Fenton试剂处理选矿废水机理研究

研究了用Fenton试剂处理选矿废水中残余的黄药,分别考查了氧化时间、反应初始pH值、Fe2+浓度及H2O2用量对黄药降解效果的影响,用正交试验确定了4个因素的最好条件。结果表明:初始pH值和H2O2用量是影响去除效果的主要因素;氧化时间为60 m in,反应初始pH=4,[Fe2+]=20 mg/L,[H2O2]=20 mg/L,黄药的浓度为125 mg/L时,黄药的去除率达到99.5%;初步探讨了Fenton试剂净化废水中黄药的机理是.OH自由基先将黄药氧化为过氧化黄原酸盐,再将其氧化为CO2,黄药得到去除。     

生活垃圾填埋场封场后种植植物中重金属迁移研究

在上海老港生活垃圾填埋场填埋单元封场的覆盖土中掺混了矿化垃圾种植植物,分析Cd、Pb、Cu、Zn 4种重金属在土壤和植物中的迁移变化,研究表明:(1)覆盖土土质从一般耕作土变成肥沃土壤;覆盖土和种植混合土重金属Cd、Pb、Cu、Zn中Cd、Pb含量相近,但种植土的Cu含量略大于覆盖原土,Zn含量远大于覆盖原土;(2)植物能富集土壤和垃圾中的重金属,木本植物的根部富集重金属的能力强于草本植物,但重金属在草本植物根、茎、叶中的迁移速度大于木本植物;(3)植物根、茎、叶的Cu、Zn含量均远大于未受污染土壤种植植物相应部位的Cu、Zn含量,种植的植物不能供家养动物食用,以免通过食物链作用危及人体安全.     

气液相组合生物法净化低浓度甲醛废气研究

对生物膜填料塔 液相生物处理的组合系统净化低浓度甲醛废气进行实验研究,结果表明,组合系统对甲醛废气的净化效果明显优于单独生物膜填料塔净化系统,甲醛净化效率提高35%以上,甲醛生化去除量增大50%以上.动力学研究结果表明,甲醛在生物膜上的生化降解反应为慢速生化反应,需要采取强化甲醛液相生化降解反应、提高反应速率的措施,来提高废气中甲醛的生物净化效果.     

Fate and transformation of naphthylaminesulfonic azo dye Reactive Black 5 during wastewater treatment process

Certain aromatic amines generated by the decolorization of some azo dyes are not removed substantially by conventional anaerobic–aerobic biotreatment. These aromatic amines are potentially toxic and often released in the wastewater of industrial plants. In this study, the fate and transformation of the naphthylaminesulfonic azo dye Reactive Black 5 (RB5) during different phases of a sequencing batch reactor were investigated. The major products of RB5 decolorization during the anaerobic phase include 2-[(4-aminophenyl)sulfonyl]ethyl hydrogen sulfate (APSEHS) and 1-2-7-triamino-8-hydroxy-3-6-naphthalinedisulfate (TAHNDS). During the aerobic phase, APSEHS was hydrolyzed and produced 4-aminobenzenesulfonic acid, which was further degraded via dearomatization. TAHNDS was transformed rapidly via auto-oxidation into TAHNDS_DP-1 and TAHNDS_DP-2, which were not further removed by the activated sludge during the entire 30-day aerobic phase. In contrast, different behaviors of TAHNDS were observed during the anoxic phase. The transformation of TAHNDS was initiated either by deamination or desulfonation reaction. TAHNDS was then converted into 3,5-diamino-4-hydroxynaphthalene-2-sulfonic acid, which was subsequently removed via ring cleavage reaction under aerobic condition. In conclusion, complete degradation of TAHNDS by activated sludge occurs only during anoxic/aerobic processes instead of the conventional anaerobic/aerobic processes.     

