印染废水回用水处理复合药剂的开发与应用

针对印染废水回用率低、回用水水质要求高等特点,采用活性炭、聚合硫酸铁(PFS)、聚合氯化铝(PAC)、膨润土等药剂对印染废水生化出水进行处理,考察单一药剂成分对废水处理效果的影响。结果表明,单一PAC、PFS难以同时有效去除印染废水中的CODCr和色度,活性炭的处理效果较好,但成本较高。基于各药剂成本、处理效果等多种因素,开发了针对漂洗回用水水质标准的复合药剂1和针对染色用水水质标准的复合药剂2。复合药剂1中m(活性炭)∶m(PAC)∶m(PFS)∶m(膨润土)=5∶60∶5∶30;复合药剂2中m(活性炭)∶m(PAC)∶m(PFS)∶m(膨润土)=45∶30∶5∶20。研究结果表明,复合药剂1和复合药剂2处理1#水样的最佳投加量均为500 mg/L,最佳初始p H值分别为6和7,反应时间均为30 min;处理2#水样的最佳投加量分别为400和500 mg/L,初始p H值为6和6~7,反应时间分别为45~60和60 min。2种印染废水经复合药剂处理后水质均能达到相关出水水质的要求。     

辽河油田AH-90温拌沥青老化动力学研究

为了更好的研究基于油溶性表面活性平台的温拌技术的抗老化性能,文章分别对辽河AH-90基质沥青和掺入OS-125油基温拌剂的温拌沥青进行基础理化性能和旋转薄膜烘箱老化实验,测定不同老化温度和老化时间下的软化点值。以软化点为参数建立老化动力学模型,求得准确的动力学参数,得到两种沥青的一级线性老化动力学方程。通过两组方程中老化动力学参数的相互比照可以看出,油基温拌沥青具有较低的反应速率和较高的活化能,说明油基温拌剂很好地改善了沥青的抗老化性能。     

Use of micellar extraction and cloud point preconcentration for valorization of saponins from sisal (Agave sisalana) waste

Sisal (Agave sisalana) is the main hard fiber produced worldwide, with an estimated generation of 400 thousands t in 2011. From its leaves, only the hard fibers, which represent 3–5% of their weight, are removed. The remaining 95–97% is referred to as sisal waste and contains steroidal saponins that can be potentially used in foods, cosmetics and pharmaceuticals formulations, as well as for soil bioremediation. The present work aimed at to evaluate strategies for the extraction and concentration of saponins from sisal waste, focused on the use of clean solvents, such as water and ethanol. For this purpose, it was firstly performed a central composite rotatable design for the optimization of the extraction conditions followed by a comparison of this strategy with other methods (Soxhlet, ultrasound-assisted extraction and micellar extraction). Cloud point preconcentration was then tested, using several types and concentrations of salts. The use of orbital shaker extraction (200 rpm) with an ethanolic solution (30%, v/v) at 50 °C, a mass/volume ratio sisal/solvent of 0.17 (g/mL) for 4 h allowed a recovery of 38.6% of the saponins. When a micellar extraction strategy using 7.5% (v/v) of Triton X-100, under the above-mentioned conditions was performed, saponins recovery raised to 98.4%. In a subsequent step, the addition of 20% (m/v) sodium carbonate led to a preconcentration factor of 20.3. The best adsorbent for Triton removal from the preconcentrated solution was Amberlite FPX-66. The process strategy proposed in the present study showed to be efficient for saponins extraction and preconcentration from a low-cost, highly available agricultural waste.     

Detecting at‐Most‐m Changes in Linear Regression Models

In this article, we provide a new procedure to test for at‐most‐ changes in the time‐dependent regression model , that is, β ₁ =  β ₂ = ? =  β _T under the no‐change null hypothesis against the alternative if and β ^(j) ≠  β ^(?) for some with . Our procedure is based on weighted sums of the residuals, incorporating the possibility of changes. The weak limit of the proposed test statistic is the sum of two double‐exponential random variables. A small Monte Carlo simulation illustrates the applicability of the limit results in case of small and moderate sample sizes. We compare the new method to the cumulative sum control chart (CUSUM) and standardized (weighted) CUSUM procedures and obtain the power curves of the test statistics under the alternative. We apply our method to find changes in the unconditional four‐factor capital asset pricing model.     

Testing Parameter Change in General Integer‐Valued Time Series

We consider the structural change in a class of discrete valued time series, which the conditional distribution belongs to the one‐parameter exponential family. We propose a change point test based on the maximum likelihood estimator of the model's parameter. Under the null hypothesis (of no change), the test statistic converges to a well‐known distribution, allowing the calculation of the critical value of the test. The test statistic diverges to infinity under the alternative, meaning that the test has asymptotic power one. Some simulation results and real data applications are reported to show the effectiveness of the proposed procedure.     

凹凸棒土膜对工业锅炉连排废水的净化性能

采用悬浮粒子法在Al_2O_3基体表面经800℃烧结制备凹凸棒土膜(ACM)。压汞仪、扫描电镜、X-射线衍射等对ACM的表征结果显示,膜孔径分布于9.05~19.57 nm,且烧结后的晶体结构无显著变化。基于工业锅炉(≤2.45 MPa)连排废水(BW)的水质特征,利用ACM在实验室条件下以死端截留模式处理BW,结果显示,ACM可有效去除CO_3~(2-)和SO_4~(2-),历经24 h过滤后,对两种离子的去除率依然可保持在90%以上。     

Recovery of polyphenols from camu-camu (Myrciaria dubia H.B.K. McVaugh) depulping residue by cloud point extraction

In this study the potential of cloud point extraction formed by a non-ionic surfactant was used in order to separate polyphenols from industrial residues of camu-camu. The effects of operational conditions of the cloud point extraction (CPE) on the polyphenol recovery and volumetric ratio were investigated. The results showed a maximum recovery of 95.71% that was obtained using 7.0 wt% Triton X-114, native pH (3.25), and 80 wt% polyphenol extract at 30 °C. The use of cloud point extraction was successful to recover the polyphenols from agroindustrial residue since it is a simple as well as of low-cost technique.     

不同催化剂对松香季戊四醇酯合成的影响

针对目前制备松香季戊四醇酯的催化剂毒性较强或成本昂贵,且所需能耗大等问题,本文以高效、无毒、绿色环保、廉价的羧酸盐和碱性盐类化合物为催化剂催化松香和季戊四醇酯化反应合成松香季戊四醇酯,考察了催化剂种类和用量、n（松香）∶n（季戊四醇）、反应时间和反应温度等因素对酯化反应的影响,得出较佳的反应条件,即n（松香）∶n（季戊四醇）为1∶0.25、松香30.0g、催化剂硬脂酸锌为松香质量的0.20%、反应时间7h、反应温度250℃。在上述条件下,所得产物松香季戊四醇酯的酸值为18.07mg/g、软化点为94.7℃、色泽为9～10（铁钴法）。同传统催化剂氧化锌相比,在不使用其他助剂的情况下,所得产物色泽浅、软化点和酸值较低,且反应具有催化剂用量少、反应温度低、无需分离催化剂等优点。     

锦纶66高强低缩丝切片纺丝技术探讨

在锦纶(PA)66产业用丝的切片纺丝中,为了满足纺丝品种的特性要求,提高纺丝的稳定和改善纤维的物理指标,对PA66的熔体特性进行了分析,根据不同纺丝品种需求,确定了设备配置和调控能力。