燃煤电厂脱硫废水预处理装置设计与中试研究

针对火电厂脱硫废水的水质特点,提出“一体式软化澄清-超滤”预处理工艺并在山东某火力发电厂进行了中试研究,研究内容包括一体式软化澄清装置对Ca²⁺、Mg²⁺、浊度去除效果,超滤系统运行压力、产水流量、产水浊度及预处理工艺化学药剂费用等。结果表明：利用一体式软化澄清装置处理脱硫废水,出水Ca²⁺、Mg²⁺质量浓度可分别由400~660 mg/L和5 310~15 689 mg/L降至25 mg/L和10 mg/L,浊度小于或等于2.0 NTU;超滤系统运行稳定,产水浊度小于或等于0.1 NTU,SDI值小于3.0,可稳定达到后续反渗透系统进水水质要求。该一体式软化澄清-超滤预处理工艺中试研究成果可为火电厂废水零排放技术研究提供重要的基础数据。     

核电站二回路碱化剂ETA的检测与干扰问题

乙醇胺（ETA）是我国第三代核电确定采用的二回路水质调节碱化剂,二回路中微量ETA浓度的测定及干扰问题是关注的焦点之一。系列试验表明,无干扰离子时,3种色谱分析柱（CS12A、CS16、CS18）都能准确测定ETA浓度。在模拟核电站二回路水质条件下,重点探讨了使用CS18分析柱测定ETA时NH₄⁺、Li⁺、Na⁺、K⁺、Mg²⁺、Ca²⁺、吗啉的干扰问题。结果表明：通过优化色谱条件,在柱温50 ℃、抑制电流20mA、淋洗液流速0.36mL/min、梯度淋洗方式下,可以准确测量核电站二回路水中微量ETA浓度。     

海水直流冷却电厂烟气脱硫废水处理工艺的研究

某海水直流冷却电厂除脱硫废水外,所有生产废水均已处理回用。为达到废水零排放目的,拟采用软化预处理–微滤–反渗透–电渗析工艺对脱硫废水进行膜法减量浓缩处理。对浓缩减量核心工艺进行了试验研究,结果表明反渗透装置在75%回收率下将微滤处理后的脱硫废水进行初步浓缩,反渗透系统运行压力、压差稳定,水中的Ca²⁺、Mg²⁺可被基本去除,单支膜脱盐率可达99%以上;采用电渗析将反渗透浓水进一步浓缩,可将反渗透浓水可溶解固形物质量分数由7%浓缩至21%;最终脱硫废水流量由20 m³/h浓缩减量至2 m³/h,大幅降低了后续结晶设备的成本及能耗。此工艺方案实施后,可提高水资源利用率,实现全厂废水零排放。     

RESALT技术在燃煤电厂脱硫废水浓缩处理中的应用

基于电渗析技术的离子重组技术（简称RESALT技术）能够将废水中的钙离子和硫酸根离子分开,因而可避免形成硫酸钙垢,同时可实现废水的浓缩减量。在华电莱州发电有限公司现场进行了脱硫废水处理量为3~4 m³/h规模的RESALT技术中试研究。脱硫废水在RESALT装置中的运行结果表明,利用RESALT技术能够实现硫酸根离子和钙离子的有效分离,并且同时可实现含盐废水的浓缩处理,RESALT装置运行的电耗成本随进水含盐量及浓水含盐量的升高而升高,系统运行无须加药软化预处理,运行的成本主要为电费;以硫酸根、钙离子、镁离子、氯离子、钠离子质量浓度分别为6 480 mg/L、1 820 mg/L、2 462 mg/L、20 680 mg/L、10 465 mg/L的脱硫废水为例,系统回收率为70%,水处理电耗总计为49.5 kW·h/t,水处理直接成本为22.6元/t。     

脱硫废水处理前后喷射Cl析出特性

脱硫废水中含有高浓度的氯盐,影响脱硫系统的安全运行。采用Factsage热力学计算软件来模拟单一氯盐溶液和处理前后脱硫废水经过尾部烟道喷射后Cl析出特性。结果表明：CaCl₂,MgCl₂和NH₄Cl溶液喷射过程析出Cl主要以含Cl气体形式析出;喷射NaCl溶液时,Cl全部以NaCl（s）形式析出,而无气体析出。未处理的脱硫废水烟道喷射蒸发过程,75%以上的Cl以NaCl（s）的形式析出。除去Ca²⁺,Mg²⁺、NH₄⁺等离子后,脱硫废水烟道喷射蒸发过程不会析出HCl气体,产物NaCl（s）会被电除尘除去。因此脱硫废水的预处理减少了含Cl气体的析出,减轻了对尾部烟道的腐蚀。     

