农村污水设施车载式剩余污泥脱水技术与设备研究

日益增长的农村污水设施剩余污泥已成为农村污水治理工作开展面临的新难题,农村剩余污泥适合采用多台污水设施共用车载式剩余污泥脱水设备进行脱水后收运集中处理,而农村道路的宽度和限高以及污水设施与道路间的距离等是主要的限制因素,因此急需研发适合农村作业环境的小型车载式剩余污泥脱水关键技术与设备.本研究的车载式剩余污泥脱水通过主要脱水设备负压运行方式,有效减小设备的尺寸,设备外观尺寸为5.995 m×1.905 m×2.56 m,吸污管道50 m.结果表明：可适应农村的作业环境,满足90%以上的农村小型污水处理设施使用.该设备行驶油耗7.2 L·h^-1,工作油耗1.88 L·h^-1;脱水后的污泥含水率80%左右.模拟案例表明,车载式剩余污泥脱水设备脱水收运方式比不脱水直接收运方式每台户用小型设施每年可节省污泥收运费103.3元,在一个安装了4400台小型污水设施的农村区域,每年可节省污泥收运费约45.5万元.     

富氧空位MoO2强化Fe2+/过一硫酸盐体系降解四环素

采用NaBH₄超声还原法合成了富含氧空位的MoO₂,并通过多种表征方法证明了氧空位的存在.10-MoO₂作为助催化剂显著增强了Fe²⁺/过一硫酸盐体系催化性能,构建的10-MoO₂/Fe²⁺/PMS体系可快速降解四环素（TC）,10 min内对TC的降解率接近100%.系统研究了各种影响因素对TC降解效果的影响,探讨了助催化剂的稳定性及该体系的实用性.电化学、铁离子循环及自由基捕获实验的结果表明,由于氧空位（O_vacancy）的存在,降低了MoO₂的电阻,增强了电子转移能力,加速了Fe³⁺/Fe²⁺循环,提高了活性氧物种的产率,从而增强了Fe²⁺/PMS类芬顿体系的催化活性.本研究为类芬顿法处理抗生素废水提供了一种新的视角.     

不同原料生物质炭DOM组分成分特性

不同原料的生物质炭DOM含量和组分存在差异,选取水稻秸秆（RS）、小麦秸秆（WS）、大豆秸秆（SS）、油菜秸秆（YS）、花生壳（PH）、松木屑（PW）和竹粉（BS）7种生物质原料在450 ℃下制备的生物质炭,采用紫外-可见光光谱（UV-vis）、荧光光谱（EEM）结合平行因子分析（PARAFAC）技术对生物质炭中DOM的光谱特征和荧光组分进行表征.结果表明：木本类生物质炭的DOM含量较秸秆类生物质炭低,分子量较高.从生物质炭DOM中鉴定分离可见区类富里酸组分（C1）、较短波长类腐殖酸组分（C2）、较长波长类腐殖酸组分（C3）和类蛋白质组分（C4）等4种组分.不同原料生物质炭DOM各组分的最大荧光强度（F_max）值表现为C1 ＞ C2 ＞ C3 、C4,秸秆类炭DOM各组分的F_max值显著高于木本类.生物质炭DOM中以C1组分占主导地位,占比达48.87% ~ 79.97%.C2、C3组分在YSB、SSB-DOM中占比最高,分别达32.71%和23.25% ,仅在YSB和PHB-DOM中发现少量C4组分.木本类原料的有机和无机矿物含量远低于秸秆类,原料中纤维素含量与生物质炭DOM总量及其C3组分呈显著的正相关关系, Ca含量与生物质炭的DOM含量及其F_max值和C3组分呈显著正相关,说明不同生物质原料的组成对生物质炭DOM组成特性具有显著的影响,研究结果为全面评估不同原料生物质炭DOM的环境效应提供重要的科学理论依据.     

Characterization of extracellular polymeric substance (EPS) fractions produced by Microcystis aeruginosa under the stress of linoleic acid sustained-release microspheres

Environmental Science and Pollution Research - This paper focuses on the characterization of extracellular polymeric substances (EPS), which are composed of soluble EPS (SL-EPS), loosely bound EPS...     

