Optimization of the recovery of plastics for recycling by density media separation cyclones

Material recovery processes are presented as the optimum option for recycling plastic wastes as a means of recovering hydrocarbon resources. There exist a large variety of automated material recovery processes for recycling of such wastes but each with significant limitations. Of these, the separation based on differences in densities is advocated as the optimum process either for producing recycled products or preparing wastes for subsequent recovery processing.Density separation processes based on cyclone type density media separation (DMS) is presented as an important, potential method for increasing plastics recycling process capacities. It is demonstrated to have the capacity to separate a significantly larger range of particle sizes than those presently processed industrially. The mathematical relationship for the prediction of quality of typical LARCODEMS type density media separations by particle size and density as expressed by the Ecart Probable is presented.A proposed device configuration is presented for density media separation to optimize the recovery and purity of both density fractions produced. It is also suggested that to be economically viable, a large scale of operation is required for industrial plastics recycling operations recovering and producing a number of different plastics with a purity to be used as a substitute for virgin material.     

全面安全管理-6 Sigma方法论

概述了最新全面管理工具 6Sigma方法论的概念、原理 ,以及 6Sigma持续循环的 5个阶段在现代企业全面安全管理中的应用     

6-苄氨基腺嘌呤对江汉平原小麦开花后渍害的缓减效应研究

于2011~2012年度及2012~2013年度开展小麦开花后渍水试验,研究开花后渍水对小麦产量的影响及渍水前喷施6-苄氨基腺嘌呤(6-BA)对产量的效应。结果表明,2011~2012年度及2012~2013年度江汉平原小麦开花期至成熟期均有持续降水分布,其中2011年4~5月累计降雨量达1941 mm,2012年同期累计降雨量达2855 mm,表明江汉平原小麦生殖生长期有较大渍害风险。本试验研究表明,开花后渍水,小麦植株衰老进程加速,叶片严重早衰失绿,旗叶光合速率降低;渍水前喷施6-BA,可缓减叶片衰老趋势,缩小旗叶光合速率降低幅度。开花后渍水亦导致根系活力降低,渍水前喷施6-BA可缓减根系活力降低,其中至灌浆中期,渍水处理根系活力仅为对照的563%,6-BA+渍水处理根系活力较渍水处理提高66%,差异达显著水平。渍水处理生物产量及籽粒产量均显著低于对照,渍水前喷施6-BA,生物产量、籽粒产量较渍水处理比较均有所提高,其中生物产量较渍水处理提高77%,籽粒产量提高137%。总之,在本试验条件下,开花后渍水导致光合速率、根系活力、生物产量、籽粒产量等显著降低,渍水前喷施6-BA可在一定程度上缓减渍害效应,在渍害发生后促进籽粒产量形成,据2011~2012年度及2012~2013年度产量结果估算,渍水前喷施6-BA相当于每6667 m2可减少427 kg 产量损失,即约1/3以上的田块未发生渍害     

Treatment of 2-phenylamino-3-methyl-6-di-n-butylaminofluoran production effluent by combination of biological treatments and Fenton＇s oxidation

High strength refractory organic stream is produced during the production of 2-phenylamino-3-methyl-6-di-n-butylaminofluoran （One Dye Black 2, abbr. ODB 2）, a novel heat-sensitive material with a promising market. In this study, a combination of acidificationprecipitation, primary biological treatment, Fenton＇s oxidation and another biological treatment was successfully used for the removal of COD from 18000-25000 mg/L to below 200 mg/L from the ODB 2 production wastewater in a pilot experiment. A COD removal of 70%-80% was achieved by acidification-precipitation under a pH of 2.5-3.0. The first step biodegradafion permitted an average COD removal of 70% under an hydraulic residence time （HRT） of 30 h. By batch tests, the optimum conditions of Fenton＇s oxidation were acquired as： Fe^2＋ dose 6.0 mmol/L; H2O2 dose 3000 mg/L; and reaction time 6 h. The second step biological treatment could ensure an effluent COD below 200 mg/L under an HRT of 10 h following the Fenton＇s treatment.     

BiOBr/Bi2MoO6异质结的构筑及对甲基橙的吸附/光催化性能的协同作用机制

采用简单的沉积-沉淀法合成了BiOBr/Bi_2MoO_6(BOB/BMO)异质结,采用XRD、XPS、TEM、SEM、EDS、FT-IR、UV-Vis-DRS、PL、PC和EIS等测试技术对光催化剂的物相组成、形貌、光吸收特性和光电化学性能等进行系统表征,并以模型污染物甲基橙(MO)的吸附和光催化降解作为探针来评价BiOBr/Bi_2MoO_6异质结的吸附性能与光催化活性增强机制.SEM和TEM分析结果表明,所得Bi_2MoO_6微球由大量厚度约为20~50 nm的纳米片组成;沉淀-沉积法所得样品的形貌分析显示,尺寸约为10 nm的BiOBr量子点均匀沉积在Bi_2MoO_6微球表面,形成的新颖的BOB/BMO异质结.N2吸附/脱附结果表明,Bi_2MoO_6和BiOBr形成异质结具有大的比表面积(64.94 m2·g-1),且表面孔结构丰富.吸附/光催化降解实验结果表明,与纯Bi_2MoO_6或者BiOBr相比,BOB/BMO异质结表现出更好的吸附性能和光催化活性.吸附/光催化协同作用机理分析表明,BOB/BMO异质结具有大的比表面积和丰富的孔结构是其吸附性能增强的主要原因.此外,光致发光(PL)谱、光电流(PC)和交流阻抗(EIS)分析进一步揭示了BOB/BMO异质结有利于光生载流子的分离与转移,导致光催化活性增强,二者的协同作用使其对MO具有优越的去除性能.此外,BOB/BMO异质结较稳定,重复使用性能良好,有望用于MO废水的实际处理.     

