In this study, a one-part alkali-activated slag (AAS) composed of ground-granulated blast furnace slag, desulfurized gypsum, and hydrated lime is proposed as alternative to cement for the production of cemented fine tailings backfill (CFTB), which is an environmentally friendly binder consisting of 93.72 wt.% industrial solid waste. Results show that AAS with 67.83 wt.% slag, 25.92 wt.% desulfurized gypsum, and 6.25 wt.% hydrated lime yields the highest strength, which is 1.7–3.2 times that of ordinary Portland cement (OPC). Aside from calcium silicate hydrate gel, appreciable quantity of ettringite characterized by interlocking needles structure and high bound water is also produced during the AAS hydration process. In addition, the hydration heat of the AAS binder is 48% less than that of OPC. Moreover, CFTB made of AAS provides better workability than that of CFTB with OPC up to 20 h. The findings of this study will contribute to the production of more cost-effective, durable, and environmental-friendly cemented fine tailings backfill.
Norfloxacin (Nor) sorption and the factors (soil organic matter (SOM), pH, and exogenous copper (Cu) influencing the sorption were investigated in a black soil (soil B), a fluvo-aquic soil (soil F), and a red soil (soil R). With increasing of Nor concentrations, sorption amount of norfloxacin increased in both the bulk soils and their SOM-removed soils, but the sorption capacity in SOM-removed soils was higher than that of their corresponding bulk soils, indicating that the process of norfloxacin sorption in soil was influenced by the soil properties including SOM. The sorption data in all bulk soils and SOM-removed soils were fitted to Freundlich and Langmuir models. The correlation coefficients suggested that the experimental data fitted better to Freundlich equation than to Langmuir equation. Furthermore, the data from soil F and SOM-removed F could not be described by Langmuir equation. The norfloxacin sorption amount decreased in soil B and soil F, whereas it increased in soil R as solution pH increased. The maximum KD and KOC were achieved in soil R when the equilibrium solution pH was 6. And the norfloxacin sorption was also influenced by the exogenous Cu2+ ions, which depended on the soil types and Cu2+ concentrations. With increasing of Cu2+ concentrations in solution, generally, sorption amount, KD and KOC for norfloxacin in soils increased and were up to a peak at 100 mg/L Cu2+, and then the sorption amount decreased regardless of norfloxacin levels. 相似文献
Abstract The characteristics of fine particulate pollution (PM10 and PM2.5) were measured at urban and suburban sites in Jinan during the 2008–2009 heating and non-heating seasons. The results showed that PM10 and PM2.5 pollution was quite serious, and PM mass concentration was higher during the heating season than the non-heating season. PM was the highest in the chemical factory and lowest in the development zone. The mass concentrations of PM10 and PM2.5 were linearly related, and the mass concentration ratio of PM2.5/PM10 was up to 0.59 in urban areas. PM pollution in Jinan was related to local meteorological factors: PM2.5 mass concentration and humidity were positively correlated, and PM2.5 mass concentration was negatively correlated with both click on the temperature and wind speed, although wind speed varied more. 相似文献
Environmental Science and Pollution Research - As common meteorological factors in daily life, there is limited evidence for the effect of ambient temperature and humidity during pregnancy on the... 相似文献
• Bi2O3 cannot directly activate PMS.• Bi2O3 loading increased the specific surface area and conductivity of CoOOH.• Larger specific surface area provided more active sites for PMS activation.• Faster electron transfer rate promoted the generation of reactive oxygen species.• 1O2 was identified as dominant ROS in the CoOOH@Bi2O3/PMS system. Cobalt oxyhydroxide (CoOOH) has been turned out to be a high-efficiency catalyst for peroxymonosulfate (PMS) activation. In this study, CoOOH was loaded on bismuth oxide (Bi2O3) using a facile chemical precipitation process to improve its catalytic activity and stability. The result showed that the catalytic performance on the 2,4-dichlorophenol (2,4-DCP) degradation was significantly enhanced with only 11 wt% Bi2O3 loading. The degradation rate in the CoOOH@Bi2O3/PMS system (0.2011 min−1) was nearly 6.0 times higher than that in the CoOOH/PMS system (0.0337 min−1). Furthermore, CoOOH@Bi2O3 displayed better stability with less Co ions leaching (16.4% lower than CoOOH) in the PMS system. These phenomena were attributed to the Bi2O3 loading which significantly increased the conductivity and specific surface area of the CoOOH@Bi2O3 composite. Faster electron transfer facilitated the redox reaction of Co (III) / Co (II) and thus was more favorable for reactive oxygen species (ROS) generation. Meanwhile, larger specific surface area furnished more active sites for PMS activation. More importantly, there were both non-radical (1O2) and radicals (SO4−•, O2−•, and OH•) in the CoOOH@Bi2O3/PMS system and 1O2 was the dominant one. In general, this study provided a simple and practical strategy to enhance the catalytic activity and stability of cobalt oxyhydroxide in the PMS system. 相似文献
The characteristics of fine particulate pollution(PM10and PM25)were measured at urban and suburban sites in Jinan during the 2008-2009 heating and non-heating seasons.The results showed that PM10 and PM2.5 pollution was quite serious,and PM mass concentration was higher during the heating season than the non-heating season.PM was the highest in the chemical factory and lowest in the development zone.The mass concentrations of PM10 and PM2.5 were linearly related,and the mass concentration ratio of PM2.5/PM10 was up to 0.59 in urban areas.PM pollution in Jinan was related to local meteorological factors: PM2.5 mass concentration and humidity were positively correlated,and PM2.5mass concentration was negatively correlated with both click on the temperature and wind speed,although wind speed varied more. 相似文献