日本研究成功废旧塑料高效转化技术

日本石川岛播磨重工业公司最近宣布，公司已开发成功将PE、PP等废旧塑料转化为石化原料的工艺。利用这项技术可将废PE、PP塑料制品用催化剂将其裂解为苯、甲苯、二甲苯的混合物和氢。     

二甲苯胺生产过程中的污染治理方法试验

二甲苯胺是重要的化工原料，在其生产过程中每生产１ｋｇ二甲苯胺，约产生１．７ｋｇ废酸，２．２ｋｇ硝苦物洗涤废水，０．３ｋｇ加氢还原水，７０ｇ残渣等。经试验表明，用产品起以废酸，可使废酸中硝基物浓度从１０７降至２０ｍｇ／Ｌ，并可回收大部分废酸供利用，硝化废水和还原废水各进行二级萃取后，硝基物和二甲苯胺去除率均在９０％以上，废渣用焚烧法处理，各项指标均达标排放。     

催化燃烧在漆包机上的应用和改进

<正> 随着工业的迅速发展,有机废气污染日益严重,特别是电工厂排出大量含苯、酚的刺激性气体,恶化着厂区周围环境。电工产品和绝缘材料在生产过程中有机溶剂挥发或蒸发进入大气,吸入会引起头晕、头痛、失眠、流泪、恶心、呕吐、食欲不振、全身无力,重者肝肾遭到损害,昏迷失去知觉,神经麻木,呼吸道和结膜发炎。我国环境标准对工厂排放有机废气未作限量规定,对居住区大气中有机物质最高容许浓度作了规定,如     

In situ adsorption-catalysis system for the removal of o-xylene over an activated carbon supported Pd catalyst

An activated carbon (AC) supported Pd catalyst was used to develop a highly efficient in situ adsorption-catalysis system for the removal of low concentrations of o-xylene. In this study, three kinds of Pd/AC catalysts were prepared and tested to investigate the synergistic efficiency between adsorption and catalysis for o-xylene removal. The Pd/AC catalyst was first used as an adsorbent to concentrate dilute o-xylene at low temperature. After saturated adsorption, the adsorbed o-xylene was oxidized to CO2 and H2O by raising the temperature of the catalyst bed. The results showed that more than 99% of the adsorbed o-xylene was completely oxidized to CO2 over a 5% Pd/AC catalyst at 140℃. Brunauer-Emmett-Teller (BET) analysis, scanning electron microscopy (SEM), temperature-programmed desorption (TPD), and temperature-programmed oxidation (TPO) were applied to investigate the physical properties of o-xylene adsorption-desorption and the in situ adsorption-catalysis activity of the AC support and Pd/AC catalyst. A synergistic relationship between the AC support and the active Pd species for the removal of low concentrations of o-xylene was established.     

炼焦过程中单环芳烃排放及源特征

通过不锈钢采样罐采样和液氮预浓缩/气相色谱/质谱系统分析,研究我国山西某地的土法炼焦和机械炼焦生产过程中单环芳烃(MAHs)的排放情况.炼焦过程MAHs以苯、甲苯、(间+对)-二甲苯为主要成分,苯和总MAHs浓度在土法炼焦烟气中最高达3421.0μg/m3和4865.9μg/m³,在机械炼焦无组织排放气体和烟气中分别为548.7μg/m³、1054.8μg/m³和1376.4μg/m³、1819.4μg/m³.焦炭生产过程中MAHs浓度变化显著:土法炼焦过程MAHs前期释放浓度高于后期;机械炼焦无组织排放MAHs在装煤和出焦时明显升高;而机械炼焦烟气中则是装煤时最高,出焦时最低.苯、甲苯、乙苯和二甲苯(BTEX)散点图和相关性分析显示机械炼焦释放MAHs主要来自煤的高温分解,而土法炼焦中MAHs释放则可能除焦煤不完全燃烧释放外还受别的因素影响.苯/甲苯/乙苯/二甲苯比值(B/T/E/X)特别是苯/乙苯(B/E)值显示炼焦释放的MAHs具有不同于其它来源的特征.     

