Remove of Phenolic Compounds in Water by Low-Temperature Plasma: A Review of Current Research

Phenolic compounds have very strong toxicity, so it has been paid sharply attention to find an effective way of controlling the wastewater containing phenolic compounds. The work on this subject done by domestic and overseas scholars is studied in this paper, and the progress of researches on low-temperature plasma treatment is summarized through the electrical discharge types, mechanism, kinetics of phenolic compounds decomposition and combination of several methods with low-temperature plasma treatment. In addition, the crucial problem and the developing tendency on low-temperature plasma treatment for phenol-bearing wastewater are briefly discussed.

Research progress and development direction of low-temperature drilling fluid for Antarctic region

By combing the characteristics of drilling in Antarctic region, performance requirements on drilling fluid for Antarctic low temperature conditions, and research progress of low temperature drilling fluid, current problems of the drilling fluid have been sorted out, and the development direction of the drilling fluid has been pointed out. Drilling in the Antarctic region mainly includes drilling in snow, ice and subglacial rock formations, and drilling in Antarctic low temperature conditions will face problems in four aspects:(1) low temperature and large temperature changes in the drilling area;(2) likely well leakage and drillstring-sticking in the snow layer, creep in the ice layer, ice chip gathering jamming in the warm ice layer, well wall collapse in the subglacial rock formations;(3) lack of infrastructure and difficulty in logistical support;(4) fragile environment and low carrying capacity. After years of development, progresses have been made on low-temperature drilling fluids for the Antarctic region. Low-temperature petroleum-based drilling fluid, ethanol/ethylene glycol-based drilling fluid, ester-based drilling fluid and silicone oil-based drilling fluid have been developed. However, these drilling fluids have problems such as insufficient low-temperature tolerance, low environmental performance and weak wellbore stability, etc. In order to meet the performance requirements of drilling fluid under low-temperature conditions in Antarctic region, the working mechanisms of low-temperature drilling fluid must be examined in depth;environment-friendly low-temperature base fluid of drilling fluid and related additives must be developed to prepare environmentally friendly low temperature drilling fluid systems;multi-functional integrated adjustment method for drilling fluid must be worked out to ensure well wall stability and improve cutting-carry capacity when drilling ice formations and ice-rock interlayers;and on-site support operation codes must be established to provide technical support for Antarctic drilling.

Low-temperature synthesis of ultrasmall spinel MnxCo3-xO4 nanoparticles for efficient oxygen reduction

Spinel-type manganese-cobalt oxides have been regarded as important class of electrocatalysts for oxygen reduction reaction(ORR).However,they are usually synthesized through oxidation-precipitation under aqueous ammonia and then crystallization at high temperature(150–180℃),which not only increases the energy consumption but also induces the growth of particles that is unfavorable for ORR.Herein,through a facile precipitation-dehydration method,ultrasmall spinel manganese-cobalt oxide nanoparticles(~5 nm)homogeneously dispersed on conductive carbon black(MnxCo3-xO4/C)were fabricated at low temperature(60℃).And the bimetallic composite oxide(Mn1.5Co1.5O4/C)with cubic spinel structure and high Mn content exhibits remarkable enhancement of ORR activity and stability compared with single metal oxide(both Mn3O4/C and Co3O4/C).The essential reason for the enhancement of activity can be attributed to the presence of the mixed Mn^3+ and Mn^4+ cations in Mn1.5Co1.5O4/C.Moreover,the ORR activity of Mn1.5Co1.5O4/C is comparable to that of commercial 20 wt% Pt/C,and the relative current density only decreases 1.4% after 12 h test,exceeding that of Pt/C and most reported manganese-cobalt oxide electrocatalysts.

