我国青霉素钾盐特征VOCs的挥发损失估算

针对我国典型制药行业--青霉素钾盐生产工艺过程中,特征VOCs的排污节点分析,利用大量调研数据、物料衡算和经验公式,估算了生产每吨青霉素钾盐各排污节点VOCs的挥发量,结合我国近年来青霉素钾盐产量情况,估算出其总排放量.结果表明,在青霉素钾盐生产过程中,特征VOCs为醋酸丁酯和丁醇,主要产生在提取阶段、精制阶段以及储罐呼吸过程中,并且在我国,生产单位质量青霉素钾盐醋酸丁酯和丁醇的挥发量大约为20.49kg/t和12.93kg/t.该研究可为制药行业青霉素钾盐生产工艺过程中VOCs的管理与控制提供科学依据.     

碳纤维环氧复合材料的加速腐蚀老化试验方法

碳纤维环氧复合材料是目前飞机制造中主要使用的结构材料,其在使用过程中可能会遇到各种环境,如雨雪、阳光、盐雾等,这些都能引起碳纤维环氧复合材料的腐蚀老化。主要介绍了海洋环境下碳纤维环氧复合材料的3种加速腐蚀老化的试验方法,即湿热老化试验、盐雾试验、人工气候老化试验。     

复杂景观中营养型非点源污染物时空变异特征分析

非点源污染的形成不仅受到地表物质来源、景观格局的影响,同时还受到土壤侵蚀过程、降雨过程、灌溉过程、地表和地下水文过程的影响.由于影响非点源污染的因子复杂多样,从而导致它的时空变化较大.正确认识非点源污染的时空变异特征对于科学布设监测点和研究它的变化规律具有重要意义.本文通过野外定点监测,研究了非点源污染的时空变异.结果发现:①干旱年份各种污染物空间变异小于降雨正常年份.②对于不同污染物,无论在干旱年份还是正常年份,地表水中固体悬浮颗粒物的空间变异均较大,其他污染物的空间变异相对较小.③对于固体悬浮颗粒物,干旱年份不同水文期之间的空间变异比较接近,而正常年份的空间变异不同水文期之间差异较大.④非点源污染季节变异较小的监测点主要出现在具有稳定水源和地表径流季节变化较小的地区;而非点源污染空间变异较大的监测点主要出现在山区河流上游地表径流季节变化明显、农业用地面积较大且地表径流季节变化较大和明显受到点源污染影响的地区.     

Chemical characteristics of haze particles in Xi'an during Chinese Spring Festival: Impact of fireworks burning

Fireworks burning releases massive fine particles and gaseous pollutants, significantly deteriorating air quality during Chinese Lunar New Year(LNY) period. To investigate the impact of the fireworks burning on the atmospheric aerosol chemistry, 1-hr time resolution of PM_(2.5) samples in Xi'an during the winter of 2016 including the LNY were collected and detected for inorganic ions, acidity and liquid water content(LWC) of the fine aerosols. PM_(2.5) during the LNY was 167 ± 87 μg/m~3, two times higher than the China National Ambient Air Quality Standard(75 μg/m~3). K~+(28 wt.% of the total ion mass) was the most abundant ion in the LNY period, followed by SO_4~(2-)(25 wt.%) and Cl-(18 wt.%). In contrast, NO_3~-(34 wt.%) was the most abundant species in the haze periods(hourly PM32-2.5 75 μg/m), followed by SO_4(29.2 wt.%) and NH_4~+(16.3 wt.%), while SO_4~(2-)(35 wt.%) was the most abundant species in the clean periods(hourly PM_(2.5) 75 μg/m~3), followed by NO_3~-(23.1 wt.%) and NH_4~+(11 wt.%). Being different from the acidic nature in the non-LNY periods, aerosol in the LNY period presented an alkaline nature with a pH value of 7.8 ± 1.3. LWC during the LNY period showed a robust linear correlation with K_2SO_4 and KCl, suggesting that aerosol hygroscopicity was dominated by inorganic salts derived from fireworks burning. Analysis of correlations between the ratios of NO--3/SO_4~(2-) and NH_4~+/SO_4~(2-) indicated that heterogeneous reaction of HNO_3 with NH_3 was an important formation pathway of particulate nitrate and ammonium during the LNY period.     

乙草胺降解菌A-3的筛选及其降解特性

采用富集培养的方法从农药厂污泥和长期受乙草胺污染的土壤中分离到1株能以乙草胺为氮源生长的细菌命名为A-3,经16S rRNA鉴定,菌株A-3属于粘着剑菌属(Ensifer adhaerens).研究结果表明,菌株A-3能以乙草胺作为唯一氮源生长并高效降解乙草胺.在含10 mg/L乙草胺的无机盐培养基中培养10 d后,菌...     