网络版论文摘要

水体中非离子表面活性剂在自然光光照下的光降解,超声波降解二甲苯的研究,矿用大型风机扩散消声器的研制,生物膜法非稳态可控制技术在污水处理中的应用,废弃锂离子二次电池的再生技术进展……     

纳米TiO2负载CuMnOx对二甲苯完全燃烧的催化性能研究

以金红石型纳米TiO2为载体,采用等体积浸渍法制备了负载型CuMnOx/TiOo2催化剂,研究了其对易挥发性有机物二甲苯完全燃烧反应的催化活性.结果表明,控制锰铜质量比为1:1和锰铜负载量为20%(质量分数)时,经500℃焙烧2 h制备的催化剂具有良好的催化活性,二甲苯催化燃烧的起燃温度(T10%)和完全燃烧温度(T95%)分别为155℃和270℃.由X射线衍射(XRD)分析结果得出,催化剂的主要活性相是类尖晶石Cu1.5Mn1.5O4,纳米TiO2载体对活性相有很好的分散作用,其晶粒小,使得CuMnOx/TiO2催化剂的活性高.     

Levels of synthetic musk fragrances in human milk from three cities in the Yangtze River Delta in Eastern China

Synthetic musks are used as additives in many household products. After absorption into the human body, they accumulate and their concentrations in human milk reflect both the mother and her infant’s exposure level. Concentrations of four synthetic musks, musk xylene (1-tert-butyl-2,6-dimethyl-2,4,6-trinitrobenzene, MX), musk ketone (4-tert-butyl-2,6-dimethyl-3,5-dinitroacetophenone, MK), 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta[ ]-2-benzopyran (HHCB) and 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4- tetrahydronaphthalene (AHTN), were determined in human milk samples collected from Shanghai, Wuxi, and Shaoxing in Eastern China. The four synthetic musks were found in most samples analyzed, with HHCB the dominant component followed by MX. The median (mean) values for HHCB, AHTN, MX and MK concentrations were 63 (82), 5 (12), 17 (24) and 4 (9) ng/g lipid weight, respectively. These data suggested the total synthetic musk contamination was low, and the distribution percentage was HHCB > MX > AHTN MK. The relative high ratio of nitro to polycylic musk indicated that nitro musks were still widely used. The musk concentrations in these cities were not significantly different from each other (p > 0.05). Principal components score plots were obtained, which showed similar exposure sources. The amount of total synthetic musks in human milk were not associated with mother’s age, although HHCB was significantly correlated with AHTN (p < 0.05). Daily ingestion of HHCB, AHTN, MX and MK for infants from human milk were estimated as (2526 2926), (370 524), (7391 832), and (277 462) ng/day, respectively. Those doses were 1–2 orders of magnitude below the provisional tolerable daily intakes.     

水力空化技术降解含苯酚、二甲苯废水的实验研究

采用水力空化技术的新方法降解水体中的有机污染物苯酚及二甲苯。实验研究了循环时间、苯酚初始浓度、二甲苯初始浓度等因素对降解率的影响以及水温、pH值随循环时间的变化。结果表明：苯酚、二甲苯的适宜初始浓度分别为28-38mg／L、2．9-3．6mg／L：水力空化技术适宜于处理微污染水;苯酚、二甲苯的降解率随循环时间呈线性关系,具有一级反应动力学特征;随循环时间的延长,废水的pH值可升高1个pH,水温增加18℃后趋于稳定,水温的升高会影响到苯酚、二甲苯的降解率。     

不同芳香烃对地下水中细菌群落结构的影响

为给化工污染地下水进行污染评价和自然修复提供理论支持,揭示不同芳香烃污染地下水中微生物群落结构与污染物的响应关系,该文选取江苏省常州市某典型污染场地为研究对象,采集6样点4季节共24组具有代表性的地下水水样,采用水化学分析方法和高通量测序方法对其理化因子与细菌群落结构进行测定分析。地下水理化结果表明,地下水中的氯苯、二氯苯、甲苯与二甲苯浓度严重超过国家标准,该地块地下水受到较为严重污染。微生物群落结构解析结果显示,研究区域地下水的细菌群落以变形菌门、拟杆菌门、厚壁菌门和放线菌门为主。相关性分析结果表明,该地块环境因子对地下水样品中的微生物群落结构的影响程度为：甲苯>NH₃-N>邻二氯苯>对、间二甲苯>邻二甲苯>对二氯苯>NO₃^->总有机碳>氯苯>间二氯苯>pH>SO₄^2-。甲苯与二甲苯对研究区域地下水微生物群落结构的影响明显大于氯苯与二氯苯。