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431.
螺旋藻废水主要来源于采藻废水、报废培养基、池子冲洗水三部分,采藻废水占70%以上,废水中主要污染物为总磷、氨氮、BOD5、pH。据预测,当年产量达600吨干藻粉时,不到1年,程海的总磷将由现在的Ⅲ类标准值降为Ⅳ类,到2000年将降为Ⅴ类。因此必须改革采藻工蕊,统一规划集中治理,加强绿化,加强管理。  相似文献   
432.
调查了两个果园15~20年树龄的苹果树在连续用福美胂喷涂7~10年后树根、树皮、枝条、叶片、果实和土壤的砷含量,并和未使用福美胂的果树含量做了比较。结果表明,果实中有砷积累,但未超过食品卫生标准。使用福美胂的树皮、技条、叶片中砷含量比未使用福美胂的高儿倍~十几倍,树皮和短梢叶含量最高。枝条和叶片与树皮的砷含量有密切正相关。土壤表层虽有轻度积累,但不会对土壤生态环境有太大影响。  相似文献   
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435.
高填方路基诱发滑坡机理分析   总被引:1,自引:0,他引:1  
通过对上三高速公路K92滑坡工程地质条件、滑坡特征及滑坡稳定性的分析,采用不分离接触数值模型模拟边坡的变形破坏,初步揭示了松散覆盖土层上厚度较大的高填方路基是诱发滑坡的内在机理。该类型滑坡的产生是由于路基堆载使坡体产生垂直方向的压缩变形,也使坡体向坡脚方向产生一定的挤出变形,最后诱发了推动式滑坡。  相似文献   
436.
滇池水华蓝藻干粉制剂的生物脱毒实验   总被引:7,自引:0,他引:7  
滇池属长江流域的一个内陆湖泊,近年来水体富营养化日益严重,每年夏季都出现大面积的水华。由品种单一,主要为蓝藻门,其中微囊藻是优势种,产生的微囊藻毒素具有很强的毒性。本实验以富营养化湖湖滇池中的水华蓝藻作为主要原料,将其制成干粉后,利用双协菌株在28-32℃条件下对其进行固态发酵,培养基质初始水份为65%。发酵培养2d后,培养基质中微囊藻毒素含量明显降低,6d后,基质中微囊藻毒素含量未检出(最低浓度检测限1μg/mg)。同时对实验所获得时间序列进行动力学研究,结果表明利用双协菌降解微囊藻毒毒的反应为准一级动力学反应。  相似文献   
437.
通货膨胀的生态经济原因及其对策   总被引:1,自引:0,他引:1  
文章从我国通货膨胀的现实表现及其危害入手 ,分析了生态经济平衡的含义、基本要求及其失衡的原因和后果 ,并在此基础上提出了在生态经济大系统范围内治理通货膨胀的对策建议。  相似文献   
438.
Installing material recovery facilities (MRFs) in a solid waste management system could be a feasible alternative to achieve sustainable development goals in urban areas if current household and curbside recycling cannot prove successful in the long run. This paper addresses the optimal site selection and capacity planning for a MRF in conjunction with an optimal shipping strategy of solid waste streams in a multi-district urban region. Screening of material recovery and disposal capacity alternatives can be achieved in terms of economic feasibility, technology limitation, recycling potential, and site availability. The optimization objectives include economic impacts characterized by recycling income and cost components for waste management, while the constraint set consists of mass balance, capacity limitation, recycling limitation, scale economy, conditionality, and relevant screening constraints. A case study for the City of San Antonio, Texas (USA) presents a vivid example where scenario planning demonstrates the robustness and flexibility of this modeling analysis. It proves especially useful when determining MRF ownership structure. Each scenario experiences two case settings: (1) two MRF sites are proposed for selection and (2) a single MRF site is sought. Cost analysis confirms processing fees are not the driving force in the City's operation, but rather shipping cost. Sensitivity analysis solidifies the notion that significant public participation plays the most important role in minimizing solid waste management expenses.  相似文献   
439.
The impacts of the aeration and the agitation on the composting process of synthetic food wastes made of dog food were studied in a laboratory-scale reactor. Two major peaks of CO(2) evolution rate were observed. Each peak represented an independent stage of composting associated with the activities of thermophilic bacteria. CO(2) evolutions known to correlate well with microbial activities and reactor temperatures were fitted successfully to a modified Gompertz equation, which incorporated three biokinetic parameters, namely, CO(2) evolution potential, specific CO(2) evolution rate, and lag phase time. No parameters that describe the impact of operating variables are involved. The model is only valid for the specified experimental conditions and may look different with others. The effects of operating parameters such as aeration and agitation were studied statistically with multivariate regression technique. Contour plots were constructed using regression equations for the examination of the dependence of CO(2) evolution potentials on aeration and agitation. In the first stage, a maximum CO(2) evolution potential was found when the aeration rate and the agitation parameter were set at 1.75 l/kg solids-min and 0.35, respectively. In the second stage, a maximum existed when the aeration rate and the agitation parameter were set at 1.8 l/kg solids-min and 0.5, respectively. The methods presented here can also be applied for the optimization of large-scale composting facilities that are operated differently and take longer time.  相似文献   
440.
Both planning and design of municipal solid waste management systems require accurate prediction of solid waste generation. Yet achieving the anticipated prediction accuracy with regard to the generation trends facing many fast-growing regions is quite challenging. The lack of complete historical records of solid waste quantity and quality due to insufficient budget and unavailable management capacity has resulted in a situation that makes the long-term system planning and/or short-term expansion programs intangible. To effectively handle these problems based on limited data samples, a new analytical approach capable of addressing socioeconomic and environmental situations must be developed and applied for fulfilling the prediction analysis of solid waste generation with reasonable accuracy. This study presents a new approach--system dynamics modeling--for the prediction of solid waste generation in a fast-growing urban area based on a set of limited samples. To address the impact on sustainable development city wide, the practical implementation was assessed by a case study in the city of San Antonio, Texas (USA). This area is becoming one of the fastest-growing regions in North America due to the economic impact of the North American Free Trade Agreement (NAFTA). The analysis presents various trends of solid waste generation associated with five different solid waste generation models using a system dynamics simulation tool--Stella. Research findings clearly indicate that such a new forecasting approach may cover a variety of possible causative models and track inevitable uncertainties down when traditional statistical least-squares regression methods are unable to handle such issues.  相似文献   
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