Application of calcium alginate-PANI@sawdust wood hydrogel bio-beads for the removal of orange G dye from aqueous solution

Environmental Science and Pollution Research - This work aims to investigate the adsorption performance of orange G (OG) dye from aqueous solutions employing PANI@sawdust biocomposite enrobed by...     

电催化氧化处理除草剂异噁草酮废水的效能

为有效处理含异噁草酮除草剂废水,以Sb掺杂Ti／SnO2电极为阳极,不锈钢板为阴极,采用电催化氧化技术对异噁草酮废水进行降解,研究了不同影响因素对异噁草酮去除率的影响,并分析了异噁草酮的降解效果。结果表明,当异噁草酮初始浓度为100mg／L、电流密度为20mA／cm2、电解质投加量为0．10mol／L,反应120min后,异噁草酮去除率达到94％,此时TOC去除率为57．9％,能耗为25kWh／m2,且废水的可生化性能显著提高。     

响应面法优化袋式除尘器脉冲清灰性能

基于计算流体动力学的方法采用三维、可压缩、非稳态流动数学模型对袋式除尘器脉冲清灰过程进行了数值模拟,得到了滤袋内外压差,并与文献实验值进行了比较,验证了仿真模型的可靠性。基于响应面法研究了喷吹压力、喷吹高度、滤袋直径和滤袋长度对脉冲清灰性能的影响,得到这4个影响因子的二次多项式预测模型,并进行优化。结果表明,喷吹压力为0.3 MPa,喷吹高度为0.2 m,滤袋直径为0.16 m,滤袋长度为6 m时,内外压差峰值最优,优化结果与仿真模拟结果相差小于3%。研究结果为袋式除尘器脉冲清灰系统的设计与优化提供了重要参考。     

电催化氧化处理除草剂异草酮废水的效能简

为有效处理含异草酮除草剂废水,以Sb掺杂Ti/SnO₂电极为阳极,不锈钢板为阴极,采用电催化氧化技术对异草酮废水进行降解,研究了不同影响因素对异草酮去除率的影响,并分析了异草酮的降解效果。结果表明,当异草酮初始浓度为100 mg/L、电流密度为20 mA/cm²、电解质投加量为0.10 mol/L,反应120 min后,异草酮去除率达到94%,此时TOC去除率为57.9%,能耗为25 kWh/m³,且废水的可生化性能显著提高。     

底物初始浓度对光合细菌产氢动力学特性的影响

实验研究了底物初始浓度对光合细菌产氢动力学特性的影响,并对光合细菌产氢得率和初始底物转化为氢气得率进行比较,分析底物初始浓度对光合细菌产氢代谢的影响,实验发现底物初始浓度为120 mmol/L时最适合光合细菌的产氢代谢,底物初始浓度达到140 mmol/L时,光合细菌主要进行生物量合成和产酸代谢,得到各浓度梯度下的最大生物量,但对产氢代谢产生抑制作用,表明最大生物量与最大的产氢能力之间不成正比关系及光合细菌产生CO2机制与产氢机制不同;光合细菌最大比产氢活性表现在对数生长期,最大生物量出现在稳定期。实验证明,光合细菌对数生长期受底物浓度影响大,底物浓度低,最大生物量所对应的时间相对较早,底物浓度增大,最大生物量所对应的时间相对延后。     

双硫腙法研究废电池中汞的分布及浸出

用双硫腙法测定了几种废电池中汞的含量和分布及在不同水环境条件下,汞的浸出率,试图为废电池中各组分去汞后的回收提供理论依据。结果表明,双硫腙测定废电池中汞的方法是可靠的;汞在废电池中主要分布在锌皮（锌粉）和碳包部分;pH对汞的浸出率有较大的影响,浸出率与pH呈负相关。     

