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71.
以苏州市餐厨垃圾管理为例,从资源化处理、市场化运营模式与政府监管的角度出发,通过理论与实践相结合,对中国餐厨废弃物资源化利用的特点和现状进行分析,借鉴国内外先进工艺及管理经验,结合中国实施餐厨废弃物资源化利用和无害化处理地区的实施情况,指出并剖析在餐厨废弃物资源化不同处理模式中存在的问题,提出了加强餐厨废弃物管理的建议方案和对策.  相似文献   
72.
为了研究餐厨垃圾固态发酵过程中挥发性脂肪酸(VFAs)与产气的变化关系,采用中温(37.0±0.2)℃连续式发酵,在完全混合CSTR反应器中连续运行100 d,分析餐厨垃圾固态发酵过程的启动、运行、失衡、失衡后恢复及实现固态发酵全过程各参数的变化趋势,重点研究VFAs各成分与产气、pH等的关系.结果表明,餐厨垃圾固态发酵实验过程可划分为4个时期:适应期(0~13 d)、启动期(14~30 d)、抑制期(31~50d)、恢复及稳定期(51~100 d).不同时期的容积产气率、VFAs及各参数均表现出不同的阶段性变化.在餐厨垃圾固态发酵全过程中,pH保持在5~7之间,正丁酸比例一直处于较高水平;VFAs与pH和容积产气率在初期基本保持反比关系,最终在稳定期达到平衡,均稳定在一定范围内波动.在恢复及稳定阶段以NaOH稀碱液调节当日回流渗滤液的pH值,在第63 d时pH值上升至6.76,VFAs含量稳定在20~22 g·L~(-1)之间,产气量明显提高;在81 d时TS达到20%以上,系统容积产气量和生物降解率均保持相对稳定.  相似文献   
73.
农业综合开发投资不足的理性预期分析   总被引:3,自引:0,他引:3  
为解决农业综合开发投资不足的问题,根据理性预期理论研究了投资预期不足的制度原因。与农业资源开发的巨大资金需求、农业可持续发展需求、提高农业综合生产能力的要求及提高国际竞争力相比,农业综合开发投资明显不足,投资预期不高是农业综合开发投资不足的重要原因,投资预期不足的制度原因是收益低、风险高,农业公共财政制度缺位,分级财政投资体制所产生的贫困地区财政紧张、土地产权制度和农村社会保障制度及金融制度缺陷等。应从建立健全农业公共财政制度框架下的农业综合开发投资机制及开展土地产权等农业基础制度创新和改革金融制度等方面健全农业综合开发投资预期机制。  相似文献   
74.
矿物材料对餐厨垃圾厌氧消化的影响研究   总被引:16,自引:0,他引:16  
在试验的基础上研究了3种矿物材料膨润土、斜发沸石、粉煤灰对富含钠离子的餐厨垃圾厌氧消化过程的影响.结果表明,在发酵温度为35℃、底物固含量(TS)为10%、添加物用量为1%(质量分数,以消化底物计)时,膨润土、沸石粉、粉煤灰对含盐餐厨垃圾的厌氧发酵消化液中的钠离子具有良好的吸附性能,吸附率分别为13.75%、10.11%、7.99%.在未使用无机矿物的情况下,当钠离子浓度为3000~4000mg·L-1时,含盐餐厨垃圾的的厌氧消化过程受到Na 离子的明显抑制.从产气量分析,3种矿物材料均能明显促进餐厨垃圾的厌氧消化过程,与空白对照试组相比,膨润土、斜发沸石、粉煤灰分别使产气量提高了131%、82%和45%.三者对甲烷气产量的促进影响强弱顺序是,膨润土>斜发沸石>粉煤灰.初步讨论了这3种矿物材料提高餐厨垃圾厌氧消化甲烷产量的作用机理.  相似文献   
75.
This article discusses the system of classification of forest types used by the Pwo Karen in Thung Yai Naresuan Wildlife Sanctuary in western Thailand and the role of nontimber forest products (NTFPs), focusing on wild food plants, in Karen livelihoods. The article argues that the Pwo Karen have two methods of forest classification, closely related to their swidden farming practices. The first is used for forest land that has been, or can be, swiddened, and classifies forest types according to growth conditions. The second system is used for land that is not suitable for cultivation and looks at soil properties and slope. The article estimates the relative importance of each forest type in what concerns the collection of wild food plants. A total of 134 wild food plant species were recorded in December 2004. They account for some 80–90% of the amount of edible plants consumed by the Pwo Karen, and have a base value of Baht 11,505 per year, comparable to the cash incomes of many households. The article argues that the Pwo Karen reliance on NTFPs has influenced their land-use and forest management practices. However, by restricting the length of the fallow period, the Thai government has caused ecological changes that are challenging the ability of the Karen to remain subsistence oriented. By ignoring shifting cultivators’ dependence on such products, the involvement of governments in forest management, especially through restrictions imposed on swidden farming practices, is likely to have a considerable impact on the livelihood strategies of these communities.  相似文献   
76.
