وحید محققی

In this research, preparation, characterization, and evaluation of TiO2 encapsulated into zeolitic imidazolate framework (TiO2@ZIF-8) nanophotocatalyst was investigated as an efficient photo-degradation of paraquat (PQ) herbicide from aqueous samples. This study was performed using a ZIF-8-based nanophotocatalyst and a reactor consisting of an ultraviolet (UV) source and a reaction chamber. The effects of various parameters including contaminant concentration, amount of nanophotocatalyst, and pH reaction time were investigated on the removal efficiency of contaminant by the TiO2@ZIF-8 nanophotocatalyst. The results showed by increasing the amount of the TiO2@ZIF-8 nanophotocatalyst and pH, the removal of paraquat showed an increase. The optimal condition was found as nanophotocatalyst concentration (0.05 g.L-1), pH (7) at room temperature for 15 min for removal of 99.8% paraquat. According to the results, TiO2@ZIF-8 emerged as an efficient, robust, and recyclable nanophotocatalyst, which is a potential and environmentally friendly process for the removal of toxic chemical herbicide as hazardous organic contaminants from aqueous samples. The facile fabrication approach and the enhanced photocatalytic activity of TiO2@ZIF-8 were highlighted and notably showed good reusability in 8 consecutive cycles.

Choosing the right set of projects is the first step of project oriented firms in strategic project portfolio management. Since economic growth depends on environmental and social issues, sustainable development has been an essential part of firm's plans to keep their competitive advantage. Moreover, market conditions, fast worldwide changes and other similar issues have given these issue ever-growing uncertain elements. As a result, this paper provides a method of sustainable construction-project portfolio selection under interval-valued type-2 fuzzy sets. This method consists of two main parts. The first level evaluates the proposed projects and omits the unsuitable ones. Then, in the second level, the portfolio is selected by means of mathematical programming. Eventually, to display applicability of the method, an application example is presented and solved.