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铁屑去除酸法地浸采铀地下水中硝酸盐的试验研究 总被引:1,自引:0,他引:1
在酸法地浸采铀过程中,硝酸及硝酸盐的广泛使用使硝酸盐在地下不断累积并扩散到地下水中,这给矿区地下水造成了一定程度的污染.本试验以铁屑为还原剂,对该地下水中NO3--N的去除进行了批试验和动态试验研究.试验结果表明,铁屑可有效去除地下水中的NO3--N,其去除率随pH值的降低而逐渐升高;溶液中共存的Ca2 、Mg2 对NO3--N的去除影响不大,而SO42-、HCO3-的存在可明显降低NO3--N去除率;铁屑最佳投加量为120 g/L,铁炭最佳体积比为1∶1;二级柱可以明显提高柱子的稳定运行时间,在55 h内NO3--N去除率可保持在93%以上,去除效果较好. 相似文献
4.
Chindaprasirt P Jaturapitakkul C Chalee W Rattanasak U 《Waste management (New York, N.Y.)》2009,29(2):539-543
This research was conducted to compare geopolymers made from fly ash and ground bottom ash. Sodium hydroxide (NaOH) and sodium silicate (Na(2)SiO(3)) solutions were used as activators. A mass ratio of 1.5 Na(2)SiO(3)/NaOH and three concentrations of NaOH (5, 10, and 15M) were used; the geopolymers were cured at 65 degrees C for 48 h. A Fourier transform infrared spectrometer (FT-IR), differential scanning calorimeter (DSC), and scanning electron microscope (SEM) were used on the geopolymer pastes. Geopolymer mortars were also prepared in order to investigate compressive strength. The results show that both fly ash and bottom ash can be utilized as source materials for the production of geopolymers. The properties of the geopolymers are dependent on source materials and the NaOH concentration. Fly ash is more reactive and produces a higher degree of geopolymerization in comparison with bottom ash. The moderate NaOH concentration of 10 M is found to be suitable and gives fly ash and bottom ash geopolymer mortars with compressive strengths of 35 and 18 MPa. 相似文献
5.
Liang Peng Yanqing Ren Jidong Gu Pufeng Qin Qingru Zeng Jihai Shao Ming Lei Liyuan Chai 《Environmental science and pollution research international》2014,21(12):7631-7640
Novel magnetic carbonaceous bio-char was hydrothermal prepared from microalgae under different loadings of iron and its structures and surface chemistry were characterized with Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and nitrogen adsorption-desorption isotherm (BET). The morphology of bio-char changed from sheet to particle as iron loading increased and its surface area also increased. When 3.0 g of dried microalgae and 6.0 mmol iron salt ((NH4)2SO4·FeSO4·6H2O) were mixed and treated, the obtained bio-char possessing the highest amount of oxygen-containing functional groups resulted in the best adsorption performance on tetracycline (TC). This adsorption process was fitted to Langmuir adsorption isotherm and the maximum adsorption capacity was 95.86 mg/g, which is higher than other bio-char reported. The iron loading contributed to the higher adsorption capacity of bio-char, which may be due to three factors, the high surface area, more hydrogen bonding, and bridging effects of the structural Fe for TC. Our data suggest that bio-char may have more important role in stabilization of pollutants in the environment. 相似文献
6.
Influence of root-exudates concentration on pyrene degradation and soil microbial characteristics in pyrene contaminated soil 总被引:2,自引:0,他引:2
The effect of ryegrass (Lolium perenne L.) root-exudates concentration on pyrene degradation and the microbial ecological characteristics in the pyrene contaminated soil was investigated by simulating a gradually reducing concentration of root exudates with the distance away from root surface in the rhizosphere. Results showed that, after the root-exudates were added 15 d, the pyrene residue in contaminated soil responded nonlinearly in the soils with the same pyrene contaminated level as the added root-exudates concentration increased, which decreased first and increased latter with the increase of the added root-exudates concentration. The lowest pyrene concentration appeared when the root exudates concentration of 32.75 mg kg(-1) total organic carbon (TOC) was added. At the same time, changes of microbial biomass carbon (MBC, C(mic)) and microbial quotient (C(mic)/C(org)) were opposite to the trend of pyrene degradation as the added root-exudates concentration increased. Phospholipid fatty acid (PLFA) analysis revealed that bacteria was the dominating microbial community in pyrene contaminated soil, and the changing trends of pyrene degradation and bacteria number were the same. The changing trend of endoenzyme-dehydrogenase activity was in accordance with that of soil microbe, indicating which could reflect the quantitative characteristic of detoxification to pyrene by soil microbe. The changes in the soils microbial community and corresponding microbial biochemistry characteristics were the ecological mechanism influencing pyrene degradation with increasing concentration of the added root-exudates in the pyrene contaminated soil. 相似文献
7.