Low-temperature Denitration Mechanism of NH_(3)-SCR over Fe/AC Catalyst

To study the modification mechanism of activated carbon(AC)by Fe and the low-temperature NH_(3)-selective catalytic reduction(SCR)denitration mechanism of Fe/AC catalysts,Fe/AC catalysts were prepared using coconut shell AC activated by nitric acid as the support and iron oxide as the active component.The crystal structure,surface morphology,pore structure,functional groups and valence states of the active components of Fe/AC catalysts were characterised by X-ray diffraction,scanning electron microscopy,nitrogen adsorption and desorption,Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy,respectively.The effect of Fe loading and calcination temperature on the low-temperature denitration of NH_(3)-SCR over Fe/AC catalysts was studied using NH_(3)as the reducing gas at low temperature(150℃).The results show that the iron oxide on the Fe/AC catalyst is spherical and uniformly dispersed on the surface of AC,thereby improving the crystallisation performance and increasing the number of active sites and specific surface area on AC in contact with the reaction gas.Hence,a rapid NH_(3)-SCR reaction was realised.When the roasting temperature remains constant,the iron oxide crystals formed by increasing the amount of loading can enter the AC pore structure and accumulate to form more micropores.When the roasting temperature is raised from 400 to 500℃,the iron oxide is mainly transformed fromα-Fe_(2)O_(3)toγ-Fe_(2)O_(3),which improves the iron oxide dispersion and increases its denitration active site,allowing gas adsorption.When the Fe loading amount is 10%,and the roasting temperature is 500℃,the NO removal rate of the Fe/AC catalyst can reach 95%.According to the study,the low-temperature NH_(3)-SCR mechanism of Fe/AC catalyst is proposed,in which the redox reaction between Fe~(2+)and Fe~(3+)will facilitate the formation of reactive oxygen vacancies,which increases the amount of oxygen adsorption on the surface,especially the increase in surface acid sites,and promotes and adsorbs more reaction gases(NH_(3),O_(2),NO).The transformation from the standard SCR reaction to the fast SCR reaction is accelerated.

Study on Free Surface and Channel Flow Induced by Low Temperature Plasma via Lattice Boltzmann Method

Active boundary layer flow control and boundary layer manipulation in the channel flow that was based on low temperature plasma were studied by means of a lattice Boltzmann method. Two plasma actuators were placed in a row to obtain the influence rule of their separation distance on the velocity profile at three locations and maximum velocity in the flow field. Two plasma actuators were placed symmetrically inside a channel to examine the effect of channel height and voltage on the velocity profile and flow rate. It was found that the channel height controls the distribution of flow velocity, which affected the flow rate and its direction. Increasing plasma voltage had a negative effect on the flow rate due to the generation of a larger and stronger flow vortex.

Establishment of water quality index(Na^+,Ca^(2+)) for purified water reused to zinc electrolysis process

The effects of Na+ and Ca2+ in the purified water on the conductivity of zinc electrolyte and the current efficiency of zinc electrolysis were studied by the alternating current bridge method and the simulated electrolysis experiments,and the water quality index of reused water was established. The results show that the conductivity of the solution and the current efficiency decrease as these two kinds of positive ions are added in the electrolyte. The effect of Ca2+ is much more remarkable than that of Na+. ρ(Na+)≤ 8 g/L and ρ(Ca2+)≤20 mg/L are the quality indexes in the zinc electrolysis process and the concentrations of Na+ and Ca2+ in the purified water reused to the process should be less than the limited values,i.e. the water quality index of the purified water should be controlled by its reused amount.

八种湿地植物对净化生活污水的影响

试验探究了荷花、燕子花、西伯利亚鸢尾花、再力花、水菖蒲、黄菖蒲、菰和梭鱼草8种湿地植物在秋季对生活污水中TN、NH_(3)-N、NO_(3)-N、BOD_(5)、COD_(Cr)和TP的去除效果,并采用模糊数学中隶属函数法对水质净化效果进行综合评估。结果表明:秋季气温低,植物吸收作用、细菌硝化及反硝化作用弱,湿地植物对NH_(3)-N、NO_(3)-N和TN的去除效果均不理想;湿地植物对COD_(Cr)的去除效果较好但差异不明显,均达到70%以上,其中再力花、水菖蒲和黄菖蒲去除效果最好,三者对COD_(Cr)的去除率均为79.3%;湿地植物对BOD_(5)的去除效果较好且大致相同,均在70%左右,其中西伯利亚鸢尾花去除效果最好,对BOD_(5)的去除率达74.1%;湿地植物对TP的去除效果最好,均达80%以上,其中西伯利亚鸢尾花对TP的去除率高达92.4%。8种湿地植物对生活污水综合净化能力为荷花>菰>水菖蒲>梭鱼草>再力花>燕子花>西伯利亚鸢尾花>黄菖蒲。

Methods for enhancing the capacity of electrode materials in low-temperature lithium-ion batteries

Lithium-ion batteries(LIBs)have evolved into the mainstream power source of ene rgy sto rage equipment by reason of their advantages such as high energy density,high power,long cycle life and less pollution.With the expansion of their applications in deep-sea exploration,aerospace and military equipment,special working conditions have placed higher demands on the low-temperature performance of LIBs.However,at low temperatures,the severe polarization and inferior electrochemical activity of electrode materials cause the acute capacity fading upon cycling,which greatly hindered the further development of LIBs.In this review,we summarize the recent important progress of LIBs in low-temperature operations and introduce the key methods and the related action mechanisms for enhancing the capacity of the various cathode and anode materials.It aims to promote the development of high-performance electrode materials and broaden the application range of LIBs.

