L.     

CuxZn1-xS/RGO复合材料的制备及其光催化降解环丙沙星性能研究

通过一步水热法制备了光催化剂Cu_xZn_(1-x)S/RGO,实现了Cu_xZn_(1-x)S纳米颗粒的可控生长和氧化石墨烯(GO)还原的同步进行,并将所制备的Cu_xZn_(1-x)S/RGO用于环丙沙星(CIP)的催化降解研究.采用X-射线衍射(XRD)、电感耦合等离子体-原子发射光谱仪(ICP-AES)、傅立叶变换红外光谱(FTIR)、紫外可见漫反射光谱(UV-Vis)、电子显微镜(SEM)和透射电子显微镜(TEM)对复合物的组成形貌进行表征.结果表明,球状的Cu_xZn_(1-x)S颗粒成功负载在石墨烯表面.Cu~(2+)的掺杂增强了Cu_xZn_(1-x)S/RGO光催化剂在可见光范围的响应,石墨烯的引入抑制了Cu_xZn_(1-x)S纳米颗粒的团聚,提高了光催化性能.此外,Cu_(0.1)Zn_(0.9)S/RGO_(10)对CIP的降解速率分别是ZnS、Cu_(0.1)Zn_(0.9)S的8倍和4.4倍.     

超亲水石墨烯/二氧化硅复合膜的制备优化和表征

膜表面亲水性是主导膜污染发生的关键因素,亲水膜的抗污染能力较强。基于氧化石墨烯(GO)和氨基修饰的纳米SiO_2之间的自组装反应,分别通过真空抽滤、多巴胺辅助抽滤、热辅助法以及高温煅烧辅助抽滤法制备了多种GO/SiO_2复合膜,结合纯水接触角测定、表面官能团分析以及电镜观察等,对制备方法和条件进行了优化。结果表明:高温煅烧法制备的超亲水GO/SiO_2复合膜,其初始接触角为6.1°,并于2 s内,在膜表面实现完全铺展,表现出超亲水特性;此外,所制备的GO/SiO_2超亲水膜的纯水通量分别是传统PVDF超滤膜、超亲水SiO_2/PVDF复合膜和0.22μm有机商业膜的3.21、11.10和1.22倍,显示出良好的应用潜力。     

National Park Development in China: Conservation or Commercialization?

The rapid development of parks and ecotourism in China has attracted worldwide attention, not only for the beauty of the landscape that the parks are protecting but also for their abundant and often unique biodiversity. However, in some areas, the development of ecotourism has actually led to the degradation of local ecological, economic, and social systems. Using National Forest Parks for demonstration, this article analyzes the current political, institutional, legal, environmental, and economic issues concerning National Parks in China, and examines their potential future development. Although the intention of National Park systems in China is to raise environmental quality, and to protect biodiversity and social livelihoods, their success has varied. Future success will be measured by their capacity to reduce poverty, to promote long-term rehabilitation of wildlife habitats, and to simultaneously protect Chinese culture and biodiversity.     

Assessment and management of the performance risk of a pilot reclaimed water disinfection process

Chlorination disinfection has been widely used in reclaimed water treatment plants to ensure water quality. In order to assess the downstream quality risk of a running reclaimed water disinfection process, a set of dynamic equations was developed to simulate reactions in the disinfection process concerning variables of bacteria, chemical oxygen demand （COD）, ammonia and monochloramine. The model was calibrated by the observations obtained from a pilot disinfection process which was designed to simulate the actual process in a reclaimed water treatment plant. A Monte Carlo algorithm was applied to calculate the predictive effluent quality distributions that were used in the established hierarchical assessment system for the downstream quality risk, and the key factors affecting the downstream quality risk were defined using the Regional Sensitivity Analysis method. The results showed that the seasonal upstream quality variation caused considerable downstream quality risk; the effluent ammonia was significantly influenced by its upstream concentration; the upstream COD was a key factor determining the process effluent risk of bacterial, COD and residual disinfectant indexes; and lower COD and ammonia concentrations in the infiuent would mean better downstream quality.     

