重金属和油处理剂对水稻根系的影响

试验了Ｎｉ、Ｚｎ、Ｍｎ、Ｓｎ、Ｃｒ和Ｃｕ等６种重金属及油处理剂对水稻根系的影响，结果表明．水中含Ｎｉ０．００７ｍｇ／１、Ｃｕ０．００５ｍｇ／１时，能阻碍根系的伸长；含Ｚｎ０．５ｍｇ／１以上时。不利于根系的伸长；水中含Ｍｎ２０ｍｇ／１，Ｓｎ、Ｃｒ￣（６－）各５ｍｇ／１时，对根系有明显危害；水中含Ｃｒ￣（２＋）＋Ｃｒ￣（６＋）时，当１种离子浓度保持不变，根系的抑制程度随着另１种离子浓度的增加而增大。水中含油处理剂１０００ｍｇ／１时，能抑制水稻发根。     

炉内喷钙脱硫技术及其主要影响因素简述

本文介绍国外炉内喷钙脱硫技术的最新发展,综述影响脱硫效率的各种因素.简介芬兰Tampella有限公司开发的LIFAC技术和国外有关利用吸收剂再循环等方式提高脱硫率和钙利用率的研究结果,展望了炉内喷钙脱硫技术的发展前景.     

Evaluation of the RAMS Continuous Monitor for Determination of PM2.5 Mass Including Semi-Volatile Material in Philadelphia,PA

Abstract

The real-time ambient mass sampler (RAMS) is a continuous monitor based on particle concentrator, denuder, drier, and tapered element oscillating microbalance (TEOM) monitor technology. It is designed to measure PM_2.5 mass, including the semi-volatile species NH₄NO₃ and semi-volatile organic material, but not to measure PM_2.5 water content. The performance of the RAMS in an urban environment with high humidity was evaluated during the July 1999 NARSTO-Northeast Oxidant and Particles Study (NEOPS) intensive study at the Baxter water treatment plant in Philadelphia, PA. The results obtained with the RAMS were compared to mass measurements made with a TEOM monitor and to constructed mass obtained with a Particle Concentrator-Brigham Young University Organic Sampling System (PC-BOSS) sampler designed to determine the chemical composition of fine particles, including the semi-volatile species. An average of 28% of the fine particulate material present during the study was semi-volatile organic material lost from a filter during particle collection, and 1% was NH₄NO₃ that was also lost from the particles during sampling. The remaining mass was dominantly nonvolatile (NH₄)₂SO₄ (31%) and organic material (37%), with minor amounts of soot, crustal material, and nonvolatile NH₄NO₃. Comparison of the RAMS and PC-BOSS results indicated that the RAMS correctly monitored for fine particulate mass, including the semi-volatile material. In contrast, the heated filter of the TEOM monitor did not measure the semi-volatile material. The comparison of the RAMS and PC-BOSS data had a precision of ±4.1 μg/m³ (±9.6%). The precision of the RAMS data was limited by the uncertainty in the blank correction for the reversible adsorption of water by the charcoal-impregnated cellulose sorbent filter of the RAMS monitor. The precision of the measurement of fine par-ticulate components by the PC-BOSS was ±6-8%.     

中国降水量高度效应及全球升温对它的影响

利用中国气象中心160站点的实际观察资料,对中国半个世纪的降水变化进行了系统分析,发现中国的夏季降水量与海拔高度存在着很好的反相关关系;同时,全球升温使得降水量的高度效应增强,主要表现为高海拔降水量海拔效应明显增强,这主要是由全球升温引起环流系统增强所引起的.     

黄杆菌P3-2降解对硫磷的质粒

黄杆菌(Flavobacterium sp.)P3-2具有水解对硫磷农药的能力.该菌在L.B培养基或以乙酸、乙醇或甘油为碳源的合成培养基上能产生对硫磷水解酶.用碱裂解法从P3-2菌株中分离出一种质粒(PAR).P3-2菌株经丝裂霉素C处理后,消除质粒的原菌株丧失了产生对硫磷水解酶的性能.用蔗糖梯度离心纯化的质粒DNA经EcoRI和BamHI消化,分别产生16和2个DNA片段、以EcoRI消化λDNA产生的6个片段的分子量作标准,测得PAR质粒的分子量约为37.16×10~6 dalton.在电镜下观察呈环状的DNA分子.     