Fabrication and performance of PET mesh enhanced cellulose acetate membranes for forward osmosis

Polyethylene terephthalate mesh(PET) enhanced cellulose acetate membranes were fabricated via a phase inversion process. The membrane fabrication parameters that may affect the membrane performance were systematically evaluated including the concentration and temperature of the casting polymer solution and the temperature and time of the evaporation, coagulation and annealing processes. The water permeability and reverse salt flux were measured in forward osmosis(FO) mode for determination of the optimal membrane fabrication conditions. The optimal FO membrane shows a typical asymmetric sandwich structure with a mean thickness of about 148.2 μm. The performance of the optimal FO membrane was tested using 0.2 mol/L Na Cl as the feed solution and 1.5 mol/L glucose as the draw solution. The membrane displayed a water flux of 3.47 L/(m2·hr) and salt rejection of95.48% in FO mode. While in pressure retarded osmosis(PRO) mode, the water flux was4.74 L/(m2·hr) and salt rejection 96.03%. The high ratio of water flux in FO mode to that in PRO mode indicates that the fabricated membrane has a lower degree of internal concentration polarization than comparable membranes.     

Size, composition, and mixing state of individual aerosol particles in a South China coastal city

Aerosol samples were collected in summer in Macao,a coastal city of the Pearl River Delta Region in China.Morphology,size,elemental composition,and mixing state of individual aerosol particles were determined by scanning electron microscopy coupled energy dispersive X-ray(SEM/EDX) and transmission electron microscopy(TEM).Based on the morphologies of 5711 aerosol particles,they consist of soot(32%),mineral(17%),secondary(22%),and unknown fine particles(29%).The sizes of these particles were mostly distributed between 0.1 and 0.4 μm.Compositions of 202 mineral particles were obtained by SEM/EDX.Mineral particles were mainly classified into three types:Si-rich,Ca-rich,and Na-rich.The compositions of typical mineral particles can indicate their sources in sampling location.For example,mineral particles,collected along the main street,were associated with trace amounts of heavy metals,such as Zn,Ti,Mn,Ba,Pb,and As.TEM observations indicate that most Na-rich particles were aged sea salt particles(e.g.,Na2SO4 and NaNO3) which formed through heterogeneous chemical reactions between sea salt and acidic gases.Additionally,aging time of soot was short in Macao due to high humidity,high temperature,and high levels of sunlight in Macao.Most of soot and fine mineral dust particles were internally mixed with secondary particles.     

苯酚、苯胺对吸附胶束絮凝过程的影响

吸附胶束絮凝(AMF)法可用于去除水体中的各种污染物,为了对其处理过程中的行为加以控制,以阴离子表面活性剂SDS和铝盐为模型,通过Zeta电位、表面张力和平均粒度等分析方法,研究了吸附胶束絮凝法对苯酚、苯胺的分离去除及苯酚、苯胺对其吸附胶束絮凝过程的影响。结果表明:苯酚的存在没有对表面活性剂胶束的絮凝产生明显的影响,由于Al3+的存在,推测苯酚以络合物的形式吸附在胶束的斯特恩层,并可通过铝盐对胶束的絮凝而与水相分离去除,其去除率在40%~50%左右。而极少量的极性有机物苯胺可使表面活性剂胶束的絮凝发生较大改变,推测苯胺的存在抑制了絮凝胶团的形成。当苯胺浓度低于100 mg/L时,苯胺的去除率可达90%左右。该研究为胶束絮凝分离溶解性有机物提供了实验参考。     

两种铝盐处理纸浆CEH漂白废水的混凝特性的研究

运用Ｚｅｔａ电位测定技术研究了聚合铝ＰＡＣ、聚硅铝ＰＳＡ两种不同形态铝盐对漂白废水絮凝反应特性，通过絮凝过程中Ｚｅｔａ电位及傅立叶红外光谱对原水及两种铝盐沉淀物进行了分析，结果表明：吸附架桥为其反应的主要机理，两种铝盐与漂白废水中污染物之间反应均以铝的羟基化合物与漂白废水中氯化木素氢键缔合的形式相结合     

壳聚糖季铵盐的合成及其絮凝性能

对壳聚糖进行季铵化改性制得壳聚糖季铵盐,用于味精废水的絮凝实验证明了其絮凝性能较壳聚糖好,投药量低,ｐＨ值适用范围宽,絮体沉降快且含水率低,是一种具有良好反应活性的高分子絮凝剂。