ABSTRACT
Rethinking of plastic rigid shampoo bottles based on "Design for the Environment" concepts is proposed. Bottles of most consumed shampoo brands with different capacities were selected. Bottle weight/capacity ratio was assessed and compression mechanical properties were evaluated. Oversizing of bottles and high amounts of material used in caps only for aesthetic purposes was proved. The analysis confirmed the need to change marketing strategies based on aesthetic attractiveness by an ecodesign based on functionality and sustainability aspects. The use of single material for the overall bottle is recommended, and it seems that HDPE is more suitable as it is appropriate to make all bottle parts, is recyclable, and has a low price/performance relationship. From a marketing point of view, a proper ecodesign would lead to a paradigm shift from an aesthetic approach to a sustainable one, in line with the environmental awareness of today's consumer.
ABSTRACT
The amount and type of municipal solid waste (MSW) in Bahía Blanca (Argentina) were assessed and correlated with population socioeconomic level. In this sense, seven areas with different quality of life were selected. In addition, a parallel study on a control area was performed and validated for obtaining a representative result to provide analogous conclusions for the whole city. From this study, a combination of sorting methodologies is proposed in order to reduce the actual amount of waste sent to landfill. If these methodologies are implemented in Bahia Blanca city, MSW in landfill could be reduced at least 80%. The proposed strategy is to combine waste sorting at source and at destination. An alternative separation at source could be proposed as follows: packaging (including plastic, cans and Tetra Pak), other plastics, paper and glass. The rest of MSW could be included in a container which would be collected daily or three times a week without changing inhabitants' habits and promoting their collaboration. Then, it could be separated at destination for waste-to-energy, composting, and biogas obtaining. Residuals from incinerators and biogas/composting plants would be sent to landfill. On the other hand, regarding the relationship between the proposed strategy and population quality of life, obtained results from this study could be useful to size and to efficiently locate disposal bins/containers for source separation as well as to redesign routes of municipal solid waste collection. Also, this strategy allows to add value to different components of MSW, improving working conditions of waste workers and creating new jobs in Bahia Blanca city.
ABSTRACT
A structural study about the changes induced by plasticization of native corn starch was carried out in this work. The influence of talc nanoparticles presence during starch thermal processing was also evaluated. Macroscopic observation of the granules appearance evolution during melt-mixing and thermo-compression was supported by a theoretical description related to these processing methods. Melt-mixing induced a polymorphic transformation from A- to Vh-type and a reduction in the degree of crystallinity. Homogenous appearance of the plasticized starch was in accordance to the disruption of granules integrity, evidenced by SEM. This observation agreed to the distinctive XRD pattern of plasticized starch from unprocessed granules. Talc incorporation did not require the adjustment of processing parameters in order to obtain a homogenous thermoplastic material, with an adequate particles distribution within the matrix. Regardless talc presence, plasticized starch presented a Vh-type crystalline structure. Thermo-compression led to particles alignment promoted by talc laminar morphology.
ABSTRACT
Talc is proposed as a low-cost mineral for wastewater clarification. In this sense, adsorption of methylene blue (MB) from aqueous solutions was studied comparatively by using sepiolite (qualified as very good adsorbent) and two talc samples with different particle size and purity degree. The MB adsorption was assessed by determining remnant dye in the supernatant using UV-vis spectroscopy and by detecting dye adsorbed on mineral samples through thermogravimetric analysis and infrared spectroscopy. Both isothermal curves and kinetic studies demonstrate that talc is a good dye adsorbent. Particularly, with dye concentrations similar to those of textile wastewater, talc was demonstrated to adsorb the same dye content of sepiolite at similar times. Natural talc could be employed as a low-cost alternative in wastewater treatment for the removal of cationic dyes.
