电渗析技术的新进展

电渗析技术是膜分离技术之一 ,由于具有高效、低能耗等特点已经被多个行业广泛使用。本文阐述了几种新的电渗析技术 ,包括无隔板电渗析、填充床电渗析、双极膜电渗析等 ,并探讨和综述其研究现状和发展前景。     

New High-Efficiency Mist Collector

The recently developed York Type P acid mist scrubber collects phosphoric acid mists and other very fine liquid particulates with very high efficiency with moderate pressure drop and high throughput. The collector consists of a single vessel containing two stainless steel wire mesh contactors. The collector converts submicron size acid mist into larger liquid particles which are collected and separated from the gas stream before being discharged from the collector. The first commercial unit started operation in July 1964, and four additional units have since been installed. Collection efficiency is 99.9+% at a pressure drop of 35-40 in W.G. The scrubber is compact and has no moving parts. Collected acid drains by gravity to a receiving tank. Experimental development work is described and design parameters such as efficiency, gas velocity, and pressure drop are discussed.     

Source apportionment of polychlorinated biphenyls in the New York/New Jersey Harbor

The New York/New Jersey Harbor (also known as the Hudson River Estuary) is heavily contaminated with polychlorinated biphenyls (PCBs) arising in part from inputs from the Upper Hudson River, which is a Superfund site containing historical PCB contamination, and also due to inputs from the New York City metropolitan area. The Contamination Assessment and Reduction Project (CARP) measured PCBs and other contaminants in ambient water samples collected throughout the Harbor region during 1998-2001. In order to investigate the sources of PCBs to the NY/NJ Harbor, this data base of PCB concentrations was analyzed using Positive Matrix Factorization (PMF). This analysis resolved seven factors that are thought to be associated with sources such as the Upper Hudson River, storm water runoff, combined sewer overflows (CSOs), and wastewater effluents. The PMF model also produced a factor that appears to be related to sites contaminated with Aroclor 1260. To the extent that the NY/NJ Harbor is typical of urbanized estuaries throughout the United States, these results suggest that storm water runoff is probably a significant source of PCBs to surface waters in urban areas.     

污水处理技术新突破—硅藻精土处理污水的新技术

用硅藻精土作为处理污水的新材料，辅以相配套的处理工艺技术，创造了污水处理新方法，与传统工艺相比，显示出新工艺诸多的优势。     

一种新型垃圾焚烧装置——SLC立式垃圾焚烧炉

介绍了一种新型垃圾焚烧处理装置，用此装置对解决“二恶英”难题的重要技术措施进行了阐述，并对装置的特点作了分析比较。     

New insights into pesticide photoprotection

Photolysis may be a significant route of pesticide dissipation on crops, leading to an increase of pesticide use. Spraying strong absorbing compounds (photoprotector) along with pesticide is an attractive strategy to prevent the photodegradation phenomenon. The aim of this study is to get a better understanding of the parameters governing the photoprotection efficiency. Experiments were conducted using formulated sulcotrione as a pesticide and a grape wine extract as a photoprotector. These compounds were irradiated using simulated solar light as dried deposits on carnauba wax films or on disks of tobacco leaves and analyzed by ultra performance liquid chromatography ultraviolet (UV), spectroscopy, and microscopy. It is shown that photolysis is faster on leaves than on carnauba wax and that the photoprotection effect of grape wine extract is more efficient on leaves than on wax. Images recorded by microscopy bring evidence that deposits are very different on the two supports both in the absence and in the presence of the photoprotector. The grape wine extract plays a double role; it is antioxidant and UV screen. Photoprotection by the grape wine extract is a complex mixing of UV screen and antioxidant effects. The UV screen effect can be rationalized by considering the rate of light absorption by sulcotrione. Our results demonstrate that the rates of sulcotrione phototransformation are mainly governed by the repartition of the deposit on the solid support.     

生物修复的新方法——菌根根际生物修复

本文介绍了菌根根际生物修复方法 ,讨论了菌根根际生物修复方法的理论依据、机理和优缺点 ,探讨了从引入固氮菌、外源细菌两个方面对菌根根际调控以提高修复效果的可能性     

New Perspectives on Marine Biodiversity

Marine and terrestrial ecosystems are so fundamentally different in some aspects that many of the issues concerning biodiversity cannot be interpreted using a single theory of common application to all ecosystems. Their limitation is evident when it comes to highly biodiverse and interconnected marine ecosystems such as coral reefs. Trophic links are a major factor, but space, breeding, shelter from predators, environmental cues, behavior ingrained in genotypes, genetic variability, mutations, and connectivity of marine critical habitats are also important. The importance of the connectivity of habitats such as coral reefs, seagrasses, and mangrove in biodiversity preservation should be recognized. Migratory species require corridors for gene flow and that influences diversity. The existing theories do not address the biodiversity issues related to life in the abyssal plains and deep sea trenches and the challenge posed by climate change. An accurate understanding of marine biodiversity requires comprehensive knowledge of ecological interrelationships and new perspectives that reflect the reality of global environmental change.     

A New Gas-Liquid Interphase Reactor

A first-order differential equation describes the dynamic response of many continuous air sampling instruments: C_t = C_i + p(dC_i/dt), where C_t is true concentration, C_i is indicated concentration, p is the time constant, and t is time. The time constant, lag time, delay time, and response time are all functions of the volume and flow through the sensor reservoir. All of them can be expressed by the same general equation: t = k₃V/Q, where t is the selected time variable, k₃ is a constant appropriate to the particular system and selected time variable, V is sensor reservoir volume, and Q is the flow rate through the reservoir. The time constant is the time a sampler takes to indicate 63.2 percent of its final response. Select time constants equal to about half of the shortest desired averaging time. Solve the second equation for the reagent flow to give the desired time constant. Selection of such a time constant eliminates spurious “noise” produced by a fast-responding system. It also provides values within 5 percent of true for atmospheres that change markedly between successive intervals. If a slow-responding system must be used, use the first equation to increase apparent response time. A digital computer can be programmed to automatically correct all measured values. Similarly, analog circuitry can be installed in an air sampling instrument to increase or decrease response time. The analog circuitry to increase response time will continuously solve and plot the first equation.