纳滤技术治理染料废水的尝试

通过采用纳滤技术分别对配制染料废水和实际染料废水的染料截留和脱色进行实验 ,讨论了纳滤技术处理染料废水的可行性和应用条件 ,发现纳滤技术可应用于对染料废水的脱色 ,并实现染料与盐分的分离 ,有利于染料废水的后继处理 ,纳滤对染料废水的染料截留率 ,即脱色率很高 ,对染料含量 10 0 0mg L的进水 ,脱色率大于 99%     

絮体性质对纳滤膜污染的影响

混凝过程产生的絮体会对后续膜过滤性能产生一定的影响。实验中利用激光粒度仪研究2种混凝剂(AlCl3和PAC)在不同投加量下的絮体性质,混凝出水(不经过沉淀)直接进入纳滤膜(NF270)装置进行过滤实验。研究表明,投加量低(<0.20 mmol/L)的情况下,混凝出水反而使纳滤通量衰减发生恶化,随着投加量的增加,纳滤膜通量衰减得到有效的减缓。直接过滤腐殖酸(HA)的膜通量衰减(J/J0)为0.65,投加量为0.50 mmol/L时,AlCl3和PAC 2种混凝剂产生的通量衰减(J/J0)分别为0.78和0.75。滤饼层阻力受到絮体尺寸的影响较大,絮体尺寸越大,形成的滤饼层透水性更好。通过污染模型分析,混凝出水的纳滤膜污染机理主要是滤饼层阻力。     

纳米膜染料行业清洁生产试验研究

纳米膜技术用在染料有化工行业可代替原有的盐析生产工段,减少ＣＯＤ,色度,氯化钠等污染物的排放,提高物料回收率,改善产品质量。     

DETERMINATION OF DDT AND ITS METABOLITES IN CATTLE DIP SOIL AVAILABLE IN AQUEOUS PHASE AFTER REMEDIATION

Soil taken from a former cattle tick dip site in NSW Australia, was remediated with a chemical leaching technology. The pre- and post-remediated soil (20g) was dispersed in water (100mL) and subjected to passive diffusion using polymeric membranes. The remediation reduced tDDT from 1174.3μg/g to 102.9μg/g (ash weight basis), which was further reduced to 43.2μg/g with composting. The membranes accumulated 41.3μg tDDT/g from the dip soil, 49.2μg tDDT/g from the chemically leached soil and 3.1μg tDDT/g from the leached composted soil. The chemical leaching removed over 90% of the tDDT, but released soil bound DDT, which was converted to DDE, while 2.99μg/g was accumulated by the membranes from dip soil, 37.52μg/g was accumulated from remediated soil. Composting, however, almost eliminated the availability for passive diffusion by the membranes from 50 – 60μg/g in remediated soil to 3–3.5μg/g in composted soil. Variability studies of the membranes using eight replicates demonstrated that the accumulation by the membranes was reproducible with an average relative error of 20.3% for p,p'-DDT in soil type two, whilst the lowest average relative error for p,p'-DDE was 4.3%, suggesting that triplicate analyses will achieve acceptable accuracy.     

吸附氧化/纳滤/吸附组合工艺处理丙烯腈工业废水

针对高浓度丙烯腈工业废水,采用絮凝、吸附氧化、纳滤以及吸附的组合工艺进行处理,考察了不同工艺过程处理高浓度丙烯腈工业废水的效果和费用。结果表明,废水经过絮凝-纳滤-吸附氧化处理工艺,使废水的COD降低到1 000 mg/L以下,氨氮含量低于25 mg/L,CN-含量降低至5 mg/L以下,满足丙烯腈工业废水处理出水指标要求,且操作费用适中,为实现丙烯腈生产工业废水的循环利用奠定了坚实的技术基础。     

卷式超滤膜在蓝藻收集中的应用

利用微孔滤布-卷式超滤膜组合工艺,构建蓝藻收集中试系统,用于处理高藻期富营养化水体。考察了高藻期该工艺的蓝藻收集效率、膜通量变化及膜污染状况。结果表明,该组合工艺在进水泵频率40 Hz,进水压力0.2 MPa的条件下,定期排蓝藻浓缩液实验和蓝藻连续浓缩实验的蓝藻截留率均能达到95%以上;6 d后定期排蓝藻浓缩液实验最低...     

The boll weevil‐cotton plant complex

The boll weevil, Anthonomus grandis Boheman was introduced from Mexico into the United States about 1892. More than three‐fourths of all insect losses to cotton in this country have been attributed to this insect, and it is generally agreed that cotton cannot be profitably grown in areas where it occurs without adequate control measures. This review summarizes the chemically oriented research conducted on this plant‐insect complex during the past seventy years with emphasis on the program conducted since 1962 at the Boll Weevil Research Laboratory.

Of plant‐insect relationships, host plant resistance, feeding stimulants, plant attractants, and plant constituents are discussed. Insect‐insect relationships treated include insecticides, chemosterilants and hormones, sex attractants, and insect constituents. The development of an integrated program for the attempted eradication of this insect is also discussed.     

Absorption and retention of polydimethylsiloxanes (silicones) in fish: Preliminary experiments†

Hydrophobicity and bioaccumulation potential of linear and cyclic polydimethylsiloxane (PDMS) oligomers were estimated by reversed‐phase liquid chromatography and feeding experiments with guppies (Poecilia reticulata). PDMS concentrations in fish were determined by capillary column gas chromatography and gas chromatography‐mass spectrometry. In contrast to polychlorinated biphenyls (PCBs), only very small amounts of PDMS were retained by the fish after six weeks feeding.     

Mechnism of combination membrane and electro-winning process on treatment and remediation of Cu2+ polluted water body

Mechnism of treatment and remediation of synthetic Cu2+ polluted water body by membrane and electro-winning combination process was investigated.The influnce of electrolysis voltage,pH,and electrolysis time on the metal recovery efficiencies were studied.Relationship between trans-membrane pressure drop (ΔP),additions ratio,initial Cu2+ concentration on operating efficency,stability of membrane and the possibility of water reuse were also investigated.The morphology of membrane and electrodes were observed using scanning electron microscopy (SEM),the composition of suface deposits was ascertained using combined energy dispersive X-ray spectroscopy (EDX) and atomic absorption spectrophotometer.The results showed that using low presure reverse osmosis (LPRO),the Cu2+ concentration could increase from 20 mg/L to 100 mg/L or even higher in the concentrate solutions and permeate water conductivity could be less than 20 μS/cm.The addition of SDS can improve the Cu2+ removal efficiency,while EDTA had little side influence.In electro-reduction process,using plante electrode cell,Cu2+ concentration can be further reduced to 5 mg/L,and the average current efficiency ranged from 9% to 40%.Using 3D electrolysis treatment,Cu2+ concentration could be reduced to 0.5 mg/L with a current efficiency range 60%-70%.