A multi-objective optimization approach for green supply chain network design for the sea cucumber (Apostichopus japonicus) industry.

In China, aquatic supply chain network design does not include the green concept or the coordination of environmental and economic performance. Sea cucumber (Apostichopus japonicus) is an aquatic product of high economic value; however, studies on sea cucumber supply chain network optimization are lacking. This study is the first to design the sea cucumber supply chain and construct an optimization model. Considering the characteristics of the sea cucumber industry, LCA for Experts software and the CML-IA-Aug. 2016-world method were used to assess each aquaculture model's global warming potential (GWP), as the environmental performance indicator. In addition, multi-objective genetic algorithm (MOGA) coupled with Modified Technique for Order of Preference by Similarity to Ideal Solution (M-TOPSIS) integrates yield production, economic benefits, and environmental performance. The results demonstrated that cage seed rearing (CSR) combined bottom sowing aquaculture (BSA) represents the best production strategy upstream of the sea cucumber supply chain. In the downstream, the best proportion of sales channels in supermarkets, boutique stores and online shops accounted for 14.79 %, 58.02 % and 27.19 % of the production, respectively. The proposed optimization scenario 4 (S4) can increase product profit by 27.88 % and reduce GWP by 56.89 %. The following improvement measures are proposed: using sea cucumber aquaculture industry standards (cleaner production and green supplier selection) to regulate the behavior of enterprises, adopting an ecological and green production strategy, eliminating high-energy consumption and high emission production practices, and promoting widespread adoption of green consumption concepts. Finally, these measures may improve the sea cucumber supply chain, achieve coordinated environmental and economic performance development in the sea cucumber industry, and provide guidance for green optimization of other aquatic product supply chains in China.

Life cycle assessment of tiger puffer (Takifugu rubripes) farming: A case study in Dalian, China.

In China, energy consumption and carbon emission by the aquaculture industry have become major problems. The tiger puffer (Takifugu rubripes) is an emerging aquaculture species in China, but its environmental impact during the farming process has not yet been evaluated systematically. To the best of our knowledge, this is the first life cycle assessment (LCA) of tiger puffer land-sea relay strategy in Dalian, China. To analyze the environmental impact of the tiger puffer farming process, the following four stages were considered: seed rearing, deep-sea cage farming-1, industrial recirculating aquaculture, and deep-sea cage farming-2. The LCA software GaBi 10.5 academy version and CML-IA-Jan. 2016-world method were used to calculate the environmental impacts. According to the LCA results, marine aquatic ecotoxicity potential was the largest contributor to the environmental impact, and industrial recirculating aquaculture was the largest farming stage in the whole tiger puffer farming process. Energy in the form of electricity, coal, and gasoline was consumed to maintain the power supply in the tiger puffer farming process, and it was a key factor that influenced the environmental performance. Based on the sensitivity and energy analyses, energy consumption for equipment operation at the industrial recirculating aquaculture stage, feed consumption, and gasoline consumption for transportation at the deep-sea cage farming-2 stage need to be carefully considered. The following improvement measures were suggested to improve the environmental performance of tiger puffer farming and the aquaculture industry: establish electricity, wind power, and solar energy integrated management systems; ex-ante LCA for parameter optimization in future technology research and development; and new production strategies such as aquaponics and integrated multi-trophic aquaculture. Moreover, life cycle inventory (LCI) of tiger puffer land-sea relay farming was established to obtain essential information, enrich aquaculture LCI databases, and support aquaculture LCA research.

Environmental tradeoffs in municipal wastewater treatment plant upgrade: a life cycle perspective.

Municipal wastewater treatment plants (WWTPs) play an indispensable role in improving environmental water quality in urban areas. Existing WWTPs, however, are an important source of greenhouse gas (GHG) emissions and may not be able to treat increasingly complicated wastewater or meet stringent environmental standards. These WWTPs can be updated to address these challenges, and different technologies are available but with potentially different environmental implications. Life cycle assessment (LCA) is a widely used approach to identify alternatives with lower environmental footprint. In this study, LCA was applied to an actual urban WWTP, considering four scenarios involving upgrading and energy-resource recovery. The environmental performance with respect to life cycle GHG emissions and eutrophication impact was analyzed. The environmental benefits of reduced water pollution and energy and material displacement associated with energy-resource recovery process were also considered. The results showed tradeoffs among the four scenarios. Although upgrading the studied WWTP would meet discharge standard for total phosphorus and reduce total eutrophication impact by about 19%, it would increase GHG emissions by at least 16%. Besides, the energy-resource recovery mode for existing WWTP (S2) performs the best in terms of GHG emissions. For different biogas utilization methods, combined heat and power (CHP) system is superior to the existing method of delivering biogas to gas grid, in terms of energy recovery or reduction of GHG emissions and eutrophication impact. Our research results may provide a reference for plant managers to select the most environmentally friendly upgrade scheme and energy-resource recovery technique for future upgrade projects.

Comparative study on life cycle assessment of gasoline with methyl tertiary-butyl ether and ethanol as additives.

China has proposed to use ethanol instead of methyl tert-butyl ether (MTBE) as a gasoline additive, with full compliance planned for 2020. At present, previous studies on gasoline additive focus almost exclusively on effects of fuel performance and engine, however, the environmental impact production and use of additives cannot be ignored. Herein, we use the life cycle assessment (LCA) method, the environmental effects of E10 (10% maize ethanol and 90% gasoline, v/v) and M10 (10% MTBE and 90% gasoline, v/v) were evaluated and compared. Quantifying the net environmental benefits of implementing this national policy from a life cycle perspective. The results showed that the environmental impact of E10 was 15.4% lower than that of M10. Thus, replacing MTBE with ethanol reduces the total environmental impact. However, there were some negative environmental impacts such as waste solids and water use. Finally, we propose further improvements to make E10 more environmentally friendly.

Integrated Analysis of the Water-Energy-Environmental Pollutant Nexus in the Petrochemical Industry.

China has set high water-conservation, energy-saving, and pollutant-reduction goals for the petrochemical industry. This represents a challenge to petrochemical enterprises because of the complex coupling between water, energy, and environmental pollutant (WEE) subsystems, elements (different types of WEE), and production units. However, there has been little research on the element-level coupling relationship. The connection and difference between the coupling relationships of the system, element, and unit levels are not well understood. Therefore, an integrated analysis method was developed to quantify the petrochemical WEE nexus (WEEN) at these three levels, including a generic WEEN model, material and energy flow analysis, and a WEEN analysis matrix. Three indicators were proposed to analyze three-level coupling quantitatively and to formulate improvement strategies for water-conservation, energy-saving, and pollutant-reduction. A case study demonstrated significant three-level coupling. The coupled percentage of WEE subsystems were 95.87%, 61.97%, and 54.99%, respectively. The dominant energy subsystem was the root of high consumption and pollution. Based on synergies and trade-offs, we proposed element optimization priorities: High priority (deoxidized water and fuel), medium priority (steam, circulating water, and wastewater), and low priority (fresh water, demineralized water, waste gas, and electricity). The identified unit improvement potential revealed overestimation (hydrotreating and delayed coking units) and underestimation (crude distillation units) of conventional methods that overlook three-level coupling.