Treatment of Jewelry Manufacturing Effluent Containing Cyanide Using Ozone-Based Photochemical Advanced Oxidation Processes

This article considers Advanced Oxidation Processes involving O₃, O₃/UV, O₃/H₂O₂/UV, and H₂O₂/UV to destroy cyanide in jewelry manufacturing wastewaters. All experiments were performed in a semibatch reactor. The results showed that total cyanide can be reduced with different reaction rates, and the decrease of total cyanide can be described by pseudo–first-order kinetics. The reaction was performed under different pH values and H₂O₂ dosages to find the optimal conditions for the oxidation processes. The ozonation process destroyed total cyanide faster at a pH = 12, whereas ozonation combined with H₂O₂ and/or UV destroyed cyanide faster at a pH =10. The total cyanide destruction rate in the UV/H₂O₂ (700 mg/L) treatment was the highest among all studied processes, with removal efficiencies of 99% for CN^?, 99% for COD and 99% for TOC.     

PolyHIPE/pullulan composites derived from glycidyl methacrylate and 1,3‐butanediol dimethacrylate‐based high internal phase emulsions

Highly porous composites of poly(glycidyl methacrylate‐co‐1,3‐butanediol dimethacrylate) and pullulan were prepared as semi‐interpenetrating polymer networks by cross‐linking of high internal phase emulsions (HIPEs). HIPEs were prepared by using an aqueous phase made of pullulan dissolved in deionised water. Instead of conventional cross‐linkers such as divinyl benzene, 1,3‐butanediol dimethacrylate was used as a flexible co‐monomer. Morphological and mechanical properties of the porous composites with an initial pullulan loading ranging from 1 to 10 wt % have been investigated. Resulting composites were tested in terms of uniaxial compression stress and it was found out that the use of pullulan and flexible co‐monomer in the HIPE preparation increases the compression modulus from 13.53 to 30.8 MPa. Textural analyses of the resulting composites show that in all cases open cellular foams composed of primary cavities (～112–74 μm) connected with secondary interconnected pores were produced with a specific surface area in the range of 1.7–3.0 m² g^?1. In addition, the influence of using porogen in the oil phase was investigated. It was found that using a porogen reduces the cavity size diameter from ～112 to 20 µm and increases the compression modulus from 13.53 to 47.06 MPa. POLYM. ENG. SCI., 55:2636–2642, 2015. © 2015 Society of Plastics Engineers     

Color stability of bulk‐fill composites immersed in different drinks

Bulk‐fill composites show structural differences compared to those of conventional resin composites. Their more reactive photoinitiators, monomer compositions, and increased filler content may result in higher color stability than for conventional ones. Therefore, this study aimed to assess the color stability of three different bulk‐fill composites and one conventional resin composite with a higher filler load after 1 week and 1 month of immersion in different drinks. The resin composite materials that were tested demonstrated significantly different color changes after immersion in the four solutions during both evaluation periods. Immersion in coffee and red wine showed noticeable staining of all the materials. The discoloration effect of staining solutions on the resin composites depends both on the material composition and on the pigment types found in the solutions.     

Mechanical properties of reactive powder concrete containing high volumes of ground granulated blast furnace slag

The mechanical properties (flexural strength, compressive strength, toughness and fracture energy) of steel microfiber reinforced reactive powder concrete (RPC) were investigated under different curing conditions (standard, autoclave and steam curing). Portland cement was replaced with ground granulated blast furnace slag (GGBFS) at 20%, 40% and 60%. Sintered bauxite, granite and quartz were used as aggregates in different series. The compressive strength of high volume GGBFS RPC was over 250 MPa after autoclaving. When an external pressure was applied during setting and hardening stages, compressive strength reached up to 400 MPa. The amount of silica fume can be decreased with increasing amount of GGBFS. SEM micrographs revealed the tobermorite after autoclave curing.     

Multi-Criteria Analysis of Water Allocation Scenarios in a Water Scarce Basin

In 2015, a “Post-2015 Development Agenda” is defined for future global developments in water management. The proposed goal is referred to as SDG’s or Sustainable Development Goals, which will balance the economic, social and environmental dimensions of sustainable development with a strong linkage between environment and socio-economic goals. One of the major concepts of SDG’s is water security, which is the basic element of the Global Goal on Water, now defined as: “Securing Sustainable Water for All”. The proposal for a Global Goal for Water is associated with targets and indicators to help countries reach the goal by 2030. Among the five main targets specified, two major ones emphasize “water allocation” as an important support of water security, particularly in conditions of water security. This paper focuses on this latter issue in the case of water scarce Gediz Basin along the Aegean coast of Turkey, where irrigation is the major water consuming activity. In addition to allocation of water among other water use sectors and irrigation, it is important in the basin how irrigation water is allocated to various crops, as previous droughts struck crop yields the most. Thus, 16 alternative allocation scenarios are developed to assess the crop yield produced by each scenario. These alternatives are represented by social, economic and environmental indicators as criteria for selection the most favorable alternative. The selection is realized by Multi Criteria Analysis (MCA) methodology, using the Reference Point Approach (RPA). In terms of methodology, presented paper shows that RPA is a powerful tool to guide engineers and decision makers to rationally select among several possible alternatives in water allocation.