DBP对聚醋酸乙烯酯乳液性能的影响

讨论了邻苯二甲酸二丁酯(DBP)对聚醋酸乙烯酯(PVAcEm)胶膜的柔韧性、最低成膜温度(FMT)、黏度、粘接强度及稳定性的影响.     

基于动态BP网络的实验电炉温度控制系统

针对一类不允许出现超调的工艺参数,提出了采用动态BP网络对工艺参数进行控制,可以达到良好的效果。并以实验电炉为对象,用工控机对其炉温进行控制,结果表明,采用动态BP网络进行控制,可以无超调地无限逼近给定值,控制精度高,控制时间较短。因此可以认为,用动态BP网络对这一类工艺参数的控制是有效的。     

一种新的对角回归神经网络快速学习算法

提出一种新的动态对角回归神经网络学习算法－局部动态误差反传算法（LDBP），该算法定义了一种新的局部均方差函数，并为回归单元建立一种新的学习结构。如果估计出各层的期望输出值，多层回归网络便可分解成一组自适应单元（Adaline），而每个单元可通过二次优化方法进行训练。采用可在有限步人找出全局最优解的共轭梯度法（CG）进行寻优。由于学习过程采用超线性搜索，大大减少了循环步数和计算时间。     

水玻璃模数对白碳黑生产工艺的影响

利用低模数水玻璃，改变有关工艺参数，制取白碳黑产品，并探讨对产品二次结构及表面特性的影响．     

Selection of NF membrane to improve quality of chemically treated surface water

The requirement for higher quality drinking water necessitates the application of more efficient water treatment techniques. Nanofiltration is one promising option for enhanced water treatment, for example, in enhanced organic matter removal. The characteristics of different nanofiltration membranes vary remarkably, and the selection of a membrane has to be made according to the requirements of an application. In this study six nanofiltration membranes (NF70, NF255, NTR-7450, NTR-7410, Desal-5 and TFC-S) were evaluated in improving the quality of chemically pre-treated surface water in a pilot-scale process. The results indicate that the membrane with high organics removal and slightly reduced ion removal characteristics (NF255) performed best in terms of product water quality as well as membrane productivity and fouling. The most permeable membrane (NTR-7410) suffered intensive fouling and insufficient product water quality. An interesting finding was that the permeates of all the tested membranes possessed a significant potential for microbial growth, despite the low nutrient contents.     

Predicting disinfection by-product formation potential in water

Formation of regulated and non-regulated disinfection by-products (DBPs) is an issue at both potable water and wastewater treatment plants (W/WWTPs). Water samples from W/WWTPs across the USA were collected and DBP formation potentials (DBPFPs) in the presence of free chlorine and chloramine were obtained for trihalomethane (THM), haloacetic acid (HAA), haloacetonitrile (HAN), and N-nitrosodimethylamine (NDMA). With nearly 200 samples covering a range of dissolved organic carbon (0.6-23 mg/L), ultraviolet absorbance (0.01-0.48 cm⁻¹ at 254 nm wavelength), and bromide (0-1.0 mg/L) levels, power function models were developed to predict the carbonaceous DBP (C-DBP) and nitrogenous DBP (N-DBP) precursors spanning 3 orders of magnitudes. The predicted THM and HAA formation potentials fitted well with the measured data (analytical variance of less than 22%). Inclusion of dissolved organic nitrogen (DON) into the HANFP model improved the predictions. NDMAFP was the most difficult one to predict based upon the selected water quality parameters, perhaps suggesting that bulk measurements such as DOC or UVA₂₅₄ were not appropriate for tracking NDMAFP. These are the first such DBPFP models for wastewater systems, and among the few models that consider both C-DBPs and N-DBPs formation potentials from the same water sources.     

