超临界CO2回收线路板工艺研究

采用正交试验设计进行了超临界CO₂回收废弃印刷线路板的实验。以温度、压强、时间和夹带剂为实验因素,通过对实验前后样本在重量、厚度、弯曲强度和断裂强度四方面变化的分析考察了各实验因素对实验效果的影响。实验结果表明,影响超临界CO₂法回收印刷线路板的最主要因素为温度、时间和夹带剂,超临界CO₂法回收废弃印刷线路板的最佳工艺条件：温度270℃,压强大于7.38 MPa,时间3 h,夹带剂(水)160 mL。实验进一步验证了压强对实验结果的非显著性影响。     

Environmental impact assessment (EIA): Equilibrium fugacity calculations and worst case approach

A mathematical model UNITRISK which can be used for screening purposes and risk ranking was set up to calculate relative risk values of single chemicals and mixtures of chemicals towards single or mixtures of organisms via contamination of air, water, soil and food dose. The concentration values are calculated by applying the fugacity concept or a dose must be defined. The dose-response is assumed to be linear versus concentration and degradative processes are not considered which is the worst case. The assumption that equilibria between the environmental phases exist is simplifying the model and is also representing the worst case. A mean risk factor is calculated which is 1 if the endpoint values (LC₅₀, LD₅₀, ADI, etc.) are exceeded for the investigated organisms and man.     

环境样品中PCBs的测定

详细地介绍了应用ＧＣ／ＭＳ或ＧＣ／ＥＣＤ测定样品的ＰＣＢｓ的分析方法及榈前处理的方法，并给出了３０个行政检查样品的测定结果。     

膜法富氧技术在多氯联苯(PCB_S)焚烧炉中的应用研究

介绍了富氧焚烧技术在多氯联苯焚烧炉中的应用，重点探讨了其节能效果．     

Temporal distribution and fractionation of polychlorinated biphenyl congeners in a contaminated Wisconsin lake

The most thorough field investigation, to date, of the temporal distribution and fractionation of polychlorinated biphenyl (PCB) congeners in an inland lake has been conducted in Little Lake Butte des Morts, WI. Distinct seasonal variations in dissolved and particle associated PCBs were observed over a two year period at the lake outlet; the lowest values occurred during ice-cover periods while the highest values occurred during summertime. Total dissolved PCBs ranged from 1.4–34 ng/L while total particle associated PCBs varied from 2.1–105 ng/L. An average of 71% of the total PCBs were associated with particles. Both PCB fractions were dominated by ortho-chlorinated di-, tri-, and tetrachlorobiphenyls with IUPAC #28+31 accounting for the greatest portion. Some changes appear to have taken place in the environmental composition of congeners since PCBs first entered this waterway through effluent discharges.     

Synthesis of C-labelled PCB methyl sulphones

Five methylsulphonyltetrachloro-(¹⁴C)biphenyls and three methylsulphonylpentachloro-(¹⁴C)biphenyls were synthesized, 3,4-Dichloro-(¹⁴C)aniline was reacted with 2,3- and 2,6-dichlorothioanisole and 2,4,5-trichloro-(¹⁴C)aniline with 2,5-dichlorothioanisole. The PCB methyl sulphides were oxidized with hydrogen peroxide to the corresponding sulphones.     

Results from the first year of the Swedish dioxin survey

PCDD/F levels are presented for food baskets, raw and fried herring, wolf muscle and moose tallow collected from the same area, three burbot liver samples, a sediment core from the Baltic Sea and leach water from three garbage dumps. Levels in food baskets were at or below detection limits making the estimation of intake via the diet difficult. Frying herring produces no net change in PCDD/F levels. Moose have lower PCDD/F levels than wolf from the same area. Levels in burbot liver samples are much higher near industrial discharges than in a more undisturbed area. The top 4 cm of the sediment core contain the highest levels of PCDD/F. Thereafter the levels drop and reach a low level. This low level is probably caused by contamination during sampling and is not evidence of PCDD/F presence far back in time. Leach water from city dumps contains low levels of PCDD/F but that from a dump that takes industrial wastes had higher levels and a different congener pattern.     

多氯联苯在典型污染地区环境中的分布及其环境行为

利用有效的分离、分析方法对某典型地区水、土壤、底泥、生物样品中ＰＣＢｓ的污染情况进行了初步调查。指出该地区在相当严重的ＰＣＢｓ污染。在底泥中ＰＣＢｓ的渗透作用较弱。对不同ＰＣＢｓ异构体分布规律探讨表明：在水－底泥鱼体中高氯取代的ＰＣＢｓ同类物所占比例依次增加，鱼体不同组织内ＰＣＢｓ总含量的分布规律为肝＞卵＞胆汁＞肌肉。     

Modeling polychlorinated biphenyl sorption isotherms for soot and coal

Sorption isotherms (pg-ng/L) were measured for 11 polychlorinated biphenyls (PCBs) of varying molecular planarity from aqueous solution to two carbonaceous geosorbents, anthracite coal and traffic soot. All isotherms were reasonably log-log-linear, but smooth for traffic soot and staircase-shaped for coal, to which sorption was stronger and more nonlinear. The isotherms were modeled using seven sorption models, including Freundlich, (dual) Langmuir, and Polanyi-Dubinin-Manes (PDM). PDM provided the best combination of reliability and mechanistically-interpretable parameters. The PDM normalizing factor Z appeared to correlate negatively with sorbate molecular volume, dependent on the degree of molecular planarity. The modeling results supported the hypothesis that maximum adsorption capacities (Q_max) correlate positively with the sorbent’s specific surface area. Q_max did not decrease with increasing sorbate molecular size, and adsorption affinities clearly differed between the sorbents. Sorption was consistently stronger but not less linear for planar than for nonplanar PCBs, suggesting surface rather than pore sorption.