Recently,every industry has been working to achieve carbon neutrality,and the wastewater sector is no exception.However,little research focuses on the carbon accounting of wastewater treatment and the roadmap to carbo...Recently,every industry has been working to achieve carbon neutrality,and the wastewater sector is no exception.However,little research focuses on the carbon accounting of wastewater treatment and the roadmap to carbon neutrality.Here,to systematically perform accounting,we provide a sketch that describes three boundaries of the wastewater system and propose that the carbon neutrality of the wastewater system is far beyond the plant boundary.Moreover,we identify the direct and indirect carbon emissions of wastewater treatment.In addition to direct emissions of CH_(4) and N_(2)O,direct fossil CO_(2) emissions from wastewater treatment should be included in accounting to set accurate guidelines.Next,the technologies that assist in achieving carbon-neutral wastewater treatment both within-thefence of wastewater treatment plants and beyond the plant boundary are summarized.All measurements of energy recovery,resource recovery,and water reuse contribute to reaching this goal.The concepts of energy neutrality and carbon neutrality are identified.Successful wastewater treatment cases in energy self-sufficiency may not achieve carbon neutrality.Meanwhile,resource recovery methods are encouraged,especially to produce carbon-based materials.Ultimately,the trend of preference for the decentralized sewage treatment system is pinpointed,and systematic thinking to set the urban infrastructure layout as a whole is advocated.展开更多
Presenting a hard-to-predict typography-varying system predicated on Nazi-era cryptography, the Enigma cipher machine, this paper illustrates conditions under which unrepeatable phenomena can arise, even from straight...Presenting a hard-to-predict typography-varying system predicated on Nazi-era cryptography, the Enigma cipher machine, this paper illustrates conditions under which unrepeatable phenomena can arise, even from straight-forward mechanisms. Such conditions arise where systems are observed from outside of boundaries that arise through their observation, and where such systems refer to themselves in a circular fashion. It argues that the Enigma cipher machine is isomorphous with Heinz yon Foersters portrayals of non-triviality in his non-trivial machine （NTM）, but not with surprising human behaviour, and it demonstrates that the NTM does not account for spontaneity as it is observed in humans in general.展开更多
基金This work was supported by the National Natural Science Foundation of China(No.52070059).
文摘Recently,every industry has been working to achieve carbon neutrality,and the wastewater sector is no exception.However,little research focuses on the carbon accounting of wastewater treatment and the roadmap to carbon neutrality.Here,to systematically perform accounting,we provide a sketch that describes three boundaries of the wastewater system and propose that the carbon neutrality of the wastewater system is far beyond the plant boundary.Moreover,we identify the direct and indirect carbon emissions of wastewater treatment.In addition to direct emissions of CH_(4) and N_(2)O,direct fossil CO_(2) emissions from wastewater treatment should be included in accounting to set accurate guidelines.Next,the technologies that assist in achieving carbon-neutral wastewater treatment both within-thefence of wastewater treatment plants and beyond the plant boundary are summarized.All measurements of energy recovery,resource recovery,and water reuse contribute to reaching this goal.The concepts of energy neutrality and carbon neutrality are identified.Successful wastewater treatment cases in energy self-sufficiency may not achieve carbon neutrality.Meanwhile,resource recovery methods are encouraged,especially to produce carbon-based materials.Ultimately,the trend of preference for the decentralized sewage treatment system is pinpointed,and systematic thinking to set the urban infrastructure layout as a whole is advocated.
文摘Presenting a hard-to-predict typography-varying system predicated on Nazi-era cryptography, the Enigma cipher machine, this paper illustrates conditions under which unrepeatable phenomena can arise, even from straight-forward mechanisms. Such conditions arise where systems are observed from outside of boundaries that arise through their observation, and where such systems refer to themselves in a circular fashion. It argues that the Enigma cipher machine is isomorphous with Heinz yon Foersters portrayals of non-triviality in his non-trivial machine （NTM）, but not with surprising human behaviour, and it demonstrates that the NTM does not account for spontaneity as it is observed in humans in general.
