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971.
Sonodegradation of bromobenzene, bromophenolate ion, and 2,4,5-trichlorobiphenyl was studied in the presence of various types of solid particles suspended in water. Three particle diameters (10 nm, 15 microm, and 35 microm) and two particle types (silica particles and organic resin) were investigated over a range of particle concentrations (0.05-10 g l(-1)). The sonochemical decomposition rate constant for bromobenzene (k = 0.044 +/- 7.50 x 10(-4) min(-1) at 20 kHz) was not significantly impacted by very fine silica particles (10 nm). The presence of 15 microm silica decreased sonication rates slightly (<7%) even at a concentration of 10 g l(-1). Organic resin particles demonstrated a more significant impact, particularly at higher concentration and with very hydrophobic compounds. These findings are significant for the application of ultrasound to treatment streams containing solid particles. 相似文献
972.
研究了有机磷酸羟基亚乙基二膦酸(HEDP)对生活垃圾焚烧飞灰中重金属的稳定方法.通过对不同HEDP投加量处理后的飞灰试样作危险废物浸出毒性鉴别试验,分析HEDP最佳使用剂量,并评价了稳定化飞灰的长期稳定性.结果表明,HEDP最适使用剂量为0.03 Ml/g(以商品级HEDP与飞灰的体积质量比计),处理后飞灰与原状飞灰相比,Pb、Zn和Hg的浸出浓度分别降低了98.3%、99.5%和85.0%.HEDP对飞灰中重金属稳定效果排序为:Pb>Zn>Hg>Ni>Cu>Cd>CrHAs.重金属pH相关浸出测试(pH-dependent leaching tests)表明:经0.03mL/g HEDP稳定处理的飞灰,在0.3 mol/L HNO3和0.3 mol/L NaOH的浸取条件下,其重金属浸出浓度均低于国家危险废物鉴别标准,显示具有良好的长期稳定性. 相似文献
973.
矿化垃圾(稳定化垃圾)是一种良好的生物介质,可作为生物反应床的填料处理NOX废气。实验室研究表明,稳定化垃圾反应床可有效地处理NOX气体,其硝化能力(以N计)可达0.83g/(kg·d)(干重)。NOX去除率受停留时间的影响显著,NOX去除率随着停留时间的缩短而降低。当空床停留时间为1.5min时,NOX气体的平均去除率为76.7%;空床停留时间为15min时,NOX气体的平均去除率为91.0%。在NOX进气负荷低于110mmol/(m3·h)时,NOX消除能力随进气负荷的增加而线性增加。当进气流量一定时,NOX去除能力随着进气NOX浓度的增加而线性增加。 相似文献
974.
The effect of the photosensitizer riboflavin (0, 10, 50, 100 microM) on the fate of atrazine (10 mg/l) in a freshwater environment was studied. It was found that at 100 microM riboflavin significantly enhanced the degradation of atrazine and more than 80% of atrazine in a natural water environment was depleted in 72 h. The relative contribution of microbial assemblages and the freshwater matrix to the degradation of atrazine and the degradation kinetics of atrazine were compared under different experimental conditions. The products and pathways of atrazine transformation were studied with GC-MS and HPLC with a photodiode array detector. The results show that dealkylation and alkyl chain oxidation are involved in the degradation of atrazine. 相似文献
975.
976.
Jian Hua Chih-Wen Cheng Daw-Shang Hwang 《Journal of the Air & Waste Management Association (1995)》2019,69(2):131-144
This study proposes an easy-to-apply method, the Total Life Cycle Emission Model (TLCEM), to calculate the total emissions from shipping and help ship management groups assess the impact on emissions caused by their capital investment or operation decisions. Using TLCEM, we present the total emissions of air pollutants and greenhouse gases (GHGs) during the 25-yr life cycle of 10 post-Panamax containerships under slow steaming conditions. The life cycle consists of steel production, shipbuilding, crude oil extraction and transportation, fuel refining, bunkering, and ship operation. We calculate total emissions from containerships and compare the effect of emission reduction by using various fuels. The results can be used to differentiate the emissions from various processes and to assess the effectiveness of various reduction approaches. Critical pollutants and GHGs emitted from each process are calculated. If the containerships use heavy fuel oil (HFO), emissions of CO2 total 2.79 million tonnes (Mt), accounting for 95.37% of total emissions, followed by NOx and SOx emissions,which account for 2.25% and 1.30%, respectively.The most significant emissions are from the operation of the ship and originate from the main engine (ME).When fuel is switched to 100% natural gas (NG), SOx, PM10, and CO2 emissions show remarkable reductions of 98.60%, 99.06%, and 21.70%, respectively. Determining the emission factor of each process is critical for estimating the total emissions. The estimated emission factors were compared with the values adopted by the International Maritime Organization (IMO).The proposed TLCEM may contribute to more accurate estimates of total life cycle emissions from global shipping.
Implications: We propose a total life cycle emissions model for 10 post-Panamax container ships. Using heavy fuel oil, emissions of CO2 total 2.79 Mt, accounting for approximately 95% of emissions, followed by NOx and SOx emissions. Using 100% natural gas, SOx, PM10, and CO2 emissions reduce by 98.6%, 99.1%, and 21.7%, respectively. NOx emissions increase by 1.14% when running a dual fuel engine at low load in natural gas mode. 相似文献
977.
Comparison of the adsorption of lead,cadmium, copper,zinc and barium to freshwater surface coatings 总被引:9,自引:0,他引:9
Measurements were made regarding the adsorption of lead, cadmium, copper, zinc and barium to freshwater surface coatings (biofilms and associated minerals), which were collected in Nanhu Lake in Jilin Province, PR China, in order to investigate the variability of adsorption capacities of these heavy metals mentioned in the above surface coatings. The adsorption of lead and other heavy metals to the biofilms was observed to decrease in the following order: copper, lead, zinc, cadmium, and barium. Generally, the values of Gamma(max) (the maximum adsorption, micromol/m(2)) increased with the standard electrode potential of metal elements used and were recorded as 166.7, 40.0, 29.4, 10.8, and 1.8 for copper, lead, zinc, cadmium and barium, respectively. The values of 1/Gamma(max) increased linearly with the decrease in values of the standard electrode potential of metal elements with a significant correlation (n=5, p=0.01) and increased linearly with the increase in values of covalent radius of metal elements with a significant correlation (n=5, p=0.05). This indicates that standard electrode potential and covalent radius were two of the principal characteristics of metals employed, causing the variation of lead and other heavy metal adsorption to the surface coatings. 相似文献
978.
979.
980.