光谱法与传统荧光法测量北京大气NO2浓度及其对臭氧生成效率的影响

利用腔衰减相移式NO2光谱仪(CAPS)和传统化学荧光法(CL)同时测量北京2012年8月21—29日大气NO2浓度变化.对比两种仪器的NO2浓度,两种仪器结果在白天光化学反应较强期间偏差较大,最高可达25%.结合O3以及NOy观测计算了臭氧生成效率(OPEx),结果显示CAPS仪器结果计算得出的OPEx比CL小40%.对比低浓度和高浓度O3时期,前者差异小于后者,说明准确的NO2浓度测量对OPEx的计算至关重要,在O3污染期间尤为重要,是影响臭氧敏感性控制指标的一个显著因素.     

Eukaryotic community diversity and pathogenic eukaryotes in a full-scale drinking water treatment plant determined by 18S rRNA and metagenomic sequencing

Environmental Science and Pollution Research - In this study, 18S rRNA high-throughput sequencing was applied to investigate the eukaryotic community in a full-scale drinking water treatment plant....     

Porous Cd0.5Zn0.5S nanocages derived from ZIF-8: boosted photocatalytic performances under LED-visible light

Environmental Science and Pollution Research - A facile strategy was adopted to prepare porous Cd0.5Zn0.5S (CZS-X) nanocages by sulfurizing the rhombic dodecahedral ZIF-8 as precursor with...     

碳交易政策如何影响工业碳生产率:来自中国省级数据的准自然实验

当前,在中国奋力实现"碳达峰"碳中和"目标的背景下,不仅给碳排放量相对较高的工业企业带来较大环境治理压力,同时也给其在经济增长方面带来较大冲击.对其随着碳交易政策的提出,是否能够产生"减碳促经"效果展开深入研究.基于2005~2019年30个省市数据,通过双重差分等方法和多重中介效应模型对碳交易政策与工业碳生产率的影响效果和作用路径展开深入分析.结果表明,碳交易政策能够明显提升工业碳生产率水平;同时该种作用效果会随着试点区域的不同存在明显差异;该政策能够产生显著的环境规制、结构优化、技术和能源结构优化效应.建议通过加速完善环境规制层面法律制度、加快构建环保产业发展新体系、加强绿色技术创新研发力度和加速优化能源结构方面促进中国工业经济向低碳化发展转型.     

二氧化钛光催化消毒技术在水处理中的研究

二氧化钛光催化消毒是一种新型的水处理技术,可以有效地去除水中常规的和新出现的致病微生物,杀菌效果好且相对常规消毒手段消毒副产物较少,处理工艺自身不会对处理水造成二次污染。通过总结光催化技术的研究历史,阐述了光催化氧化机理和杀灭微生物的具体过程,综述了二氧化钛光催化技术在水处理领域中杀灭细菌、真菌、藻类、原生动物和病毒的研究成果,论述了二氧化钛光催化消毒的必要性,并对二氧化钛光催化消毒的应用前景作了展望。     

生物洗涤+生物滴滤组合工艺处理炼油污水场恶臭气体工程设计

采用生物洗涤+生物滴滤技术处理炼油污水场恶臭气体,具有抗冲击性强、运行稳定、处理效率高的特点。监测表明:出口气中H2S<0.06 mg/m3,NH3<1.5 mg/m3,CH3SH<0.004 mg/m3,臭气浓度<20,达到GB 14554—93《恶臭污染物排放标准》规定的一级厂界要求。该工程与炼油污水场现有污水处理工程紧密相结合,可缩短微生物的培养、驯化周期,减少公用工程投资,便于工业化应用。     

Influencing factors and degradation products of antipyrine chlorination in water with free chlorine

Owing to its low cost, free chlorine is one of the most common disinfectants for wastewater and drinking water treatment. However, the formation of disinfection byproducts has been found to occur after free chlorine disinfection in recent decades. Antipyrine (ANT), an anti-inflammatory analgesic, has been frequently detected in the aquatic environment. In this work, the removal efficiency of ANT by free chlorine oxidation in ultrapure water was investigated with batch experiments. The influencing factors on the removal of ANT were explored at initial concentrations of ANT from 0.04 to 0.64 mg/L, free chlorine dosage from 0.30 to 1.31 mg/L, and pH from 1.5 to 9.0. The main degradation products were identified by solid phase extraction-gas chromatography-mass spectrometry. The results showed that ANT reacted rapidly with free chlorine in ultrapure water systems and up to 90.6% removal efficiency of ANT was achieved after 25 sec (initial free chlorine 1 mg/L, ANT 0.5 mg/L, pH 7.0). Higher oxidant dosage, lower ANT initial concentration and low pH favor the ANT removal. The main degradation product in ANT chlorination was a monochlorine substitution product (4-chloro-1,2-dihydro- 1,5-dimethyl-2-phenyl-3H-pyrazol-3-one), which can be further chlorinated by free chlorine. In addition, the total organic carbon result indicated that ANT is difficult to be mineralized using chlorine.     

