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741.
742.
构建纳米铁(nZVI)-生物耦合系统,探讨连续流反应器中耦合系统处理刚果红废水的可行性和可控性.研究发现nZVI将刚果红大分子降解为小分子后,提高了废水的可生化性(由0.04提高至0.69)并降低了毒性(由90.25%降至30.57%),为生物单元提供良好的环境条件.反应器连续运行期间,耦合系统对初始浓度为500mg/L的刚果红废水脱色率达99%,COD从167mg/L降低到约50mg/L.而单一生物系统的脱色率仅为30%~70%,COD降至116mg/L,且波动较大.研究结果表明,nZVI-生物耦合系统是一种能够深度处理难降解有机染料废水的技术手段. 相似文献
743.
随着我国钢铁企业安全生产标准化的不断深入开展,钢铁企业安全生产状况趋于稳步好转。本文分析了钢铁企业安全生产的现状,并就近年来大中型钢铁企业安全生产事故情况进行了统计分析,对存在的问题进行了深入的探讨,提出了相应的改进对策与建议。 相似文献
744.
Salar Rezapour 《Chemistry and Ecology》2014,30(2):147-155
A factorial design with different levels of elemental S and cow manure was used to investigate the effects of S and manure on SO4-S, P and micronutrient availability in a calcareous saline–sodic soil. The results revealed that the recovery of SO4-S increased significantly (p≤0.05) in all treatments as elemental S increased, particularly when in combination with manure. The interactional effects of S° and manure application rates resulted in a decrease in soil pH of 0.1 to 0.9 units and increases in soil EC from 0.1 to 2.6 dS m?1 as result of an increase in the number of oxidisers and the oxidation rate of elemental S. Application of S° in combination with manure led to an increase in soil-available-P (0.6–40 mg kg?1), DTPA-Zn (0.2–3.9 mg kg?1) and DTPA-Fe (0.1–5.6 mg kg?1). 相似文献
745.
John F. Elder Richard H. Fuller Alexander J. Home 《Journal of the American Water Resources Association》1979,15(6):1608-1617
ABSTRACT: Some physical and chemical characteristics of Lake Perris, a new southern California reservoir, were investigated with regard to their influence on phytoplankton biomass and community structure. The concentration of three major nutrients – nitrogen, phosphorus, and iron – was approximately equivalent to the demand ratio of fresh water plants. Large increases in iron and phosphorus concentrations in late summer due to releases from sediments, however, tended to shift the balance toward a nitrogen-limited situation. Nitrogen limitation favored nitrogen-fixing blue-green algae, and after a decline of competing algae during the summer, the blue-green population bloomed in September. Series of measurements taken over one-day periods during summer stratification showed that some iron, phosphorus, and manganese from the hypolimnion could move upward, corresponding to diel shifts in the thermocline depth. Vertical transport of nutrients could thus occur long before complete lake mixing and could support summer/fall algal blooms. 相似文献
746.
随着我国钢铁工业的发展,焦化行业进入到一个大发展时期。大量焦炉煤气的产生,为焦炉煤气的合理开发利用提出了新的课题。焦炉煤气的有效利用可产生巨大的经济效益,并且可避免环境污染和二次能源的浪费。 相似文献
747.
铁促双电极电化学氧化处理丙烯腈生产废水的研究 总被引:1,自引:0,他引:1
采用钛基二氧化锡(Ti/SnO2)和金属铁构成组合阳极,并以石墨为阴极,研究了铁促双电极电化学氧化处理丙烯腈生产废水的效果及反应过程的相关规律.结果表明,与传统电化学氧化相比,采用组合阳极的双电极氧化过程获得了更高的有机物去除率并提高了电流效率.在相同电压下,当不外加H2O2时,COD去除率比采用传统电化学氧化提高11.0%~13.8%,电流效率提高8.0%~15.0%,而当外加H2O2浓度为2 200 mg·L-1,且电压为4.0V时,COD去除率达74.6%, TOC去除率达67.9%.随着外加H2O2浓度的增加,COD和TOC去除率增加.反应初始阶段H2O2浓度较高而Fe2+浓度很低,随反应时间延长H2O2浓度迅速下降而Fe2+浓度则逐渐升高.反应过程中H2O2与Fe2+浓度变化速率与电压密切相关. H2O2初始浓度一定的情况下,阳极通电时间对电流效率影响显著.双电极电化学氧化对丙烯腈生产废水色度也具有良好的去除作用.铁促双电极电化学氧化为有机废水的处理提供了一个新的选择. 相似文献
748.
为了考察提供氧分子以外的其它电子受体时微生物对石油污染的修复效果,在缺氧和厌氧条件下,采用批式试验方法研究了活性污泥在供给硝酸盐、亚硝酸盐、EDTA铁盐或硝酸盐+EDTA铁盐条件下对苯的降解效果,探讨了这些电子受体对缺氧和厌氧微生物降解苯的影响以及这些电子受体之间的相互作用.结果表明:①在供给硝酸盐时,苯的生物降解作用、硝酸盐还原和亚硝酸盐暂时累积现象同时出现;②当供给亚硝酸盐时,苯的生物降解作用不明显;③在供给EDTA铁盐为电子受体时,苯的生物降解作用明显,亚铁盐浓度逐渐升高;④当同时供给硝酸盐和EDTA铁盐时,苯的生物降解作用明显.并且没有出现明显的亚硝酸盐和亚铁盐累积现象.这表明,同时供给硝酸盐和EDTA铁盐时,伴随苯的降解首先硝酸盐和铁盐还原产生亚硝酸盐和亚铁盐,随后亚硝酸盐将亚铁盐氧化为铁盐.氧化产生的铁盐又继续作为苯降解的电子受体来降解苯;铁离子和亚铁离子之间构成的氧化还原循环,从而促进了苯的缺氧降解和硝酸盐还原. 相似文献
749.
Effect of microbial mediated iron plaque reduction on arsenic mobility
in paddy soil 总被引:4,自引:0,他引:4
The potential of microbial mediated iron plaque reduction, and associated arsenic (As) mobility were examined by iron reducing
bacteria enriched from As contaminated paddy soil. To our knowledge, this is the first time to report the impact of microbial iron plaque
reduction on As mobility. Iron reduction occurred during the inoculation of iron reducing enrichment culture in the treatments with
iron plaque and ferrihydrite as the electron acceptors, respectively. The Fe(II) concentration with the treatment of anthraquinone-2,
6-disulfonic acid (AQDS) and iron reducing bacteria increased much faster than the control. Arsenic released from iron plaque with
the iron reduction, and a significant correlation between Fe(II) and total As in culture was observed. However, compared with control,
the increasing rate of As was inhibited by iron reducing bacteria especially in the presence of AQDS. In addition, the concentrations
of As(III) and As(V) in abiotic treatments were higher than those in the biotic treatments at day 30. These results indicated that
both microbial and chemical reductions of iron plaque caused As release from iron plaque to aqueous phase, however, microbial iron
reduction induced the formation of more crystalline iron minerals, leading to As sequestration. In addition, the presence of AQDS
in solution can accelerate the iron reduction, the As release from iron plaque and subsequently the As retention in the crystalline iron
mineral. Thus, our results suggested that it is possible to remediate As contaminated soils by utilizing iron reducing bacteria and AQDS. 相似文献
750.