Assessment of teratogenic potential of trichlorfon in mice and rats

Trichlorfon was evaluated for its teratogenic potential in the CD-1 mouse at doses of 200, 300 or 400 mg/kg/day administered by gavage on days 7-16 of gestation. In the CD-1 mouse, TCF was teratogenic, fetotoxic and lethal at the two highest dose levels which were also maternally lethal. At the lowest dose level which was not maternally lethal, there was a significant decrease in the number of calcified centers in the forepaws and hindpaws indicating fetotoxicity and a delay in maturation. TCF was administered at doses of 50, 100 or 200 mg/kg/day to CD rats by gavage on gestational days 7-19 (study I) or 8-20 (study II). In the CD rat in body study I and II, the highest dose level was maternally lethal. In study I, TCF was teratogenic with a shift in rib profile. In study II, TCF was teratogenic with an increased incidence in malformations of the urinary system. Additionally, TCF was fetotoxic with reduced ossification of the skulls at the lowest and highest dose levels.     

阳离子交换膜对Cu~（2＋）离子交换的动力学及热力学研究

对阳离子交换膜离子交换Cu2＋的动力学及热力学现象进行了研究,结果表明：温度25℃,溶液pH=6时,干膜对Cu2＋饱和交换容量为0.506 mmol/g;随Cu2＋初始浓度的升高,离子交换速率常数随之增加;随温度升高,离子交换速率常数随之增加;随转速升高,离子交换速率常数随之增加;离子交换过程与一级反应速率方程拟合结果良好;△G0〈0,表明离子交换反应能自发进行;△H0m〉0,表明的交换反应为吸热反应;△S0〉0,表明交换反应是熵变增加的反应。     

光合细菌强化二级流化床工艺处理焦化废水的研究

采用厌氧酸化加二级流化床组合工艺处理焦化废水。一级反应器内光合细菌与兼性厌氧菌处于共生状态,二级反应器内光合细菌与亚硝酸细菌处于共生状态。一级反应器内光合细菌有充分的小分子有机酸可降解并形成二次酸化,在二级反应器内完成进一步降解。结合反应条件：温度,pH,DO和基质浓度等,将二级反应器内硝化反应控制在亚硝化阶段,有效地保证了废水中碳源的利用。稳定运行了60 d,结果显示,出水COD和NH₃-N浓度分别为105～135 mg/L和14～20 mg/L,去除率分别稳定在90.3%～92.5%和92%～95%。TN去除率稳定在83%～86%。酚、氰化物和BOD5的去除率均在95%以上。     

固定化降解菌Q5去除喹啉的性能研究

为了研究固定化微生物在土壤生物修复中的应用,以实验室筛选出来的高效降解菌 Q5 为生物活性物质,利用生物大分子仿生合成出的纳米多孔氧化硅为载体,通过表面吸附同定化方法将其固定,制备出固定化微生物.考察固定化微牛物初始 pH 值、温度、摇床转速和菌种的接种量对喹啉去除的影响,得到适宜的去除条件,在相同条件下比较固定化微生物与游离菌种对底物的去除情况,研究单一固定化菌种对不同浓度的喹啉的去除情况,考察固定化微生物的稳定性.实验结果表明,菌株 Q5 经固定化后,对喹啉的去除能力大大增强,在 500 mg/L 浓度下,40 h 固定化 Q5 对底物去除率达96.6%,远高于未固定化 Q5 的去除率 56.1%;对于高底物浓度,固定化微生物的去除效果明显,初始底物浓度为1 500 mg/L,反应 70 h 后去除率为 91.6%,且这种固定化微生物的重复使用性能良好.     

