Model experiment on the dynamic process of oil leakage from the double hull tanker

This paper presents an experimental investigation on oil leakage from the double hull tanker (DHT). It is designed to explore the dynamic process of oil leakage from bottom-rupture hole of DHT. The experimental test shows the leakage resistance mechanism of ballast tank space. The behavior of oil leakage from damaged DHT and dynamic features of flow in the overall process are demonstrated from experimental results. The overall process of oil leakage is divided into free-leakage and resistance-leakage stage according to the corresponding power to study the dynamic features of oil-water flow inside or outside the tank. The corresponding dominated factors of oil leakage in different stage are also pointed out, and the unsteady Bernoulli’s equation is used to verify experimental results. Meanwhile, viscous effect in leakage process is discussed and the importance of hydrodynamic features associated with the mechanism of oil leakage is explored from experimental results.     

RGO/TiO2光催化降解2,4-二氯苯氧乙酸研究

通过Hummers法及紫外光/热还原工艺制得还原氧化石墨烯(RGO),采用溶胶-凝胶-煅烧法,以RGO和钛酸酊脂为前驱体制备出RGO/TiO2光催化复合材料,并利用XRD、FT-IR等对其进行了表征.对RGO/TiO2光催化降解性能的研究发现,复合光催化剂RGO/TiO2对2,4-二氯苯氧乙酸(2,4-D)的光催化降解活性显著优于纯TiO2,并且发现负载量和pH值对光催化降解性能有较大的影响:RGO/TiO2投加量为1.2g·L~(-1)、RGO负载量2%、pH为3、初始浓度为50 mg·L~(-1)反应12 h,2,4-D去除率达到98.75%;2,4-D降解率随着RGO/TiO2投加量的增大先增大后减小;RGO/TiO2对2,4-D的降解为脱氯还原和催化氧化过程,产生氯酚、苯酚等中间产物.     

不同进口模式对我国出口产品碳足迹的影响——以木质橱柜为例

产品碳足迹及其绿色贸易壁垒的研究越来越得到重视,但另一方面,进口模式对碳足迹的影响研究尚不充分.本研究采用生命周期评价方法,对橱柜的国内加工阶段的碳排放、国外不同原材料生产阶段碳排放分别进行计算,并分析不同进口模式情景下上游原材料对橱柜整体碳足迹的影响.主要结论如下:1不同进口模式原材料碳排放差异较大:北欧的原材料碳排放高于中欧和美国,碳排放的主要来源材料为胶合板.2全球的原材料碳排放波动最大,最大原材料碳排放是最小原材料碳排放的7.26倍;美国的原材料碳排放波动最小;3不同进口模式对我国产品碳足迹的影响不同,从贡献结构上看,除了北欧最大碳排放进口模式和全球最大碳排放进口模式是外源型以外,其余模式的产品碳足迹来源皆为内源型,即主要贡献仍为国内加工阶段.4从减排潜力看贸易策略,减排潜力最大的是全球进口模式,为30%~52%,并建议转变北欧为其它进口模式,以寻求更大的减排空间.本文结论可服务于企业绿色采购策略中原材料减排潜力的发掘,以及国家贸易政策的制定.     

铜藻基载铁活性炭的制备及其对亚甲基蓝的吸附特性研究

以一种大型海藻——铜藻为原料,Fe Cl3·6H2O为活化剂,采用超声浸渍-原位合成法制备了铜藻基载铁活性炭(Fe/SAC),并以活性炭得率和亚甲基蓝吸附值为指标,通过正交法考察了活化温度、活化时间和浸渍比的影响.同时,采用X射线衍射、扫描电镜和比表面积分析仪对最优结果进行表征,并考察了Fe/SAC吸附亚甲基蓝的热力学与动力学特性.结果表明,Fe/SAC的最优制备工艺条件为活化温度600℃、活化时间1 h、浸渍比1∶1,此时的活性炭得率为39.5%,亚甲基蓝吸附值为255.67 mg·g~(-1);最优工艺条件下制得的Fe/SAC比表面积为558.31 m2·g~(-1),其负载的铁组分主要为Fe3O4和Fe O;亚甲基蓝在Fe/SAC上的吸附过程符合准二级动力学模型,Langmuir等温吸附模型能够很好地描述吸附平衡过程,该吸附是熵增加的自发吸热(ΔS0、ΔG0、ΔH0)过程,升温有利于吸附.     

