Removal of disinfection by-products formation potential by biologically intensified process

The removal of disinfection by-products formation potential(DBPFP) in artificially intensified biological activated carbon(IBAC) process which is developed on the basis of traditional ozone granular activated carbon was evaluated. By IBAC removals of 31% and 68% for THMFP and HAAFP were obtained respectively. Under identical conditions, the removals of the same substances were 4% and 32% respectively only by the granular activated carbon(GAC) process. Compared with GAC, the high removal rates of the two formed potential substances were due to the increasing of bioactivity of the media and the synergistic capabilities of biological degradation cooperating with activated carbon adsorption of organic compounds. A clear linear correlation ( R^2 = 0.9562 and R^2 = 0.9007) between DOC HAAFP removal rate and Empty Bed Contact Time(EBCT) of IBAC process was observed, while that between THMFP removal rate and EBCT of GAC was R^2 = 0.9782. In addition certain linear correlations between THMFP, HAAFP and UV254 ( R^2 = 0.855 and R^2 = 0.7702) were found for the treated water. For IBAC process there are also more advantages such as long backwashing cycle time, low backwashing intensity and prolonging activated carbon lifetime and so on.     

Effects of process conditions on nano-dot array formation by thermal dewetting

In this paper, three kinds of self-organization processes for metal nano-dot array fabrication are compared; one is the conventional thermal dewetting, another is thermal dewetting of a grid patterned deposited metal layer, the other is thermal dewetting of a metal layer deposited on a patterned substrate. In these processes, nano plastic forming technique is utilized for patterning of groove grid. Effects of process conditions on nano-dot formation, such as substrate material, deposited metal, thickness of deposited layer, annealing condition, are experimentally studied. Also, effect of grid patterning on improvement of nano-dot array formation is studied. It is shown that grid patterning on a deposited metal layer is effective to improve alignment and configuration of nano-dot array.     

On zero water discharge solutions in the process industry

This paper presents a mathematical programming approach to analyze the feasibility of zero liquid discharge option in different industries. Mathematical programming methodologies are applied to four industrial cases—a tricresyl phosphate plant, an ethyl chloride plant, a paper mill and a refinery. In each case study various end of pipe and regeneration configurations using different treatment technologies are explored to determine the possibility of zero liquid discharge and its economical feasibility. The results show that the relationship between the cost of regeneration and the cost of freshwater as well as the discharge concentration of the treatment is the determining factor for the feasibility of zero liquid discharge.     

循环水养殖系统中自然微生物生物膜形成过程实验

进行了不同初始NH4-N浓度,在实验水温20～24℃条件下,利用微生态制剂辅助,循环水养殖系统中自然微生物生物膜形成过程的实验研究。结果表明:不同NH4-N浓度对自然微生物生物膜形成产生显著影响,5、10和20 mg/L高浓度NH4-N更易于微生物的扩繁生长和生物膜形成,其生物膜达到预期水质净化效果的形成周期,即生物挂膜成熟周期,约需要35～40 d。生物挂膜成功后,形成很好的硝化作用,实验生物滤池中的NH4-N、NO2-N浓度均保持低于0.05 mg/L,COD浓度低于3 mg/L,显示出对NH4-N、NO2-N和COD很高的去处效果,但对PO4-P处理效果不明显。而1和2 mg/L低浓度NH4-N不易于微生物的扩繁生长,难以形成具有较好水质净化效果的生物膜,即生物挂膜难以成功。     

萃取第三相形成过程中废水处理的去污机理

用漏斗试验法研究了［β－萘磺酸＋劳伦酸（钠）］－水－三辛胺（煤油）体系的萃取去污机理,结果表明,在萃取过程中除水溶性β－萘磺酸和劳伦酸的可溶部分各自与三辛胺萃取剂反应生成胺盐,并进一步聚合后形成萃取第三相外,劳伦酸的悬浮颗粒部分被第三相粘结除去,劳伦酸钠以分子形态被第三相吸附除去。并在合适的萃取条件下所涉及体系以COD计的去污率可达到95％左右。由此提出＂萃取－混凝－浮上＂的去污机理。     

Acute toxicity formation potential of benzophenone-type UV filters in chlorination disinfection process

