排序方式: 共有38条查询结果,搜索用时 15 毫秒
1.
Youssouf Boundou Sylla Masao Kuroda Masayuki Yamada Naoko Matsumoto 《Waste management & research》2006,24(5):456-464
Pilot-scale composting was carried out with cow manure to evaluate the performances of two passive aeration systems: a conventional passive aeration system equipped with horizontal pipes and an unusual passive aeration method based on air delivery by means of vertical pipes. The effects of both types of passive aeration apparatus were investigated in order to determine the degree of composting rate by continuously monitoring temperature, moisture content, organic matter, electrical conductivity, pH and C/N ratio in the piles. Temperatures in the range of thermophily (55-65 degrees C) were reached in all runs within 1-2 days then lasting for about 1 week, a span long enough for pathogen abatement. Results suggest that passive aeration carried out by vertical pipes is more effective for air delivery into compost piles than conventional passive aeration of air adduction with horizontal pipes. The variation in the number of vertical pipes was revealed to be an important parameter for the control of composting rate and temperature. Composting rates estimated from the heat balance equation were substantially in agreement with those computed through the conversion ratio of total organic matter decrement. The conversion ratios and composting rates obtained in this study using passive aeration with vertical pipes were well aligned with those found using forced air delivery systems. 相似文献
2.
Biodegradation of Polycaprolactone Powders Proposed as Reference Test Materials for International Standard of Biodegradation Evaluation Method 总被引:1,自引:0,他引:1
Masahiro Funabashi Fumi Ninomiya Masao Kunioka 《Journal of Polymers and the Environment》2007,15(1):7-17
Polycaprolactone (PCL) powders were prepared from PCL pellets using a rotation mechanical mixer. PCL powders were separated
by sieves with 60 and 120 meshes into four classes; 0–125 μm, 125–250 μm, 0–250 μm and 250–500 μm. Biodegradation tests of
PCL powders and cellulose powders in an aqueous solution at 25°C were performed using the coulometer according to ISO 14851.
Biodegradation tests of PCL powders and cellulose powders in controlled compost at 58°C were performed by the Mitsui Chemical
Analysis and Consulting Service, Inc. according to ISO 14855-1 and by using the Microbial Oxidative Degradation Analyzer (MODA)
instrument according to ISO/DIS 14855-2. PCL powders were faster biodegraded than cellulose powders. The reproducibility of
biodegradation of PCL powders is excellent. Differences in the biodegradation of PCL powders with different class were not
observed by the ISO 14851 and ISO/DIS 14855-2. An enzymatic degradation test of PCL powders with different class was studied
using an enzyme of Amano Lipase PS. PCL with smaller particle size was faster degraded by the enzyme. PCL powders with regulated sizes from 125 μm to 250 μm
are proposed as a reference material for the biodegradation test. 相似文献
3.
在前文的基础上,进一步研究了更常用的在限制最高和同时限制平均与最高出水有机物浓度两种排放标准的约束条件下,使其运行费用最省的最优周期控制问题.计算结果都表明,最优控制变量QW和DO的变化规律都尽可能使其满足约束条件和节省运行费用,但是,当进水负荷变化幅度非常大时,任何控制也难于使出水水质达标,而运行费用还会大幅度增大.相对而言,同时限制平均与最高出水BOD浓度是更合理的排放标准,它既有利于污水处理厂的运行管理又能有效地保护受纳水体.初始状态S(0)对最优控制的影响不大.而X(0)的影响较大,在本研究中,X(0)的最优值在2400-2600mg/L范围内. 相似文献
4.
Environmental Kuznets Curve: the case of Bangladesh for waste emission and suspended particulate matter 总被引:1,自引:0,他引:1
Md Danesh Miah Md Farhad Hossain Masum Masao Koike Shalina Akther Nur Muhammed 《The Environmentalist》2011,31(1):59-66
Economists have shown the empirical relationships between the economic growth of a nation and its environmental quality using
the hypothesis of the Environmental Kuznets Curve (EKC). To understand the EKC phenomena, a study of the literature was undertaken.
As waste, waste emission, and suspended particulate matter (SPM) are the active agents of environmental degradation, the study
focused on those agents for EKC consideration. Through understanding the different EKC trajectories, an attempt was made to
relate the economic development of Bangladesh to the EKC. It is shown that the EKCs for waste, emissions from waste, and SPM
follow the conventional EKC trajectory with a turning point related to higher income per capita in most cases. The type of
economic policy that Bangladesh should follow to deal with the pollutants and their sources is also shown. The study recommends
creating a tunnel in the EKC to lower the turning point in Bangladesh. The study is likely to help stimulate policy development
in Bangladesh. 相似文献
5.