Learning and the transformative potential of citizen science

The number of collaborative initiatives between scientists and volunteers (i.e., citizen science) is increasing across many research fields. The promise of societal transformation together with scientific breakthroughs contributes to the current popularity of citizen science (CS) in the policy domain. We examined the transformative capacity of citizen science in particular learning through environmental CS as conservation tool. We reviewed the CS and social‐learning literature and examined 14 conservation projects across Europe that involved collaborative CS. We also developed a template that can be used to explore learning arrangements (i.e., learning events and materials) in CS projects and to explain how the desired outcomes can be achieved through CS learning. We found that recent studies aiming to define CS for analytical purposes often fail to improve the conceptual clarity of CS; CS programs may have transformative potential, especially for the development of individual skills, but such transformation is not necessarily occurring at the organizational and institutional levels; empirical evidence on simple learning outcomes, but the assertion of transformative effects of CS learning is often based on assumptions rather than empirical observation; and it is unanimous that learning in CS is considered important, but in practice it often goes unreported or unevaluated. In conclusion, we point to the need for reliable and transparent measurement of transformative effects for democratization of knowledge production.     

Specific biotests to assess eco-toxicity of biodegradable polymer materials in soil

Eco-toxicity investigation of polymer materials was considered extremely necessary for their potential menace, which was widely use as mulching materials in agricultural. In this study, polyethylene (PE), polystyrene (PS) and synthetic biomaterials-Ecoflex and cellulose were applying into soil cultivated with two potential indicator plants species: oat (Avena sativa) and red radish (Raphanus sativum). Variety of chemical, biochemical parameters and enzyme activity in soil were proved as effective approach to evaluate polymers phytotoxicity in plant-soil mesocosm. The F-value of biomass, pH, heavy metal and electoral conductivity of Raphanus behaved significant different from T0. Significant analysis results indicated biodegradation was fast in PE than PS, besides, heavy metals were dramatically decrease in the end implied the plant absorption may help decrease heavy metal toxicity. The increase value at T2 of Dehydrogenase activity (0.84 higher than average value for Avena & 0.91 higher for Raphanus), Metabolic Index (3.12 higher than average value for Avena & 3.81 higher for Raphanus) means during soil enzyme activity was promoted by biodegradation for its heterotrophic organisms’ energy transportation was stimulated. Statistics analysis was carried on Biplot PC1 (24.2% of the total variance), PC2 (23.2% of the total variance), versus PC3 (22.8% of the total variance), which indicated phosphatase activity and metabolic index was significant correlated, and high correlation of ammonium and protease activity. Furthermore, the effects were more evident in Raphanus treatments than in Avena, suggesting the higher sensitivity of Raphanus to polymers treatment, which indicate biodegradation of polymers in Raphanus treatment has produced intermediate phytotoxic compounds.     

水合肼中混入尿素后的非催化还原脱硝研究

在对比了尿素和水合肼(N2H4·H2O)选择性非催化还原(SNCR)脱除烟气中NOx温度特性的基础上,尝试将两者混合以降低SNCR脱硝反应的温度窗口.实验结果显示,水合肼有一中温区温度窗口(550～650℃),最佳温度在600℃左右,远低于尿素SNCR脱硝的温度窗口和最佳温度.对比尿素和水合肼在不同条件下混合后的脱硝规律发现,将部分水合肼用尿素替代后虽然脱硝效率有所下降,但维持了水合肼的中温脱硝特征,某些条件下甚至出现脱硝效率上升的现象;并且反应过程中无氨分解产生和逸出;而尿素单独使用时在此温区内则有氨逸出.研究还表明,将水合肼加入到尿素中并无有益效果.而当还原剂/NO的化学计量比(Normalized stoichiometric ratio,NSR)为2.0时,在水合肼中加入尿素,以16.7％的尿素N替代水合肼N,混合还原剂的峰值脱硝效率出现在530℃左右,并维持在单独使用水合肼时峰值的93.3％的水平;温度在503 ～ 567℃范围变化时,混合还原剂维持了可观的中温脱硝效率.研究表明,有望通过在水合肼中添加适量尿素以降低水合肼SNCR中温脱硝的成本.