In situ preparation of g-C3N4/Bi4O5I2 complex and its elevated photoactivity in Methyl Orange degradation under visible light

A graphite carbon nitride(g-C_3N_4) modified Bi_4O_5I_2 composite was successfully prepared insitu via the thermal treatment of a g-C_3N_4/Bi OI precursor at 400°C for 3 hr.The as-prepared g-C_3N_4/Bi_4O_5I_2 showed high photocatalytic performance in Methyl Orange(MO) degradation under visible light.The best sample presented a degradation rate of 0.164 min~(-1),which is 3.2 and 82 times as high as that of Bi_4O_5I_2 and g-C_3N_4,respectively.The g-C_3N_4/Bi_4O_5I_2 was characterized by X-ray powder diffractometer(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),Raman,X-ray photoelectron spectroscopy(XPS),ultraviolet-visible diffuse reflectance spectra(DRS),electrochemical impedance spectroscopy(EIS) and transient photocurrent response in order to explain the enhanced photoactivity.Results indicated that the decoration with a small amount of g-C_3N_4 influenced the specific surface area only slightly.Nevertheless,the capability for absorbing visible light was improved measurably,which was beneficial to the MO degradation.On top of that,a strong interaction between g-C_3N_4 and Bi_4O_5I_2 was detected.This interplay promoted the formation of a favorable heterojunction structure and thereby enhanced the charge separation.Thus,the g-C_3N_4/Bi_4O_5I_2 composite presented greater charge separation efficiency and much better photocatalytic performance than Bi_4O_5I_2.Additionally,g-C_3N_4/Bi_4O_5I_2 also presented high stability.·O_2~-and holes were verified to be the main reactive species.     

新型负载型纳米TiO_2光催化降解苯酚的试验研究

以岩棉为载体制备一种新型负载型纳米TiO2,对有机污染物苯酚的降解效果较好。岩棉对苯酚有一定的吸附作用。经过120min的处理,苯酚基本上被完全降解。流速对降解率的影响较大,本试验选择流速为5mL/min。初始浓度越小,苯酚的降解效果越好。通入O2和加入适量H2O2均有利于苯酚的降解,且少量的H2O2可使苯酚的降解率大大提高。苯酚在pH=4.5时降解效果最好。     

染化废水厌氧生物处理技术的研究

鉴于厌氧微生物对偶氮染料的还原裂解作用，开发了以易降解工业有机废水作为外加碳源的染化废水厌氧生物处理的新技术．试验结果表明：在进水ＣＯＤ３１００—３５００ｍｇ／Ｌ，ＣＯＤ总／ＣＯＤ染化比值４０，ＨＲＴ３．０ｄ下，ＣＯＤ去除率＞８０％，最低染化ＣＯＤ去除率＞４５％，色度去除率＞８５％；实验证实，在厌氧处理过程中，染料组分的结构已发生了明显的变化；反应器内的污泥大多呈颗粒状；污泥活性和工艺性能可控制工艺运行参数得以维持．     

Study on nitrile-degrading microorganisms

Two strains of bacteria were isolated from nitrile polluted soils, and identified as Corynebacterium boffmanii and Arthrobacter flavescens. Acetonitrile, propionitrile, butyronitrile and acrylonitrile were degraded by these bacteria to yield corresponding amides, carboxylic acids and ammonia. The nitrile-degrading abilities of these strains were investigated. The removal rates for the nitrile were nearly 100%, after these bacteria were grown in medium containing 10000 ppm of aceto-, propio-, or butyronitrile at 28 ℃ for 24h. When the reaction mkture consisting of 5000 ppm of above mentioned nitriles or acrylonitrile and 20g (dry cell) /L resting cells of the two strains in 0.06mol/L phosphate buffer (pH7.5) was incubated separately at 25 ℃ with moderate shaking for 15 or 45 min, the nitrile could be degraded completely. The optimum growth conditions for C.hoffmanii and A.flavescens were studied as well.     

浅谈内蒙古草原生态环境现状及其保护对策

本文针对当前内蒙古草原生态环境现状以及草原资源利用所面临的问题，从利用制度、管理措施等多方面提出了加强草原保护和合理利用的相应对策。     

微等离子弧放电催化水处理技术的研究

采用钛为阳极的微等离子弧放电技术,研究了在模拟废水处理中放电催化效应及其机理,发现该技术对甲基橙有好的放电催化处理效果.甲基橙的脱色程度与峰值电压、脉冲频率、占空比、阳极电极面积等有关.在0.3mol·L-1的H3PO4电解液中,在峰值电压为550V、脉冲频率200Hz,占空比1∶180、阳极电极面积50mm×50mm条件下,20min内600mL、20mg·L-1的甲基橙溶液脱色率达90%.实验结果表明,该放电催化体系具有协同效果好、能效高、反应器设计要求简单等特点,是一种有发展前景的水处理新技术.     

影响杉木人工林可持续经营因素探讨

杉木人工林土壤肥力和林分生产力逐代下降，直接影响杉木林地可持续经营。影响杉木人工林可持续经营的因素是多方面的，主要和杉木人工林所处亚热带红壤区生态系统的脆弱性和杉木人工林群落的单一性及杉木生物学特性等有关，而传统杉木人工林培育过程中采取一系列传统的营林措施则加剧了林地地力衰退。根据目前杉木人工林经营现状，建议在杉木人工林经营过程中应尽量降低营林措施干扰强度，特别是炼山措施的采取；同时开展有关林地可持续模式试验及评价指标体系的研究，以寻找适合不同地区的杉木人工林可持续经营模式。在此基础上，搞好杉木人工林规划和发展，这对南方杉木产区林地可持续经营实践具有较大的指导意义     

沼泽红假单胞菌H3对酸性红B2GL染料的厌氧脱色和降解作用

从印染厂污泥中分离到一株沼泽红假单胞菌（ＲｈｏｄｏｐｓｅｕｄｏｍｏｎａｓｐａｌｕｓｔｒｉｓＨ３），在光照厌氧条件下该菌生长细胞可将１００ｍｇ／Ｌ酸性红Ｂ２ＧＬ染料去除到３０ｍｇ／Ｌ．完整细胞脱色的最适条件为ｐＨ７０，温度３０℃，细胞浓度２０—２５ｍｇ／ｍＬ（湿重）．低浓度的阳离子对脱色影响不大．在通Ａｒ气使严格厌氧和加有还原性辅酶Ｉ的条件下无细胞提取液的脱色活性最高，比活率为１５４×１０－２ｍｇ／（ｍｇ·ｈ）．根据降解产物的分析，推断了该菌对酸性红染料的降解代谢途径．     

甲氰菊酯在土壤中的降解与移动性

采用模拟试验和田间试验相结合的方法,研究了甲氰菊酯在南方菜地土壤中的降解和移动.得出了一些基本数据,为甲氰菊酯在菜地(旱地)生态中的安全使用,提出了合理的评价.