Masahiro Funabashi Fumi Ninomiya Edgar Dulay Flores Masao Kunioka 《Journal of Polymers and the Environment》2010,18(2):85-93
The evaluation method of biomass carbon ratio of polymer composite samples including organic and inorganic carbons individually
was investigated. Biodegradable plastics and biobased plastics can have their mechanical properties improved by combining
with inorganic fillers. Polymer composites consisting of biodegradable plastics and carbonate were prepared by two different
methods. Poly(lactic acid) (PLA) composite was prepared by synthesis from l-lactide with catalyst and calcium carbonate (CaCO3) powders from lime. Poly(butylene succinate) (PBS) composite was prepared by hot-pressing the mixture of PBS powder and CaCO3 powders from oyster shells. The mechanical properties of composite samples were investigated by a tensile test and a compression
test using an Instron type mechanical tester. Tensile test with a dumbbell shape specimen was performed for PBS composite
samples and compression test with a column shape specimen for PLA composite samples. Strength, elastic modulus and fracture
strain were obtained from the above tests. Biomass carbon ratio is regulated in the American Standards for Testing and Materials
(ASTM). In ASTM standards on biomass carbon ratio, it is required that carbon atoms from carbonates, such as CaCO3, are omitted. Biomass carbon ratio was evaluated by ratio of 14C to 12C in the samples using Accelerator Mass Spectrometry (AMS). The effect of pretreatment, such as oxidation temperature and
reaction by acid, on results of biomass carbon ratio was investigated. Mechanical properties decrease with increasing CaCO3 content. The possibility of an evaluation method of biomass carbon ratio of materials including organic and inorganic carbons
was shown. 相似文献
6.
Effect of limited aeration on the anaerobic treatment of evaporator condensate from a sulfite pulp mill 总被引:2,自引:0,他引:2
Serious inhibition was found in the regular up-flow anaerobic sludge blanket (UASB) reactor in treating the evaporator condensate from a sulfite pulp mill, which contained high strength sulfur compounds. After applying the direct limited aeration in the UASB, the inhibition was alleviated gradually and the activity of the microorganisms was recovered. The COD removal rate increased from 40% to 80% at the organic loading rate of 8kgCODm(-3)d(-1) and a hydraulic retention time of 12h. Limited aeration caused no oxygen inhibition to the anaerobic microorganisms but instigated sulfide oxidization and H(2)S removal, which was beneficial to the methanogens. The experiment confirmed the feasibility of applying limited aeration in the anaerobic reactor to alleviate the sulfide inhibition. It also proved that the anaerobic system was actually aerotolerant. SEM observation showed that the predominant microorganisms partly changed from rod-shaped methanogens to cocci after the UASB reactor was aerated. 相似文献
7.
硫酸盐木浆厂排出的蒸发冷凝水具有高温、高浓度、营养物质含量低等特点,并含有一定浓度的挥发性恶臭硫化合物.本研究采用空气吹脱-UASB流程处理此类废水.结果表明,70%~80%的挥发性有机硫化物能够在气提过程中被去除.除硫后的蒸发冷凝水在UASB反应器中能够得到有效处理,当COD容积负荷达到30 kg·(m3.d)-1时,COD去除率仍能保持在95%左右.另一方面,试验开始时接种的颗粒污泥在反应器中破碎并逐渐被新形成的颗粒污泥代替,扫描电镜观察显示,新形成的颗粒污泥具有与接种污泥不同的微生物相. 相似文献
8.
高硫酸盐难降解废水高温厌氧处理中限量曝气的应用及影响 总被引:3,自引:0,他引:3
由于硫酸盐还原的影响,普通高温UASB反应器处理亚硫酸盐纸浆厂排出的高硫酸盐难降解废水过程中甲烷菌活性受到了严重抑制.考虑到空气对硫化氢的吹脱和对硫化物的氧化作用可能减轻硫化物对甲烷菌的抑制,本研究在厌氧反应器中引入限量曝气措施.试验结果表明,反应器的运行稳定性和处理能力均得到大幅提高.在有机负荷提高到原来2倍的情况下,曝气后COD去除率仍有提高,从40%~50%提高到60%~70%.试验证明部分甲烷菌可以耐氧,而某些种类的水解酸化细菌则对不完全厌氧环境比较敏感. 相似文献
9.
在前文的基础上,进一步研究了更常用的在限制最高和同时限制平均与最高出水有机物浓度两种排放标准的约束条件下,使其运行费用最省的最优周期控制问题.计算结果都表明,最优控制变量QW和DO的变化规律都尽可能使其满足约束条件和节省运行费用,但是,当进水负荷变化幅度非常大时,任何控制也难于使出水水质达标,而运行费用还会大幅度增大.相对而言,同时限制平均与最高出水BOD浓度是更合理的排放标准,它既有利于污水处理厂的运行管理又能有效地保护受纳水体.初始状态S(0)对最优控制的影响不大.而X(0)的影响较大,在本研究中,X(0)的最优值在2400—2600mg/L范围内. 相似文献
10.