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982.
在温度为70~80℃、单体质量浓度为30%~35%、羧甲基纤维素∶丙烯酸(质量比)为10∶2.5、反应时间为3.5~4 h条件下对CMC进行改性,接枝率可达68%以上。以改性前后的CMC为吸附剂,对模拟酸法地浸含铀废水进行了对比吸附实验研究。结果表明:改性CMC对铀吸附效果最佳的实验条件为:改性CMC质量浓度为0.10 g/L,温度为25℃,pH为5.0,吸附时间100 min,此时铀去除率达到了97.1%,比CMC改性后对铀的吸附率平均提高了近21%。影响吸附效果程度由强到弱的顺序为:改性CMC投加量、pH、吸附时间、温度。 相似文献
983.
通过试验研究,探索了焦化废水生物脱氮半生产性启动条件,指出了顺利启动的关键技术是适宜的接种污泥及必须提供的环境条件。 相似文献
984.
“四沿”化工企业污水处理系统安全事故状态下负荷缓冲及安全环境(SE)联锁探讨 总被引:2,自引:1,他引:1
在对"四沿"(沿江、沿河、沿湖、沿海)化工行业污水处理方法及流程特点总结的基础上,归纳出应对水力和污染物冲击负荷的缓冲方法。为克服缓冲控制能力有限的缺点,提出一种新方法——SE(安全和环境)联锁,以期达到完善管理、提高控制效果的目的,并详细阐述了该方法在管理及技术层面的实施途径。 相似文献
985.
Impact of Bioaugmentation with a Consortium of Bacteria on the Remediation of Wastewater-Containing Hydrocarbons (5 pp) 总被引:1,自引:0,他引:1
Domde P Kapley A Purohit HJ 《Environmental science and pollution research international》2007,14(1):7-11
Goals, Scope and Background It has been observed that hydrocarbon treated wastewaters still contain high COD and a number of intermediates. This suggests
that the required catabolic gene pool for further degradation might be absent in the system or, that its titer value is not
significant enough. By providing the desired catabolic potential, the overall efficiency of the treatment system can be improved.
This study aims to demonstrate this concept by bioaugmentation of a lab-scale reactor treating refinery wastewater with a
consortium having the capacity to complement the alkB genotype to the available microbial population.
Methods Two reactors were set up using activated biomass collected from a refinery treatment plant and operated at a continuous mode
for a period of 8 weeks. The feed to both reactors was kept constant. Crude oil was spiked regularly. One reactor was bioaugmented
with a consortium previously described for crude oil spill remediation. The efficiency of the bioaugmented reactor was demonstrated
by reduced COD. The changes in the microbial population over a period of time were analyzed by RAPD. Catabolic activity of
the biomass in both reactors was monitored by PCR. The presence of the catabolic loci was confirmed by Southern Hybridization.
Results and Discussion 52.2% removal of COD was observed in the bioaugmented reactor while only 15.1% reduction of COD was observed in the reactor
without bioaugmentation. The change in microbial population can be seen from the 4th week, which also corresponds to improved
catabolic activity. The presence of the bedA locus was seen in all samples, which indicates the presence of aromatic degraders,
but the appearance of the alkB locus, from the 6th week onwards, which was observed only in the samples from the bioaugmented
reactor. The results suggest that the gene pool of the bioaugmented reactor has catabolic loci that can degrade accumulated
intermediates, thus improving the efficiency of the system.
Conclusions In this study, improvement of efficiency of bioremediation was demonstrated by addition of catabolic loci that are responsible
for degradation. Bioaugmentation was carried out in biomass that was collected from an ETP (effluent treatment plant) treating
hydrocarbon containing wastewater to study the strategies for improvement of the treatment system. Biostimulation, only marginally
improved the efficiency, when compared to bioaugmentation. The improved efficiency was demonstrated by COD removal. The presence
of the alkB locus suggests the importance of a catabolic gene pool that acts on accumulated intermediates. It is well documented
that straight chain aliphatics and intermediates of aromatic compounds after ring cleavage, accumulate in refinery wastewater
systems, thereby hindering further degradation of the wastewater. Supplementation of a catabolic gene pool that treats the
lower pathway compounds and alkanes will improve the overall efficiency. In this study, results suggest that the alkB locus
can also be used to monitor the degradative mode of the activated biomass.
