This article provides an economic investigation into the underlying causes of industrial wastewater emissions. We examine the direct and the structural break-induced effect of national environmental regulation on industrial wastewater emissions. The results show that strict environmental regulation can partially offset the energy-induced effects imposed by the scale effects of foreign direct inflows and cause positive behavioral responses by either limiting coal usage or improving upon coal usage technology and shift towards clean energy sources. We find the absence of scale economies in the provision of environmental services in the industrial sector due to the poor nature of the technical processes of industries. We further highlight the importance of raising the investment in environmental treatment and embracing trade liberalization in the improvement of industrial wastewater management.

This paper is concerned with mathematical modelling in the management of a wastewater treatment system. The problem is formulated as looking for a Nash equilibrium of a multiobjective pointwise control problem of aparabolic equation. Existence of solution is proved and a first order optimality system is obtained. Moreover, a numerical method to solve this system is detailed and numerical results are shown in a realistic situation posed in the estuary of Vigo (Spain).