氯代芳香化合物的KOW与对数拓扑指数和路径指数的相关性

本文用１ｇＫｏｗ表征氯代芳香化合物的生物降解能力,并分别以对数拓扑指数（ＬＴＩ）和路径指数（ＰＩ）为自变量,建立了新的预测模型。结果表明,回归方程的预测值与实验值十分吻合,相关系数接近于１,平均标准偏差小于０．１。     

喹啉季铵盐絮凝-缓蚀剂FNQ-C的制备及其性能研究

本文研究了天然高分子改性喹啉季铵盐型阳离子絮凝-缓蚀剂FNQ-C的制备,确定了其最佳制备反应条件;考察了FNQ-C在模拟循环冷却水中的絮凝、缓蚀性能.絮凝实验表明FNQ-C的絮凝净水效果优于国产阳离子聚丙烯酰胺絮凝剂PAM-C,挂片腐蚀实验表明FNQ-C的缓蚀性能与国产商品缓蚀剂EDTMP相当.实验亦证实FNQ-C的缓蚀用药量与其絮凝净化用药量相容,可以一次投药同步满足絮凝、缓蚀两种水质要求.     

Application of the simplified toxicity identification evaluation procedures to a chemical works effluent

Toxicity of a Chemical Works effluent from the Southeast China to the Daphnia magna was compared to determine the most representative aqueous fraction for simplified toxicity identification evaluation (TIE) studies. Toxicity characterization procedures revealed that the primary toxicant(s) was a nonpolar organic compound. Toxicity was recovered through C₁₈ solid-Phase extraction and concentration steps. Gas chromatography-mass spectroscopy of these concentrates revealed the presence of chlorobenzene, nitrobenzene, naphthalene, 1-chloro-3-nitrobenzene, 1-chloro-4-nitrobenzene, 2-naphthol and aniline. The mass balance approach of TIE implicated the seven chemicals as the primary toxicants. The simplified TIE procedures can save our cost and time. The significance of the TIE results may indicate a more widespread problem what chemical(s) has priority to be controlled when being discharged.     

气流噪声治理及设计

本文根据气流噪声的频率特性和发声部位,提出重点降噪与综合整治的方法,对城市气流噪声污染进行控制。     

PVC的热解脱氯动力学分析

采用动态热重法对PVC热解脱氯反应动力学进行了研究,对不同升温速率下TG曲线采用下同方法分析,计算出反应速率常数、反应级数、活化能等脱氯反应动力学参数,并推断出反应机制,分析结果表明,PVC热解存在两个阶段,氯原子主要在250℃-300℃之间以HCl的形式释放,且反应为一级反应。     

Degradation of rhodamine B by Fe(0)-based Fenton process with H2O2

Degradation of rhodamine B by Fe(0)-based Fenton process with H₂O₂ was investigated. The effects of H₂O₂ dose, Fe(0) dose, initial concentration of rhodamine B and initial pH value on the degradation of rhodamine B were examined. The results showed that the degradation and mineralization of rhodamine B occurred with low dose of H₂O₂ and Fe(0). The intermediates of rhodamine B were analyzed with UV-Vis spectrophotometry and ion chromatography and the mechanism of oxidative degradation of rhodamine B was also discussed. The reactive oxygen species (·OH) produced in Fe(0)-based Fenton process with H₂O₂ is the key to the degradation of rhodamine B by ways of N-de-ethylation, chromophore cleavage, ring-opening and mineralization.     

膜基材对动态膜生物反应器性能的影响研究

选用5种滤布作为动态膜生物反应器(DMBR)的膜基材在相同操作条件下进行对比实验,考察反应器运行周期、反冲洗前后过滤压力、膜通量的恢复情况,分析DMBR进出水水质.结果表明,应用DMBR处理模拟生活污水,其中孔径为24μm的涤纶短纤滤布组成的DMBR对COD、氨氮和总氮的去除率分别为90%、80%和48%以上;运行周期...     

蓝藻治理方法概述

近年来,随着社会工业化进程的加快,人类在生产以及日常生活中,向水体中排入大量含氮、磷的污染物,加速了湖泊、水库的富营养化进程,水华频频暴发,严重破坏了水体的生态平衡,危害人类和其他生物的安全。蓝藻水华的形成机制,对于科学预测湖泊中蓝藻水华的产生及采取相应措施减少其带来的影响,具有重要的生态和环境意义。     

Rapid biotransformation of arsenic by a model protozoan Tetrahymena pyriformis GL-C. [corrected

Arsenic biomethylation and biovolatilization are thought to be two important metabolic pathways in aquatic and soil environments. Tetrahymena thermophila is a genus of free-living ciliated protozoan that is widely distributed in freshwater environments around the world. In this study, we studied arsenic accumulation, speciation, efflux, methylation and volatilization in this unicellular eukaryote exposed to various concentrations of arsenate. Our results show that T. thermophila accumulated 187 mg.kg⁻¹ dry weight of arsenic when exposed to 40 μM for 48 h, with MMAs(V) (monomethylarsenate) and DMAs(V) (dimethylarsenate) as the dominant species, accounting for 66% of the total arsenic. Meanwhile, arsenate, arsenite, MMAs(V) and DMAs(V) were detected in the culture medium; the last three were released by the cells. The production of volatile arsenic increased with increasing external As(V) concentrations and exposure time. To our knowledge, this is the first study on arsenic metabolism, particularly biomethylation and biovolatilization, in protozoa.     

Combined effects of titanium dioxide and humic acid on the bioaccumulation of cadmium in Zebrafish

The combined effects of titanium dioxide (TiO₂) nanoparticles and humic acid (HA) on the bioaccumulation of cadmium (Cd) in Zebrafish were investigated. Experimental data on the equilibrium Cd bioaccumulation suggest that only the dissolved Cd effectively contributed to Cd bioaccumulation in HA solutions whereas both the dissolved and TiO₂ associated Cd were accumulated in TiO₂ or the mixture of HA and TiO₂ solutions, due likely to the additional intestine uptake of the TiO₂-bound Cd. The equilibrium Cd bioaccumulation in the mixed system was comparable to that in the corresponding HA solutions, and significantly lower than that in the corresponding TiO₂ solutions (n = 3, p < 0.05). The presence of either HA or TiO₂ (5-20 mg L⁻¹) in water slightly increased the uptake rate constants of Cd bioaccumulation whereas combining HA and TiO₂ reduced the uptake rate constants.