Search

Under the uncertain market demand and quality level, a total profit model of green closed-loop supply chain system (GCL-SCS) considering corporate environmental responsibility (CER) and government differential weight subsidy (GDWS) is constructed. Based on incentive-compatibility theory, the optimal subsidy allocation policy and green investment level were explored. Fuzzy chance-constrained programming (FCCP) is used to clarify the uncertainty factors of this model; while genetic algorithm (GA) and CPLEX are used to find and compare a calculating example's approximate optimal solution about this model. The main calculating results indicate that: (1) Enterprises can make optimal recycling, production and sales strategies according to different potential demand; (2) Without government subsidy, enterprises' higher green investment level will reduce their average gross profit, increase the quality level of recycled products and decrease the recycling rate, hence reduce their environmental protection willingness; (3) Based on incentive-compatibility theory, when government subsidy weight is set as 0.34~0.41 for consumers, enterprises' higher green investment level will enhance their average gross profit, reduce the quality level of recycled products and increase the recycling rate, which will improve their environmental protection willingness; (4) Under uncertain environment, the combination of reasonable government subsidy policy and enterprises green investment can make up for the defect of enterprises green investment alone, maximize utilities of government and enterprises, and optimize the green closed loop supply chain.

Photolysis of iron chlorides is a well-known photolytic source of Cl • in environmental waters. However, the role of particulate chlorine radicals (Cl • and Cl 2 •- ) in their multiphase oxidative potential has been much less explored. Herein, we examine the effect of Cl • /Cl 2 •- produced from photolysis of particulate iron chlorides on atmospheric multiphase oxidation. As a model system, experiments on multiphase oxidation of SO 2 by Cl • /Cl 2 , comparable to the values necessary for explaining the observations in the haze events in China. The experimental and modeling results found a good positive correlation between the uptake coefficient, γ •- were performed. Fast sulfate production from SO 2 oxidation was observed with reactive uptake coefficients of ∼10 -5 , comparable to the values necessary for explaining the observations in the haze events in China. The experimental and modeling results found a good positive correlation between the uptake coefficient, γ SO2 , and the Cl • production rate, d[Cl • ]/dt, as γ SO2 = 5.3 × 10 -6 × log(d[Cl • ]/dt) + 4.9 × 10 -5 . When commonly found particulate dicarboxylic acids (oxalic acid or malonic acid) were added, sulfate production was delayed due to the competition of Fe 3+ between chloride and the dicarboxylic acid for its complexation at the initial stage. After the delay, comparable sulfate production was observed. The present study highlights the importance of photochemistry of particulate iron chlorides in multiphase oxidation processes in the atmosphere.

Heterogeneous oxidation of SO 2 is one of the promising mechanisms to account for high loading of sulfate during severe haze periods in China. Our earlier work reported on the SO 2 oxidation by OH and NO 2 produced during 250 nm nitrate photolysis ( Environ. Sci. Technol. Lett . 2019 , 6 , 86-91). Here, we extend that work to examine sulfate production during nitrate photolysis at 300 nm irradiation, which can additionally generate NO 2 - or HNO 2 , N(III). Flow cell/in situ Raman experiments showed that the reactive uptake coefficient of SO 2 , γ SO 2 , can be expressed as γ SO 2 = 1.64 × p NO3- M s p NO3- is the nitrate photolysis rate in the range of (1.0-8.0) × 10 -5 M s -1 contribution. Furthermore, the addition of OH scavengers (e.g., glyoxal or oxalic acid) does not suppress the sulfate production because of the reduced N(III)-consuming reactions and the high particle pH sustained by their presence. Our calculations illustrate that under characteristic haze conditions, the nitrate photolysis mechanism can produce sulfate at ∼1 μg m p NO3- predicts that N(III) is the main contributor to the SO 2 oxidation, followed by NO 2 M s -3 h -1 at pH 4-6 and p NO3- = 10 -5 M s -1 . The present study highlights the importance of in-particle nitrate photolysis in heterogeneous oxidation of SO 2 by reactive nitrogen (NO 2 - /HNO 2 and NO 2 ) under atmospherically relevant actinic irradiation. However, the nitrate photolysis rate constant needs to be better constrained for ambient aerosols.