长春市南湖大气降尘长期演变规律

本文统计分析了１９８４－１９９３年长春市南湖大气降尘数据，探讨了冬季与夏季的代表月份以及１０年间的代表年份大气降尘长期演变规律。１０年间冬季降法量呈波浪式递减趋势；从统计来看，冬季１月份降尘最是夏季７朋份降尘量的２．３倍左右；同年度内冬季、春季大风时段的除尘量一般高于夏、秋季；冬季煤烟型大气污染已逐年在所改善，一些自然因素对大气除尘的影响逐渐突出。     

改性活性炭吸附净化黄磷尾气中的PH3

通过钢瓶配气模拟和气相色谱GC-14C测定的方法，研究了改性活性炭吸附净化黄磷尾气中PH₃的相关问题。得到了吸附反应的最佳吸附温度、氧含量、气体流量、改性液浓度、活性炭粒径和焙烧温度。再生方法可行，可通过再生液回收磷酸。热重差热分析和孔径分布初步证明吸附质为磷和磷氧化物。     

Organohalogenated compounds in pine needles from Beijing city, China

Pine needles collected from 22 sites of six areas in Beijing city, China, were analyzed by instrumental neutron activation analysis (INAA) combined with organic extraction for extractable organohalogens (EOX) and extractable persistent organohalogens (EPOX). The concentrations of EOX (EOX = ECl + EOBr + EOI) were in the order of EOCl > EOBr > EOI. About 1.6-34% of EOCl remained as extractable persistent organochlorine (EPOCl) after treatment with concentrated sulfuric acid, which suggested that major fractions of EOCl in pine needles were an acid-liable or acid-soluble fraction. The fact that pine needle contained higher EOCl contents in chemical industrial and traffic hub areas indicated that chemical industries and exhaust emission from vehicle were the main sources of organochlorines in the Beijing's air. The relative proportions of the known organochlorines (such as HCHs, DDTs, chlordanes, HCB and PCBs) to total EOCl and EPOCl were 0.32-0.76% and 2.5-11.4%, respectively, which implied that a major portion of the EOCl and EPOCl measured in pine needles was unknown. The organochlorinated pesticides (OCPs) and PCBs concentrations in six areas were as follows: sigma HCH (sigma HCH = alpha- + beta- + gamma- + delta-HCH), 11.7-20.8 ng/g; sigma DDT (p,p'-DDT + p,p'-DDE + p,p'-DDD), 12.5-113.3 ng/g; hexachlorobenzene (HCB), 1.1-5.3 ng/g; sigma chlordane (cis-chlordane + trans-chlordane + heptachlor), 1.7-9.5 ng/g, sigma PCB, 41.8-270.5 ng/g, on dry weight basis. The samples from chemical industrial area and residential area nearby chemical industries contained the highest concentrations of sigma DDT, HCB, sigma chlordane and sigma PCB, while the contamination levels of most OCPs and PCBs in iron-steel industrial area were the lowest. The ratios of alpha/gamma-HCH (ranged from 0.9-1.5) and p,p'-DDT/DDTs (ranged from 72.1% to 91.0%) revealed the presence of the recent use of lindane and DDTs or impure dicofol in Beijing.     

Photodegradation of Dyes in Aqueous Solutions containing Fe(III) -hydroxy Complex II. Solar Photodegradation Kinetics

The solar photodegradation of five dyes, C.I. reactive red 2, C.I. reactive blue 4, C.I. reactive black 8, C.I. basic red 13, and C.I. basic yellow 2, were studied in a sunlight/Fe(III)-hydroxy system. It was observed that the photodegradation of these five dyes were pseudo-first order reactions, which has a little difference with the photodegradation kinetics of the dyes with UV-light as the irradiation source. The comparison between the two studies is also conducted.     