PDT effect of different photo sensitizers on a single nerve cell:electrophysiological and pharmacological study

The study of the single neuron response to photodynamic effect provides information on the dynamics of cytotoxic events leading to cell death and allows comparison of the phototoxicity of different photosensitizers. Isolated crayfish stretch receptor neurons were incubated 30 min with different concentrations of various photosensitizers and then irradiated with a He-Ne laser (632.8 nm; 0.3 W/cm²) until irreversible firing abolition. The dynamics of neuron impulse response was continuously recorded throughout the experiment. The following photosensitizers were studied: hematoporphyrin derivatives Photoheme and Photofrin II, 6 deuteroporphyrin IX derivatives and sulphonated aluminum and zinc phthalocyanines. Nerve cells were found to be insensitive to either He-Ne laser irradiation or photosensitization alone, but very vulnerable to photodynamic effect: neurons changed their firing rate and irreversibly ceased their impulse activity at nanomolar (phthalocyanines and hematoporphyrin derivatives) and even pikomolar (deuteroporphyrin derivatives) concentrations of photosensitizers. The dynamics of the neuron responses to photodynamic effects included stages of firing activation and/or inhibition followed by irreversible firing abolition. It depended on the photosensitizer type and concentration. Decrease of extracellular pH or action of pharmacological agents increasing intracellular Ca²⁺ concentration or inhibiting ATP synthesis exacerbated photodynamic neuron injury. In contrast, agents decreasing intracellular calcium concentration or bioenergetic substrates protected the neuron against photodynamic injury. The dependencies of neuron lifetimes on the photosensitizer concentration provide comparison of photodynamic efficiencies of different photosensitizers     

纳滤处理火电厂循环水补充水提高浓缩倍率试验研究

火电厂用水量很大,其中循环水用量最大,占电厂用水总量的70%以上。为探索循环水高浓缩倍率运行控制技术,对纳滤工艺处理电厂循环水补充水进行研究,并在某电厂进行了中试试验,规模为18 m³/h。试验结果表明,在回收率为90%时,纳滤膜脱盐率70%左右,对Ca²⁺、Mg²⁺、SO₄^2-等二价离子的去除率大于80%,产水COD质量浓度≤2 mg/L。以纳滤产水为试验水源进行循环水静态阻垢试验及挂片腐蚀试验,结果表明,若采用纳滤产水作为循环水补充水,循环水的极限浓缩倍率可高达33.98,循环水系统将可实现超高浓缩倍率运行和冷却塔零排污,节水效果和环保效益均显著。     

Laser-Induced Line Patterning of Nonlinear Optical Crystals in Glass

This paper reports the progress in the patterning of nonlinear optical crystal lines on a glass surface by laser irradiation techniques. Two techniques for the patterning of crystal lines have been developed, i.e., rare-earth atom heat processing and transition metal atom heat processing, in which continuous-wave lasers such as Nd:YAG laser (wavelength: lambda = 1064 nm) are irradiated onto the glasses containing rare-earth ions such as Sm³⁺ and Dy³⁺ or transition metal ions such as Ni²⁺ and Cu²⁺. The patterning of lines consisting of nonlinear optical crystals such as beta-BaB₂O₄, SmxBi_1- xBO₃, (Sr,Ba)Nb₂O₆, and LiNbO₃ has been achieved. It is clarified from the azimuthal dependence of second harmonic intensities and polarized micro-Raman scattering spectra that nonlinear optical crystals in the lines are highly oriented along the laser scanning direction, i.e., the patterning of single-like crystal lines. It is also possible to pattern two-dimensional crystal bending or curved lines by just changing the laser scanning direction, and such bending crystal lines have a potential for optical waveguides.     

Electric field interactions between closely abutting excitablecells

This review article summarizes some of the electrophysical evidence and morphological evidence against the hypothesis that the myocytes of cardiac muscles and visceral smooth muscles are profusely interconnected by low-resistance pathways (e.g., tunnels or gap-junction channels), which would give rise to a long length constant. Instead, propagation of the action potential (AP) is discontinuous, with a substantial junctional delay time at the cell junctions. Since the entire surface membrane of each cell becomes excited nearly simultaneously, a plot of propagation time versus distance (along a strand of cells) exhibits a typical staircase shape. This article demonstrates that the electric field that develops in the narrow junctional cleft (negative cleft potential) when the prejunctional membrane (pre-JM) fires an AP acts to depolarize the post-JM to its threshold. This mechanism, by itself, can account for transmission of excitation from cell to cell, but accessory mechanisms that act additively include K⁺ accumulation in the junctional clefts, gap-junction channels, and capacitive coupling     

On the definition of power factor and apparent power in unbalancedpolyphase circuits with sinusoidal voltage and currents

