Abstract: This paper, probing into the present situation of urban domestic garbage by analyzing its growing trend, compositional change and regional difference, reveals the problems existing in its disposal and management in China. Meanwhile, a questionnaire was conducted in five big cities around China for surveying urban residents' attitudes towards garbage disposal and management policies and measures. Results showed the output of urban domestic garbage in Chinese cities is ever increasing, and the recoverable materials and energy in garbage composition are also increasing. The population growth, economic development, and increase of residents' expenditure level are the main factors influencing the growing…output and changing composition of the garbage. Information acquired from the questionnaire showed that majority of the urban residents are in favor of the garbage reduction policies and managerial measures and are willing to collaborate with municipal government in battling against garbage.Based on the analysis and questionnaire, some polieymaking-oriented suggestions such as operating the garbage disposal from a social welfare service to a sector of profit-gaining enterprises, transferring the garbage management from passive end control to active source control, promoting the classified garbage collection in cities around China, and charging garbage fees for its cleanup and disposal, have also been put forward in the paper.
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Abstract: The sorption behavior was determined for a model polycyclic aromatic hydrocarbon (PAH), i.e., phenanthrene (PHN), from water to three humic acids (HAs) and three sediments in different reacting time. The chemical compositions of HA samples were measured using cross polarization magic angle spinning carbon-13 (CPMAS^{13} C) NMR along with elemental analysis. The dissolved humic substances dissociating from solid HAs and sediments were characterized by ^1 H NMR. The experiments indicated that the sorption modes and mechanisms of natural sorbents for PHN varied significantly between short (<7 d) and long contact time and the reaction time should be taken into consideration…in studying the overall sorption process. The sorption capacity (K'_1 ) and exponent (n) might be relative to the properties of dissolved humic materials in initial stage but the solid aromatic organic matter after long time reaction. According to the experiments performed in this investigation and the previous researches, a conceptive sorption model was established.
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