Emission of intermediate volatility organic compounds from a ship main engine burning heavy fuel oil

Intermediate volatility organic compounds (IVOCs) are crucial precursors of secondary organic aerosol (SOA). In this study, gaseous IVOCs emitted from a ship main engine burning heavy fuel oil (HFO) were investigated on a test bench, which could simulate the real-world operations and emissions of ocean-going ships. The chemical compositions, emission factors (EFs) and volatility distributions of IVOC emissions were investigated. The results showed that the main engine burning HFO emitted a large amount of IVOCs, with average IVOC EFs of 20.2–201?mg/kg-fuel. The IVOCs were mainly comprised of unspeciated compounds. The chemical compositions of exhaust IVOCs were different from that of HFO fuel, especially for polycyclic aromatic compounds and alkylcyclohexanes. The volatility distributions of IVOCs were also different between HFO exhausts and HFO fuel. The distinctions in IVOC emission characteristics between HFO exhausts and HFO fuel should be considered when assessing the IVOC emission and related SOA formation potentials from ocean-going ships burning HFO, especially when using fuel-surrogate models.     

Evaluation of soil washing process with carboxymethyl-β-cyclodextrin and carboxymethyl chitosan for recovery of PAHs/heavy metals/fluorine from metallurgic plant site

Polycyclic aromatic hydrocarbons(PAHs)/heavy metals/fluorine(F) mixed-contaminated sites caused by abandoned metallurgic plants are receiving wide attention. To address the associated environmental problems,this study was initiated to investigate the feasibility of using carboxymethyl-β-cyclodextrin(CMCD) and carboxymethyl chitosan(CMC) solution to enhance ex situ soil washing for extracting mixed contaminants. Further,Tenax extraction method was combined with a first-three-compartment model to evaluate the environmental risk of residual PAHs in washed soil. In addition,the redistribution of heavy metals/F after decontamination was also estimated using a sequential extraction procedure. Three successive washing cycles using50 g/L CMCD and 5 g/L CMC solution were effective to remove 94.3% of total PAHs,93.2% of Pb,85.8% of Cd,93.4% of Cr,83.2% of Ni and 97.3% of F simultaneously. After the 3rd washing,the residual PAHs mainly existed as very slowly desorbing fractions,which were in the form of well-aged,well-sequestered compounds; while the remaining Pb,Cd,Cr,Ni and F mainly existed as Fe–Mn oxide and residual fractions,which were always present in stable mineral forms or bound to non-labile soil fractions. Therefore,this combined cleanup strategy proved to be effective and environmentally friendly.     

工业废气中甲苯的生物降解研究

采用生物膜填料塔进行净化低浓度甲苯废气的研究结果表明，构成生物膜的假单胞菌属中的短杆菌对废气中甲苯有很强的生化降解能力，每升体积的生物膜填料对甲苯的生化去除量最大可达１０４．４ｍｇ／ｈ，且当入口气体甲苯浓度约低于２．０ｍｇ／Ｌ时，单塔净化效率可保持在８０％以上。反应级数的转换约在其液相浓度为０．８—１．２ｍｇ／Ｌ（相当于气相浓度约１．７—２．１ｍｇ／Ｌ）时发生。     

废旧线路板回收的污染防治技术综述

废旧线路板回收不仅能够解决电子废弃物迅速增长带来的环境污染问题,而且可以实现资源再生利用,是中国当前鼓励发展的行业。线路板回收过程也将不可避免的带来一定环境污染问题。中国企业现阶段常用的线路板回收工艺主要包括机械物理法、湿法冶金、火法冶金、热解法等。废旧线路板的回收工艺不同,污染物产生特点也不同,企业应根据线路板回收工艺有针对性的选择污染防治措施。线路板回收过程中产生的废渣再利用应成为今后研究的重点。     

牡丹江流域水质变化趋势及水环境污染特征研究

通过对牡丹江近10年水质监测、评价及变化趋势研究,采用单项污染指数评价法、环境功能区达标评价法,评价牡丹江丰水期、平水期、枯水期水质现状,给出超标项目与超标倍数,计算污染分担率、污染负荷比,绘制主要污染物各断面浓度变化图,总结牡丹江污染特点和水质变化趋势,得出牡丹江水环境污染特征,为环境管理提供科学依据。     

制氧机组排气噪声消声器设计

冶金行业制氧机组氧气排气噪声属 4极子亚声速喷注噪声 ,其声功率与流速的八次方成正比 ,产生的噪声很强。本文以河北某钢铁集团公司为例 ,对制氧机组排气噪声的特性进行了探讨 ,设计了阻抗复合式三级扩容减压小孔喷注消声器 ,工程实施后证明 ,消声器设计合理 ,达到了预期的降噪效果