Systematic analysis of microfauna indicator values for treatment performance in a full-scale municipal wastewater treatment plant

The indicator values of microfauna functional groups and species for treatment performancewere systematically evaluated based on the continuous monitoring of the entire microfauna communities including both protozoa and metazoa over a period of 14 months, in two parallel full-scale municipalwastewater treatment systems in a plant in Beijing, China. A total of 57 species of ciliates, 14 species (units) of amoebae, 14 species (units) of flagellates and4 classes of small metazoawere identified,with Arcella hemisphaerica, Vorticella striata, Vorticella convallaria, Epistylis plicatilis and small flagellates (e.g. Bodo spp.) as thedominant protozoa, and rotifers as thedominant metazoa. The abundance of the sessile ciliateswas correlatedwith the removals of BOD 5 (Pearson’s r = 0.410, p < 0.05) and COD Cr (r = 0.397, p < 0.05)while the testate amoebaewas significantly positively related to nitrification (r = 0.523, p < 0.01). At the same time, some other associationswere also identified: the abundances of the large flagellates (r = 0.447, p < 0.01), the metazoa (r = 0.718, p < 0.01) and species Aspidisca sulcata (r = 0.337, p < 0.05)were positively related to nitrification; the abundance of Aspidisca costatawas correlated to the TN (total nitrogen) removal (r = -0.374, p < 0.05 ); the abundances of the sessile species Carchesium polypinum (r = 0.458, p < 0.01) and E. plicatilis (r = 0.377, p < 0.05)were correlatedwith the removal of suspended solids.     

Occurrence and infection risk of waterborne pathogens in Wanzhou watershed of the Three Gorges Reservoir, China

The Three Gorges Reservoir (TGR), formed by China’s Yangtze Three Gorges Project, is the largest lake in the world, but there is too little information available about fecal contamination and waterborne pathogen impacts on this aquatic ecosystem. During two successive 1-year study periods (July 2009 to July 2011), the water quality in Wanzhou watershed of the TGR was tested with regard to the presence of fecal indicators and pathogens. According to Chinese and World Health Organization water quality standards, water quality in the mainstream was good but poor in backwater areas. Salmonella, Enterohemorrhagic Escherichia coli (EHEC), Giardia and Cryptosporidium were detected in the watershed. Prevalence and concentrations of the pathogens in the mainstream were lower than those in backwater areas. The estimated risk of infection with Salmonella, EHEC, Cryptosporidium, and Giardia per exposure event ranged from 2.9 × 10 -7 to 1.68 × 10-5 , 7.04 × 10-10 to 2.36 × 10-7 , 5.39 × 10-6 to 1.25 × 10-4 and 0 to 1.2 × 10-3 , respectively, for occupational divers and recreational swimmers exposed to the waters. The estimated risk of infection at exposure to the 95% upper confidence limit concentrations of Salmonella, Cryptosporidium and Giardia may be up to 2.62 × 10-5 , 2.55 × 10-4 and 2.86 × 10-3 , respectively. This study provides useful information for the residents, health care workers and managers to improve the safety of surface water and reduce the risk of fecal contamination in the TGR.     

城市生物质厌氧产酸构建碳源的研究进展

城市污水生物处理脱氮除磷阶段缺乏高效优质碳源,是国内外污水处理厂普遍面临的主要问题之一。通常采用投加外部碳源的方法提高脱氮除磷效率。常用的外加碳源包括传统的甲醇、乙酸、葡萄糖等,以及高浓度的有机废水及其发酵产物,污泥消化液等。传统投加外碳源如甲醇、乙酸、葡萄糖等成本较高,并且甲醇存在一定的毒性和运输问题。开发经济有效的新型可替代碳源成为目前新的研究热点。利用城市废弃生物质,如可生化性好的啤酒废水、淀粉废水,或城市污水厂剩余污泥的厌氧发酵产物作为污水厂外加碳源,研究发现产物中含有较多的短链挥发性脂肪酸(如乙酸、丙酸、丁酸等),其反硝化效率较单一乙酸做碳源要高,同时还可以节约碳源成本,是一种经济有效的可替代碳源。