Efficiency assessment of industrial solid waste generation and treatment processes with carry-over in China

Industrial solid waste (ISW) harms the eco-environment as well as human health; thus, both the generation and treatment processes of ISW are important aspects of a reduction of discharged ISW. Currently, only part of the generated ISW is treated, while the remainder is stored for later treatment, which is referred to as carry-over between two adjacent periods. According to such a two-stage process (with carry-over), a network slacks-based measure model is proposed to measure the overall and divisional efficiencies of 30 Chinese regions during 2011-2015. The main findings are summarized in the following: firstly, failing to consider carry-over underestimates both overall and divisional efficiencies. Secondly, the average annual generation efficiency exceeded the average annual treatment efficiency during the study period; however, this gap increasingly narrowed. Thirdly, the overall efficiency is more closely related to the treatment efficiency than to the generation efficiency. Moreover, synergies were identified between generation efficiency and treatment efficiency for each region. Fourthly, significant regional differences affect both overall and divisional efficiencies, and significant stage efficiency differences also affect both coastal and inland areas. To increase the overall efficiencies of different regions of China, different policies are suggested.