Benzophenones （BPs） are a class of widely used UV filters, which have been frequently detected within multiple environmental matrices. Disinfection is a necessary process in water treatment processes. The transformation behaviors and toxicity changes of 14 BP-type UV filters during chlorination disinfection treatment were investigated in this study. A new index, the acute toxicity formation potential, was proposed to evaluate the toxicity changes and potential risks of BP-type UV filters during chlorination treatment. It was found that 13 of 14 BP-type UV filters exhibited toxicity decreases in the chlorination disinfection process, more or less, while one showed a toxicity increase. The toxicity changes were dependent on substitution effects, such that 2,4-di-hydroxylated or 3-hydroxylated BPs exhibited significant toxicity decreases after chlorination treatment due to the ready cleavage of the aromatic ring. Importantly, the acute toxicity changes could be duplicated in an ambient water matrix.     

Toluene decomposition performance and NOx by-product formation during a DBD-catalyst process

Characteristics of toluene decomposition and formation of nitrogen oxide(NOx) by-products were investigated in a dielectric barrier discharge(DBD) reactor with/without catalyst at room temperature and atmospheric pressure. Four kinds of metal oxides, i.e., manganese oxide(Mn Ox), iron oxide(Fe Ox), cobalt oxide(Co Ox) and copper oxide(Cu O), supported on Al2O3/nickel foam, were used as catalysts. It was found that introducing catalysts could improve toluene removal efficiency, promote decomposition of by-product ozone and enhance CO2 selectivity. In addition, NOx was suppressed with the decrease of specific energy density(SED) and the increase of humidity, gas flow rate and toluene concentration, or catalyst introduction. Among the four kinds of catalysts, the Cu O catalyst showed the best performance in NOx suppression. The Mn Ox catalyst exhibited the lowest concentration of O3 and highest CO2 selectivity but the highest concentration of NOx. A possible pathway for NOx production in DBD was discussed. The contributions of oxygen active species and hydroxyl radicals are dominant in NOx suppression.     

Differences of the oxidation process and secondary organic aerosol formation at low and high precursor concentrations

Current atmospheric quality models usually underestimate the level of ambient secondary organic aerosol(SOA), one of the possible reasons is that the precursors at different concentrations may undergo different oxidation processes and further affect SOA formation. Therefore, there is a need to perform more chamber studies to disclose the influence. In this work, SOA formation over a wide range of initial precursor concentrations(tens of ppb to hundreds of ppb levels) was investigated in a 30 m3 indoor smog chamber,and mainly through the analysis of multiple generations of VOCs detected from HR-To FPTRMS to expound the difference in the oxidation process between low and high precursor concentrations. Compared to high initial concentrations, gas-phase intermediates formed at low concentrations had a higher intensity by about one order of magnitude, and the lowvolatility compounds also had a higher formation potential due to the competition between semi-volatile intermediates and precursors with oxidants. In addition, the formed SOA was more oxidized with higher f44 value(0.14 ± 0.02) and more relevant to real atmosphere than that formed at high concentrations. This work should help to deeply understand SOA formation and improve the performance of air quality models for SOA simulation.     

江西相山巴泉隐爆角砾岩型铀矿床地质特征及形成过程

以相山巴泉隐爆角砾岩型铀矿床为研究对象,介绍该矿床的成矿地质背景及矿床地质特征,探讨隐爆角砾岩的形成过程及铀成矿过程。相山巴泉隐爆角砾岩受火山机构制约,成岩成矿作用与火山—次火山作用密切相关。铀矿化与隐爆角砾岩(筒)在时空上具有密切关系,矿化严格受岩筒控制,且产于岩筒内及其接触带附近裂隙中。矿化与岩筒范围、形态相吻合,矿体与岩筒产状相同。矿化富集程度与岩筒内的角砾大小密切相关,角砾愈小矿化愈富集。矿化在水平和垂直方向上也呈规律性变化,自隐爆角砾岩(筒)中心至边缘、从顶部至底部,铀矿品位逐渐降低。     

Application of FEM simulation of chip formation to stability analysis in orthogonal cutting process

Models for chatter prediction in machining often use a mechanistic force model that calculate the force as the product of a material dependent cutting constant and chip area. However, in reality, the forces are the result of complex interaction between the tool and the chip, and are affected by many factors. The effects of these complex, and often nonlinear, factors on the machining dynamics may only be included in chatter prediction if the chip formation process is simulated concurrently with simulation of the machining dynamics. In this paper, finite element simulation of the chip formation process is combined with simulation of chatter dynamics and the inter-relationship between the chip formation process and the chatter phenomenon is investigated. Mesh adaptation technique is used to simulate the chip formation within an FEM elastoplastic analysis with dynamic effects and frictional contact. The combined modeling predicts the occurrence of process damping at low cutting speeds, which other models are generally unable to predict.     

