共查询到20条相似文献,搜索用时 15 毫秒
1.
The ability of near‐surface disposal facility cover designs to meet percolation performance criteria is influenced by degradation occurring over long periods of time. This study was conducted to determine the effect of degradation on percolation based on probabilistic distributions derived from historical climate data. Water‐balance predictions were evaluated using the HELP model, employing several variations of degradation in a traditional Resource Conservation and Recovery Act disposal facility cover design over a 100‐year simulation period. Analysis results were evaluated relative to two different selected thresholds for annual percolation (1 mm and 3 mm). Approximately 20 percent of the results did not exceed both the 1‐mm and 3‐mm thresholds, while 10 percent of the realizations exceeded the 1‐mm threshold but not the 3‐mm threshold, with remaining cases exceeding the 3‐mm threshold. These results demonstrate the importance of considering degradation in designing near‐surface disposal facilities, especially given the very long performance periods desired by different regulators. © 2013 Wiley Periodicals, Inc. 相似文献
2.
将处理柠檬酸废水的内循环厌氧反应器的出水以不同比例回流至水解酸化池,研究了厌氧出水回流对水解酸化过程及厌氧处理过程的影响。实验结果表明:厌氧出水参与水解酸化能明显提高水解酸化池的出水pH及废水的预酸化度,厌氧出水添加比(V(厌氧出水)∶V(废水))为1∶4及以上时,可使水解酸化池的出水pH稳定在4.5以上,同时达到10.0%以上的预酸化度,且对NH3-N的去除能力明显增强;随水解酸化时间的延长,水解酸化池的出水pH先减小后增大,而预酸化度则呈上升趋势;水解酸化3.0 h时,厌氧出水COD降至1 200 mg/L以下。厌氧出水参与水解酸化能增强厌氧反应器中微生物对挥发性脂肪酸的利用率,提高厌氧反应器出水的pH,降低出水COD及其波动幅度,增强厌氧系统的稳定性及自我修复能力。 相似文献
3.
4.
Performance and Environmental Impact of Biodegradable Films in Agriculture: A Field Study on Protected Cultivation 总被引:5,自引:1,他引:4
Anu Kapanen Evelia Schettini Giuliano Vox Merja Itävaara 《Journal of Polymers and the Environment》2008,16(2):109-122
The performance, the degradability in soil and the environmental impact of biodegradable starch-based soil mulching and low
tunnel films were assessed by means of field and laboratory tests. The lifetime of the biodegradable mulches was 9 months
and of the biodegradable low-tunnel films 6 months. The radiometric properties of the biodegradable films influenced positively
the microclimate: air temperature under the biodegradable low tunnel films was 2 °C higher than under the low density polyethylene
films, resulting in an up to 20% higher yield of strawberries. At the end of the cultivation period, the biodegradable mulches
were broken up and buried in the field soil together with the plant residues. One year after burial, less than 4% of the initial
weight of the biodegradable film was found in the soil. According to ecotoxicity tests, the kinetic luminescent bacteria test
with Vibrio fischeri and the Enchytraeus albidus ISO/CD 16387 reproduction potential, there was no evidence of ecotoxicity in the soil during the biodegradation process.
Furthermore, there was no change in the diversity of ammonia-oxidizing bacteria in the soil determined on the basis of the
appearance of amoA gene diversity in denaturing gradient gel electrophoresis. 相似文献
5.
采用EGSB—SBR工艺处理实际果汁废水(COD 2 608~6 500 mg/L,p H 5.0~7.0)。在EGSB反应器成功启动及驯化完成的情况下,连续运行49 d。实验结果表明:第25天起,控制EGSB回流比为3.00∶1,EGSB反应器可在无须添加Na HCO3的条件下稳定运行,从而降低了废水处理成本;第25天起,平均进水COD,BOD5,SS分别为5 968,2 130,1 020 mg/L,平均出水COD,BOD5,SS分别降至131,11,50 mg/L,平均COD,BOD5,SS去除率分别为98%,99%,95%;组合工艺对该实际果汁废水具有良好的处理效果。 相似文献
6.
