烟气脱硫装置增容改造技术探讨

国内大量石灰石-石膏湿法烟气脱硫装置需进行增容改造,介绍了增容改造的主要方案及各方案的应用案例,分析了方案选择的影响因素,总结了增容改造的主要特点,提出了改造项目的建议,为火电机组的脱硫增容改造提供借鉴。     

Iron and lead ion adsorption by microbial flocculants in synthetic wastewater and their related carbonate formation

Although microbial treatments of heavy metal ions in wastewater have been studied, the removal of these metals through incorporation into carbonate minerals has rarely been reported. To investigate the removal of Fe^3＋ and Pb^2＋, two representative metals in wastewater, through the precipitation of carbonate minerals by a microbial flocculant （MBF） produced by Bacillus mucilaginosus. MBF was added to synthetic wastewater containing different Fe^3＋ and Pb^2＋ concentrations, and the extent of flocculation was analyzed. CO2 was bubbled into the mixture of MBF and Fe^3＋/Pb^2＋ to initiate the reaction. The solid substrates were analyzed via X-ray diffraction, transmission electron microscopy and energy dispersive spectroscopy. The results showed that the removal efficiency decreased and the MBF adsorption capacity for metals increased with increasing heavy metal concentration. In the system containing MBF, metals （Fe^3＋ and Pb^2＋）, and CO2, the concentrated metals adsorbed onto the MBF combined with the dissolved CO2, resulting in oversaturation of metal carbonate minerals to form iron carbonate and lead carbonates. These results may be used in designing a method in which microbes can be utilized to combine CO2 with wastewater heavy metals to form carbonates, with the aim of mitigating environmental problems.     

Supercritical water oxidation of polyvinyl alcohol and desizing wastewater：Influence of NaOH on the organic decomposition

Polyvinyl alcohol is a refractory compound widely used in industry. Here we report supercritical water oxidation of polyvinyl alcohol solution and desizing wastewater with and without sodium hydroxide addition. However, it is difficult to implement complete degradation of organics even though polyvinyl alcohol can readily crack under supercritical water treatment. Sodium hydroxide had a significant catalytic effect during the supercritical water oxidation of polyvinyl alcohol. It appears that the OH ion participated in the C-C bond cleavage of polyvinyl alcohol molecules, the CO2-capture reaction and the neutralization of intermediate organic acids, promoting the overall reactions moving in the forward direction. Acetaldehyde was a typical intermediate product during reaction. For supercritical water oxidation of desizing wastewater, a high destruction rate (98.25%) based on total organic carbon was achieved. In addition, cases where initial wastewater was alkaline were favorable for supercritical water oxidation treatment, but salt precipitation and blockage issues arising during the process need to be taken into account seriously.     

半干法烟气脱硫灰改性及应用

文章主要对半干法脱硫灰中亚硫酸钙的氧化转化进行研究。半干法脱硫灰中亚硫酸钙对建材质量具有一定影响,通过筛选合适的催化-氧化剂体系对其进行了氧化改性。试验得到了一种复合催化剂,成功用于半干法脱硫灰改性。结合蒸压砖的生产工艺,使亚硫酸钙在生产过程中实现了部分转化,生产的蒸压砖能达到JC239-2001《粉煤灰砖》MU10强度等级。     

地下水位变化对边坡稳定性影响的模拟分析

降雨引起边坡地下水位变化、降低岩土体抗剪强度进而引起边坡失稳产生滑坡是电网工程灾害中最常见的地质灾害之一。文章在现场详细工程地质勘察的基础上,基于恢复山体极限平衡法和强度折减法,利用数值分析方法对降雨引起地下水位变化条件下某电网工程边坡稳定性进行了分析。模拟结果表明,现今地下水位条件下,该边坡整体处于极限平衡状态;在最高洪水位条件下边坡则处于失稳状态。边坡的最大变形位于边坡中上部,并呈现出由上部逐渐向下部扩展的趋势。边坡潜在破坏模式为边坡后缘张拉破坏和中下部剪切破坏的复合破坏模式。最后基于数值分析结果,对该边坡的工程治理提出了建议。     

实验室测量质量保证与质量控制研究

实验室进行的测试结果均存在测量误差,但是通过实验室的质量保证与质量控制方法,可以减少测量误差,提高数据的精确性、完整性和可比性,确保测量结果的可靠性.     

试论加强环境保护对促进人与自然和谐发展的影响

人与自然的关系,一直是人类关注的焦点。人类对于自身在自然界的地位以及二者之间关系的认识经历了漫长而曲折的过程。大家都非常重视人与自然的和谐相处。随着生产力的发展,人类对自然的征服力量越来越强,但人类从未停止对自然界的保护。党的十六届四中全会提出的构建社会主义和谐社会,不仅对人与人、人与社会的和谐提出了要求,还包括人与自然的和谐共处。显然,人与自然的和谐已成为构建和谐社会的有机组成部分。     

化工企业突发性环境污染事故的应急监测

化工企业突发性环境污染事故,具有污染毒性大,危害性强,后果严重等特性,及时有效地开展应急监测,可为应急处置和救援提供有力的保障。该文从前期准备、现场监测、数据上报等方面,探讨了如何做好应急监测工作。     

Modulation-assisted high speed machining of compacted graphite iron (CGI)

The application of controlled, low-frequency modulation (～100 Hz) superimposed onto the cutting process in the feed-direction – modulation-assisted machining (MAM) – is shown to be quite effective in reducing the wear of cubic boron nitride (CBN) tools when machining compacted graphite iron (CGI) at high machining speeds (>500 m/min). The tool life is at least 20 times greater than in conventional machining. This significant reduction in wear is a consequence of the multiple effects realized by MAM, including periodic disruption of the tool–workpiece contact, formation of discrete chips, enhanced fluid action and lower cutting temperatures. The propensity for thermochemical wear of CBN, the principal wear mode at high speeds in CGI machining, is thus reduced. The tool wear in MAM is also found to be smaller at the higher cutting speeds (730 m/min) tested. The feed-direction MAM appears feasible for implementation in industrial machining applications involving high speeds.     

巴布亚新几内亚浅成低温热液型金矿概述

巴布亚新几内亚大地构造位置上位于欧亚板块、印度-澳大利亚板块和太平洋板块三大板块结合部位,自白垩纪以来经历了复杂的构造演化过程,形成了特有的沟-弧-盆体系,使得区内广泛发育了岩浆弧有关的浅成低温热液型金矿。区内的浅成低温热液型金矿可分为低硫型和高硫型两种,而根据矿物组成、形成深度的不同,低硫型矿床又可分为石英-硫化物型、碳酸盐-贱金属型、浅成低温石英型和冰长石-绢云母型四个亚类型,低硫型金矿的不同的矿化亚类型常相互叠加,对于形成大型、超大型的金矿具有重要的意义。