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201.
Sana Ullah Xuejun Guo Xiaoyan Luo Xiangyuan Zhang Siwen Leng Na Ma Palwasha Faiz 《Frontiers of Environmental Science & Engineering》2020,14(5):89
202.
FRANCISCO GALLARDO-LARA MARIANO AZCÓN ALFREDO POLO 《Journal of environmental science and health. Part. B》2013,48(7):1187-1201
Little is known about the effects of applying composted urban wastes on the phytoavailability and distribution of iron (Fe) and manganese (Mn) among chemical fractions in soil. In order to study this concern several experiments in pots containing calcareous soil were carried out. The received treatments by adding separately two rates (20 and 80 Mg ha?1) of municipal solid waste (MSW) compost and/or municipal solid waste and sewage sludge (MSW-SS) co-compost. The cropping sequence was a lettuce crop followed by a barley crop. It was observed that treatments amended with composted urban wastes tended to promote slight increases in lettuce yield compared to the control. The highest Fe levels in lettuce were found when higher rates of MSW-SS co-compost were applied; these values were significant compared to those obtained in the other treatments. In all cases, the application of organic materials increased the concentration and uptake of Mn in lettuce compared to the control; however, these increases were significant only when higher rates of MSW compost were applied. The organic amendments had beneficial delayed effects on barley yields, showing, in most cases, significant increases compared to the control. In this context, treatments with MSW compost were found to be more effective than the equivalent treatments amended with MSW-SS co-compost. Compared to the control, composted urban wastes increased Fe concentration in straw and rachis, and decreased Fe concentration in barley grain. Similarly, a decreased concentration of Mn in the dry matter of barley crop grown in soils treated with composted urban wastes was observed. 相似文献
203.
Joachim von Schéele 《International Journal of Green Energy》2013,10(2):139-148
There is a strong political will to decrease CO2 emissions. Although the steel industry only accounts for some 5% of worldwide CO2 emissions (which totalled 1,200 million tonnes per annum in the late 1990s), it will be strongly affected by this. The EU, for example, is putting up strong economic incentives for reductions. This is taking place at a time when demand for steel products is greater than ever. To radically change existing processes and production routes to decrease the CO2 emissions would be extremely expensive, even if it were possible. Nevertheless, many of the solutions which have been discussed seem to go in this direction. The other alternative discussed seems to be the creation of process solutions and alterations that lead to a focusing of CO2 streams, i.e., much higher CO2 concentrations in flue gases than today, for entrapment of the CO2 so that it is not discharged into the atmosphere. These solutions are feasible, but expensive. However, there exists today a number of solutions and technologies which, if fully implemented, could substantially decrease CO2 emissions without seriously altering current methods of operation; they are short-term viable solutions. The present paper reviews and discusses such technologies, throughout the steel production paths. If these solutions are fully implemented, the combined impact on CO2 emissions from the steel industry worldwide is estimated to be a reduction of 100–150 million tonnes of CO2 per annum, i.e., current emissions can be reduced by some 8–10% within a relatively short time span. 相似文献
204.
The fertilizing potential of Fe-enriched biosolids has been attributed to Fe associations with humic substances contained therein. In this study, alkaline and near-neutral aqueous extractions of humic substances from an Fe-enriched biosolid were followed by gel chromatographic fractionation and characterization (CHNS elemental analysis; UV/visible and FTIR spectroscopy; FAAS analysis). The alkaline bulk humic extract had a strong fulvic character and Fe was predominantly associated with the higher molecular weight (50 000 Da) molecules, possibly including organic-coated Fe oxides from which Fe may be released more slowly. Under both near-neutral and alkaline conditions, associations with lower molecular weight humic molecules were also observed, indicative of the presence of Fe in more readily available forms. Thus the biosolid appears to have good short- and long-term fertilizing potential, particularly for alkaline, Fe-deficient soils. 相似文献
205.
