Synthesis, properties and application research of atrazine Fe3O4@SiO2 magnetic molecularly imprinted polymer

Introduction

Magnetic Fe₃O₄ nanoparticles were prepared by coprecipitation and then were coated with SiO₂ on the surface.

Materials and methods

Fe₃O₄@SiO₂ composite microspheres were modified by KH570. Using molecular imprinting technology, atrazine magnetic molecularly imprinted polymer was prepared by using atrazine as template molecule, methacrylic acid as functional monomer and ethylene glycol dimethacrylate as cross-linkers. The morphology, composition and magnetic properties of magnetic nanoparticles were characterized. The recognition selectivity of polymer was studied for template molecule and simulation by UV spectrophotometry. The adsorption properties and selectivity ability were analyzed by Scatchard analysis.

Results

Scatchard linear regression analysis indicated that there are two binding sites of the target molecules. The magnetic molecularly imprinted polymer has been applied to the analysis of atrazine in real samples.

Conclusion

The results show that: the recovery rates and the relative standard deviation were 94.0??98.7% and 2.1??4.0% in corn, the recovery rates and the relative standard deviation were 88.7??93.5% and 2.8??7.2% in water.     

混凝沉淀法深度处理酒精废水

采用混凝沉淀法对酒精废水进行深度处理实验及放大应用研究。结果表明,混凝剂种类、投加量、pH值及沉降时间对处理效果都起着重要作用。通过正交实验确定最优化组合,即聚合硫酸铝投加量为60mg／L,pH为8．0左右,沉降时间为90min条件下,废水COD去除率达41．91％;浊度去除率达46．15％;NH3-N去除率达49．61％。混凝沉淀法处理酒精废水可有效减轻后续膜处理工艺负荷,有助于提高回用水质。     

不同氨氮浓度对混凝-超滤组合工艺水质处理效果及膜通量的影响

我国地表水源污染物中氨氮是普遍存在的,且难以处理,实验选择混凝-超滤组合工艺,腐殖酸为NOM的代表物,通过考察污染物中氨氮不同含量水平的变化,考察氨氮含量对出水水质、通量下降和污染类型这3个方面的影响。结果表明,在给定实验条件下,氨氮含量由0.1 mg/L增大至0.5 mg/L时,加快了污染物在膜表面的沉积,最终导致出水有机物含量降低。PVDF和PVC膜的TOC去除率分别提高17.31%和23.21%,UV254去除率分别提高2.78%和11.72%,膜组件通量分别下降了3.51%和10.17%。考察膜污染类型,发现氨氮促进了标准孔堵塞和滤饼层形成,同时削弱完全孔堵塞和中间孔堵塞。     

海上含聚油泥处理后泥水的回注

采用热化学法处理某海上平台含聚油泥(矿物含量(w)1.30%~3.74%,聚合物含量(w)3.37%~7.42%),研究了反应后分离出的泥水的回注性能,并进行了现场回注试验。实验结果表明:泥水经研磨细化处理后,95%(w)的细化污泥粒径不超过7.86μm,远小于注入地层的平均孔喉直径;在含聚量为1 750 mg/L的注聚液中加入500 mg/L的细化污泥,65℃(油藏温度)下,细化污泥在注聚液中具有很好的稳定性,体系黏度变化小;泥水中的污水与注聚液、采出污水、现场采出液处理系统中使用的各种药剂的配伍性好。现场试验结果表明,将泥水加入注聚液中进行回注,注入井压力保持稳定。     

EGSB反应器处理焦化废水的颗粒污泥反应动力学研究

为了对处理实际焦化废水微氧EGSB反应器污染物去除机理进行研究,建立了处理实际焦化废水微氧EGSB反应器内污染物质降解动力学模型,考察EGSB反应器启动和稳定运行阶段不同运行条件时COD去除效果,并分析动力学参数的变化。研究确定了处理实际焦化废水(进水COD 2 000 mg/L左右)微氧EGSB反应器在启动和稳定运行阶段所适用的基质降解模型,动力学常数vmax、KI、KS、vmax/KS、KS/KI分别为7.34×10-3h-1、197.76 mg/L、19.53 mg/L、3.7×10-4L/(h·mg)、0.10和2.4×10-2h-1、66.64 mg/L、44.07 mg/L、5.4×10-4L/(h·mg)、0.66;微氧EGSB反应器内颗粒污泥能够逐渐适应并高效降解焦化废水中污染物质,焦化废水中毒性污染物质对颗粒污泥的抑制程度是由KS/KI决定的,KS/KI越大,抑制程度越弱,处理实际焦化废水EGSB反应器启动和稳定运行阶段的KS/KI分别为0.04~0.1和0.66~0.74;液体上升流速Vup的提高能够明显提高最大比基质降解速率vmax,降低半饱和常数KS和抑制常数KI,最终强化微氧EGSB反应器的运行效果,稳定运行阶段COD去除率高达92.7%。     

