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711.
垃圾填埋场渗滤液运移规律分析与模拟   总被引:4,自引:0,他引:4  
基于多孔介质流体力学、多相流以及土壤水动力学理论,利用理论分析和数值模拟相结合的方法,研究了垃圾填埋场中渗滤液运移过程的基本规律,并对填埋场底部可渗和不可渗2种情况下渗滤液的运移规律进行了模拟比对,研究成果可为填埋场渗滤液控制系统的设计和管理提供科学的理论依据和技术支持。  相似文献   
712.
以多孔硅酸钙滤料为吸附载体处理含磷的二沉池出水.通过静态吸附试验和动态吸附试验,研究了滤料粒径及投加量、初始pH、反应时间、温度以及滤料填充高度对除磷效果的影响.在静态吸附试验中,取初始磷质量浓度为4.98 mg/L的含磷废水100 mL,当多孔硅酸钙滤料粒径为4~14目,投加量为1.0g,吸附时间为2.5h,温度为25℃,溶液初始pH为7.0~9.0时,磷的去除率可达95%以上,出水磷满足《城镇污水处理厂污染物排放标准》(GB 18918-2002)的一级A标准(≤0.5 mg/L).动态吸附试验表明,在长期运行条件下,多孔硅酸钙滤料吸附床能持续有效地去除污水中的磷,综合考虑吸附率和运行费用,选择水力停留时间为30 min,滤料填充高度为60 cm为宜.  相似文献   
713.
锆负载型树脂用于含氟废水深度处理的研究   总被引:6,自引:0,他引:6  
本文研制了一种以火力发电厂废树脂为载体的锆负载型氟离子吸附剂 ,并在评价了该树脂对氟离子的吸附性能之后探讨了该树脂用于火力发电厂含氟废水深度处理的可能性。研究结果表明 ,锆的最佳负载的最佳浓度为0 .5mol/L ,该负载树脂的最佳吸附pH为 3.0— 4 .0 ,用填充柱进行的动态实验结果表明 ,pH =3时的吸附容量显著高于 pH=4时的值。利用该树脂对火力发电厂模拟含氟废水进行了双柱串联吸附工艺处理 ,当柱流量为 35mL/min(SV10 )、第二柱穿透时 ,第一柱的吸附容量为 10 2 2 8mg/L湿树脂 ;用 0 .1mol/L的NaOH溶液进行再生 ,柱流量选择为 35mL/min(SV10 )时 ,脱附率在 95 %以上。  相似文献   
714.
采用间歇式摇床试验,研究了葡萄糖共基质条件下Fe^0-厌氧微生物体系中Fe^0投加量、pH值、染料初始浓度对活性艳红X-3B模拟废水脱色率的影响,比较了Fe^0-厌氧微生物、纯厌氧微生物及纯Fe^0 3种体系中废水的脱色效果。结果表明:Fe^0-厌氧微生物体系中初始浓度(50~500mg/L)对活性艳红X-3B的脱色率影响不大;而Fe^0投加量、pH值存在一个最佳范围;当Fe^0投加量为260mg/L,pH值为6.0,污泥浓度为0.35gVSS/L,停留时间约为30h时,体系中活性艳红X-3B的脱色率可达90%左右,比相同试验条件下纯Fe^0、纯厌氧微生物体系达到此脱色率所需时间分别缩短了约1/2、7/10。在Fe^0-厌氧微生物体系中,由紫外可见分光光度分析可推测活性艳红X-3B的脱色机理主要是其偶氮键发生断裂,生成苯胺和萘类物质,而且苯胺和萘类物质能得到进一步降解。  相似文献   
715.
主要研究了DL1210型纳滤膜去除水中邻苯二甲酸二丁酯(DBP)、邻苯二甲酸二(2-乙基己基)酯(DEHP)、乐果和莠去津的影响因素,考察了温度、pH值、初始浓度、跨膜压力(TMP)和运行时间对膜通量和截留率的影响。结果表明,纳滤工艺是去除水中微量DBP、DEHP、乐果和莠去津的有效方法,初始pH值和温度的升高会导致纳滤膜对DBP、DEHP、乐果和莠去津的截留率的降低,膜对DBP和DEHP的截留率随初始浓度的升高而降低,TMP和运行时间不会对膜通量和目标污染物的截留率造成显著影响。当初始pH为5、初始浓度为5μg/L、温度为5℃、TMP为0.4 MPa时,纳滤工艺对DBP、DEHP、乐果和莠去津的截留率达到最佳,分别为91.8%、89.8%、98.02%和77.6%,出水中DBP、DEHP、乐果和莠去津浓度分别为0.41、0.49、0.099和1.12μg/L。  相似文献   
716.
