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1.
Upflow anaerobic sludge blanket (UASB) methane fermentation treatment of cow manure that was subjected to screw pressing, thermal treatment and subsequent solid-liquid separation was studied. Conducting batch scale tests at temperatures between 140 and 180 degrees C, the optimal temperature for sludge settling and the color suppression was found to be between 160-170 degrees C. UASB treatment was carried out with a supernatant obtained from the thermal treatment at the optimal conditions (170 degrees C for 30 minutes) and polymer-dosed solid-liquid separation. In the UASB treatment with a COD(Cr) loading of 11.7 kg/m3/d and water temperature of 32.2 degrees C, the COD(Cr) level dropped from 16,360 mg/L in raw water to 3,940 mg/L in treated water (COD(Cr), removal rate of 75.9%), and the methane production rate per COD(Cr) was 0.187 Nm3/kg. Using wastewater thermal-treated at the optimal conditions, also a methane fermentation treatment with a continuously stirred tank reactor (CSTR) was conducted (COD(Cr) in raw water: 38,000 mg/L, hydraulic retention time (HRT): 20 days, 35 degrees C). At the COD(Cr) loading of 1.9 kg/m3/d, the methane production rate per COD(Cr), was 0.153 Nm3/kg. This result shows that UASB treatment using thermal pre-treatment provides a COD(Cr), loading of four times or more and a methane production rate of 1.3 times higher than the CSTR treatment. 相似文献
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国家行为与产权:一个新制度经济学的分析框架 总被引:1,自引:0,他引:1
早期的产权理论侧重于微观层次的分析,较少考虑中观(利益集团)及宏观层次(国家)对产权结构形成的影响及不同层次产权的交互作用的机制。文章从新制度经济学关于国家的定义入手,通过对个体权力与国家、集体行动与国家以及法治化社会与国家的三个层次的分析,提出建立产权制度分析的国家模型,从而论证国家与产权制度变迁的关系。 相似文献
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The biochemical composition can be seen as a good indicator of both the biodegradability and the methane potential of a given waste. The work presented here is an attempt to elaborate a typology of wastes and to compare it to the anaerobic degradation characteristics. The first data indicate that there is a link between the ligno-cellulosic content of the waste and the biodegradability. When dealing with application to anaerobic digestion processes, having a tool to predict the ability of the waste to be degraded could be of the greatest interest for preventing failures, estimating biogas production, methane content, or for the management of co-digestion processes. 相似文献
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This paper focuses on the development of a theoretical scheme describing the transformation of primary incomes into end consumption and savings in the Russian economy. This scheme is basically a system of interrelated tables reflecting the distribution of primary incomes across the institutional sectors and their further reallocation and use. The scheme makes allowances for the specific features of the Russian economy and existing statistics. In terms of methodology, it is coordinated with the interindustry balance in current buyer prices and, from the theoretical standpoint, describes the connection between Quadrant II and Quadrant III of the balance. Therefore, the proposed system of tables is treated in the paper as Quadrant IV of the interindustry balance. The theoretical scheme is used by the authors as a necessary basis for constructing an empirical model of the relationship between value added and end product, which will be published in the next issue of this journal. 相似文献
6.
Steven N. S. Cheung 《Economic Affairs》1986,6(5):26-29
The speed with which communist China has embuaced markets has surprised Western analysis and observers, But Chinese economic progress will founder in corruption and inefficiency, argues Professor Steven Cheung of the university of Hong Kong, untess she insitutes a well-defined system of private property rights to safeguord investment and stimulate trade. 相似文献
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Four selected azo dyes (acid orange 6, acid orange 7, methyl orange and methyl red) were completely decolourised in the presence of anaerobic granular sludge, while only methyl red was degraded in aerobic conditions using a conventional activated sludge. Additional experiments with culture broth devoid of cells showed that anaerobic decolourisation of azo dyes was performed by extracellular reducing agents produced by anaerobic bacteria. This was further confirmed by abiotic experiments with sulphide and NADH. The presence of redox mediators such as riboflavin led to dramatic acceleration of the anaerobic biodecolourisation process. The azo dye reduction products were found to be sulphanilic acid and 4-aminoresorcinol for acid orange 6; sulphanilic acid and 1-amino-2-naphthol for acid orange 7; N,N-dimethyl-1,4-phenylenediamine and sulphanilic acid for methyl orange; and N,N-dimethyl-1,4-phenylenediamine and anthranilic acid for methyl red. Anaerobic toxicity assays showed that the azo dyes were more toxic than their breakdown products (aromatic amines), except 1-amino-2-naphthol. In the presence of activated sludge, only anthranilic acid was completely mineralised while sulphanilic acid was persistent. 4-aminoresorcinol, 1-amino-2-naphthol and N,N-dimethyl-1,4-phenylenediamine underwent autooxidation in aerobic conditions yielding coloured polymeric products. On the contrary, in the presence of granular methanogenic sludge, 4-aminoresorcinol, 1-amino-2-naphthol and anthranilic acid were quantitatively methanised, sulphanilic acid was partially (70%) mineralised while N,N-dimethyl-1,4-phenylenediamine was only demethylated producing 1,4-phenylenediamine as an end product. 相似文献
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