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941.
942.
混凝——吸附法处理油墨废水工艺研究 总被引:7,自引:0,他引:7
采用不同无机混凝剂及氧化还原剂对打印机生产中的油墨废水的混凝及脱色效果进行试验比较,确定了实验室工艺条件及各种混凝剂最佳用量及次序。结果表明,该工艺脱色率达100%,CODcr去除率达51%。 相似文献
943.
944.
945.
Yixiao Wu Chunlong Chen Shu He Xuesong Zhao Shaobin Huang Gongchang Zeng Yingying You Ying Cao Lishan Niu 《环境科学学报(英文版)》2021,33(1):100-109
In this study, different carbon quantum dots (CQDs)/NaBiO3 hybrid materials were synthesized as photocatalysts to effectively utilize visible light for the photocatalytic degradation of contaminants effectively. These hybrid materials exhibit an enhanced photocatalytic reduction of hexavalent chromium (Cr(VI)) in the aqueous medium. Zero-dimensional nanoparticles of CQDs were embedded within the two-dimensional NaBiO3 nanosheets by the hydrothermal process. Compared with that of the pure NaBiO3 nanosheets, the photocatalytic performance of the hybrid catalysts was significantly high and 6 wt.% CQDs/NaBiO3 catalyst exhibited better photocatalytic performance. We performed the first-principles density functional theory calculations to study the interfacial properties of pure NaBiO3 nanosheets and hybrid photocatalysts, and confirmed the CQDs played an important role in the CQDs/NaBiO3 composites. The experimental results indicated that the enhanced reduction of Cr(VI) was probably due to the high loading of CQDs (electron acceptor) on NaBiO3, which made NaBiO3 nanomaterials to respond in visible light and significantly improved their electron-hole separation efficiency. 相似文献
946.
空气质量指数计算方法是目前全国各城市空气质量重要信息发布的基础,广泛应用于城市空气自动监测的空气质量评价。依据《HJ 633-2012环境空气质量指数(AQI)技术规定(试行)》发布环境空气质量指数(AQI)计算方法,利用VBA在Excel下编写宏程序,可以轻松实现空气质量日报信息的发布,使用户从手工重复性的填充和插入函数操作方式中彻底解放出来。 相似文献
947.
Qi Yang Jun Yi Kun Luo Xiaoli Jing Xiaoming Li Yang Liu Guangming Zeng 《Process Safety and Environmental Protection》2013,91(6):521-526
The individual alkaline or microwave pretreatment has been proved to be effective in disintegration and acidification of waste activated sludge (WAS). In this study, the effects of combined alkaline and microwave pretreatment at different pH and specific energy input (Es) on WAS disintegration were investigated using response surface methodology (RSM). Combined pretreatment achieved disintegration degree (DD) of 65.87% at Es of 38,400 kJ/kg TS and pH 11.0. The ANOVA further demonstrated that pH showed more significant effect on DD than Es. Anaerobic batch experiment results showed that combined pretreatment not only significantly improved volatile fatty acids (VFAs) accumulation but also shortened the time for the highest VFAs accumulation. The maximal VFAs accumulation (1500 mg COD/L) obtained at Es of 28,800 kJ/kg TS and fermentation time of 72 h, which was about two times that of the treatment without microwave (850 mg COD/L) at 96 h. The analysis of VFAs composition showed that the VFAs mainly consisted of acetic and iso-valeric acids, accounting for 57.3–70.1% of total VFAs. 相似文献
948.
A two-dimensional water-quality model for a winding and topographically complicated river 总被引:3,自引:0,他引:3
In this paper, a two-dimensional numerical calculation algorithm for water-quality modeling is presented. The algorithm is designed specifically for river systems with complicated geometric conditions. When velocity field data of the river are not available, the numerical calculation algorithm for the water-quality modeling can be used to project river-water quality by using a topographic map of the river course and a finite element method. The calculation results of the water-quality model can show the concentration fields of various pollutants. The water-quality model was applied to a case-study in the Hengyang City section of Xiangjiang River in Hunan Province, China. The river under consideration is winding and has an isle between two branches. In 1995, Chinese government secured a World Bank loan to conduct a Waterways Project in the study region. It was expected that construction works in the river section might affect water quality. Given that the project would change the hydrological regime of the river system and discharges, and so would affect water quality, there would be a need for model results that would predict the water-quality impacts of the Waterways Project. In particular, the study intended to apply the model to identify changes in river-water quality associated with the construction of Dayuandu navigation key project. It is hoped that the numerical calculation algorithm for the water-quality modeling presented in this paper can also be applied to other shallow rivers with similar topographical conditions. 相似文献
949.
The combined effect of ultraviolet (UV)-ozonation (O3) of aqueous 14C-TNT solutions followed by direct addition of the solutions to aerobic soils was examined as a method of disposal. The effect of TNT concentration was studied on both UV-O3 and soil metabolism. The amount of TNT degraded by either process decreased as the concentration increased. UV-O3 of a 1 ppm solution of TNT using a laboratory 450 W lamp for 10, 20, and 30 minutes resulted in substantial fragmentation of the ring and an increase in polarity of the resultant products. Soil metabolism, as measured by metabolic CO2 evolution, increased as the time of prior UV-O3 increased. A large amount of the 14C associated with 14C-TNT recovered from soil was in the non-extractable fraction. When a
, adapted to metabolize
-nitrophenol or picric acid as a sole source of carbon and nitrogen, was substituted for the soil phase, about 25% of the added 14C appeared as 14CO2. 1,3,5-Trinitrobenzene, 2,4,6-trinitrobenzaldehyde, 3,5-dinitrophenol, 3, 5-dinitrocatechol, 3,5-dinitrohydroquinone, and oxalic acid were identified as products of UV-O3. Rapid destruction of TNT took place in a large 66 lamp unit, and the resultant distribution of 14C was similar to the results from the laboratory studies. 相似文献
950.
Evaluation of modified clay coagulant for sewage treatment 总被引:1,自引:0,他引:1
The use of modified clays as coagulants for sewage treatment was investigated in this study. The raw clays were montmorillonites K10 and KSF, and were modified by polymeric Al or Fe and/or Al/Fe mixing polymeric species. The comparative performance of modified clays and aluminium sulphate and ferric sulphate were evaluated in terms of the removal of turbidity, suspended solids, UV(254)-abs, colour, and total and soluble CODs. The results demonstrated that after being modified with mixing polymeric Al/Fe species, two montmorillonite clays possess greater properties to remove the particles (as suspended solids) and organic pollutants (as COD and UV(254)-abs) from the sewage and to enhance the particle settling rate significantly. 相似文献