The aim of this study was to investigate the pollution characteristics of typical veterinary antibiotics in manure and soil of livestock farms in Jiangsu province. This investigation employed solid-phase extraction (SPE) coupled with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). A total of 53 manure and 50 amended soil samples from 16 livestock farms in Jiangsu province were collected for analysis. In the manure samples, the highest detected frequencies and concentrations were those of tetracyclines (TCs, 54.1 ± 5775.6 μgkg?1), followed by fluoroquinolones (FQs, 8.4 ± 435.6 μgkg?1), sulphonamides (SAs, 3.2 ± 5.2 μgkg?1) and macrolides (MACs, 0.4 ± 110.5 μgkg?1). Statistical analysis was used to illuminate the pollution characteristics of 23 veterinary antibiotics for various animal types and different regions in Jiangsu province. The results showed that the pollution level in cow manure was relatively lower compared with pig and chicken manure due to the relative restriction of medication. Furthermore, contamination was serious in amended soil from chicken farms. The pollution level in manure among different regions was higher to the south and north compared with the centre of the region. The same outcome was found for soil. Antibiotic residues in organic fertilizer were also investigated in this study. We found that although the detected concentration was lower in organic fertilizer than in fresh manure, detection frequencies (10–90%) were high, especially for roxithromycin (90%) in MACs (30–90%). This finding suggests attention should be paid to the pollution levels in organic fertilizer. This study is the first extensive investigation of the occurrence and distribution of many kinds of typical veterinary antibiotics in manure and soil from livestock farms of Jiangsu province. This investigation systematically assesses veterinary antibiotics usage and related emissions in southeast China.  相似文献   
717.
污水快速渗滤土地处理研究进展   总被引:3,自引:0,他引:3  
针对RI系统的污染物去除机制、运行方式、系统恢复以及实践应用等方面的研究进展作一综述。RI技术的应用有着广阔的前景 ,必将促进我国环境保护与生态建设的发展  相似文献   
718.
Veterinary manure is an important pollution reservoir of antibiotics and antibiotic-resistant bacteria (ARB). However, little is known of the distribution of ARB in plant endophytic bacteria and the number/types of ARB in chicken manure. In this study, 454-pyrosequencing was used to investigate the distribution and composition of ARBs in chicken manure and fertilized vegetables. The prevalence of ARB in the samples of the chicken manure compost recovered from farms on which amoxicillin, kanamycin, gentamicin, and cephalexin were used was 20.91–65.9 % for ARBs and 8.24–20.63 % simultaneously resistant to two or more antibiotics (multiple antibiotic resistant bacteria (MARB)). Antibiotic-resistant endophytic bacteria were widely detected in celery, pakchoi, and cucumber with the highest rate of resistance to cephalexin. The pyrosequencing indicated that the chicken manure dominantly harbored Firmicutes, Bacteroidetes, Synergistetes, and Proteobacteria and that Bacteroidetes was significantly enhanced in farms utilizing antibiotics. In the total cultivable colonies, 62.58–89.43 % ARBs and 95.29 % MARB were clustered in Bacteroidetes with the dominant species (Myroides ordoratimimus and Spningobacterium spp., respectively) related to human clinical opportunistic pathogens.  相似文献   
719.
Surface sediment samples from 12 sites of the three selected rivers in Daliaohe River watershed (Hunhe River, Taizihe River and Daliaohe River) were analyzed with the objective of establishing sources and hazard of the organochlorinae pesticides (OCPs) and polychlorinated biphenyl (PCBs) in surface sediments. The total concentrations of OCPs varied from 3.06 to 23.24 ng g−1. ∑HCH (α-HCH, β-HCH, δ-HCH, γ-HCH), ∑DDT (p, p′-DDE, p, p′-DDD, o, p′-DDT, p, p′-DDT) and ∑Cyclodiene (Heptachlor, Aldrin, Heptachlor epoxide, Dieldrin, Endrin) ranged from 1.86 to 21.48, 0.5 to 2.81 and 0.56 to 1.53 ng g−1, respectively. Results of OCPs also illustrate that the most dominant pollutants among the OCPs was ∑HCH, and γ-HCH was the most dominant isomer in HCH, which was evidence of recent input of lindane. It possibly came from the runoff of polluted soils and long-scale transportation. Total PCB concentrations ranged between 1.88 and 16.88 ng g−1. The peak concentrations of PCBs were found in sediments from station T5 and D3, which are in the vicinity of industrial areas and ferry, respectively. These data show a moderate level of OCPs and PCBs contaminations compared to that in other countries.  相似文献   
720.
几丁质酶是昆虫几丁质降解过程中的重要酶类,在昆虫整个生长发育过程中发挥着重要作用.为筛选及挖掘与防治有害医学昆虫相关的分子靶标,根据家蝇几丁质酶2(Musca domestica chitinase 2,MdCht2)基因序列设计并合成双链RNA(double-stranded RNA,dsRNA),采用微量注射法向家...  相似文献   
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