The influence of particle size and concentration combined with pH on coagulation mechanisms

In order to evaluate the influence of particle size and particle concentration on the coagulation process, two kinds of particle suspensions, nanoparticles and microparticles,were employed to investigate the effect of particle size on coagulation mechanisms with varying coagulation parameters. Results showed that it is easier for nanoparticles to cause self-aggregation because of Brownian motion, while interception and sedimentation are the mainly physical processes affecting particle transport for microparticles, so they are more stable and disperse more easily. The particle size distribution and particle concentration had distinct influence on the coagulation mechanisms. Under neutral conditions, as the amount of coagulant increased, the coagulation mechanism for nanoparticles changed from charge neutralization to sweep flocculation and the nanoparticles became destabilized, re-stabilized and again destabilized. For microparticles, although the coagulation mechanism was the same as that of nanoparticles, the increased rate of aluminum hydroxide precipitation exceeded the adsorption of incipiently formed soluble alum species, resulting in the disappearance of the re-stabilization zone. Under acidic conditions, Brownian motion dominates for nanoparticles at low particle concentrations, while sweep flocculation is predominant at high particle concentrations. As for microparticles, charge neutralization and sweep flocculation are the mechanisms for low and high particle concentrations respectively.Under alkaline condition, although the mechanisms for both nano-and microparticles are the same, the morphology of flocs and the kinetics of floc formation are different. At low particle concentrations, nanoparticles have larger growth rate and final size of flocs, while at high particle concentrations, nanoparticles have higher fractal dimension and recovery factors.     

污水处理行业温室气体核算模型开发及减排潜力分析

城镇污水处理行业是我国现代化进程中不可或缺的一部分,它承担着城镇污水处理和减排的重要作用,在运行过程中不可避免会产生大量的温室气体。本研究基于污水处理过程中的温室气体排放机理及排放因子法,构建了污水处理温室气体核算模型,并应用于国内典型的某厌氧—缺氧—好氧工艺的污水处理厂。研究结果表明,开发的模型能够有效识别出厌氧—缺氧—好氧工艺温室气体排放占比较高的环节,该环节为污水处理过程中电耗和污水处理过程中的甲烷排放,其在整个温室气体排放系统内占比高达93.09%。污水处理厂可以采取减小曝气量的措施使溶解氧达到2 ～ 3 mg/L,从而降低污水处理系统曝气电耗;另外,优化泵及鼓风机的运行,选用变频调速水泵等措施,可以降低污水提升环节能耗,达到温室气体间接减排的目的。污水处理厂还可以采取甲烷产能回收利用措施,将CH₄燃烧产生的能量作为污水处理系统内的能源供应,这样不仅可以有效减少污水处理厂的能耗,而且可以实现污水处理过程中温室气体排放减量化。     

相变材料填充率影响锂电池组热失控传播特性的实验研究

复合相变材料(PCM)应用于锂电池组的热管理是当前研究的热点。然而,PCM对锂电池组热失控传播特性的影响规律仍不甚明晰。实验研究了不同PCM填充率对锂电池组的影响,分析其热失控触发时间、最高温度、质量损失和热释放速率等参数变化规律。结果发现,添加PCM后,电池表面温度、CO和SO2浓度均出现了不同程度的降低,但对热释放速率没有明显的影响。PCM填充率为0%和10%的电池组均发生了热失控传播,而30%、50%、100%的PCM填充率能有效阻隔热失控传播的发生。     

复合惰气在采空区遗煤中竞争吸附的分子动力学模拟研究*

为明确作用于采空区的复合惰气的竞争吸附,进行不同温度、压力及组分下烟煤对N2、O2、CO2多元气体竞争吸附分子的模拟研究。研究结果表明:当注入压力达到3 MPa后,竞争吸附效果不再明显,为高压注入提供一定的理论基础;随着CO2分压的增大,O2吸附量降低速度逐渐平缓,初步确定最佳注入配比范围为2∶1至3∶1,为进一步结合实际工程中成本等因素确定最佳注入配比提供参考;等量吸附热受吸附条件的影响较小,仅与吸附质本身有关;随着CO2分压的增大,范德华能升高56.9%,分子内能升高78.7%,静电能升高67.2%,CO2对整个系统内的吸附作用强度及吸附量有着较大的影响;随着CO2分压增大,N2竞争吸附能力逐渐弱于O2,竞争吸附能力大小顺序为CO2>O2>N2。     

上海市大气颗粒物中金属元素特征

分析上海市５个采样点，１９８６年至１９８７年连续１２个月的大气颗粒物样品中的１１种金属元素含量。结果表明，市区各功能区之间，以及各个季节之间，元素分布特征差异；细粒子中的重金属元素主要受局部地区工业源和气象条件的影响；与其它城市相比，上海市大气颗粒物中的重金属元素含量高数倍；通过粒径－成份以及富集因子分析，探讨了这些元素的来源。