Efficient degradation of semi-coking wastewater in three-dimensional electro-Fenton by CuFe2O4 heterocatalyst

Semi-coking wastewater contains a rich source of toxic and refractory compounds. Three-dimensional electro-Fenton (3D/EF) process used CuFe₂O₄ as heterocatalyst and activated carbon (AC) as particle electrode was constructed for degrading semi-coking wastewater greenly and efficiently. CuFe₂O₄ nanoparticles were prepared by coprecipitation method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy disperse spectroscopy (EDS). Factors like dosage of CuFe₂O₄, applied voltage, dosage of AC and pH, which effect COD removal rate of semi-coking waste water were studied. The results showed that COD removal rate reached to 80.9% by 3D/EF process at the optimum condition: 4 V, 0.3 g of CuFe₂O₄, 1 g of AC and pH?=?3. Trapping experiment suggesting that hydroxyl radical (?OH) is the main active radical. The surface composition and chemical states of the fresh and used CuFe₂O₄ were analyzed by XPS indicating that Fe, Cu, and O species are involved into the 3D/EF process. Additionally, anode oxidation and the adsorption and catalysis of AC are also contributed to the bleaching of semi-coking waste water. The possible mechanisms of 3D/EF for degrading semi-coking waste water by CuFe₂O₄ heterocatalyst were proposed.

     

Construction of double tube granular sludge microbial fuel cell and its characteristics and mechanism of azo dye degradation

Environmental Science and Pollution Research - Microbial fuel cells (MFCs) can obtain electrical energy from extensive organic matter and complete wastewater treatment at the same time. The...     

中国固体废物监测技术问题分析及对策

从样品采集和制备、样品前处理、分析测试方法方面对固体废物监测现状进行分析,对现有分析方法标准进行梳理和总结。提出了中国固体废物监测方面存在控制标准和监测分析方法衔接不完善、部分浸出方法应用目的不明确、分析方法可比性不强或缺乏操作性、质量控制手段单一及监测技术水平不高等问题。针对存在的问题,提出梳理现有方法标准、加快标准制修订、加大对现有问题的研究力度、加强培训、提升固体废物监测能力等对策,以期推动中国固体废物监测能力的提升。     

不同四环素浓度对好氧堆肥和蚯蚓堆肥过程影响的对比研究

好氧堆肥及蚯蚓堆肥是对畜禽粪便进行肥料化处置的有效方式,但畜禽粪便中残留的不同浓度四环素对二者堆肥过程的影响是否相同却并不清楚.因此,将不同浓度(5、25、125 mg·kg^-1)的四环素添加到牛粪-秸秆物料中,对比了好氧堆肥与蚯蚓堆肥堆制过程中堆体腐熟度指标的变化、堆肥产品养分含量的区别以及堆肥产品中四环素去除效率的差异,以期为不同浓度四环素的畜禽粪便肥料化提供适宜的处置方法 .研究结果显示,高浓度(125 mg·kg^-1)四环素添加延缓了好氧堆肥的升温进程,但与低浓度(5、25 mg·kg^-1)四环素添加处理相比并未显著影响堆体的腐熟度指标、堆肥产品总养分含量及速效养分含量.高浓度(125 mg·kg^-1)四环素添加导致了蚯蚓堆肥中蚯蚓密度和生物量的显著下降,并导致蚯蚓堆肥无法正常启动.在蚯蚓堆肥中,低浓度(5、25 mg·kg^-1)四环素添加处理之间在堆体的腐熟度指标,堆肥产品总养分含量及速效养分含量方面无显著差异.好氧堆肥对畜禽粪便中四环素的去除率可达90%以上,显著高...     

基于CO2气体分离的固载离子液体@介孔二氧化硅混合基质膜

为提升混合基质膜对CO₂的气体分离性能,将具有良好CO₂吸附特性能的离子液体首先固载于介孔SiO₂中,而后将该复合材料掺杂到 聚酰亚胺高分子中构建高效分离CO₂的混合基质膜.研究结果表明,固载离子液体主要进入介孔SiO₂的孔道内部,但当绝大部分介孔孔道被离子液体填满后,过多离子液体在SiO₂颗粒外围形成连接.由于离子液体对CO₂优异的吸附性能,其固载后介孔SiO₂对CO₂的吸附性能得到的显著提升,这进一步增强了固载离子液体的介孔SiO₂掺杂混合基质膜对CO₂气体的捕获,随着混合基质膜中离子液体固载量增加其CO₂渗透性能也明显提升.但当固载离子液体加入量达到1.0 g时,固载离子液体的介孔SiO₂在PI高分子中出现了团聚,其CO₂渗透性能反而下降.IL@C-SiO₂-2/PI膜的渗透性能和对CO₂的渗透选择性都达到最佳,其对CO₂/N₂理想选择性可达到30.     