3种载体固定化菌藻共生系统脱氮除磷效果的对比 总被引:1,自引:0,他引:1
采用3种不同载体(海藻酸钠、聚乙烯醇、复合载体),分别将小球藻和栅藻与活性污泥固定成菌藻共生系统,制成菌藻凝胶小球,单独菌、单独藻的凝胶小球,用于处理人工污水。结果表明,(1)复合载体固定的菌藻共生系统氮磷去除效果最好,PVA载体的脱氮除磷效果次于复合载体优于海藻酸钠;(2)固定化菌藻共生系统的脱氮除磷效果明显优于单独固定菌和单独固定藻,固定菌的效果较差;(3)3种载体包埋下的固定化小球藻的脱氮除磷效果均较相同载体固定化的栅藻效果好。 相似文献
8.
Floodplain soils containing elevated levels of polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) were collected from several locations along the Tittabawassee River (Michigan, USA). The PCDD/F profiles of these soils exhibited distinct congener patterns consistent with byproducts from either chloralkali manufacturing or chlorophenols productions. Black carbon (BC) particles were isolated for the first time from floodplain soil impacted by PCDD/Fs. Petrographic analysis showed that BC particles, including coal, oxidized coal, metallurgical coke, depositional carbon, coal tar/pitch, cenosphere, and charcoal, comprised approximately 30% by volume of the organic fraction with size range of 250 μm-2000 μm from a typical floodplain soil. The BC particles with anthropogenic origin such as pitch and coke associated with the chloralkali production process served as both the source and subsequent transporter for the highly hydrophobic PCDD/Fs. These anthropogenic BC particles were enriched with high levels of PCDFs, containing approximately 1000-fold the concentration found in the bulk soil. The strong association of PCDD/Fs with anthropogenic BC directly impacts the physicochemical and biological availability thus the risk associated with these hydrophobic organochlorines in soils and sediments. 相似文献
9.
Luyao Wen Chun Yang Xiaoliang Liao Yanhao Zhang Xuyang Chai Wenjun Gao Shulin Guo Yinglei Bi Suk-Ying Tsang Zhi-Feng Chen Zenghua Qi Zongwei Cai 《环境科学学报(英文版)》2022,34(5):443-452
The COVID-19 pandemic has raised awareness about various environmental issues,including PM2.5 pollution.Here,PM2.5 pollution during the COVID-19 lockdown was traced and analyzed to clarify the sources and factors influencing PM2.5 in Guangzhou,with an emphasis on heavy pollution.The lockdown led to large reductions in industrial and traffic emissions,which significantly reduced PM2.5 concentrations in Guangzhou.Interestingly,the trend of PM2.5 相似文献
10.
利用西湖淤泥进行低成本有机型基质栽培试验 总被引:6,自引:0,他引:6
以西湖淤泥为主要原料,配以砻糠灰、干鸡粪、菜籽饼等,组配低成本有机型基质,旨在合理开发利用西湖淤泥。处理Ⅰ(西湖淤泥 砻糠灰 干鸡粪)与处理Ⅱ(西湖淤泥 砻糠灰 菜籽饼)均有良好的理化性质,其孔隙度、有机质含量及N、P、K含量适宜樱桃番茄的生长。处理Ⅰ樱桃番茄早期营养生长及前期产量、总产量等方面与对照(泥炭 珍珠岩 泡沫粒)无显著性差异,果实中Vc含量显著高于对照。处理Ⅱ早期营养生长不如对照,但前期产量、总产量与对照无显著性差异,干物质、Vc含量与糖度显著高于对照。处理Ⅰ、处理Ⅱ的成本约为对照的1/2左右。 相似文献