Definition for the apparent power S and for the power factor PF in unbalanced polyphase circuits with sinusoidal waveforms are presented. It is proved that the definition S²=(V_a²+V _b²+V_c²) (I _a²+I_b²+I _c²) has a definite physical meaning, leading itself to a convenient resolution in positive, negative and zero sequence, nonactive and active power. It is suggested that the power factor be represented with the help of the ratio P⁺/ S, where P⁺ is the positive sequence active powers     

The ion-specific behavior of watertree growth in LDPE

The growth of water trees in low-density polyethylene (PE) has been studied. Trees were grown in solutions containing a fixed anion, Cl ^-, but different cations with valences of +1 (Li⁺), +2 (Mn²⁺) and +3 (Fe³⁺). An ion-specific effect on tree growth and tree appearance has been found. Generally, these results have been shown to be correlated with either the ion-water interactions or the interionic attractions. However, for the specific case of adding small amounts of 3+ cations into univalent ion solutions, such a correlation was not found: it is likely that the hydrogen ions, introduced by the multivalent ions through their electrostatic interaction with water molecules, play an important role. The abnormal transport behavior of such hydrogen ions in the solution and probably in the polymer, may expand the overall region affected by treeing but reduce the visibility of the individual trees themselves. A similar process may account for the particularly translucent appearance of trees formed with pure FeCl₃ solutions. This argument is further demonstrated through tree growth experiments using KCl solution and its mixtures with small amounts of HCl. It was found that this additive accelerated tree growth. It is argued that small amounts of KOH might be expected to show an effect similar to HCl because of the similar transport behavior of OH^- ions and H⁺ ions respectively and such enhanced tree growth was demonstrated, using small quantities of KOH added to KC1 solutions     

Experimental study on the ion migration of rod samples for high voltage DC porcelain support insulators

The ion migration testing used for DC porcelain support insulators was carried out in this paper. Ten rod samples for DC porcelain support insulators were subjected to a long-term ion migration testing in our laboratory in accordance with the reported procedure of IEC. The changes of Na⁺ distribution along with the samples under the long-term testing were analyzed, compared to that of the untested samples. The mechanical performance of the tested samples was verified by using bending breakdown testing. The research findings indicate that the ion migration testing designed for support insulators does not cause Na⁺ ion apparent migration in the samples and does not influence the mechanical performance of the tested samples     

Electrical surface resistance, hydrophobicity and diffusionphenomena in PVC

Polymeric materials are used increasingly in both outdoor and indoor insulation and it has become imperative to find a convenient and a practical method to evaluate the performance of the insulation in situ. The hydrophobicity of a polluted surface particularly in the presence of moisture, determines the level of the leakage current which may result in a flashover and an outage of the power system. However, it is difficult to measure the hydrophobicity of insulators in the field, and therefore the measurement of the electrical surface resistance in situ has been suggested as an alternative method that might give information on the surface state. In the present study, polyvinylchloride (PVC) was used to study the characteristics of the surface resistance, the change of the hydrophobicity and the relationship between both of them in the presence of salt-fog. The dependence of the surface resistance on factors such as the duration of the wetting in salt-fog, the recovery during drying time, the length of the specimens, the level of the applied dc stress used to measure the resistance and the ac stress is reported. The surface free energy per unit area of PVC, during exposure to salt-fog, was calculated using the harmonic-mean method and was found to be consistent with the changes in both the surface resistance and the hydrophobicity of the surface. The surface tension γ_s, increased from 43.1×10^-3 J/m² for the virgin specimen to 76.8×10^-3 J/m² after complete wetting in un-energized salt-fog. The diffusion coefficients of a saline solution having a conductivity of 1 mS/cm into the pvc were found to increase from 2.8×10^-15 m²/s at 74°C to 1.6×10^-14 m² /s at 98°C     

HT-PEMFC耐CO多层复合结构阳极研究

高温聚合物电解质膜燃料电池(HT-PEMFC)使用富氢重整气代替纯氢进料时,其中高浓度CO(可达3×10-2)会导致电极毒化,使电池性能降低.采用Pt/C和PtRu/C催化剂制备多层结构阳极,研究了不同阳极结构在重整气进料时对电池性能的影响,优化得到最佳阳极结构(内侧Pt/C、外侧PtRu/C复合阳极).与传统Pt/C...     

