Constructed wetlands (CWs) have been used as a green technology to treat various wastewaters for several decades. CWs offer a land-intensive, low-energy, and less-operational-requirements alternative to conventional treatment systems, especially for small communities and remote locations. However, the sustainable operation and successful application of these systems remains a challenge. Hence, this paper aims to provide and inspire sustainable solutions for the performance and application of CWs by giving a comprehensive review of CWs' application and the recent development on their sustainable design and operation for wastewater treatment. Firstly, a brief summary on the definition, classification and application of current CWs was presented. The design parameters and operational conditions of CWs including plant species, substrate types, water depth, hydraulic load, hydraulic retention time and feeding mode related to the sustainable operation for wastewater treatments were then discussed. Lastly, future research on improving the stability and sustainability of CWs were highlighted.

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To overcome the problem that Bi3+-activated phosphors suffer from, it is an urgent need to realize narrow-band light emission of Bi3+-activated phosphors, which not only improves their luminescence characteristics, but also increases their competitiveness with rare earth-activated commercial phosphors. In our work, a novel Bi3+-activated narrow-band cyan phosphor has been achieved in a highly condensed and symmetrical crystal structure of Ca3Lu2Ge3O12, and its full width of half-maximum (fwhm) of the emission band reaches 47 nm. The result indicates that Bi3+-activated Ca3Lu2Ge3O12 is comparative to the commercial green phosphor β-sialon: Eu2+ (fwhm ≈ 55 nm), and its strong excitation band locates at 390 nm, implying that Ca3Lu2Ge3O12: Bi3+ can be well excited by near-ultraviolet (NUV) LED chips. Furthermore, Ca3Lu2Ge3O12: Bi3+ possesses promising cathodoluminescence properties accompanied by good antiaging characteristics. The fascinating PL and CL properties of Ca3Lu2Ge3O12: Bi3+ have been proved to relate to their garnet-type structure; thus, the structure–property relations of Bi3+-activated Ca3Lu2Ge3O12 were discussed in detail in this work, which may provide an effective way for exploring better Bi3+-activated phosphors for use in WLEDs and FEDs.

In an effort to reduce costs, a systematic optimization approach is proposed to address the energy consumption of dividing-wall columns (DWCs). This iterative optimization procedure begins by minimizing the overall heat duty using an innovative objective function within a constrained design space. A sensitivity analysis is then carried out on the manipulated variables to obtain their optimal ranges. Optimal operating parameters are obtained through the evaluation of the total annualized cost (TAC). For the separation process of benzene/toluene/o-xylene, the optimal DWC flow sheet exhibits a significant decrease in TAC when compared to conventional flow sheet optimum designs. The applied optimization method and sensitivity analysis have proven to produce results at the global optimum. This method is both practical and easily applied to other systems, even to systems with more than three components.