Effects of redox potential and pH value on the release of rare earth elements from soil

Equilibrium release experiments were conducted under three different pH values of 3.5, 5.5 and 7.5 as well as three redox potentials of 400, 0 and -100 Mv to investigate the influence of redox potential and pH value on the La, Ce, Gd and Y release of from the simulated-REEs-accumulation (SRA) soil. Oxygen and nitrogen were allowed to flow into soil suspension to adjust redox potential to a preset value, and 1 mol/l HCl or 1 mol/l NaOH solutions were added into the soil suspension to keep pH at a preset value. Results indicated that La, Ce, Gd and Y release increased gradually with the decrease of pH value or Eh, and the influence of redox potential on Ce was more remarkable than on La, Gd and Y. At the same time. It was observed that La, Ce, Gd and Y releases were positively correlated with the release of Fe and Mn, indicating that La, Ce, Gd and Y releases might originate from dissolution of Fe-Mn oxyhydroxides under reduction and low pH conditions. Moreover, it was found that alteration of pH value and redox potential might affect the change of La, Ce, Gd and Y species in the soil. The contents of La, Ce, Gd and Y in exchangeable fraction and Fe-Mn oxide fraction in the solid phase from soil suspension separation decreased with the decline of pH value and redox potential. Multiple stepwise regression analysis showed that exchangeable fraction and Fe-Mn oxide fraction predominately contributed to the La, Ce, Gd and Y release. Low pH value and redox potential were more favorable to La, Ce, Gd and Y releases following the change of their species. The La, Ce, Gd and Y contents in exchangeable fraction and Fe-Mn oxide fraction are the main contributors to their release.     

Evaluation of mercury emissions to the atmosphere from coal combustion,China

Mercury emissions from the coal smoke is the main source of anthropogenic discharge and mercury pollution in atmosphere. The calculated total amount of mercury emissions of China in 1995 is approximately 213.8 tonnes, which accounts for c. 5% of estimated total global discharge of 4000 tonnes in the same period. From 1978 to 1995, total coal consumption increased fourfold. Based on these data it is estimated that the mercury emissions will increase at a rate of 5% a year, and the predicted emissions will be 273 tonnes in China in 2000. Controlling and solving mercury emissions from coal combustion are among the most important environmental tasks facing China.     

Photocatalytic degradation of p-nitrophenol on nanometer size titanium dioxide surface modified with 5-sulfosalicylic acid

The surface of nanometer size TiO(2) was simply and fast modified by chemical adsorption in saturated solution of 5-sulfosalicylic acid. After surface modification, a stable, yellow surface complex was formed quickly, the wavelength response range of TiO(2) was expanded, it has obvious absorption in the region from 320 to 450 nm; the adsorption efficiency of p-nitrophenol (PNP) by TiO(2) was enhanced from 42% to 84%. The photocatalytic activity was tested on the degradation of PNP. The influences of catalyst and its dosage, pH value, and PNP concentration on the degradation were investigated. On optimal photodegradation conditions, including initial pH 4.0, PNP 5 mg l(-1), catalyst 100 mg, irradiation time 120 min with 160 W high-pressure mercury lamp, the degradation efficiency of PNP was increased from 40% to 88% after surface modification. Surface modification led not only to an increase in the light utilization, but also improved the surface coverage of PNP in comparison with the pure TiO(2). Both of these factors are crucial for the photocatalytic activity of heterogeneous photocatalysis, especially for photodegradation of benzenoid pollutants.     

铁（Ⅲ）氧化物对染料溶液的光化学脱色研究

将铁氧化物引入染料溶液挑化学脱色研究，在高压汞灯照射下，比较了铁氧化物对活性艳红Ｘ－３Ｂ水溶液的脱色效果，结果满意，其中ａｍ－Ｆｅ（ＯＨ）３的脱色作用尤为突出，光照１０ｍｉｎ后脱色率为９８５，动力学研究表明：在染料浓工于６０ｍｇ／Ｌ，ｐＨ２－４的条件下，α－ＦｅＯＯＨ的活性艳红产溶液的光化学脱色对动力学零级反应；     

用萃取剂LIX84I从电子废弃物处理液中选择性萃取铜

考察了相比、水相pH、混合时间等因素对LIX84I萃取铜的影响，结果表明：这些因素对铜的萃取率都有一定的影响，最优化的条件是有机相为30％LIX84I＋70％煤油、室温、相比=2：1、出口水相pH值=2．0、搅拌速度=910r／min、萃取级数为3级，每级的时间为3min。对铜进行三级萃取和一级反萃，可以得到符合电积要求的硫酸铜溶液，萃取率和反萃取率分别可以达到94．6％和97．8％。     

江西省乳腺癌与微量元素

通过对土壤微量元素１９７２９４４个数据及１２５９例乳腺癌死亡调查资料的研究，发现了乳腺癌死亡率与土壤微量元素Ｃｒ显著相关性，相对危险度为１．２４。