Food ecologies and economies are vital to the survival of communities, non-human species, and our planet. While environmental communication scholars have legitimated food as a topic of inquiry, the entangled ecological, cultural, economic, racial, colonial, and alimentary relations that sustain food systems demand greater attention. In this essay, we review literature within and beyond environmental communication, charting the landscape of critical food work in our field. We then illustrate how environmental justice commitments can invigorate interdisciplinary food systems-focused communication scholarship articulating issues of, and critical responses to, injustice and inequity across the food chain. We stake an agenda for food systems communication by mapping three orientations—food system reform, justice, and sovereignty—that can assist in our critical engagements with and interventions into the food system. Ultimately, we entreat environmental communication scholars to attend to the bends, textures, and confluences of these orientations so that we may deepen our future food-related inquiries.  相似文献   
77.
为提高乳品工业废水生物处理的去污脱氮能力,以新型螺旋状纤维填料作为载体,采用多级氧化槽内不同种类微生物形成的食物链系统(food chain reactor),详细考察了不同水力停留时间COD、TN、NH4-N、TP等的去除率及其去除机理,并对污泥减量化效果进行了初步探讨.结果表明,当进水COD为842~1 843  mg/L、TN为36.3~92.2  mg/L、NH4-N为30.1~52.1  mg/L,HRT=6 h时,系统COD的平均去除率达到93.3%;TN和NH+4-N的去除效果显著,其平均去除率分别达到73.3%和80.7%,出水COD、TN、NH+4-N平均值分别为79.4 mg/L、9.6  mg/L、6.1 mg/L,均低于《污水综合排放标准》(GB 8978-2002)的一级标准.该系统不仅具有较高的去污脱氮效果,而且产生的剩余污泥量极少,其污泥产率的平均值为7.7%.该系统运行费用低,操作管理方便,长期运行稳定,可应用于城市污水、中高浓度有机废水(如餐厅污水、食品工业废水)等的处理.  相似文献   
78.
UV-B辐射增强对褶皱臂尾轮虫摄食的影响   总被引:4,自引:4,他引:0  
冯蕾  韩洪蕾  唐学玺 《海洋环境科学》2007,26(3):229-231,240
运用生态毒理学方法,研究了UV-B辐射条件下褶皱臂尾轮虫(Brachinonus plicatilis)对6株海洋微藻:小球藻(Chlorella sp.、绿色巴夫藻(Pauloua uiridis)、扁藻(Tetraselmis chuii)、球等鞭金藻8701(Isochrysis galbana Park 8701)、牟氏角毛藻(Chaetoceros muelleri Lermumerman)和小新月菱形藻(Nitzschia clostertum)的摄食.结果表明:UV-B辐射增强对褶皱臂尾轮虫的摄食有显著的抑制作用.与对照组相比,褶皱臂尾轮虫对每一种饵料单胞藻的滤水率和摄食率都表现出,随UV-B辐射剂量的增大而显著减小(P<0.5).而且对每一种饵料单胞藻的滤水率和摄食率是不相同的,这说明褶皱臂尾轮虫对饵料单胞藻是有选择性的.  相似文献   
79.
Cyclops of zooplankton propagated excessively in eutrophic water body and could not be effectively inactivated by the conventional disinfections process like chlorination due to its stronger resistance to oxidation. In this study, an ecological project was put forward for the excess propagation control of Cyclops by stocking the filter-feeding fishes such as silver carp and bighead carp under the condition of no extraneous nutrient feeding. The results of experiments with different stocking biomass showed that the propagation of Cyclops could be controlled effectively, and the water quality was improved simultaneously by impacting on nutriment level and plankton community structure at proper stocking density of 30 g/m^3 of water. The growth of Cyclops may not be effectually controlled with lower biomass of fish (10 g), and the natural food chain relation may be destroyed for Cyclops dying out in water while the intense stocking of 120 g per cubic meter of water. In addition, the high predator pressure may accelerate supplemental rate of nutrients from bottom sediments to water body to add the content of total nitrogen and phosphorus in water.  相似文献   
80.
Bioaccumulation of heavy metals in fishes from Taihu Lake, China   总被引:9,自引:0,他引:9  
The Cr,Zn,Cu,Cd,Pb contents were determined in Cyprinus carpio Linnaeus,Carassius auratus Linnaeus,Hypophthalmichthys molitrix and Aristichthys nobilis,which were caught from Meiliang Bay,Taihu Lake,a large,shallow and eutrophic lake of China.The results showed that:(1)the Cr,Cu,Pb,Cd contents in the edible parts of the four fish species were much lower than Chinese Food Health Criterion(1994),but the Zn contents were higher than the Criterion;(2)Cd contents were the highest in the liver of fish,Pb contents were almost the same in all organs of fish,Cr contents mainly enriched in the skin and gonads,Zn contents were the highest in the gonad(♀),and Cu contents were the highest in the liver;(3)the total metal accumulation was the greatest in the liver and the lowest in the muscle.The total metal accumulation was the highest in C.auratus L.This investigation indicated that fish products in Taihu Lake were still safe for human consumption,but the amount consumed should be controlled under the Chinese Food Health Criterion to avoid excessive intake of Zn.  相似文献   
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