表面活性剂强化超滤法处理亚甲基蓝废水

采用无机陶瓷超滤膜和低浓度阴离子表面活性剂十二烷基苯磺酸钠(SDBS)处理亚甲基蓝(MB)模拟废水,考察了废水中SDBS、MB浓度及废水pH对超滤过程的影响.实验结果表明:SDBS浓度影响MB在最大吸收波长处的吸光度值;当废水中SDBS浓度为1.20 mmol/L(即25℃时的临界胶束浓度)、废水中MB浓度为1.00 mmol/L、废水pH为9.0时,超滤效果最好;在此条件下,透过液中SDBS浓度和MB浓度分别为0.06 mmoL/L和0.01 mmol/L,MB的截留率为99.2%,膜通量为309.6 L/(m~2·h).SDBS对MB超滤过程的强化机理主要为MB与SDBS形成结合体析出及SDBS胶束的增溶作用.     

炭黑尾气用于精煤干燥新技术的探讨与应用

论述了炭黑尾气的组成、成分分析,国内外利用技术发展状况,利用技术工艺,以及根据工程实例,提出了炭黑尾气用于精煤干燥机燃烧炉燃料的利用新技术,给我国炭黑生产企业尾气利用提供了有益的借鉴,也丰富了我国炭黑尾气的利用技术范畴。     

用螯合树脂研究光解作用对水中铝形态的影响

本文对用螯合树脂分离水中无机铝和有机铝的方法、螯合树脂的制备及其对无机铝的交换进行了探讨。结果表明,水体中的有机铝在紫外光照射下能分解为无机铝,其分解速度随光照时间的增加而增加。由于无机单聚体铝对鱼类有致毒作用,因此,光解作用的结果使水体中铝的毒性增加。     

Estimation of septic tank setback distances based on transport of E. coli and F-RNA phages

Setback distances between septic tank systems and the shorelines of Lake Okareka, New Zealand were determined from model simulations for a worst-case scenario, using the highest hydraulic conductivity and gradient measured in the field, removal rates of the microbial indicators (Escherichia coli and F-RNA phages) determined from a column experiment, and maximum values of the design criteria for the disposal system, and assuming an absence of an unsaturated zone, a continuous discharge of the raw effluent from a failed or non-complying treatment system (both indicators at concentrations of 1x10(7) counts/100 ml) into the groundwater and no sorption of pathogens in the aquifer. Modelling results suggest that the minimal setback distances were 16 m to satisfy the New Zealand Recreational Water Quality Guidelines for E. coli <126 per 100 ml (Ministry for the Environment, 1999) and 48 m to meet the Drinking-Water Standards for New Zealand 2000 for enteric virus <1 per 100 l (Ministry of Health, 2000). These distances may be applicable for other lakeshores in pumice sand aquifers with groundwater velocities <7 m/day. Findings of laboratory column and batch experiments provided an insight into the microbial attenuation and transport processes in pumice sand aquifers. Bacterial removal was predominately through filtration (87-88%) and partially by die-off (12-13%), while viral removal was by both die-off (45%) and filtration (55%). In addition, microbial die-off in groundwater without aquifer material (i.e., free microbes) was much lower than die-off in groundwater with aquifer material (i.e., sorbed microbes) and contributed only 2-6% to the total removal. This implies that the setback distances estimated from die-off rates for the free microbes, determined in the laboratory without considering aquifer media and other removal processes, which are often reported in the literature, could be larger than necessary.     

热锻-冷锻复合塑性成形技术

热锻-冷锻复合塑性成形技术将热锻和冷锻技术结合起来使用，可成形高精度的复杂形状零计，且降低了成本，取得了良好的效果。介绍了热锻冷报技术的概况及其在工业生产中的若干应用实例。