湿式电除尘器性能测试方法及排放特征研究

湿式电除尘器收尘极被水膜覆盖,放电区域存在水雾,无振打二次扬尘,且细颗粒物团聚现象显著,可有效减少细颗粒物、SO₃等排放。采用一体化采样头（内置滤膜）采集颗粒物,采用重量法（PM-10）和电荷法（ELPI）测定PM_2.5;采用冷凝法或冷凝法与异丙醇吸收相结合的采样方法测定SO₃。测定结果表明,不同型式的湿式电除尘器颗粒物、PM_2.5一般分别在2~5mg/m³及3mg/m³以下,除尘效率一般在75%~95%,金属极板湿式电除尘器为连续喷淋,因不存在细颗粒物的二次扬尘,颗粒物排放可达1mg/m³以下;不同型式的湿式电除尘器SO₃排放一般在5mg/m³以下,SO₃脱除效率一般在60%~80%,导电玻璃钢湿式电除尘器板电流密度一般比金属极板湿式电除尘器大,因此其SO₃脱除效率普遍更高一些。     

燃煤电站烟气中汞脱除与减排技术

对现有环保设施的脱汞效果进行评价,简介燃烧前脱汞处理方法、烟气脱汞方法和涉及脱汞的多污染物脱除技术。已有的测试数据表明,SCR系统可将烟气中的元素态汞氧化为氧化态汞,使下游设备的脱汞能力提高;静电除尘器和布袋除尘器均能捕集烟气中的颗粒态汞和氧化态汞,后者效果更好;飞灰中的碳含量对除尘器脱汞效率有很大影响,碳含量越高,除尘器脱汞效率越高;现有的湿法烟气脱硫系统能够捕集烟气中的氧化态汞,但也能将氧化态汞还原成元素态汞。采用燃煤中添加溴化物的方法可以有效提高烟气中氧化态汞的比率,因此可提升现有设施的脱汞效率;多污染物控制技术能够实现SO_x、NO_x和汞等多污染物的联合脱除,将具有广阔的发展前景。     

The influence of reaction conditions on SO2 oxidation ina discharge plasma reactor

In this paper, experimental approaches have been carried out to investigate the removal of sulfur dioxide (SO₂) using pulsed discharge nonthermal plasma in the absence of ammonia (NH₃). The gas-phase reaction was found to be less attractive due to its large energy cost. The increase in temperature decreased the SO₂ removal rate, resulting in large energy cost. SO₂ removal was increased as the concentration of water vapor increased. The presence of SO₂ did not influence the gas-phase removal of NO in an NO-SO ₂-O₂-H₂O-N₂ system. In the case of the wet-type plasma reactor, gas-phase discharge plasma directed to the surface of water film greatly enhanced the liquid-phase oxidation of HSO₃^- to SO₄^2-. Comparing the results with different absorbents indicated that the hydroxyl (OH) radical plays a key role in the plasma induced liquid-phase reactions     

Electrical relaxation in iron-containing glasses

Glasses with composition 70 mol%(SiO₂, B₂O ₃, P₂O₅, TeO₂)-15 mol% Fe ₂O₃-15 mol%(BaO, CaO) were prepared by the conventional melt quenching technique. The electrical relaxation of these glasses has been studied in the frequency range 20 to 10⁵ Hz. The small polaron hopping between iron ions in a different valence state Fe²⁺ to Fe³⁺ is found to be the principal conduction mechanism. The ratio of Fe²⁺ ions to the total iron content, C=Fe²⁺/Fe_tot, is one of the factors determining the electrical conductivity. The glass former has a minor influence on dc conductivity, except of TeO₂ glass where conductivity is three order of magnitude higher than those of other glasses. The ac conductivity as a function frequency is divided into two domains, a dc plateau, followed by a power law in frequency. These two regions are well distinguished in the complex plot of electric modulus where all data points for different temperatures reside on the single plot. The results are discussed in the frame of the Hunt theory of dielectric relaxation in glasses containing mobile charge carriers     

Determination of charge mobility in He gas from current-voltagemeasurements in point-plane geometry

In order to clarify whether or not is it possible to extract reliable values of positive and negative mobility for ions and even for electrons in gas when using sharp point-plane geometry, the authors have undertaken a systematic study using He gas. Monitoring the purity level of the same gas filling two different cells (point-plane and plane-parallel), they have compared mobility values deduced from current-voltage curves (mobility K) with time of flight measurements (actual mobility μ) as a function of gas pressure (0.1-15 MPa) and purity. For negative charge carriers (ions or electrons), they have directly measured K^- and μ^- and then compared the results. They observed, as expected, that the measured negative charge carriers mobility was strongly dependent on gas purification. For commercial gas (O₂ of the order of 100 ppm), K^- was very close to the data obtained for negative O₂^- ions (i.e., K^- ≅ μ(O₂^-)) but, for better purification level, K^- increases quickly and can reach electronic values μ_e (K^- → μ _e). For positive ions, in all the range of studied pressure, it was shown that one can extract easily from I(V) measurements, mobility values K⁺ in accordance with the values of μ⁺ of He⁺ previously given in the literature