Degradation of phthalate esters in an activated sludge wastewater treatment plant

Efficient removal of phthalate esters (PE) in wastewater treatment plants (WWTP) is becoming an increasing priority in many countries. In this study, we examined the fate of dimethyl phthalate (DMP), dibutyl phthalate (DBP), butylbenzyl phthalate (BBP), and di-(2-ethylhexyl) phthalate (DEHP) in a full scale activated sludge WWTP with biological removal of nitrogen and phosphorus. The mean concentrations of DMP, DBP, BBP, and DEHP at the WWTP inlet were 1.9, 20.5, 37.9, and 71.9 μg/L, respectively. Less than 0.1%, 42%, 35%, and 96% of DMP, DBP, BBP, and DEHP was associated with suspended solids, respectively. The overall microbial degradation of DMP, DBP, BBP, and DEHP in the WWTP was estimated to be 93%, 91%, 90%, and 81%, respectively. Seven to nine percent of the incoming PE were recovered in the WWTP effluent. Factors affecting microbial degradation of DEHP in activated sludge were studied using [U-¹⁴C-ring] DEHP as tracer. First order rate coefficients for aerobic DEHP degradation were 1.0×10⁻², 1.4×10⁻², and 1.3×10⁻³ at 20, 32, and 43 °C, respectively. Aerobic degradation rates decreased dramatically under aerobic thermophilic conditions (<0.1×10⁻² h⁻¹ at 60 °C). The degradation rate under anoxic denitrifying conditions was 0.3×10⁻² h⁻¹, whereas the rate under alternating conditions (aerobic-anoxic) was 0.8×10⁻² h⁻¹. Aerobic DEHP degradation in activated sludge samples was stimulated 5-9 times by addition of a phthalate degrading bacterium. The phthalate degrading bacterium was isolated from activated sludge, and maintained a capacity for DEHP degradation while growing on vegetable oil. Collectively, the results of the study identified several controls of microbial PE degradation in activated sludge. These controls may be considered to enhance PE degradation in activated sludge WWTP with biological removal of nitrogen and phosphorus.     

Feasibility study of electrochemical hydrodehalogenation of 2,4-dibromophenol in a paraffin oil

The feasibility of electrochemical hydrodehalogenation (HDH) of 2,4-dibromophenol (DBP) in paraffin oil has been evaluated for short or long operation periods of up to 170 h. HDH has been performed successfully using a solid polymer electrolyte reactor in a batch recycle mode with a dilute H₂SO₄ aqueous solution as the anode feed and source of protons. The work reported in this paper expands the application of electrochemical HDH from aqueous systems to non-conductive media. The effect of the operating conditions, including current density, reactant concentration and temperature, is evaluated. The results are compared with those achieved in the aqueous solutions.     

固体酸催化合成邻苯二甲酸二丁酯的研究

以苯酐和正丁醇为原料,用自制的SO4^2-/SiO2、SO4^2-/Fe2O3、SO4^2-/SnO2及固体铁系为催化剂,催化合成邻苯二甲酸二丁酯（DBP）,分别考察固体酸催化剂的种类、固体酸催化剂的用量、醇酐摩尔比和反应时间等因素对合成DBP产率的影响。试验结果表明,其中SO42-/SnO2催化剂催化活性高。在苯酐0.1 mol（14.8 g）、固体酸催化剂m（SO4^2-/SnO2）/n（苯酐）为16（g/mol）、醇酐摩尔比2.5、带水剂二甲苯200[mL/mol（苯酐）]、反应时间4.0 h的条件下,其产率达94.0%以上,寿命长、可多次重复使用、产物易纯化分离、且产品色泽浅等优点,可望代替传统浓硫酸作催化剂应用于DBP的合成。     

NDA-66树脂处理DBP生产废水及吸附行为

通过等温吸附试验,研究了超高交联树脂NDA-66对邻苯二甲酸(ο-PA)的吸附性能及吸附行为,同时优化了NDA-66处理增塑剂DBP生产废水吸附-脱附工艺参数。经过初步筛选发现,NDA-66树脂对ο-PA具有良好的吸附性能,在温度为15℃、30℃和45℃条件下分别测定了吸附平衡数据,ο-PA在NDA-66树脂上的吸附平衡符合Freundlich等温吸附方程,温度对吸附的影响较大。参数优化试验结果表明:树脂吸附最佳工艺参数是:pH 2.0~2.4,温度30℃,流速为1.5 BV/h;树脂脱附最佳工艺参数,脱附剂用量及组成为1 BV 8%NaOH+2 BV H_2O,脱附温度为55℃,脱附流速为1.5 BV/h。