Recommendations and Perspective . Pollution from petroleum and petroleum products around the globe are known to have grave consequences on the environment.
Bioremediation, using activated sludge, is one option for the treatment of such wastes. Effluent treatment plants are usually
unable to completely degrade the wastewater being treated in the biological unit (the aerator chambers). The efficiency of
degradation can be improved by biostimulation and bioaugmentation. This study demonstrates the improved efficiency of a treatment
system for wastewater containing hydrocarbons by bioaugmentation of a consortium that supports degradation. Further experiments
on a pilot scale are recommended to assess the use of bioaugmentation on a large scale. The use of molecular tools, like DNA
probes for alkB, to monitor the system also needs to be explored. 相似文献
986.
不同条件下高炉渣吸附水中无机磷的研究 总被引:2,自引:1,他引:1
高炉渣(BFS)是在冶炼生铁过程中产生的固体废弃物,开展高炉渣的资源化研究具有重要意义.为了对水淬高炉渣净化含磷污水的应用提供理论依据,采取等温吸附的实验方法,比较了不同水淬炉渣的吸附磷效果,研究了不同pH和不同温度下水淬炉渣吸附磷的特点,结果如下:利用Langmuir等温吸附方程炉渣吸附磷的过程进行拟合,其相关系数均能达到显著水平.炉渣的碱度越高,吸附磷的效果越好;炉渣对磷的吸附能力随溶液pH的增加而降低,且初始为酸性(pH=2、4)的溶液在吸附达到平衡后pH有所上升,而初始为碱性的溶液(pH=10、12)在吸附达到平衡后pH有所下降;炉渣对磷的吸附是一个自发放热过程. 相似文献
987.
利用MgSO4·7H2O和Na2HPO4·12H2O作为试验药剂,通过正交试验和单因素优化试验,对化学沉淀法处理甲胺生产废水中氨氮的工艺条件进行优化.结果表明,在pH=9.4、反应时间15 min、搅拌速度150 r/min、Mg:N(摩尔比值)=1.1、P:N(摩尔比值)=1.0时,化学沉淀法处理300 mL甲胺生产废水,氨氮去除率维持在92%以上,COD去除率可达37%以上.同时为验证工艺条件适应性和沉淀物(MgNH4PO4)作为农作物肥料使用的价值性,对最优条件下得到的沉淀物进行研究.与MgNH4PO4纯度为100%相比,沉淀物MgNH4PO4纯度达到86%以上.因此,化学沉淀法处理氨氮不仅具有良好的效果,而且得到的MgNH4PO4含有较高N、P,可以用作农作物肥料. 相似文献
988.
989.
Yu FC Chen CY Lin SC Lin YC Wu SY Cheung KW 《Environmental monitoring and assessment》2007,132(1-3):419-428
As the embodiment of human activities, the change of regional industrial structure is an essential driving factor of global
environmental change. Consequently, the research on the change of regional industrial structure and associated effects on
the environment is one of the key issues of researches on sustainable development, human–environment relationship, and regional
response to global environment change. However, compared to the flourish of researches on environmental impact assessment
of industrial departments, few studies have been conducted to assess the environmental impact of regional industrial structure.
In this study, based on a synthetic analysis of environmental disturbances of different industrial departments, the environmental
impact coefficient of industrial department associated with the index of environmental impact of industrial structure was
constructed, so as to make a quantitative assessment of environmental impact of the change of regional industrial structure.
And the results of the case study in Lijiang City, a rural region of China, have showed that there are two obvious changes
of industrial structure in the study area from 1992 to 2003, associated with a continuous decreasing of the index of environmental
impact of industrial structure, which indicated a positive environmental effects of the change of regional industrial structure. 相似文献
990.