四川彭县银厂沟峡谷自然景观成因初探

四川省彭县银厂沟峡谷全长21公里,峡谷和原始森林保存完整。时隐时现的“彩虹”出现于峡谷两岸的瀑布上。区内自然景观丰富多彩。本文根据旅游地质调查工作成果,对自然景观的成因作了初步探讨。     

绵阳市大气降水pH值时空分布及酸雨成因研究

通过对绵阳市9个测点1998－1999年大气降水监测数据的统计分析，并结合历史数据，对大气降水pH值的时空分布及酸雨成因进行了研究。结果表明：绵阳市大气降水酸化严重，除主要受本地区大气污染影响外，还受大气中、长距离输送的影响。     

常熟市农业资源的开发潜力与对策

该文就常熟市农业资源的实际出发,从改造中低产田、开发长江滩地、复耕零星废弃地、利用庭园空间、立体利用水面、开发杂草资源、加工植物蛋白饲料及发展棉田套作等8个方面的途径,评价了农业开发潜力,说明在经济发达地区的农业开发是大有可为的。文章提出了相应的实施对策。     

The ecological effects of trichloroacetic acid in the environment

Trichloroacetic acid (TCAA) is a member of the family of compounds known as chloroacetic acids, which includes mono-, di- and trichloroacetic acid. The significant property these compounds share is that they are all phytotoxic. TCAA once was widely used as a potent herbicide. However, long after TCAA's use as a herbicide was discontinued, its presence is still detected in the environment in various compartments. Methods for quantifying TCAA in aqueous and solid samples are summarized. Concentrations in various environmental compartments are presented, with a discussion of the possible formation of TCAA through natural processes. Concentrations of TCAA found to be toxic to aquatic and terrestrial organisms in laboratory and field studies were compiled and used to estimate risk quotients for soil and surface waters. TCAA levels in most water bodies not directly affected by point sources appear to be well below toxicity levels for the most sensitive aquatic organisms. Given the phytotoxicity of TCAA, aquatic plants and phytoplankton would be the aquatic species to monitor for potential effects. Given the concentrations of TCAA measured in various soils, there appears to be a risk to terrestrial organisms. Soil uptake of TCAA by plants has been shown to be rapid. Also, combined uptake of TCAA from soil and directly from the atmosphere has been shown. Therefore, risk quotients derived from soil exposure may underestimate the risk TCAA poses to plants. Moreover, TCE and TCA have been shown to be taken up by plants and converted to TCAA, thus leading to an additional exposure route. Mono- and di-chloroacetic acids can co-occur with TCAA in the atmosphere and soil and are more phytotoxic than TCAA. The cumulative effects of TCAA and compounds with similar toxic effects found in air and soil must be considered in subsequent terrestrial ecosystem risk assessments.     

微波消毒技术在医疗废物处理中的应用

本文通过对微波技术的调查,全面总结了医疗废物微波消毒系统的机理、设备组成、影响消毒效果的主要因素、设备的优越性和人体保护注意事项等。     

BACTERIAL RELATIONSHIPS IN STORMWATERS1

ABSTRACT: Data were developed within a three-year period for indicator bacteria and three species of bacterial pathogens following rural storm event hydrographs. The first flush concept was confirmed in all hydrographs. Bacterial density peaking occurred at or before the hydrograph peaks. FC and FS values were higher in more developed areas than the primary rural test site and their numerical ratios followed similar trends. Chlorine demand of storm waters varied between 8 and 16 mg/l and, the ozone requirement was greater than 32 mg/l in the same waters. Aftergrowth of total coliform bacteria occurred following chlorine and ozone doses of 16 mg/l and 32 mg/l respectively. Fecal coliform, fecal streptococci, Salmonella sp., and Pseudomonas sp. all were reduced to near detectable limits by the disinfectants up to 8 days. Staphylococcus sp. demonstrated a propensity to restablish their populations. Multiple regression analysis of the bacterial groups and species in storm waters suggested the fecal streptococci to have been the most useful group in evaluating bacterial storm water quality, with staphylocci have been closely related insofar as their statistical significance was concerned.     

Formation of Soluble Complexes of Metals with Humic Acid and Its Environmental Significance

In order to investigate the role of functional groups present in humic acid(s) (HA) during complex formation, water soluble complexes between HA isolated from soil and metals (Pb, Ca, As, Ni, Cr, Co, Cu, Cd, Fe, Mn, Mg and Zn) were prepared and subjected to infrared (IR) spectroscopy. the IR data revealed the involvement of the - OH group of humic acid in complex formation with all metals except copper and arsenic, whereas the - COOH group of HA was found to be the preferred site of binding for all the metals. the significance of findings in relation to detoxification of environmental pollutants is discussed in this paper.     

Application of cavitational reactors for water disinfection: current status and path forward

Cavitational reactors are a novel and promising form of multiphase reactors, based on the principle of release of large magnitude of energy due to the violent collapse of the cavities. An overview of cavitational reactors in the specific area of water disinfection, in terms of the basic mechanism, different reactor designs including recommendations for optimum operating parameters and applicability of the cavitation phenomena for disinfection of different micro-organisms have been presented. A design of a pilot scale sonochemical reactor has been presented, which forms the basis for development of industrial scale reactors. Economic analysis for comparison of cavitation phenomena with other conventional techniques of disinfection has been discussed. It appears that though cavitation is quite successful in treatment of water at laboratory scale operations, comparatively higher cost of treatment as compared to the conventional chemical methods is a hindrance in its industrial scale application. Intensification of cavitational activity and efficient design of industrial scale hydrodynamic cavitation reactors is required for ensuring successful application of cavitational reactors at industrial scale operation.     

深圳市工业区VOCs污染特征与臭氧生成敏感性

于2020年9~10月在深圳北部典型工业区开展在线观测以分析该地VOCs污染状况,并使用基于观测的模型(OBM)研究臭氧生成敏感性.观测期间VOCs的总浓度为48.5×10^-9,浓度水平上烷烃>含氧有机物(OVOCs)>卤代烃>芳香烃>烯烃>乙炔>乙腈.臭氧生成潜势(OFP)为320μg/m³,其中芳香烃、OVOCs以及烷烃贡献最大,这3类物种OFP贡献总和超过90%.乙烯与苯呈现“两峰一谷”的日变化特征,主要受到机动车排放的贡献.相对增量反应性(RIR)分析表明,削减人为源VOCs对控制当地臭氧生成最为有效,当中又应优先控制芳香烃;经典动力学曲线(EKMA)分析表明该片区臭氧生成处于过渡区,在开展VOCs区域联防联控的同时,需要在当地进行有力的NOx控制以强化该地区臭氧污染长期管控.