Characterization of odorous charge and photochemical reactivity of VOC emissions from a full-scale food waste treatment plant in China

Food waste treatment plants(FWTPs) are usually associated with odorous nuisance and health risks, which are partially caused by volatile organic compound(VOC) emissions. This study investigated the VOC emissions from a selected full-scale FWTP in China. The feedstock used in this plant was mainly collected from local restaurants. For a year, the FWTP was closely monitored on specific days in each season. Four major indoor treatment units of the plant, including the storage room, sorting/crushing room, hydrothermal hydrolysis unit, and aerobic fermentation unit, were chosen as the monitoring locations.The highest mean concentration of total VOC emissions was observed in the aerobic fermentation unit at 21,748.2–31,283.3 μg/m3, followed by the hydrothermal hydrolysis unit at 10,798.1–23,144.4 μg/m3. The detected VOC families included biogenic compounds(oxygenated compounds, hydrocarbons, terpenes, and organosulfur compounds) and abiogenic compounds(aromatic hydrocarbons and halocarbons). Oxygenated compounds,particularly alcohols, were the most abundant compounds in all samples. With the use of odor index analysis and principal components analysis, the hydrothermal hydrolysis and aerobic fermentation units were clearly distinguished from the pre-treatment units, as characterized by their higher contributions to odorous nuisance. Methanthiol was the dominant odorant in the hydrothermal hydrolysis unit, whereas aldehyde was the dominant odorant in the aerobic fermentation unit. Terpenes, specifically limonene, had the highest level of propylene equivalent concentration during the monitoring periods. This concentration can contribute to the increase in the atmospheric reactivity and ozone formation potential in the surrounding air.     

大气排污交易政策在我国的试点

在分析国内外近年来环境管理思想及策略发展的基础上,以实例说明了大气排污交易政策在我国实施的重要意义及强大的生命力。大气排污交易由泡泡政策、补偿政策、净得政策、排污量存储政策组成。现阶段我国实施大气排污交易政策主要在同一厂区＂以新带老＂、排污补偿及可用购买盈余排污量来达到排放标准三方面进行。文章还论述了排污交易量、排污交易费用确定的原则及管理办法。     

藻细胞不同生长阶段的海泡石凝聚除藻性能

对铜绿微囊藻(Microcystis aeruginosa 469)的4个不同生长阶段:延迟末期,对数中期,对数末期和衰老初期的表面疏水性(疏水分配法)和表面电性(Zeta电位)进行了测定,并利用0.2 g/L的海泡石进行了凝聚除藻性能实验.结果显示以上4个生长阶段的藻细胞表面疏水性平均为:64%, 48%, 58%和70%,而凝聚沉降60 min后的藻细胞去除效率为:97%, 87%, 81%和99%,表明藻细胞表面疏水性与粘土凝聚性能之间有较好的相关性(R＝0.7～0.8),但与表面电性的关系不大.M.A.469各个生长阶段的表面疏水性和凝聚性能的强弱顺序可依次确定为:衰老期>延迟期>对数增长期.     

基于PNGV模型的锂离子电池荷电状态估计

目的 提升不同老化情况下的锂离子电池荷电状态(SOC)估计精度。方法 基于PNGV模型(Partnership for a New Generation of Vehicles)，对锂离子电池SOC进行估计。首先通过双线性变换对PNGV模型进行离散化，采用带有遗忘因子的递归最小二乘法(FFRLS)，对电池模型参数进行在线辨识，利用卡尔曼滤波(EKF)算法进行SOC估计，并通过动态工况验证SOC估计精度。结果 以多种误差指标考察不同循环下的试验数据，在不同电池老化状态下具有较好的预测精度。相比基于Thevenin模型的算法，基于PNGV模型的算法可以将SOC平均绝对误差减少约60%，同时也可以将SOC估计最大绝对误差波动范围降低53.8%。结论 本算法引入PNGV模型后，解决了基于Thevenin模型算法误差大、不稳定的问题，提升了动力电池系统在不同老化环境下的适应性。     

水中天然有机物混凝过程的光学在线监测及控制

以腐殖酸为去除对象，用光散射颗粒分析仪（PDA）对水中天然有机物的混凝过程进行在线监测，结果表明PDA输出信号（FI曲线）的特征值与絮凝体粒径和有机物去除率之间具有相关性，在弱酸性（pH=5.0)T和中性（pH=7.0)条件下，通过合理控制混凝剂投量，腐殖酸的TOC去除率可达50％，UV254去除率可达80％－90％，但pH=7.0时的投量为pH=5.0的5倍以上，在pH＝5．0的条件下，吸附电和中是有机物混凝的主要机理，但在混凝剂投量非常高的情况下，卷扫絮凝也起重要作用。在pH=7.0条件下，卷扫絮凝则是有机物混凝的主要机理。