计算流体力学技术在膜分离过程中的应用与进展

计算流体力学（ComputationalFluidDynamics，CFD）技术近年被广泛地应用于膜分离过程模拟中。本文评述了CFD研究膜分离过程中流体力学、膜污染机理和浓差极化等现象，以及CFD技术在微滤、超滤、反渗透中的研究进展及待解决问题等。     

封存过程中CO2流体与煤中矿物作用关系研究进展

利用深部煤层封存二氧化碳(CO2),既能减排主要人为温室气体CO2,又能同步开采煤层气(主要成分为甲烷,即CH4)。在适宜CO2封存的含煤储层条件下,CO2属于超临界流体,其易与煤中部分无机矿物发生作用,进而改变煤的理化性质,最终影响煤层的CO2封存效果。为此,归纳了煤中易与CO2发生作用的矿物分布特征,分析了CO2与矿物间的作用规律及其对煤理化性质的影响,并指出了后续研究方向。结果表明,煤中易与CO2流体发生作用的无机矿物主要包括碳酸盐矿物和黏土矿物。上述矿物的分布与煤变质程度和沉积环境有关。在封存过程中,超临界CO2流体与煤中矿物间的作用会改变煤体孔隙结构、煤的CO2吸附能力和含煤储层渗透率。针对CO2与煤中矿物的作用关系,后续需开展以下研究:CO2流体与煤中矿物之间的微观作用机理;CO2流体与煤层顶底板中主要无机矿物的作用规律;实际储层条件(温度、压力和地应力等)对CO2与矿物之间作用关系的影响;CO2与矿物之间的相互作用对同步采收CH4的影响。     

Modelling Dissolved Organic Carbon Turnover in Humic Lake Örträsket, Sweden

The organic carbon balance of a lake with high input of allochthonous organic carbon is modelled integrating physical, chemical and biological processes. The physical model captures the behaviour of real thermal stratification in the lake for different flow situations during the period 1993–1997. The dissolved organic carbon model is based on simulated trajectories of water parcels. By tracking parcels, account is kept of environmental factors such as temperature and radiation as well as DOC quality for each parcel. The DOC concentration shows seasonal variations primarily dependent on inflow. The organic matter degradation (bacterial- and photodegradation) in the lake amounts to 1.5–2.5 mg C l^–1 yr^–1, where photooxidation is responsible for approximately 10%. The estimated DIC production in the lake is large compared to sediment mineralisation and primary production. The main conclusion is that the model with the selected parameterisations of the degradation processes reasonably well describes the DOC dynamics in a forest lake.     

光皮桦资源的开发利用与发展前景

光皮桦是一种用途较广的珍贵树种 ,近年来皖南山区对光皮桦资源的需求日益增大。对光皮桦资源的利用现状、经济效益、造林技术及发展前景进行了论述。     

废水生物处理中固定化微生物技术方法与载体使用

固定化微生物技术由于具有许多传统污水处理工艺所没有的特点和优势，得到了越来越多的研究和应用。文章就现有的固定化微生物技术方法与常用的载体进行了分类，对各种固定化微生物技术的优劣性和适用范围进行了比较和总结，指出了固定化微生物技术在今后污水处理中的研究发展方向。     

冷凝膜油气回收技术在轻质油汽车装车中的应用

介绍了油气回收技术的基本原理,着重介绍了冷凝膜回收工艺技术的特点,及冷凝膜回收装置在中国石化青岛石油化工有限责任公司轻质油汽车装车的应用情况,分析了存在的问题及改进建议。     

CFD simulations of dust dispersion in the 20 L vessel: Effect of nominal dust concentration

Measurements of flammability and explosion parameters for dust/air mixtures require uniform dispersion of the dust cloud inside the test vessel. In a previous work, we showed that, in the standard 20 L sphere, the dust injection system does not allow generation of a uniform cloud, but rather high gradients of dust concentration are established. In this work, we used a previously validated three-dimensional CFD model to simulate the dust dispersion inside the 20 L sphere at different dust nominal concentrations (and fixed dust diameter). Results of numerical simulations have shown that, as the dust nominal concentration is increased, sedimentation prevails and, thus, when ignition is provided, the dust is mainly concentrated at the vessel walls.     

The nexus between eco-friendly technology and environmental degradation in India: Does the N or inverted N-shape load capacity curve(LCC) hypothesis hold?

This study aims to investigate the impact of eco-friendly technology on environmental degradation indicated using the load capacity factor (LCF) with the framework of the Load Capacity Curve (LCC) hypothesis. In this regard, an environmental degradation function is formed and analyzed using the Augmented Autoregressive Distributed Lag (AARDL) approach during the period spanning from 1975 to 2021 for India. The outcome indicates that eco-friendly technology reduces the LCF, thereby fostering environmental degradation in the long run, but the relationship is not significant in the short run. Further, an N-shaped LCC hypothesis has been observed in both long and short runs. Besides, energy consumption exhibits a LCF reducing or environmental degradation boosting role in the short run and long run. These findings are consistent with other models that are used to check the robustness of AARDL-based results. Thus, the study recommends policies for promoting eco-friendly technology, judicious economic growth, and cautious energy consumption to attain sustainable development by increasing the LCF in India.     

超临界水气化处理对脱水污泥中重金属环境风险的影响

为探究超临界水气化前后脱水污泥中重金属的变化及生态风险,从重金属(Ni、Cu、Zn、Pb、Cr)的含量、化学形态分布及浸出毒性等多方面出发,利用地层累积指数(Igeo)、潜在生态风险指数(RI)和风险评估指数法(RAC)对江苏地区10种不同种脱水污泥超临界水气化前后重金属的环境生态风险进行综合评价.结果表明:不同污水厂脱水污泥经超临界水气化处理后,绝大部分污泥中重金属浸出毒性和生物可利用组分重金属含量明显降低,即处理后重金属的直接环境风险大大降低.不同重金属含量的脱水污泥经超临界水气化处理后,重金属环境污染程度及潜在生态风险程度显著降低,环境风险值被降至相对安全水平,对环境表现出低风险或无风险.p H值在一定程度上影响处理后污泥中重金属的环境风险.超临界处理时,污泥的p H呈现酸性时会引起反应釜腐蚀,从而导致固相残渣中Ni、Cr的生物可利用组分含量增加,当p H呈现碱性时则更利于重金属以稳定形态富集到固相产物中.     

毒死蜱在香蕉、土壤中的残留动态及安全性评价

为了监测香蕉中毒死蜱的残留量,科学、安全地使用毒死蜱防治香蕉上的害虫,确保产品质量,采用气相色谱法及田间试验方法,研究了毒死蜱在香蕉及其土壤中的残留降解动态.结果表明:在香蕉中,毒死蜱的原始沉积量较高,残留降解规律符合一级动力学关系,推荐剂量和加倍剂量处理的降解动态方程分别为y=1.0724e-014149t和y=1.7840e-0.1468t,半衰期(T1/2)为4.8 d,降解99％所需要的时间(T0.99)为31.4～31.8d;在土壤中,毒死蜱的残留降解动态方程为y=6.4365e-1412t,T1/2为4.9d,T0.99为32.7 d.距第2次施药后60～68d,最终在香蕉与土壤中均未检出毒死蜱残留量(检出限为0.005mg/kg).研究表明,漳州蕉区在香蕉生产上科学、合理地施用毒死蜱,其最终残留符合NY/T 750-2011规定的MRL要求,不会对蕉园土壤环境造成污染.