煤矸石堆场Fe、Mn迁移累积效应研究

通过对贵州织金典型煤矿区矸石堆场周边地表水体及耕地进行调查与采样分析,探讨了煤矸石堆场Fe、Mn元素迁移对周边地表水体及耕地累积效应的影响。研究结果表明:受煤矸石堆场酸性排水的影响,煤矸石堆场周边溪沟水Fe、Mn含量分别达0.81~32.14mg/L、1.17~8.42mg/L,超过"集中式生活饮用水地表水源地标准"限值的3~107、12~84倍。堆场周边旱作土中Fe、Mn含量分别达63 530~85 990mg/kg、243.1~910.1mg/kg,水稻土达46 940~75 810mg/kg、144.5~409.1mg/kg,Fe、Mn累积指数旱作土分别达1.61、2.97,水稻土分别达1.24、1.33。随着与堆场距离的增大,水稻土Fe、Mn含量逐步降低,在500m范围内Fe降低了35%,Mn降低了61%,而旱作土变化规律不明显。     

南水北调东线（江苏段）沿线污染物总量达标研究

基于江苏省2010年污染源普查资料和统计年鉴,选取化学需氧量（ COD）和氨氮（ NH4－N）为研究因子,统计南水北调东线江苏段污染物排放量并计算入输水干线污染物量;根据南水北调办治污工程规划,计算污染物削减量;根据2012年江苏省水环境功能区划,核定研究区域限排总量;结果污染物量COD、氨氮削减量分别为33114吨、2935吨,污染源结构中城镇生活源比例从23．34％降到9．10％,工业企业源比例从15．13％降到8．96％,污染源点源呈下降趋势,面源呈增长趋势,污染物入输水干线总量达到2015年限排总量要求。     

滨海石化项目环境综合风险评估方法研究

研究针对国内目前的研究现状,运用环境风险评价指数法建立滨海石化项目环境风险评估体系,采用层次分析法和熵权法结合的组合赋权法,结合专家咨询法进行指标的修改与完善,运用线性加权组合法对评估体系中指标权重的赋值,并计算滨海石化项目的环境风险等级,确定项目的风险强弱.实例分析表明环境风险管理在环境风险的产生和预防占有十分重要的地位,通过加强和完善环境风险的管理体系,结合环境因素的敏感程度及风险源的产生和影响,能降低环境风险及事故的影响程度.     

A new process to improve short-chain fatty acids and bio-methane generation from waste activated sludge

As an important intermediate product, short-chain fatty acids(SCFAs) can be generated after hydrolysis and acidification from waste activated sludge, and then can be transformed to methane during anaerobic digestion process. In order to obtain more SCFA and methane,most studies in literatures were centered on enhancing the hydrolysis of sludge anaerobic digestion which was proved as un-efficient. Though the alkaline pretreatment in our previous study increased both the hydrolysis and acidification processes, it had a vast chemical cost which was considered uneconomical. In this paper, a low energy consumption pretreatment method, i.e. enhanced the whole three stages of the anaerobic fermentation processes at the same time, was reported, by which hydrolysis and acidification were both enhanced, and the SCFA and methane generation can be significantly improved with a small quantity of chemical input. Firstly, the effect of different pretreated temperatures and pretreatment time on sludge hydrolyzation was compared. It was found that sludge pretreated at 100°C for 60 min can achieve the maximal hydrolyzation. Further, effects of different initial p Hs on acidification of the thermal pretreated sludge were investigated and the highest SCFA was observed at initial p H 9.0with fermentation time of 6 d, the production of which was 348.63 mg COD/g VSS(6.8 times higher than the blank test) and the acetic acid was dominant acid. Then, the mechanisms for this new pretreatment significantly improving SCFA production were discussed. Finally,the effect of this low energy consumption pretreatment on methane generation was investigated.     

填料型A2/O工艺污水处理及反硝化除磷效能

填料型A~2/O工艺是在A~2/O工艺的基础上通过向厌氧池、缺氧池、好氧池中投加醛化纤维式组合填料,将传统活性污泥法与生物膜法相结合组成一套脱氮除磷的新系统,文章对填料型A~2/O工艺与传统A~2/O工艺处理生活污水的效果进行了对比研究,以及对该复合式工艺在不同硝化液回流比下反硝化除磷能力进行了分析.研究结果表明,相同条件下,填料型A~2/O工艺对生活污水的处理效果要优于传统A~2/O工艺,分别使COD和氨氮的去除率达到92.5%和93.1%.试验通过增加硝化液回流比的措施使得反硝化聚磷菌在填料上富集程度增大,当硝化液回流比为300%时,缺氧池的NO-3-N浓度为3.03 mg·L~(-1),吸磷量最大为26.28 mg·L~(-1),胞内聚合物PHB代谢活性最好,利用率最高为1.32 g·g~(-1)·L~(-1).体现了填料型A~2/O工艺具有显著的反硝化除磷效果.     

包覆型纳米零价铁活化过硫酸处理柴油污染土壤

采用Tween-20作为包覆材料对纳米零价铁(n ZVI)进行改性(T-n ZVI),并利用T-n ZVI活化过硫酸盐(PS)降解柴油,同时与未改性纳米零价铁活化过硫酸盐体系(n ZVI/PS)进行对比.结果显示,在n ZVI/PS体系中,柴油降解率随着n ZVI及PS用量的增加而增加.在T-n ZVI/PS体系中,反应90 d后,柴油最大降解率为78%.与n ZVI/PS体系相比,T-n ZVI/PS体系所有组别的柴油降解率均有所提升,但提升幅度不大.同时对T-n ZVI活化PS的机理进行了推测.