基于安全稀释法的柴油车CO综合海拔系数研究

为准确进行高海拔隧道施工通风设计,对高海拔隧道施工通风需风量计算方法及参数展开研究。对柴油车辆CO排放量进行多海拔测试,得到柴油车CO海拔系数;采用安全稀释法,推导出不同海拔下单位功率需风量及同时考虑CO排放量和控制标准变化的综合海拔系数。结果表明,柴油车CO浓度随海拔增高而增大,当海拔为3172 m时,柴油车释放的CO浓度约为平原地区(海拔590 m)的2倍;现有规范中柴油车CO海拔系数明显偏大,海拔3000 m处实测值较规范值减少25.61%;基于安全稀释法的施工通风需风量可根据海拔高度分3段计算,其结果较额定功率法计算需风量明显增大;根据现场测试结果,提出不同海拔区间(海拔2000 m以下、2000~3000 m和3000 m以上)柴油车CO综合海拔系数计算模型;安装DOC尾气净化器可以减少作业面处80%的CO排放量,在净化效率仅达到60%的情况下,基于安全稀释法计算的海拔5000 m处的计算需风量只有6.59 m^(3)/(kW·min)。

Effect of Magnetic Field on Synthesis of Nano-FeOOH by Low-Temperature Neutralization Method

Using XRD,TEM and VSM methods,the phase,morphology and magnetic property of iron hydroxide oxide(FeOOH) which has been prepared by low-temperature neutralization reaction under different magnetic fields were analyzed.It can be found that the magnetic field had a great influence on the product.Acicular goethite(α-FeOOH) was synthetized without magnetic field.When the magnetic flux density was increased to 0.1T,γ-FeOOH was obtained.If the magnetic field intensity was raised to 0.5T,the product was all composed of δ-FeOOH.Moreover,the crystallization of FeOOH was greatly influenced by magnetic field as well.Thermodynamic calculation results show that the magnetic free energy of chemical reaction reached to more than hundreds KJ/mol when the magnetic field is applied.It meaned that the application of magnetic field was conducived to producing the products with higher susceptibility.Even under the low magnetic field,due to the stability of the reaction products was broken by the magnetic field,the magnetic free energy was also effective.

捕集纯化CO_(2)气体技术在水泥行业中的应用研究

介绍了工业窑炉废气中的CO_(2)气体捕集纯化常用的MEA(乙醇胺)化学吸附技术,外加热式回转窑及立窑直接捕集纯化技术的工艺流程、主要装置及研发过程;重点对比介绍了化学吸附技术和外加热式回转窑捕集技术在国内水泥行业中的应用。化学吸附技术捕集纯化CO_(2)气体,产品品质较差,生产成本较高,投资回收期>10年;外加热式回转窑捕集技术,可直接捕集碳酸盐加热分解产生的CO_(2),产品品质高、能耗低,投资回收期仅3~4年。某水泥生产线应用外加热式回转窑捕集技术,回转窑规格ϕ(2.2~2.8)m×65.8m,年可捕集纯化食品级液态CO_(2)>6.0×10^(4)t、年可生产石灰粉(CaO)>15.3×10^(4)t,投资收益较高,推广应用前景广阔。

生物法净化处理工业废气的研究进展

随着世界范围内环境污染的加剧,环境问题引起了强烈的重视,尤其是大气污染,成为了大众关注的焦点。在空气污染治理中,生物法净化工业废气具有高效、低成本等优点,成为目前研究的热点。本文介绍了生物法净化处理废气的基本原理,主要包括生物膜理论中的传质和降解过程,阐述和比较了生物滤池、生物洗涤和生物滴滤这3种处理工艺,分析了影响生物法处理废气的重要因素,如填料、营养物、微生物、压降。同时对国内外发展现状进行了详细评述,与国外研究相比,特别是在污染物种类的研究上还有一定差距。生物滴滤工艺相对研究的较晚,提出今后研发重点和方向,将生物滴滤工艺全面推向工业化,加强对降解微生物的深入研究,实现单种到多种污染物的降解。

饱和硫酸铵法提取血清中IgG最佳条件的研究

利用饱和硫酸铵法对牛血清中的免疫球蛋白进行分离提取,得到免疫球蛋白的粗提物,研究不同单因素对IgG质量浓度及IgG纯度的影响,确定最佳提取参数如下:提取温度为50℃,静置时间为50min,血清-PBS比例2︰1(体积比),缓冲溶液pH值7.4,离心机转速4500r/min。

