Large plant area and high cost of the wastewater treating plant have already become banters in the development of environment protection and the occupation of large land area is contrary to the original intention of environment protection. 污水处理场占地面积大,投资高已成为限制环境保护事业发展的障碍之一,而大面积占用土地与环境保护的初衷也是相违背的。