Hybrid Method of Coagulation-Flocculation and Adsorption-Filtration Processes for the Removal of Hexavalent Chromium from the Aqueous Systems

摘要

The rapid development of the agricultural industry has led to the excessive waste of agriculturalresources and the serious destruction of the ecological environment. Agriculture is the basis ofnational livelihood and economic development, and agricultural ecological efficiency is an importantindicator of a region’s agricultural productivity. Guizhou province of China is used as an example in thisstudy to analyse the environmental pollution caused by the agricultural development process,quantitatively determine the agricultural ecological efficiency of a region, and propose measures toimprove agricultural ecological efficiency. This study summarizes the development status of naturalresources, environmental pollution etc. of agro-ecosystem in Guizhou province, and establishes theagricultural ecological efficiency evaluation indicator system. The agricultural ecosystem panel data ofGuizhou province from 2005 to 2015 are also obtained. The data envelopment analysis-Malmquistmodel is used to calculate the agricultural ecological efficiency of Guizhou province from two levels,i.e., year and city, and the improvement measures for agricultural ecological efficiency are proposed.Results show that the agricultural ecological efficiency of Guizhou province is in the medium developmentlevel and increases by 7% on average. Technological progress is the most important factor of thegrowth of agricultural ecological efficiency. However, comprehensive technical efficiency decrease,and the decrease in scale efficiency are the main factors that cause the reduction in comprehensiveefficiency level. The total factor productivity of all the cities in Guizhou province is greater than 1;among the cities, Liupanshui City reaches the highest growth rate, i.e., 12%. The results of this studypossess a positive reference value for the adjustment of the agricultural ecosystem structure and theimprovement of the agricultural ecological environment level. The findings may also serve as a basisfor the enhancement of the comprehensive agricultural sustainable development and the alleviation ofthe serious destruction of the ecological environment caused by the rapid development of the agriculturalindustry.