利用黄磷尾气生产二甲醚的初步研究

生产lt黄磷要排放250Nm^3-3000Nm^3尾气，经过尾气净化和精制、甲醇合成和甲醇催化脱水等工艺，可利用黄磷尾气制取二甲醚。以年产5千t的黄磷厂为例，每年可减少1280万Nm^3尾气排放，从而减少3．63t硫、3．47t磷和0．14t氟排入空中，同时可生产二甲醚3500t、甲醇500t。本方法技术上可行，经济效益良好，环境效益显著。     

十溴联苯醚对紫花苜蓿种子萌发及幼苗的影响

为评价十溴联苯醚(BDE-209)对植物的生态毒性效应,探明植物抵抗BDE-209胁迫的反应机制,文章选用紫花苜蓿作为受试植物,考察了不同浓度BDE-209污染土壤对紫花苜蓿种子萌发及幼苗生长的影响,并对幼苗体内的抗氧化酶活性(POD、CAT、SOD)及可溶性蛋白质(SP)对污染物胁迫的响应进行了研究,同时还对植株的根、叶片进行扫描电镜观察。结果表明,BDE-209胁迫处理与各项生长指标呈显著负相关,抑制作用强度依次为根长>鲜重>芽长>发芽率。植株体内的抗氧化酶活性和可溶性蛋白含量随污染物浓度的增加不断上升,符合线性关系,POD、CAT、SOD的活性最大可高达对照的3倍、1.77倍和2.81倍,可溶性蛋白含量可达到对照的1.89倍。扫描电镜结果显示,随着污染物浓度的提高,植物根部发根增多,叶片上气孔密度增大,气孔开度变小。     

Study of the explosion parameters of vapor–liquid diethyl ether/air mixtures

The knowledge of the vapor–liquid two-phase diethyl ether (DEE)/air mixtures (mist) on the explosion parameters was an important basis of accident prevention. Two sets of vapor–liquid two-phase DEE/air mixtures of various concentrations were obtained with Sauter mean diameters of 12.89 and 22.90 μm. Experiments were conducted on vapor–liquid two-phase DEE/air mixtures of various concentrations at an ignition energy of 40.32 J and at an initial room temperature and pressure of 21 °C and 0.10 MPa, respectively. The effects of the concentration and particle size of DEE on the explosion pressure, the explosion temperature, and the lower and upper flammability limits were analyzed. Finally, a series of experiments was conducted on vapor–liquid two-phase DEE/air mixtures of various concentrations at various ignition energies. The minimum ignition energies were determined, and the results were discussed. The results were also compared against our previous work on the explosion characteristics of vapor–liquid two-phase n-hexane/air mixtures.     

冠醚交联壳聚糖在Cr(Ⅲ、Ⅵ)分析中的应用

研究冠醚交联壳聚糖（DCTS）对铬的吸附行为，建立了DCTS富集分离测定环境水样中痕量铬Cr(Ⅲ、Ⅵ）的新方法。在pH=7.5的溶液中，DCTS对铬的吸附率为100％，富集倍数可达50倍以上，用0.20g/L酒石酸2mL溶液可定量解吸总铬，用0.20g/L柠檬酸溶液2mL可定量解吸Cr(Ⅲ）。本法用于配置的南极水样中超痕量Cr(Ⅲ、Ⅵ）的测定，回收率98％－112％，变异系数1.8%，检出限0.004μg/L。     

碱性及含硫化合物对十溴联苯醚热降解的影响

将十溴联苯醚（BDE-209）于400~600℃的温度范围内进行热降解,利用GC、GC/MS对产物种类及含量变化进行分析,讨论了温度、时间、碱性化合物和含硫化合物对BDE-209降解以及对溴代二噁英生成的影响.结果表明.温度和时间均是BDE-209热降解和生成溴代二噁英的重要影响因素;热降解40min时,450℃条件下溴代二噁英生成量最多;产物种类证实碱性化合物通过与BDE-209脱溴形成的HBr反应促进降解,且可抑制二噁英的生成;含硫化合物的添加同样促进BDE-209降解,抑制二噁英的形成,其详细的抑制机理有待进一步确定,BDE-209的降解反应有两种情况,即苯环上的脱溴反应和醚键的断裂反应.     