数值模拟结合SF_6示踪法确定煤层钻孔瓦斯抽采有效半径

为准确确定煤层钻孔的瓦斯抽采有效半径,实现最优钻孔设计及最佳抽采效果,根据煤层瓦斯流动理论与煤岩体变形理论,建立钻孔抽采煤层瓦斯的气固耦合数学模型。并利用COMSOLMultiphysics软件,模拟SF6气体在瓦斯渗流场内的运移过程。利用SF6气体示踪法进行现场测试。依据相似定律,结合模拟与实测结果确定钻孔抽采有效半径的范围。以黄陵集团一号煤矿306工作面为例进行试验研究。试验结果表明,模拟结果与实测结果基本吻合;在钻孔直径为94 mm,抽采负压为15 kPa的条件下,预抽30天后,试验工作面抽采有效半径为5.88 m。     

The legitimation of contested carbon markets after Paris – empirical insights from market stakeholders

ABSTRACT

After the Paris Agreement the global carbon offset markets face regulatory uncertainty and new legitimation challenges. This paper examines the discursive legitimation of the carbon markets between 2015 and 2018 and is based on 37 qualitative interviews with market stakeholders. The results show that the carbon markets remain contested and require new ideas and concepts to construct legitimacy. Some stakeholders consider moving beyond carbon offsetting, mainly due to new risks of double counting. Others continue to portray carbon offsetting as a ‘false solution’. Nevertheless, the trust in carbon markets as an appropriate way to address climate change remains high. Therefore, new forms of international emission trading are likely to evolve under Article 6 of the Paris Agreement.     

三氯卡班对小鼠血浆内源性物质影响的代谢组学研究

三氯卡班被认定为一种新型的环境污染物,可能对动植物和人体产生危害,为探究三氯卡班的有害作用机制,选择C57BL6小鼠作为载体,利用分子生物学和报告基因方法考察了三氯卡班对肝脏的作用,同时利用代谢组学技术考察三氯卡班对血浆内源性代谢物变化的影响。结果表明,三氯卡班是核受体CAR的激活剂,可以提高肝脏CYP2b10的m RNA表达。同时血浆主要的内源性代谢物也产生了显著性变化,血浆中的脂肪酸比例都呈下降趋势,肉毒碱与乙酰肉碱的比例都呈上升趋势,花生四烯酸与肌酸的比例都呈上升趋势,这都与核受体CAR被激活密切相关,由此说明利用代谢组学技术能够全面地反映三氯卡班所造成的对机体的影响。     

南海北部海域底泥微生物的腐殖质还原性能研究

微生物的腐殖质还原过程自1996年发现以来,日益成为环境领域的一个研究热点。以南海北部海域的8个底泥为实验材料,利用蒽醌-2,6,-双磺酸（AQDS）为腐殖质模式物,初步探讨了南海北部8个底泥培养物对腐殖质的还原能力,并探讨了驯化后的8个底泥微生物对腐殖质的还原过程。结果发现：从南海北部深海海域到海陆交接的香港米浦红树林的8个底泥样品培养液均能很好的还原AQDS;驯化后的8个站点底泥微生物对腐殖质还原的能力有所不同,在48 h,E425站点培养液中的OD450只有0.74,其余7个站点培养液中的OD450都在2.0~3.0之间,推测其原因是8个站点中腐殖质还原微生物的数量具有明显差异,使得各站点的OD450差异很大。研究结果为认知腐殖质还原微生物的分布和探究腐殖质还原微生物在环境中的生态学意义提供重要的理论依据。     

三硝基甲苯的γ-辐照降解实验研究

基于三硝基甲苯(TNT)溶液采用常规处理方法难以降解,采用60Co-γ射线对三硝基甲苯溶液进行辐照降解,研究了吸收剂量、初始浓度、溶液初始pH值、双氧水(H2O2)等因素对辐照降解效果的影响.实验结果表明,60Co-γ射线辐照能够有效地降解三硝基甲苯.三硝基甲苯溶液初始浓度为5—50 mg.L-1,当接受不超过15 kGy剂量时,三硝基甲苯的降解率可达100%,化学需氧量(COD)去除率可达55%;弱酸性和碱性环境更有利于三硝基甲苯的降解和COD的去除;加入少量H2O2时,三硝基甲苯降解率和COD去除速率均随之增加,但过高的H2O2加入量将会抑制三硝基甲苯的去除,并且加入H2O2的量愈大其抑制作用愈明显.