江西省严重酸雨地带形成的影响因素

采用数字模拟技术,绘制了江西省降雨pH值曲面投影图及其等值线图,发现江西省在南昌(鹰潭(临川(吉安(赣州一线形成南北方向的“r”字形的严重酸雨带,并指出这条严重酸雨带的走向与信风环流圈和副热带高压带纬向环流一致.提出了矿山废石堆的硫化矿物是造成严重酸雨的主要致酸物质来源,揭示了江西省降雨pH值随副热带高压脊季节性南北推移而变化的规律.     

Toluene decomposition performance and NOx by-product formation during a DBD-catalyst process

Characteristics of toluene decomposition and formation of nitrogen oxide (NO_x) by-products were investigated in a dielectric barrier discharge (DBD) reactor with/without catalyst at room temperature and atmospheric pressure. Four kinds of metal oxides, i.e., manganese oxide (MnOx), iron oxide (FeOx), cobalt oxide (CoOx) and copper oxide (CuO), supported on Al₂O₃/nickel foam, were used as catalysts. It was found that introducing catalysts could improve toluene removal efficiency, promote decomposition of by-product ozone and enhance CO₂ selectivity. In addition,NO_xwas suppressedwith the decrease of specific energy density (SED) and the increase of humidity, gas flow rate and toluene concentration, or catalyst introduction. Among the four kinds of catalysts, the CuO catalyst showed the best performance in NO_x suppression. The MnOx catalyst exhibited the lowest concentration of O₃ and highest CO₂ selectivity but the highest concentration of NOx. A possible pathway for NOx production in DBD was discussed. The contributions of oxygen active species and hydroxyl radicals are dominant in NOx suppression.     

Toluene decomposition performance and NOx by-product formation during a DBD-catalyst process

Characteristics of toluene decomposition and formation of nitrogen oxide (NOx) by-products were investigated in a dielectric barrier discharge (DBD) reactor with/without catalyst at room temperature and atmospheric pressure. Four kinds of metal oxides, i.e., manganese oxide (MnOx), iron oxide (FeOx), cobalt oxide (CoOx) and copper oxide (CuO), supported on Al₂O₃/nickel foam, were used as catalysts. It was found that introducing catalysts could improve toluene removal efficiency, promote decomposition of by-product ozone and enhance CO₂ selectivity. In addition, NOx was suppressed with the decrease of specific energy density (SED) and the increase of humidity, gas flow rate and toluene concentration, or catalyst introduction. Among the four kinds of catalysts, the CuO catalyst showed the best performance in NOx suppression. The MnOx catalyst exhibited the lowest concentration of O₃ and highest CO₂ selectivity but the highest concentration of NOx. A possible pathway for NOx production in DBD was discussed. The contributions of oxygen active species and hydroxyl radicals are dominant in NOx suppression.     

Study on the mechanism of copper–ammonia complex decomposition in struvite formation process and enhanced ammonia and copper removal

Heavy metals and ammonia are difficult to remove from wastewater, as they easily combine into refractory complexes. The struvite formation method (SFM) was applied for the complex decomposition and simultaneous removal of heavy metal and ammonia. The results indicated that ammonia deprivation by SFM was the key factor leading to the decomposition of the copper–ammonia complex ion. Ammonia was separated from solution as crystalline struvite, and the copper mainly co-precipitated as copper hydroxide together with struvite. Hydrogen bonding and electrostatic attraction were considered to be the main surface interactions between struvite and copper hydroxide. Hydrogen bonding was concluded to be the key factor leading to the co-precipitation. In addition, incorporation of copper ions into the struvite crystal also occurred during the treatment process.     