污染负荷及植被生物量变化对缓冲带污染物净化效果的影响

模拟上海地区农业面源污染和降雨特征,进行缓冲带污染物净化效果和植被生物量监测试验研究。结果表明：植被缓冲带对径流污染物质的净化效果明显高于空白对照,百慕大缓冲带SS截留率最高,达到74％;白花三叶草对TN、TP的净化效果最好,去除率分别为28％和25％;百慕大和白花三叶草生物量最大,栽种当年9月份,两者地上部分的生物量鲜重分别达到了6.14和6.49 kg/m²,百慕大生长速度最快,当年9月份生物量几乎达到5月份的6倍;植被生物量增长明显提高了缓冲带截留径流污染物的效果,缓冲带SS截留率与生物量成显著线性相关,而污染负荷变化对缓冲带污染物净化效果的影响很小,明显弱于植被种类和生物量的变化。     

不同人工湿地基质对污水总有机碳去除能力初探

选择4种常见基质及基质配比,研究其碳含量和组分对污水中总有机碳(TOC)的去除影响。结果显示当污水的TOC浓度为27 mg/L时,4种基质都向水体中释放碳,且释放碳的大小顺序为:砂子-土壤-泥炭混合基质土壤砂子-土壤混合基质砂子,基质的碳含量越高,释放到水体中碳越多。3种基质对水体中TOC的去除率大小顺序为:土壤砂子-土壤混合物基质砂子,基质碳含量越高,微生物活性越强,对TOC的去除率越高。在第12天,砂子-土壤-泥炭混合基质处理中TOC浓度的增加,与其稳结合态有机碳含量较高有关。有机碳含量和组分影响了人工湿地基质对TOC的去除。     

丙烯酸废水超临界水氧化动力学研究

用H2O2作为氧化剂,对丙烯酸生产废水进行超临界水氧化研究.得到了反应速率方程表达式.COD、H2O2和水的反应级数分别为1、0和0,指前因子A为4.97 s-1,反应活化能Ea为20.64 kJ/mol,诱导时间为8 s左右.     

Adsorption of phenol by bentonite

The potential of bentonite for phenol adsorption from aqueous solutions was studied. Batch kinetics and isotherm studies were carried out to evaluate the effect of contact time, initial concentration, pH, presence of solvent, and the desorption characteristics of bentonite. The adsorption of phenol increases with increasing initial phenol concentration and decreases with increasing the solution pH value. The adsorption process was significantly influenced by the solvent type in which phenol was dissolved. The affinity of phenol to bentonite in the presence of cyclohexane was greater than that in water and was lowest in the presence of methanol. Methanol was used to extract phenol from bentonite. The degree of extraction was dependent on the amount of phenol adsorbed by bentonite. X-ray diffraction analysis showed that the crystalline structure of bentonite was destroyed when cyclohexane was used. The ability of bentonite to adsorb phenol from cyclohexane decreased as the water to cyclohexane ratio was increased. Furthermore, hysteresis was observed in phenol desorption from bentonite in aqueous solutions. The equilibrium data in aqueous solutions was well represented by the Langmuir and Freundlich isotherm models. The removal of phenol from aqueous solutions was observed without surface modification.     

Photo-oxidation of biodegraded crude oil and toxicity of the photo-oxidized products

We investigated the physicochemical changes resulting from irradiation by sunlight of biodegraded crude oil. An Arabian light crude oil sample was first subjected to microbial degradation. n-Alkanes and aromatic compounds such as naphthalenes, fluorenes, dibenzothiophenes and phenanthrenes possessing short, alkyl side chain(s) were almost completely degraded, while the contents of the saturated and aromatic fractions were reduced by 70% and 40%, respectively. This biodegraded oil was then suspended in seawater and exposed to sunlight irradiation for several weeks. The most remarkable change caused by the irradiation was a substantial decline in the aromatic fraction with a concomitant increase in the resin and asphaltene fractions. A 13C-nuclear magnetic resonance (NMR) spectroscopic analysis showed that the aromaticity of the biodegraded oil was significantly lower in the irradiated sample. A field desorption-mass spectrometric (FD-MS) analysis showed that sunlight irradiation reduced the average molecular weight of the oil components and formed oxygenated compounds. Consistent with this observation is that the oxygen content in the oil increased as the irradiation was prolonged. The bioavailability of the biodegraded oil was increased by the photo-oxidation: the growth of seawater microbes was minimal when the non-irradiated biodegraded oil was used as the source of carbon and energy; however, growth was significant when irradiated biodegraded oil was used. The concentration of dissolved organic carbon (DOC) increased linearly during the sunlight irradiation of the biodegraded oil, and this increase was matched by an increase in ultraviolet-absorptive materials in the seawater. The photochemically formed, water-soluble fraction (WSF) showed acute toxicity against the halophilic crustacean, Artemia.     

