Dissolved organic matter in pore water of freshwater sediments: effects of separation procedure on quantity, quality and functionality

Pore water was separated either with or without water extraction prior to centrifugation (7600 or 20 000 × g) in order to investigate the effects of separation procedure on the amount and properties of dissolved organic matter (DOM i.e. the material passing through a 0.45-μm filter) in three freshwater sediments. On the basis of solubility in alkaline, organic matter was concluded to compose of humic substances in two (S1 and S3) and of humin (S2) in one of the sediments. DOM in the samples was quantified by total organic carbon measurement. Specific UV-absorption (SUVA) and high performance size exclusion chromatography (HPSEC) analyses were used to characterize DOM. Sorption of pyrene was used as a measure for functionality of DOM. Both water extraction and centrifugation speed were shown to affect the properties of DOM; however, the effects were sediment dependent. Water extraction increased the amount of DOM separated from the two sediments that had humic character (S1 and S3). In most cases water extraction increased SUVA and shifted the molecular size distribution of DOM towards larger sizes. The separation procedure had also an effect on the functionality of DOM. In water extracted samples of S2 and S3 the sorption of pyrene was higher than in the corresponding samples separated without water extraction, whereas in S1 similar effect was not found. Generally, centrifugation speed had smaller effects on the properties of DOM than water extraction. The fact that the effects of separation procedure on DOM depend on the sediment characteristics complicates the comparison between samples and evaluation of functionality in field conditions.     

工业污水回用是节约新鲜水的重要途径

介绍了二级出水深度处理工艺、药剂选择、试运行处理效果及深度处理后出水的回用情况。     

膜技术在水处理中的应用前景

介绍了膜分离技术的定义,种类,膜技术的应用领域及国内发展动态。     

砂,纤维球,纤维球-砂过滤效果的比较

通过过滤实验从过滤周期、水头损失及比沉积量三个方面对砂、纤维球和纤维球-砂滤床的过滤效果进行了比较.实验结果证实了纤维球-砂滤料的优越性。      

用物化法处理卷烟厂综合废水的实践

根据卷烟厂废水的特性,采用气浮加过滤,并在调节池辅以射流曝气的处理工艺,对郴州卷烟厂综合废水进行处理。实践证明,污染物的去除率达85%~95%,满足了达标排放的要求。      

鸡毛用作油烟净化过滤材料的实验研究

通过一系列试验对鸡毛吸附油脂及净化油烟的性能进行了研究 ,并将鸡毛制成过滤吸附板置于油烟净化设备中作为二级净化段对饭店厨房油烟净化进行了实际应用研究。结果表明净化效率较为理想。     

铁和铝氧化物涂层砂的过滤与吸附性能评价

总结性地对3种不同氧化物涂层砂和未涂层砂的表面特性、过滤和吸附性能进行了比较与分析,明确了适用范围。改性滤料的高温加热和碱性沉积两种制备方法中,涂铁宜选前者,涂铝宜用后者。涂层砂的比表面积增大,吸附容量增加,使石英砂表面电荷的带电性质改变,有利于水中杂质的去除。涂铁砂适合于除氟和除砷及除有机物;涂铝砂适合于除浊、除有机物和除锌。     

Removal of virus aerosols by the combination of filtration and UV-C irradiation

● The removal of virus aerosols by filtration and UV-C irradiation was proposed. ● The filtration efficiency for virus aerosols was affected by the filtration rate. ● The inactivation rate by UV-C was not linear with irradiation intensity or time. ● The virus trapped by filter material had a shielding effect on UV-C irradiation. The COVID-19 pandemic remains ever prevalent and afflicting—partially because one of its transmission pathways is aerosol. With the widely used central air conditioning systems worldwide, indoor virus aerosols can rapidly migrate, thus resulting in rapid infection transmission. It is therefore important to install microbial aerosol treatment units in the air conditioning systems, and we herein investigated the possibility of combining such filtration with UV irradiation to address virus aerosols. Results showed that the removal efficiency of filtration towards f2 and MS2 phages depended on the type of commercial filter material and the filtration speed, with an optimal velocity of 5 cm/s for virus removal. Additionally, it was found that UV irradiation had a significant effect on inactivating viruses enriched on the surfaces of filter materials; MS2 phages had greater resistance to UV-C irradiation than f2 phages. The optimal inactivation time for UV-C irradiation was 30 min, with higher irradiation times presenting no substantial increase in inactivation rate. Moreover, excessive virus enrichment on the filters decreased the inactivation effect. Timely inactivation is therefore recommended. In general, the combined system involving filtration with UV-C irradiation demonstrated a significant removal effect on virus aerosols. Moreover, the system is simple and economical, making it convenient for widespread implementation in air-conditioning systems.     

不同去除浊度方法对水中总磷测定影响的比较

本文研究了去除浊度方法的不同是否会导致各监测单位测定结果可比性差异。首先,通过在线自动监测仪器法和实验室钼酸铵分光光度法测定水中总磷浓度的比对实验所得出的监测数据结果发现,两者的结果误差较小,说明自动监测仪器分析结果与常规实验室手工法测定结果基本一致,未发现可比性差异,同样稳定可靠。同时,通过实验系统研究了手工法中应用浊度-色度补偿法、过滤法及离心法等去除浊度干扰的前处理方法,实验结果表明:三种分析方法测定结果基本一致,精密度和加标回收率均符合质量控制要求,测定结果无显著差异。     

过滤捕集法去除盐酸雾中试研究

含HCl浓度小于350mg／Nm^3的盐酸雾气体，经洗涤水洗涤后再进行过滤捕集处理，出口气体中HCl浓度不大于6．40mg／m^3，去除率大于95％。