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531.
532.
改性粉煤灰对活性艳兰染料吸附性能的研究 总被引:11,自引:0,他引:11
采用添加熟石灰并升温活化的方法对粉煤灰进行改性,研究了粉煤灰改性的适宜条件及其对活性艳兰染料的吸附脱色规律。试验结果表明,活性艳兰染料溶液浓度60mg/L,改性粉煤灰用量40g/L,pH范围5~10,搅拌吸附时间30min,脱色率可达98%以上。改性粉煤灰对活性艳兰染料的脱色吸附符合Freundlich方程。随着吸附温度的升高,改性粉煤灰的吸附能力下降。 相似文献
533.
累托石-粉煤灰颗粒吸附剂的制备及除铜性能 总被引:1,自引:0,他引:1
研究了累托石-粉煤灰颗粒吸附剂制备工艺条件及其去除铜冶炼废水中Cu(Ⅱ)的条件。实验结果表明:累托石与粉煤灰的比例为7∶3,另加入15%的添加剂(St)和50%的水,焙烧温度为500℃时,制成的颗粒吸附剂不仅吸附效果最佳,而且其散失率较低。在不调节铜冶炼工业废水pH值的条件下,颗粒吸附剂用量为0·01g/mL,作用时间为60min,温度为25℃(常温)时,Cu(Ⅱ)的去除率达99·5%,处理后的水符合国家污水综合排放标准(GB8978-1996)一级标准。 相似文献
534.
介绍了粉煤灰的产生过程和特性 ,以及水泥型粉煤灰的生产工艺。简述了新型粉煤灰混凝土混合比试验 ,分析了水泥型粉煤灰利用的经济效益 相似文献
535.
ROGELIO NOGALES RAQUEL MELGAR EMILIO BENITEZ 《Journal of environmental science and health. Part. B》2013,48(8):1405-1415
A greenhouse study was conducted to evaluate the potential use of olive-cake ash as a soil amendment, using pepper (Capsicum annuum, L. cv Italian sweet). Three soils of different pH (acidic, neutral and calcareous) were used. Treatments included a control (no fertilizer application), NPK fertilizer, and two ash-application rates that provided a complete dose (equivalent to the K2O amount in the fertilizer) and a half dose (equivalent to half the K2O amount in the fertilizer), respectively. The ash was effective in raising soil pH. Ash treatments increased the pepper (stems and leaves) dry matter yield over control; although these increases were lower than treatment including NPK. Application of ash significantly increased leaf P concentration and AB-DTPA extractable P in soil, especially in the acidic and neutral soils. Leaf K concentrations and readily and slowly available K forms in soils were affected positively by the addition of the ash. These results demonstrate that ash from the combustion of wet olive cake can be used as a beneficial organic soil amendment. 相似文献
536.
537.
The influence of aluminium cation as a strong electrophilic centre on the thermolysis of chlorophenols chemisorbed on Al(OH)3 surface was investigated. If thermolysis is carried out at 300 °C the spontaneous rupture of the bond between aluminium and oxygen of phenol takes place in the temperature range of 260–280 °C. The thermolysis of chlorophenoxy aluminium compounds occurs through homolytic and heterolytic bond cleavage. In the case of heterolytic cleavage the leaving chlorophenoxy anion causes a simultaneous formation of the aluminium cation, which is the driving force for the rearrangement of the unstable intermediate. By homolytic cleavage of the Al–O bond the chlorophenoxy radical is formed. The isolation of reaction products of the thermolysis of the system Al(OH)3/2,4,6-trichlorophenol gave five isomers of dimeric compounds of resonance stabilised 2,4,6-trichlorophenoxy radical. The compounds are stable in nonaqueous, aprotic solution, but they are very sensitive to acid catalysis. They quickly transform into aromatic hydroxydiphenyl ethers. The process of dechlorination and aromatisation of cyclohexadienone dimers gives PCDD/PCDF. 相似文献
538.