长江原水臭氧-生物活性炭挂膜中试研究

为了探究面向长江水源的臭氧-生物活性炭深度处理工艺的挂膜技术,进行了长江原水常州段的臭氧-生物活性炭挂膜中试研究.结果表明,在挂膜前期,由于炭柱的物理吸附作用逐渐饱和,炭柱对DOC(溶解性有机碳)、UV_(254)和COD_(Mn)(高锰酸盐指数)的去除率逐渐降低,对氨氮几乎没有去除,在挂膜中后期,由于活性炭上生物膜逐渐成熟,生物降解起主导作用,有机物和氨氮去除率升高并趋于稳定.90 d后,炭柱对DOC、UV_(254)和COD_(Mn)这3个有机物指标的去除率分别稳定在30.64%、57.50%和30.00%以上,氨氮去除率稳定在88.93%左右,认为挂膜成功.扫描电镜图显示活性炭表面出现丰富的菌胶团,同时高通量测序也验证了活性炭中丰富多样的微生物群落结构.     

一个沿海城市大气臭氧的本地生成过程及其对前体物的敏感性

在威海市两个采样点用苏码罐采集了全空气样品,利用三级冷阱预浓缩-GC/MS方法离线测定了空气样品中109种大气挥发性有机物(VOCs).使用基于观测的MCM机理大气化学模式(OBM-MCM)分析了大气臭氧生成对VOCs组分的敏感性及本地生成过程.结果表明:观测期间两个采样点的总挥发性有机物(TVOCs)平均浓度分别为27.84×10~(-9)和17.85×10~(-9),对TVOCs贡献最大的均是烷烃.模拟分析表明,大气臭氧生成与前体物的控制关系存在空间差异性,在一个观测点受VOCs控制,而在另一个观测点受NO_x和VOCs共同控制;模拟结果还表明,臭氧生成对活性烃类最为敏感,但是,含氧有机物、卤代烃和高碳烷烃对臭氧生成的影响和贡献也不可忽视;此外,计算了日平均臭氧净生成速率P(O_3)_(net),分别为6.41×10~(-9) h~(-1)和3.22×10~(-9) h~(-1),臭氧的本地生成过程扮演重要角色.     

DBP formation from degradation of DEET and ibuprofen by UV/chlorine process and subsequent post-chlorination

The formation of disinfection by-products(DBPs) from the degradation of N,N-diethyl-3-methyl benzoyl amide(DEET) and ibuprofen(IBP) by the ultraviolet irradiation(UV)/chlorine process and subsequent post-chlorination was investigated and compared with the UV/H_2O_2 process.The pseudo first-order rate constants of the degradation of DEET and IBP by the UV/chlorine process were 2 and 3.1 times higher than those by the UV/H_2O_2 process, respectively, under the tested conditions. This was due to the significant contributions of both reactive chlorine species U(RCS) and hydroxyl radicals(HO) in the UV/chlorine process. Trichloromethane, 1,1,1-trichloro-2-propanone and dichloroacetic acid were the major known DBPs formed after 90% of both DEET and IBP that were degraded by the UV/chlorine process. Their yields increased by over 50%after subsequent 1-day post-chlorination. The detected DBPs after the degradation of DEET and IBP comprised 13.5% and 19.8% of total organic chlorine(TOCl), respectively, and the proportions increased to 19.8% and 33.9% after subsequent chlorination, respectively. In comparison to the UV/H_2O_2 process accompanied with post-chlorination, the formation of DBPs and TOCl in the UV/chlorine process together with post-chlorination was 5%–63% higher,Ulikely due to the generation of more DBP precursors from the attack of RCS, in addition to HO.     

论浙东南磨石山群祝村组的解体

对浙东南磨石山群祝村组层型———丽水祝村剖面及其附近进一步地质调查时发现祝村组“下伏”的九里坪组为一个英安玢岩侵出体。祝村组建组的基础不存在。祝村组下部英安质熔结凝灰岩和上部流纹岩Nd同位素测定结果 :εNd(t)值和T2DM值分别为 - 9.6、- 7.2和1.70Ga、1.5 1Ga ,表明它们物质来源不同 ,属于不同火山旋回的产物。根据地层层序、岩石组合及与区域磨石山群地层对比 ,祝村组应解体为西山头组、茶湾组和九里坪组。祝村组一名不宜继续使用