撞击流反应器萃取电镀废水中Cr6+的实验研究 总被引:1,自引:0,他引:1
以磷酸三丁酯(TBP)为萃取剂,用撞击流反应器对模拟含铬电镀废水中的Cr^6+进行了萃取脱除实验研究。与相同条件下的传统单级化学萃取相比,撞击流反应器利用两喷嘴的射流作用在两流体相对撞击时获得高效传质区域,能有效强化液液萃取的相际传质过程,其单级萃取率最多可提高20.11%。当萃取剂中TBP的体积分数为10%、相比(有机相与水相的体积比)为1:2、萃取时间为1min、H^+的浓度为1.0mol/L时,通过实验得出适宜的操作条件为:喷嘴间距离为喷嘴直径的3.4倍,搅拌转速600r/min,萃取温度30—40℃,在此条件下Cr^6+的萃取率为31.5%。 相似文献
7.
The aim of this study was to justify the method to determine biochemical methane potential (BMP) of biosludges and investigate the effect of ozonation and sonication on the biosludge from textile mill effluent to its biodegradability and toxicity. This study revealed that the exented anaerobic toxicity assay at a chemical oxygen demand (COD) concentration in the assay of about 1,500 mg/L was the appropiate technique to determine BMP of the biosludge. Moreover, it was found that the biodegradability of biosludge was satisfactorily increased by both of ozonation and sonication. The use of ozone dose of 0.005 g O3/g COD and 0.01 O3/g COD increased the biodegradability from 62% to 69% and 76%, respectively. While for sonication on frequency 51 kHz ±6%, 120 W for 30 and 60 min increased the biodegradability from 62% to 68% and 73%, respectively. 相似文献
8.
9.
10.
11.
12.
《Waste management & research》1984,2(4):339-345
Various sludge composting methods used in France are described and evaluated in terms of the daily capacity and other factors. Simple windrows with mechanical turning, aerated static piles, BAV aerated reactors and Siloda mechanically turned and aerated chambers are described. Capacities range from 0.5 to more than 50 dry tons of sludge per day. 相似文献
13.
采用污泥、石灰、氧化镁和水泥等药剂稳定固化强酸性硫化砷废渣(简称砷渣)。以浸出液中砷的质量浓度为考核指标,采用正交实验考察了稳定化药剂加入量对废渣浸出毒性的影响。实验结果表明:污泥加入量是影响废渣浸出毒性的最主要因素;在m(污泥):m(砷渣)=2.0、m(石灰):m(砷渣)=1.0、m(氧化镁):m(砷渣)=0.10、m(水泥):m(砷渣)=0.3的最佳实验条件下,砷的浸出质量浓度由1780.00 mg/L降至1.37 mg/L,低于GB 18598—2001《危险废物填埋污染控制标准》中砷浸出质量浓度为2.5 mg/L的填埋限值;处理后废渣中其他金属的浸出质量浓度也低于标准限值。 相似文献
14.
15.
采用Fenton试剂氧化—活性炭吸附工艺处理炼油厂循环水排污水,考察了各种因素对处理效果的影响.通过实验得出最佳处理条件为:室温,H2O2加入量600 mg/L,m(H2O2):m(Fe2+)=4,水样pH5.0~5.5,Fenton试剂氧化反应时间1h,活性炭选择8~30目的无烟煤破碎炭,水样在吸附柱的停留时间约为30 min.当循环水排污水COD低于150 mg/L时,经该联合工艺处理后出水COD低于50 mg/L,达到GB8978-1996《污水综合排放标准》中的二级排放标准. 相似文献
16.