Leachate derived from unlined coal ash disposal facilities is a potential anthropogenic source of arsenic to the environment. To establish a theoretical framework for predicting attenuation of arsenic by soils subject to ash landfill leachate, which is typically enriched in calcium and sulfate, the adsorption of As(V) and As(III) was characterized from 1 mM CaSO4 for 18 soils obtained down-gradient from three ash landfill sites and representing a wide range in soil properties. As(V) consistently exhibited an order of magnitude greater adsorption than As(III). As(V) adsorption was best described by coupling pH with 15 s DCB-Fe (R2 = 0.851, = 0.001), although pH coupled to clay, DCB-Fe, or DCB-Al also generated strong correlations. For As(III), pH coupled to Ox–Fe (R2 = 0.725, = 0.001) or Ox–Fe/Al (R2 = 0.771, = 0.001) provided the best predictive relationships. Ca2+ induced increases in As(V) adsorption whereas sulfate suppressed both As(V) and As(III) adsorption. Attenuation of arsenic from ash leachate agreed well with adsorption measured from 1 mM CaSO4 suggesting that the use of 1 mM CaSO4 in laboratory adsorption tests is a reasonable approach for estimating arsenic behavior in soils surrounding ash landfills. We also showed that the impact of leachate-induced changes in soil pH over time may not be significant for As(V) adsorption at pH < 7; however, As(III) adsorption may be impacted over a wider pH range especially if phyllosilicate clays contribute significantly to adsorption. The benefits and limitations of predicting arsenic mobility using linearized adsorption coefficients estimated from nonlinear adsorption isotherms or from the relationships generated in this study are also discussed. 相似文献
539.
Meharg AA Deacon C Edwards KJ Donaldson M Davidson DA Spring C Scrimgeour CM Feldmann J Rabb A 《Chemosphere》2006,64(11):1818-1828
The impact of ancient fertilization practices on the biogeochemistry of arable soils on the remote Scottish island of Hirta, St Kilda was investigated. The island was relatively unusual in that the inhabitants exploited seabird colonies for food, enabling high population densities to be sustained on a limited, and naturally poor, soil resource. A few other Scottish islands, the Faeroes and some Icelandic Islands, had similar cultural dependence on seabirds. Fertilization with human and animal waste streams (mainly peat ash and bird carcases) on Hirta over millennia has led to over-deepened, nutrient-rich soils (plaggen). This project set out to examine if this high rate of fertilization had adversely impacted the soil, and if so, to determine which waste streams were responsible. Arable soils were considerably elevated in Pb and Zn compared to non-arable soils. Using Pb isotope signatures and analysis of the waste streams, it was determined that this pollution came from peat and turf ash (Pb and Zn) and from bird carcases (Zn). This was also confirmed by 13C and 15N analysis of the profiles which showed that soil organic matter was highly enriched in marine-derived C and N compared to non-arable soils. The pollution of such a remote island may be typical of other ‘bird culture’ islands, and peat ash contamination of marginal arable soils at high latitudes may be widespread in terms of geographical area, but less intense at specific locations due to lower population densities than on Hirta. 相似文献
540.
Lignite fly ash (LFA), being alkaline and endowed with excellent pozzolanic properties, a silt loam texture, and plant nutrients,
has the potential to improve soil quality and productivity. Long-term field trials with groundnut, maize, and sun hemp were
carried out to study the effect of LFA on growth and yield. Before crop I was sown, LFA was applied at various doses with
and without press mud (an organic waste from the sugar industry, used as an amendment and source of nutrients). LFA with and
without press mud was also applied before crops III and V were cultivated. Chemical fertilizer, along with gypsum, humic acid,
and biofertilizer, was applied in all treatments, including the control. With one-time and repeat applications of LFA (with
and without press mud), yield increased significantly (7.0–89.0%) in relation to the control crop. The press mud enhanced
the yield (3.0–15.0%) with different LFA applications. The highest yield LFA dose was 200 t/ha for one-time and repeat applications,
the maximum yield being with crop III (combination treatment). One-time and repeat application of LFA (alone and in combination
with press mud) improved soil quality and the nutrient content of the produce. The highest dose of LFA (200 t/ha) with and
without press mud showed the best residual effects (eco-friendly increases in the yield of succeeding crops). Some increase
in trace- and heavy-metal contents and in the level of γ-emitters in soil and crop produce, but well within permissible limits,
was observed. Thus, LFA can be used on a large scale to boost soil fertility and productivity with no adverse effects on the
soil or crops, which may solve the problem of bulk disposal of fly ash in an eco-friendly manner. 相似文献