技术异质视角下中国工业行业废水排放效率测度及减排潜力分析

Analysis on industrial wastewater discharge efficiency and mitigation potential from the perspective of heterogeneity

工业废水排放造成的环境污染已经成为制约中国工业经济转型的重要瓶颈,因此合理测度工业行业废水排放效率和减排潜力,可以为制订合适的工业行业废水排放减排措施提供一定的科学依据。考虑到不同工业行业间生产技术的差异性,本文在共同前沿理论框架下,基于规模方向性距离函数对我国2004—2015年37类工业行业的废水排放效率和减排潜力进行测度,并从静态和动态视角下揭示其差异性及变动趋势。研究结果显示:废水低、中等和高排放组的排放效率多年均值分别为0.512、0.250和0.168,减排潜力分别高达48.8%、75%和83.2%,减排潜力巨大。三组的技术落差率历年均值分别为0.992、0.377和0.221,说明只有废水低排放组内各工业行业的技术水平基本达到该区域的潜在最优技术水平,而其余两组则均未实现组内最优。行业间废水排放效率和减排潜力差异性较大,效率高减排潜力小的行业主要集中在废水排放量低且技术落差率高的行业,而效率低减排潜力大的行业则主要集中在废水排放量高且技术落差率低的行业。考察期内全国工业行业废水排放效率在逐年提高,废水减排潜力在逐渐降低,但是行业间差距在变大,并逐渐呈现两极分化现象。最后基于实证分析结果,本文提出了若干政策建议,包括:全面提高工业科技投入,增强管理能力,提升工业废水排放效率,减少废水排放;分行业制定工业废水排放标准,提出分类技术改进措施;积极推进行业间在废水处理技术和先进管理理念方面的交流与合作,实现工业内所有行业废水排放效率的普遍提升和改善。

As industrial wastewater discharge has become an important barrier in China’s industrial economic transformation,to formulate measure to reduce wastewater discharge,it is imperative to rationally measure wastewater discharge efficiency and mitigation potential of the industrial sectors in China.Taking the heterogeneity of production technology among industrial sectors into consideration,under meta-frontier theoretical framework,the 37 industrial sectors between the years from 2004 to 2015 in China were divided into three groups by the discharge level of wastewater.Based on scale directional distance function and nuclear density function,wastewater discharge efficiency and mitigation potential in the industrial sectors were measured and the differences and trends were analyzed.The results showed that the average values of industrial wastewater discharge efficiency with low-discharge,medium-discharge and high-discharge groups were 0.512,0.250 and 0.168,respectively.Mitigation potential were 48.8%,75%and 83.2%,and potentials were huge.The average values of technology gap ratio in three groups were 0.992,0.992 and 0.377,respectively suggesting only low-discharge industries reached the optimal in the group,while the rest of the two groups did not.And wastewater discharge efficiency and mitigation potential varied widely in the industrial sectors,the industries with high efficiency and low mitigation potential were mainly concentrated in the industries with low wastewater discharge and high technology gap ratio,while the industries with low efficiency and high mitigation potential were mainly concentrated in the industries with high wastewater discharge and low technology gap ratio,the gap between industrial sectors was getting bigger and polarization gradually appeared.Finally,according to the empirical analysis results,this paper puts forward several policy suggestions as follows.First,to improve industrial science and technology input in all-round,strengthen management ability,improve industrial wastewater emission efficiency and reduce waste emissions.Second,to formulate standards for industrial wastewater discharge in different industries and propose measures for the improvement of classification technique.Third,to promote exchanges and cooperation between industries in wastewater treatment technology and advanced management concepts,so that to realize a general improvement of wastewater discharge efficiency in all industries.