采用高效混凝沉降—超滤工艺对循环冷却水排水进行预处理后,考察了NF-A、NF-B和NF-C型纳滤膜的运行情况和处理效果.实验结果表明:NF-A膜对COD、Ca2+和Mg2+的去除率均较低,对Clˉ没有去除效果;NF-C膜对COD、Ca2+、Mg2+和SO42-的去除率均较高,对Clˉ去除率为83.1%,但运行压力较高;NF-B膜运行压力居中,对COD去除率为95.9%,对Ca2+去除率为98.3%,对Mg2+去除率为93.4%,对SO42-去除率为98.2%,对Clˉ去除率为67.4%,处理后出水达到循环回用的要求. 相似文献
17.
18.
In order to improve and optimize phytoremediation of PAH we propose to focus on the rhizospheric processes controlling PAH
degradation. In this paper the effect of root exudates on PAH availability is studied. Model organic compounds (malic acid,
malonic acid and EDTA) representing root exudates have been tested for their effect on phenanthrene sorption on a reference
non polluted agricultural soil material. Phenanthrene adsorption isotherms were first obtained with batch experiments. Results
showed linear isotherms and phenanthrene sorption was enhanced as the concentration of organic compounds in the solution increased.
Column leaching experiments were then used to simulate the effect of root exudation following the soil pollution. Inlet solutions
containing the different organic acids used were flowed through the column containing the artificially polluted soil material.
Elution curves showed that the phenanthrene was less easily eluted when the solution injected contained the organic acids.
However, magnitude of the phenomena did not fit with adsorption constants obtained in batch experiments. Phenanthrene desorption
appeared limited by sequestration but organic acids seemed able to partially disturb the soil material structure to limit
the sequestration effect. 相似文献
19.
Idris Azni Saed Katayon Muniandy Ratnasamy Megat Mohd Noor Megat Johari 《Journal of Material Cycles and Waste Management》2005,7(1):33-37
This article reports the operational results of the effective utilization of hospital waste molten slag produced using a high-temperature melting system, and being operated at a hospital in Selangor, Malaysia. The hospital waste is incinerated and subsequently melted at 1200°C. Scanning election microscope (SEM)/EDX results showed that the slag produced after melting contained amounts of SiO2, CaO, and Al2O3 in excess of 53%, 9%, and 16%, respectively. The results from a leaching analysis on the slag produced proved that the melting process had successfully stabilized the heavy metals. The use of this slag as an alternative material to replace conventional aggregates for road construction was studied. The results from aggregate and asphalt mix tests showed that the slag produced fulfills all the requirements of an alternative aggregate. The average asphalt content, or the optimum asphalt content to be mixed with hospital waste molten slag, was found to be about 5.53%. 相似文献
20.
Xinying Li Quanyuan Chen Yasu Zhou Mark Tyrer Yang Yu 《Waste management (New York, N.Y.)》2014,34(12):2494-2504
The objective of this work was to investigate the feasibility and effectiveness of silica fume on stabilizing heavy metals in municipal solid waste incineration (MSWI) fly ash. In addition to compressive strength measurements, hydrated pastes were characterized by X-ray diffraction (XRD), thermal-analyses (DTA/TG), and MAS NMR (27Al and 29Si) techniques. It was found that silica fume additions could effectively reduce the leaching of toxic heavy metals. At the addition of 20% silica fume, leaching concentrations for Cu, Pb and Zn of the hydrated paste cured for 7 days decreased from 0.32 mg/L to 0.05 mg/L, 40.99 mg/L to 4.40 mg/L, and 6.96 mg/L to 0.21 mg/L compared with the MSWI fly ash. After curing for 135 days, Cd and Pb in the leachates were not detected, while Cu and Zn concentrations decreased to 0.02 mg/L and 0.03 mg/L. The speciation of Pb and Cd by the modified version of the European Community Bureau of Reference (BCR) extractions showed that these metals converted into more stable state in hydrated pastes of MSWI fly ash in the presence of silica fume. Although exchangeable and weak-acid soluble fractions of Cu and Zn increased with hydration time, silica fume addition of 10% can satisfy the requirement of detoxification for heavy metals investigated in terms of the identification standard of hazardous waste of China. 相似文献