Zheng Huaili

Decision Model for Optimization of Coagulation/Flocculation Process for Wastewater Treatment

The dye wastewater is an important environmental problem. Coagulation-flocculation process is an available technology in treatment of this kind of wastewater. The aim of the present study was to develop a model for coagulation-flocculation process using ferric chloride as a flocculant and the model could provide an alternative to the experimental jar test for determining the operational variables for treatment of the row wastewater. Also, some parameters affecting the degradation degree such as coagulant dosage, wastewater initial pH, agitation speed and time, were examined. The results showed that the linear correlation coefficient (R) between the simulation values and the expected values was 0.94 after network training and 0.92 after testing. The simulation effect of RBF neural network is related to the maximum number of neurons of network and the spread of radial basis functions. When the maximum number of neurons of network is 28 and the spread of radial basis functions is 2.1, the ratio of test error to training error is l.36 and the simulation result is the best. The experiment was carried out based on better simulation results and the degradation degree could reach 93% when coagulant dosage, wastewater initial pH, agitation speed and rapid agitation time are 0.3ml/l, 7.6, 300rpm and 1 min respectively. In addition, the importance of the parameters on degradation degree was investigated by the model. The degradation degree was enhanced significantly as listed herein decreasing order of effectiveness: coagulant dosage > agitation speed > agitation time > wastewater initial pH.

Notice of Retraction Succession and integration, urban design in Tibet under the background of development: A study on the planning and construction of Bayi town in Tibet

Under the background of economic development and rapid process of urbanization, cities and towns in Tibet are also undergoing changes. For the development of cities in Tibet, it is both a chance and a challenge to integrating advanced technology in the process of cultural succession in urban design. In the research, a study on the current conditions in urban construction of Bayi town has been taken. It is put forward that in the process of urban renewal and construction, urban designers should keep conscious and responsible to design and construct a livable city both with traditional spirit and harmony forms.