Polybrominated diphenyl ether (PBDE) in blood from children (age 9–12) in Taizhou, China

Polybrominated diphenyl ethers (PBDEs) as ubiquitous persistent organic pollutants have attracted much attention in recent years. Exposure to PBDEs could induce a high health risk for children. The aim of this study was to investigate the PBDEs exposure of children (9–12 years) from Taizhou, China. Fifty-eight blood samples were collected in one school in a mountainous area in Taizhou. The concentrations of Σ9PBDEs (sum of BDE-28, -47, -99, -100, -153, -154, -183, -197 and -209) ranged from 2.66 to 33.9 ng/g lipid wet (lw) with a median of 7.22 ng/g lw. These concentrations were lower than those of children in USA, but close to European and Asian general population levels. The results showed that children in Taizhou countryside were at a low level of PBDEs exposure. The predominant congener was BDE-209, followed by BDE-28, -47, -197 and -153. High abundance of BDE-209 was consistent with the pollution background of PBDEs in China characterized by high brominated congeners as main pollutants.     

Thyroid disruption by technical decabromodiphenyl ether （DE-83R） at low concentrations in Xenopus laevis

Decabromodiphenyl ether (decaBDE), as a flame retardant, is widely produced and used. To study the thyroid disruption by technical decaBDE at low concentrations, Xenopus laevis tadpoles were exposed to technical decaBDE mixture DE-83R (1–1000 ng/L) in water from stage 46/47 (free swimming larvae, system of Nieuwkoop and Faber) to stage 62. DE-83R at concentration of 1000 ng/L significantly delayed the time to metamorphosis (presented by forelimb emergence, FLE). Histological examination showed that DE- 83R at all tested concentrations caused histological alterations – multilayer follicular epithelial cell and markedly increased follicle size accompanied by partial colloid depletion and increase in the peripheral colloid vacuolation, in thyroid glands. All tested concentrations of DE-83R also induced a down-regulation of thyroid receptor mRNA expression. These results demonstrated that technical decaBDE disrupted the thyroid system in X. laevis tadpoles. Analysis of polybrominated diphenyl ethers (PBDEs) (sum of 39 congeners) in X. laevis indicated that mean concentrations of total PBDEs in X. laevis exposed to 1, 10, 100, 1000 ng/L were 11.0, 128.1, 412.1, 1400.2 ng/g wet weight, respectively. Considering that PBDEs burden of X. laevis tadpoles was close to PBDEs levels in amphibians as reported in previous studies, our study has raised new concerns for thyroid disruption in amphibians of technical decaBDE at environmentally relevant concentrations.     

萃取法处理DSD酸氧化废水

以二甘醇单丁醚-二甘醇单乙醚-对二甲苯体系为萃取剂,0.1 mol/L的Na OH溶液为反萃取剂,采用三级萃取-反萃取法处理4,4’-二氨基二苯乙烯-2,2’-二磺酸氧化废水,考察了萃取和反萃取的影响因素,并对废水中的可用有机资源进行了回收。实验结果表明:在V(二甘醇单丁醚)∶V(二甘醇单乙醚)=1∶3、V(醇醚)∶V(废水)=2∶5、V(对二甲苯)∶V(废水)=1∶5的最佳萃取条件下,经三级萃取工艺处理后,平均COD去除率达92.0%、平均脱色率达96.4%、BOD5/COD0.3,可生化性明显增强;最佳反萃取条件为V(Na OH溶液)∶V(有机相)=13∶24、反萃取温度60℃;平均总硝基化合物回收率达88.9%,平均萃取剂回收率达96.7%,回收的萃取剂可循环使用。该工艺对废水处理的综合成本约为700~1 000元/t。     

水中油的测定方法探讨

探讨了重量法，紫外光度法测定水中石油类的合适条件和动物油，植物油的干扰。按选定的操作方法测定，取得了满意结果。提供了一个处理石油醚的简单方法。