黄河三角洲盐沼湿地甲烷厌氧氧化潜力及微生物群落对铁锰输入的响应研究

铁、锰是滨海湿地环境中重要的变价金属元素,金属依赖型甲烷厌氧氧化（Anaerobic oxidation of methane, AOM）过程与碳循环相耦合,在生物地球化学循环过程中起到重要的驱动作用.研究铁、锰对湿地甲烷厌氧氧化潜力及微生物群落的作用对于减缓因甲烷释放而带来的 全球气候变暖具有重要意义.以黄河三角洲滨海湿地为研究对象,通过室内厌氧培养及高通量测序方法,系统研究了碱蓬盐沼湿地下甲烷厌氧氧化潜力及微生物群落对Fe³⁺、Mn⁴⁺输入的响应.结果表明：向土壤输入不同浓度的Fe³⁺和Mn⁴⁺后,浅层土的AOM潜力皆被抑制,深层土的AOM潜力则受到促进作用,且作用显著（p<0.05）,说明不同土层对铁、锰输入的响应不同,这可能取决于土壤中铁、锰含量的本底值;在微生物层面,铁、锰输入对土壤微生物的丰富度及均匀度产生影响,土壤中的微生物群落结构同时也发生了显著变化,在门水平下,细菌中的Proteobacteria（变形菌门）和古菌中的Euryarchaeota（广古菌门）丰度显著升高,科、属水平下富集了可以促进甲烷氧化的Methylomonaceae（甲基单胞菌）且使其成为优势种,表明该菌可能深度参与了甲烷消耗及金属元素循环过程.本研究对滨海湿地甲烷厌氧氧化的机理研究及黄河 三角洲微生物的多样性保护具有重要意义,同时也可为滨海湿地CH₄减排提供科学依据.     

秸秆还田、地膜覆盖及施氮对冬小麦田N2O和N2排放的影响

为探究不同耕作方式及施氮水平下黄土高原地区旱地冬小麦田N₂O排放规律,运用静态箱-气相色谱法研究了冬小麦田N₂O排放动态.以冬小麦‘小偃22’为材料,采取双因素裂区试验设计,主区为3种耕作模式：常规耕作（CT）、秸秆还田（SM）和平膜覆盖（FM）;副区为3种氮水平处理：不施氮、减氮20%(144 kg·hm^-2)和常规施氮(180 kg·hm^-2).以常规耕作（CT）为对照,探讨不同施氮水平下FM和SM对土壤N₂O排放产生的影响,同时分析环境因子与N₂O排放通量的相关性,并根据经验公式估算N₂排放量.结果表明,各施氮处理的土壤N₂O的排放主要集中在施肥后20 d内,且N₂O排放通量峰值出现在施肥后两周之内.冬小麦田的平均N₂O通量为1.92～22.75μg·（m²·h）^-1,累积排放量为0.10～0.46 kg·hm^...     

Synthesis and Characterization of Dual-ion-Crosslinked Magnetic Sodium Alginate-Based Fe-SA-Y@Fe3O4 Biogel Composite with Ultrastrong Performance for Azo Dye Removal

Journal of Polymers and the Environment - Magnetic sodium alginate(SA)-based biogel composite Fe-SA-Y@Fe3O4 macroparticles were synthesized by co-crosslinking of Y(III) and Fe(III) ions according...     

近40年来福建省水稻土有效磷富集效应及潜在生态风险评估

水稻土磷素流失引起的水体富营养化等生态风险已受到普遍关注,而明确其动态变化和富集效应是制定合理防控措施的基础.以福建省1.8×10⁶ hm²水稻土为研究对象,以1982年全国第二次土壤普查1 471个、 2008年农业农村部测土配方施肥项目215 534个和2018年农业农村部耕地质量监测项目2 895个表层水稻土样点建立的1∶5万三期大比例尺土壤数据库为基础,分析全省水稻土有效磷含量近40年来的富集效应及潜在生态风险.结果表明,1982～2018年间福建省水稻土有效磷含量增加了47 mg·kg^-1,富集面积达到1.65×10⁶ hm²,占全省水稻土总面积的91%;其中,1982～2008年福建省水稻土有效磷含量增加了28 mg·kg^-1,富集面积为1.47×10⁶ hm²,占全省水稻土总面积的82%; 2008～2018年福建省水稻土有效磷含量增加了19 mg·kg^-1,富集面积为1.22...     

Rapid Assessment of Hydrologic Performance of Low Impact Development Practices under Design Storms

Low impact development (LID) practices are often applied to compensate for surface imperviousness caused by urban development. These practices can mitigate flood risk by reducing runoff volume and peak flow and by delaying the time to peak flow. To select a suitable LID practice type and its surface area during the preliminary design process, it is necessary to rapidly estimate the hydrologic performance of various LID designs under design storms. This study provides a method and a toolbox for rapid assessment of the hydrologic performance of various LID practices, which can be useful to developers for establishment of preliminary LID designs. The hydrologic performance of three common types of LID practices (i.e., green roofs, bioretention cells, and infiltration trenches) under various design storms is first simulated using the Storm Water Management Model (SWMM). The results are then presented as performance curves on a unit storage basis. Look‐up tables are further developed to assist the comparison and selection of the LID alternatives for various hydrologic performance targets. To facilitate SWMM modeling, a MATLAB toolbox is developed to automate the process of input modification, model simulation, result extraction, and postprocessing. Finally, the sensitivity of the look‐up curves to design storm types and design specifications of bioretention cells is also analyzed, and the assumptions used in the development of these look‐up curves are validated.