Adsorption property of direct fast black onto acid-thermal modified sepiolite and optimization of adsorption conditions using Box-Behnken response surface methodology

The adsorption of direct fast black onto acid-thermal modified sepiolite was investigated. Batch adsorption experiments were performed to evaluate the influences of experimental parameters such as initial dye concentration, initial solution pH and adsorbent dosage on the adsorption process. The three-factor and three-level Box-Behnken response surface methodology (RSM) was utilized for modeling and optimization of the adsorption conditions for direct fast black onto the acid-thermal modified sepiolite. The raw sepiolite was converted to acid-thermal modified sepiolite, and changes in the fourier transform infrared spectrum (FTIR) adsorption bands of the sample were noted at 3435 cm^-1 and 1427 cm^-1. The zeolitic water disappeared and the purity of sepiolite was improved by acid-thermal modification. The decolorization rate of direct fast black adsorbed increased from 68.2% to 98.9% on acid-thermal modified sepiolite as the initial solution pH decreased from 10 to 2. When the adsorbent dosage reached to 2.5 g·L^-1, 2.0 g·L^-1, 1.5 g·L^-1 and 1.0 g·L^-1, the decolorization rate was 90.3%, 86.7%, 61.0% and 29.8%, respectively. When initial dye concentration increased from 25 to 200 mg·L^-1, the decolorization rate decreased from 91.9% to 60.0%. The RSM results showed that the interaction between adsorbent dosage and pH to be a significant factor. The optimum conditions were as follows: the adsorbent dosage 1.99 g·L^-1, pH 4.22, and reaction time 5.2 h. Under these conditions, the decolorization rate was 95.1%. The three dimensional fluorescence spectra of direct fast black before and after treatment showed that the direct fast black was almost all adsorbed by the acid-thermal modified sepiolite.     

Combination of the direct electro-Fenton process and bioremediation for the treatment of pyrene-contaminated soil in a slurry reactor

A combined treatment technology (DEF-BIO) using the direct electro-Fenton (DEF) process and bioremediation (BIO) was established in this study. The performance of the DEF-BIO process on the remediation of a pyrene (PYR)-contaminated soil was evaluated in a slurry reactor. The appropriate order of application was to conduct the DEF process followed by BIO, evaluated through analysis of the degradation characteristics of each process individually. In addition, the application time of the DEF process affected the efficiency of the combined process. The optimum time to apply the DEF process was determined through an analysis of the induced changes in PYR intermediates, pH, soil organic matter (SOM) and bacteria. The optimum application time of the DEF process was 6 h. All the induced changes were beneficial for the BIO phase. The removal of PYR was 91.02% for DEF–BIO after 72 h, and the efficiency was almost 50% increased, compared with the individual DEF and BIO treatments. Therefore, the combined process of DEF–BIO process may be an efficient and promising method for the remediation.     

一种新的有机污染物C18 EmporeTM膜/水分配系数测定方法的探讨

本文采用C18Empore^TM膜替代正辛醇模拟生物体,建立了一套新的C18Empore^TM膜／水分配系数的测定方法,并从理论和实验两方面分析了C18Empore^TM膜／水分配 系数与正辛醇／水分配系数的异同点。实验结果表明,此法测定混合有机化合物的C18Empore^TM膜／水分配系数,可以取得较为满意的结果,这种新的有机污染物C18Empore^TM膜／水分配系数测定方法的建立,可为受污染可流中混合有机物生物富集因子（BCF）的预测和水环境纳污容量的评价提供技术支持,也为多经且分有机化合物定量结果－活性相关（QSARs）的研究和实际应用开辟广阔前景。     

中华鳖的性别决定机制

设置了6种温度条件,对中华鳖卵进行了人工孵化,以探讨其性别决定机制。结果显示,温度条件能够影响子代性比（♂/[♂ ♀]),在24℃、27℃、31℃33℃、和35℃孵育条件下,子代性比出现明显偏差（P＜0.01）;在29℃条件下雌雄比例相近（P＜0.05）,为证实孵化的结果,还对中华鳖的染色体G－带型和精母细胞联会复合体进行了分析,没有发现有异型性染色体的分化;PCR扩增Sox基因,亦未见有雌、雄个体的差异,本研究结果认为,中华鳖的性别决定属于温度依赖型（TSD）机制。     

微米零价铁对剩余活性污泥和餐厨垃圾厌氧联合消化的加强效果及机制

针对剩余活性污泥和餐厨垃圾厌氧联合消化产气效率不高的问题,通过投加微米零价铁,研究其对厌氧联合消化的强化效果及作用机制.结果说明,零价铁的添加强化了厌氧联合消化的产甲烷阶段,但对溶解、水解及酸化阶段没有明显影响.当零价铁的投加量为10 g·L-1时,经过15 d的厌氧消化,累积甲烷产量(以VS计)达到238.68 mL...     

巨牡蛎(Crassostrea sp.)的滤水率测定

在实验室条件下,测定了巨牡蛎在不同个体大小、不同个体数和不同密度单胞藻(三角褐指藻)密度不同水平条件下的滤水率。结果:(1)在上述三个影响因素中,单胞藻的密度对巨牡蛎的滤水率影响最大;(2)巨牡蛎单位体重滤水率均随着巨牡蛎个体数量、巨牡蛎大小及单胞藻密度的增大而下降,它们的关系呈负指数函数和负幂函数关系;(3)在本实验条件下,当三角褐指藻的密度为1.0×104/mL,巨牡蛎的干肉重和个体数分别为0.1114 g和10只时,巨牡蛎的滤水率最高,达2.693 L/h.g。     

雷雨季节钻探施工的安全管理

本文论述了野外施工钻机在雷雨季节可能遭遇雷击现象,就如何采取防直击雷措施进行了分析与研究,即主要对钻机的接闪器、引下线、接地极及接地电阻进行了深入探讨,对野外钻探工程施工安全具有重要意义。     

顶空气相色谱法测定水中苯胺

采用顶空气相色谱法测定水中的苯胺,对盐类及其用量、顶空温度等条件进行了优化。当加入5 g NaOH,80℃进行顶空时,苯胺在0.02~0.50 mg/L范围内线性良好,方法检出限0.002 mg/L,样品加标平行测定的RSD<5.0%,回收率>95%。方法操作简单,检出限低,适用于水体中苯胺的测定。     

燃烧氧化-非分散红外吸收测定水中总有机碳方法的改进

总有机碳测定的方法分为差减法和直接法。现对测定方法进行改进,将差减法和直接法测定结果结合,先将样品进行酸化初步吹扫,再使用差减法测定总有机碳。试验结果显示,无论在标准曲线、精密度试验、加标回收试验还是标准样品测定方面,改进法均优于直接法测定结果,且能较好地缩短测量时间。     

紫外光度法测定海水石油类质控指标研究

采取问卷调查的形式对76家"近海网"成员单位海水石油类测定情况进行调查,根据调查问卷获得的数据信息,结合实验室数据,采用控制图法确定了紫外光度法测定海水石油类质控指标限值,包括萃取剂透光率、检出限、校准曲线斜率、平行样偏差等。