L. Valisano G. Bavestrello M. Giovine A. Arillo C. Cerrano 《Chemistry and Ecology》2007,23(3):233-241
The suitability of the primmorphs system as a good model for biotechnological applications led researchers on primmorphs to look for a medium to stimulate cell proliferation and therefore growth of aggregates. Recent efforts have focused on the use of Fe+3 and Si that, supplemented to cell culture medium, were found to be promising for growth and morphogenesis of the sponge Suberites domuncula. In this work, we analysed the effect of iron and dissolved silica on primmorphs of Petrosia ficiformis, by testing them at different concentrations in successive experiments. The purpose of these experiments was to test their effect on primmorphs and individuate their optimal concentration for this species. Our results suggest a negative effect of iron on primmorphs of P. ficiformis and a positive effect of silica on primmorphs size and spiculogenesis at a concentration of 120 μM. 相似文献
206.
Atrazine, propazine and simazine were tested separately and in mixture by batch procedure in a laboratory-constructed apparatus. 3.75 l of a buffered s-triazines pesticide solution was treated at room temperature by 325-mesh zero-valent iron powder (ZVIP) (20 g/l). High performance liquid chromatography was used to separate by-products and study the decline in the pesticide’s concentrations. Results obtained show that the order of degradation was simazine, atrazine and then propazine. The half-lives (t1/2) of the s-triazines pesticides are, respectively, 7.4, 9.0 and 10.6 min when they are treated separately, and 9.8, 11.2 and 13.7 min when they are treated together under the same conditions. The final by-product obtained after 50 min of contact of simazine with ZVIP shows a shift to longer wavelength in its UV spectrum. A similar phenomenon is shown for atrazine and propazine. Identical primary by-products are produced and subsequently degraded to 4,6-(diamino)-s-triazine, which seems to be the major by-product of the reductive treatment process. Pathways for the degradation of the studied s-triazines by ZVIP are proposed. 相似文献
207.
Advanio Inácio Siqueira-Silv Camilla Oliveira Rios Eduardo Gusmão Pereira 《环境科学学报(英文版)》2019,31(4):257-266
The revegetation of mined areas poses a great challenge to the iron ore mining industry. The initial recovery process in degraded areas might rely on the use of Fe-resistant grasses. Tropical grasses, such as Paspalum densum and Echinochloa crus-galli, show different resistance strategies to iron toxicity; however, these mechanisms are poorly understood. The Fe-resistance mechanisms and direct iron toxicity as a function of root apex removal were investigated. To achieve this purpose, both grass species were grown for up to 480?hr in a nutrient solution containing 0.019 or 7?mmol/L Fe-EDTA after the root apices had been removed or maintained. Cultivation in the presence of excess iron-induced leaf bronzing and the formation of iron plaque on the root surfaces of both grass species, but was more significant on those plants whose root apex had been removed. Iron accumulation was higher in the roots, but reached phytotoxic levels in the aerial parts as well. It did not hinder the biosynthesis of chloroplastidic pigments. No significant changes in gas exchange and chlorophyll a fluorescence occurred in either grass when their roots were kept intact; the contrary was true for plants with excised root apices. In both studied grasses, the root apoplastic barriers had an important function in the restriction of iron translocation from the root to the aerial plant parts, especially in E. crus-galli. Root apex removal negatively influenced the iron toxicity resistance mechanisms (tolerance in P. densum and avoidance in E. crus-galli). 相似文献
208.
为了解决煤矿灰岩水铁含量高,较难复用的问题,进行了接触过滤氧化法处理模拟含铁原水的试验研究。结果表明:采用石英砂滤料的接触过滤氧化工艺处理铁含量为2.0mg/L的模拟原水除铁效果明显,当气水比为2.0,pH值为7.5~8.0,停留时间小于2~3min,滤速为12.0m/h时,除铁率可达90%以上,滤后水满足铁含量0.3mg/L的井下复用水质要求,且过滤周期长达36h;同时分析得出最大平均催化氧化速率系数为KFe2+=1.50×1011L3mg-3s-1和除铁拟合曲线方程-Ln(Ct/Co)=-0.0011x2+0.0517x+1.748。 相似文献
209.
210.
根据阜新地区铁矿特点,从工艺装备水平、资源能源利用指标、废物回收利用指标、环境管理等方面分析得出该地区铁矿清洁生产水平较低,尚未达至国内清洁生产基本水平,并有针对性地提出了清洁生产改进措施。 相似文献