粗级碳酸锂提纯工艺过程研究

碳酸锂产品在陶瓷、冶金、能源、医药等行业应用广泛,实际应用中对碳酸锂产品的纯度要求很高。由于生产技术和盐湖卤水自身条件的限制,直接提取的碳酸锂产品都很难达到要求。基于实际应用的需求,以从卤水制备而得的粗级碳酸锂产品为原料,通过氢化分解法对其提纯,研究了氢化反应中的二氧化碳气体流速、氢化时间、氢化温度及固液比4个氢化条件对粗级碳酸锂溶解的影响。结果表明,采用这项简单工艺可使粗级碳酸锂产品的纯度由88%提高到99%以上,一次性产率达到75%以上。

苦参生物碱工业生产新方法的探究.

用不同浓度的乙醇和阳离子交换树脂对苦参(Sophoraflavescens)总生物碱进行提取和纯化,并对不同的苦参生物碱纯化工艺进行比较和研究。结果表明,用60%的乙醇进行提取和用阳离子树脂进行纯化的工艺过程生物碱收率较高,生产成本较低,工序较为简单,有一定的进步性,更适宜工业化的生产。

烹饪油烟净化技术发展的探讨

随着我国餐饮业的飞速发展,油烟带来的环境污染日益严重。餐饮业油烟污染问题成为城市居民环保投诉的热点之一。简要说明了油烟形成过程、成分组成及对人体健康的危害,同时介绍了处理油烟的新方法——生物降解法、等离子体法等,并对国内外净化技术进行了对比。总结提出催化氧化法适用于家庭油烟净化,并有待进一步研究开发以应用于实际生活中。

液相色谱法分析龙眼及其种植土壤中的烯酰吗啉残留

紫外扫描确定250 nm作为烯酰吗啉检测波长,优化后选取甲醇＋水（V∶V=6∶4）作为流动相不易受样品中杂质峰的干扰且两个组分峰具有较好的分离度。建立了烯酰吗啉标准曲线,0.05-5 mg/kg范围内线性关系良好（R2=0.999 7）。选择乙腈高速匀浆提取后经过佛罗里硅藻土萃取柱净化处理龙眼样品,避免了杂质对目标峰的干扰,回收率77%-97%,变异系数〈7%;选择丙酮＋水（V∶V=1∶1）作为提取剂采用2种方法（振荡3 h、超声振荡各30 min）提取后土壤样品用二氯甲烷萃取后不经净化直接分析,结果表明对目标物分析无影响,对比2种提取方法选取超声振荡各30 min的方法不仅节约时间,而且回收率较高为83%-96%,变异系数〈7%。

碳化分解法制备电池级碳酸锂的研究

以工业级Li2CO3为原料,采用碳化分解法提纯制备电池级纯度Li2CO3。研究了碳化时间、固液比和CO2气体流速3个因素对Li2CO3提纯过程中纯度、产率以及杂质钙镁铁去除效果的影响。最佳工艺条件为碳化时间30min,固液比1∶30,CO2气体流速4L/min。结果表明,通过碳化分解法可使粗级Li2CO3产品的纯度由90%提高到99.75%以上,产率达到78%以上,满足了电池级Li2CO3的要求。

淫羊藿黄酮精制方法的建立(英文)

目的建立中药淫羊藿总黄酮的精制方法和质量控制标准。方法以淫羊藿苷的含量为指标,应用正交试验设计筛选淫羊藿总黄酮的最佳精制工艺;分光光度法测定总黄酮含量。结果分光光度法测定提取产物中主要活性成分淫羊藿总黄酮的含量平均为54%以上。结论本研究所建立的淫羊藿总黄酮提取工艺及质量控制方法切实可行、成本低廉。

水幕式公共厨房油烟净化装置的试验研究

目的为了提高水幕式公共厨房油烟净化装置的净化效率,设计制造了可拆装的便于安排不同试验方案的排烟罩.方法利用均匀设计法设计试验方案,通过改变罩内喷嘴布置方式、排风量和喷水量来测定各因素对净化效率的影响,利用SPSS软件对所得试验数据进行回归分析、处理.结果发现喷嘴布置方式和排风量对净化效率均有显著影响,液气比的增大可提高净化效率,得到净化效率与相关因素之间的数量关系,并依此回归方程进行了参数优化处理.结论得出喷嘴布置形式、排风量和液气比对排烟罩净化效率的影响规律,为水幕式公共厨房油烟净化装置的开发、应用提供理论参考.