HRT对异养硝化好氧反硝化菌处理高速列车真空集便废水的影响

利用具有良好异养硝化好氧反硝化功能的菌剂启动生物接触氧化工艺,用以处理经化粪池厌氧消化后的高速列车真空集便废水。重点研究了HRT对生物膜反应器中好氧反硝化菌处理列车集便废水的影响,并进行了动力学模型分析。实验结果表明,在选用立体弹性填料为生物膜载体时,系统的最佳HRT为6 h。该条件下,反应器稳定运行的COD、总氮和氨氮的去除率均大于80%。通过对系统底物降解动力学的初步探究,得出了相关降解动力学常数KS、μmax。经验证,Monod模型较好地描述了系统的基质降解动力学行为,为高速列车真空集便废水的处理提供了相对高效、简便的方法。     

Increasing tree cover while losing diverse natural forests in tropical Hainan,China

To protect biodiversity and improve environmental conditions, China has invested billions of dollars in reforestation and payments for ecosystem service programs. Here, we examine the Sloping Land Conversion Program, the largest such program in the world and found that after 13 years of implementation at our study site, it has had negative impacts on natural tropical forests. GIS and remote sensing techniques revealed that both natural forests and natural shrub and grasslands were replaced by non-native monocultural plantations on Hainan Island, China, a key tropical biodiversity hotspot. Under current Chinese policy, these plantations are classified simply as “forests”, with the assumption that they are equivalent to natural forests. This lack of a distinction in forest quality has led to substantial deforestation and plantation expansion, including encroachment into protected areas on Hainan. Additional social and economic drivers of these changes were identified by examining the participants in this program and their actions. Without a new ecologically based definition of forests and new goals for reforestation, such programs designed to improve ecosystem services, and forest quality may actually threaten remaining natural forests and other vegetation types in Hainan and in other areas of mainland China.     

Contribution ratio of freely to total dissolved concentrations of polycyclic aromatic hydrocarbons in natural river waters

The bioavailability and ecological risk of hydrophobic organic compounds (HOCs) in aquatic environments largely depends on their freely dissolved concentrations. In this work, the freely dissolved concentrations of polycyclic aromatic hydrocarbons (PAHs) including phenanthrene, pyrene, and chrysene were determined for the Yellow River, Haihe River and Yongding River of China using polyethylene devices (PEDs). The results indicated that the order of ratios of freely to total dissolved concentrations of the three PAHs was phenanthrene (66.8 ± 20.1%) > pyrene (48.8 ± 26.4%) > chrysene (5.5 ± 3.3%) for the three rivers. The ratios were significantly negatively correlated with the log K_ow values of the PAHs. In addition, the ratios were negatively correlated with the suspended sediment (SPS) and dissolved organic carbon (DOC) concentrations in the river water, and the characteristics of the SPS and DOC were also important factors. Simulation experiments showed that the ratio of freely to total dissolved concentrations of pyrene in the aqueous phase decreased with increasing SPS concentration; when the sediment concentration increased from 2 g L^?1 to 10 g L^?1, the ratio decreased from 67.6% to 38.4% for Yellow River sediment and decreased from 50.4% to 33.6% for Haihe River sediment. This was because with increasing SPS concentration, more and more DOC, small particles and colloids (<0.45 μm) would enter the aqueous phase. Because high SPS and DOC concentrations exist in many rivers, their effect on the freely dissolved concentrations of HOCs should be considered when conducting an ecological risk assessment.     

径迹法累积测定室内外氡浓度

使用ＣＲ－３９探测器和探杯型氡监测器,对本所办公楼地下室及办公室内外氡浓度进行了２－６个月春夏秋冬不同季节的累积测定。对收集后的ＣＲ－３９随机扫描读数方式对结果的影响做了比较。结果表明地下室氡浓度高于其他层,室内高于室外。除个别情况外,随机扫描的影响在统计涨落范围内。     

改性核桃壳滤料对油田含油污水的过滤效果

采用亚硫酸氢镁蒸煮法对核桃壳滤料进行亲水改性,考察了改性核桃壳滤料对油田含油污水的过滤、反洗效果,探讨了改性前后核桃壳滤料的过滤过程及乳化油捕集机理。实验结果表明:在蒸煮温度为95℃、蒸煮时间为5 h、w(MgHSO_3)为5%的条件下,核桃壳滤料接触角由改性前的117.1°降至62.4°;分4批次过滤含油污水,改性核桃壳滤料的平均出水含油量为32.3 mg/L,平均油去除率为78.5%,平均浊度为7.7 NTU,平均浊度去除率为89.7%;改性核桃壳滤料的反洗效果显著改善,反洗水含油量由520 mg/L提高到840 mg/L,核桃壳滤料增重率由4.3%下降到0.2%。