水力停留时间对MBR中溶解性微生物产物生成的影响

考察水力停留时间(HRT)对MBR中膜污染的主要污染物——溶解性微生物产物(SMP)生成的影响。结果表明,在装置稳定运行期间,MBR中SMP随运行时间出现累积。与HRT为8 h相比,HRT为12 h时,SMP在MBR中平均累积量要少10.1%,SMP中多糖含量平均高7 mg/L左右,而蛋白质含量平均低45.6%。SMP的平均粒径随装置运行呈下降趋势,并且HRT较短有利于粒径较小的SMP生成,从而堵塞膜孔;HRT较长有利于粒径较大的SMP生成,从而形成凝胶层,两种情况导致膜污染的机制不同。     

壳聚糖混凝处理丁腈橡胶废水的实验研究

利用壳聚糖作混凝剂处理丁腈橡胶废水。对投加量、pH、搅拌速率和沉降时间四因素进行L₉(3⁴)正交实验,确定壳聚糖混凝处理丁腈橡胶废水的最佳实验条件。结果表明,壳聚糖投加量为100 mg/L, pH为6,搅拌速率为200 r/min,沉降时间为5 min,COD去除率达96.7%,出水COD降为276 mg/L,达到国家三级排放标准。     

Chemo-denitrification of nitrate-polluted water

Nitrate-nitrogen reduction was studied in the presence of ferrous iron and a copper catalyst. In a batch system, it was found that the reduction was very fast at pH 8.1 and slow at pH 7.5. A temporary accumulation of nitrate and hydroxylamine was noted. It was found that the reduction of nitrite-nitrogen in the presence of ferrous iron partly continued to ammonium. Decreasing the amount of reagents led to a slower reduction rate but a lower accumulation of nitrite and hydroxylamine. A continuous system was described whereby more than 50% of the initial nitrate could be removed.     

芦苇和香蒲在人工湿地城市污泥处理系统中的应用

用有机玻璃材料做成模拟人工湿地,分别种植芦苇和香蒲考察2种模拟植物湿地对城市污泥干化和稳定化、污泥中营养元素和重金属去除效果,并和空白湿地对比。实验污泥取自当地污水厂二沉池,污水处理采用厌氧池加氧化沟工艺。模拟人工湿地进泥负荷为0.72 kg TS/(m2.d),进泥中TS平均含量为5.58 g/L,pH为6.80。实验期为1年,采用间歇式进泥,渗滤液月采集测样一次,湿地剩余污泥2月1次。实验结果受天气和气候影响较大,处理效果夏季好于冬季,出水水质和剩余污泥的干化及稳定效果芦苇湿地好于香蒲湿地。剩余污泥中各种重金属含量低于污泥农用标准中各重金属离子浓度要求。结果表明,人工湿地植物净化系统对城市污泥有较好的脱水和稳定化效果。     

响应面法优化聚磷硫酸铁的制备及其应用

采用单因素实验方法,针对制备聚磷硫酸铁(PPFS)的主要影响因素加以分析,包括酸度(nH2SO4/nFe2+、碱化度和nPO34-/nFe2+等。以生活污水中总磷(TP)的去除率为考察对象,采用Box-Behnken中心组合实验和响应面分析方法对主要影响因素加以优化,得到了二次响应曲面模型以及优化的水平值。结果表明,当把PPFS用于生活污水中TP的去除时,其最佳制备参数如下所列:酸度为0.1017,碱化度为12.21%,nPO34-/nFe2+为0.0560。通过回归分析,模型拟合性良好,在优化制备条件下得到的TP去除率预测值与实验值接近,误差为1.26%。