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A noticeable amount of dyes may remain in the wastewater downstream of dyeing facilities giving anaesthetic colorations as well as environmental concern. Conventional biological treatment alone cannot guarantee a sufficient decolouration and tertiary treatments have to be necessarily considered. Two oxidation schemes by ozone were considered in this work. A bubble column reactor (as a benchmark, in agreement with industrial applications) and a recycle well-mixed reactor were compared to reach the highest decolouration of standard dyes. In addition, hydrodynamic and ultrasonic cavitation were considered in the recycled well-mixed reactor to intensify its performance. The decolouration analysis was carried out for two dye classes (reactive and disperse), characterized by very different physical and chemical features. It appeared that some benefit was brought by ultrasound cavitation in the case of disperse dye only, while the degradation of the reactive dye was not intensified by the above hydraulic phenomenon. Ozone treatment was protracted to obtain different decolouration degrees of wastewater generated by wool dyeing. The resulting water was tested as a recycled process fluid to prepare fresh dyeing liquors, where devising the minimum decolouration degree became one of the quality specifications for recycling water back to dyeing. This article is protected by copyright. All rights reserved

The purpose of this work was to present a methodology to assess the energy consumption, specifically the energy utilized in the washing and drying processes, of textile products in their use-phase with the help of statistical tools. Regardless of the environmental impacts associated with the use-phase of textile products, analysis of energy consumption in that phase is still lacking. There is a need to design methodology for identifying the hotspots and parameters influencing the energy consumption in the use-phase of textile products. A pragmatic method that consists of a life-cycle assessment (LCA) framework plus principle component analysis (PCA), extended by Procrustes analysis (PA), is used to determine the energy consumption and minimize the possible uncertainties in the use-phase of textile product systems. The LCA plus PCA-PA method employed in this work to analyze the energy consumption of textile products in the use-phase comprises two statistical tools. First, PCA was applied to find the key parameters affecting the results. As an extension of PCA, PA was performed to highlight the most prominent variables within the dataset and extract the maximum amount of information. Lastly, hierarchical cluster analysis (HCA) was utilized for the classification of textile products on the basis of energy consumption variables and the similarity of their results. Among various energy consuming parameters in the use-phase of a textile product, both geographical and physical aspects can be prominent variables that significantly can affect the results of the energy consumption. After the LCA plus PCA-PA methodology, country of the use-phase in the geographical aspect and in the physical aspect, the fiber type and weight of the products were the influential variables. Hotspots or influential parameters being identified, a number of steps can be taken that can play an important role in decreasing environmental impacts by reducing the energy consumption in the laundering process of textile products during the use-phase. The methodology of LCA plus PCA-PA for energy consumption in textile products was employed to study the gap in currently available assessments. Using this method, the main influencing energy consuming parameters or hotspots in the use-phase of a textile product system could easily be identified and potential improvements of sustainability can be proposed.

It is well established that current flame retardant (FR) products at disposal generate various ecological hazards. Irrespective of their environmental impacts, the FR market is growing and is estimated to reach 2.8 million tons globally in 2018. In the textile domain, FRs are incorporated into baby clothing, pushchairs, car seats, etc. When disposed, these FR textile products end up in a landfill or are incinerated. These disposal processes are unsustainable. With landfilling, there is a huge chance of the FR product leaching into the environment. Similarly, FRs decrease energetic yields in the incineration process due to incomplete combustion. To cope with such issues, degradation and elimination of the FR product from the textile products before disposal could be a sustainable alternative. This study dealt with the preliminary degradation of flame retardant from the cotton textiles and its thermal characterization. Energy valorization by gasification is considered beneficial opposed to incineration with overall low energy recovery. The initial optimum gasification conditions including FR-treated cotton as a feeding material and potential outcomes of FR-treated cotton after degradation were characterized.

Renewable energy from thermal valorization plays a key part in today&rsquo, s energy from natural cellulosic textiles that are resourceful biomass and safe from toxicity at high temperature treatments. The situation is opposite, when technical textiles are treated with synthetic chemical finishes adding functionality as anti-bacterial, water repellent or flame retardant, etc. Incineration of flame retardant textile results in possible unfavorable gases, toxic fumes and contaminated ash. Other thermal valorization techniques like gasification would assist in avoiding the formation of additional toxic hazards. Herein, gasification of flame retardant textile is carried out the likelihood to get quality gas composition. For comparative analysis, flame retardant textiles, after their flame retardant ability being revoked, are also gasified. The output gas components suggested that gasification can be a useful thermal valorization approach for flame retardant textiles and relevantly improved gas composition was seen in textiles with their flame retardant substrate/species being removed.

Flame retardants (FRs) have been around us for decades to increase the chances of survival against fire or flame by limiting its propagation. The FR textiles, irrespective of their atmospheric presence are used in baby clothing, pushchairs, car seats, etc. The overall FR market in Asia, Europe, and the United States in 2007 was around 1.8 million metric tonnes. It is estimated that the worldwide consumption of FRs will reach 2.8 million tonnes in 2018. Unfortunately, a sustainable approach for textile waste, especially in the case of FR textiles, is absent. Incineration and landfill of FR textiles are hindered by various toxic outcomes. To address the need for sustainable methods of discarding FR textiles, the mechanical recycling of cotton curtains was evaluated.

A large amount of coarse wool, practically unserviceable for textile use, is generated in Europe from sheep shearing and butchery. Such a byproduct is either dumped, burned, or sent to landfill. Following the European Commission regulations on animal byproduct control, unserviceable raw wool is classified as a category 3 special waste materials. The collection, storage, transport, treatment, use, and disposal of such unserviceable raw wool are subject to European Union regulations because of a potential risk to human and animal health. This study aims at converting the waste wool into nitrogen fertilizers at a commercial scale for grassland management and cultivation purposes. The chemical transformation of waste wool in to fertilizer is based on a green economically sustainable hydrolysis treatment using superheated water. The experiments were carried out in a semi-industrial reactor feeding superheated water. The wool/superheated water system was maintained for different reaction times. The optimal conditions for this treatment were as follows: 170 °C for 60 min with a solid to liquor ratio (MLR) close to 1. The hydrolyzed product was analyzed using amino acid analysis and molecular weight distribution. Both the amino acid and molecular weight distribution analysis revealed that the wool was completely degraded and the hydrolyzed product contains a low molecular weight proteins and amino acids. Several hydrolyzed product obtained at different conditions were tested for germination which showed a germination index higher than 100% without collateral phytotoxicity. The presence of amino acids, primary nutrients, and micronutrients in wool hydrolyzates, along with a concentration of heavy metals below the standard limit, confirm the possibility of using wool hydrolyzates as a nitrogen based ecologically sound fertilizer.

Wet textile washing processes were set up for wool and cotton fabrics to evaluate the potential of ultrasound transducers (US) in improving dirt removal. The samples were contaminated with an emulsion of carbon soot in vegetable oil and aged for three hours in fan oven. Before washing, the fabrics were soaked for 3 min in a standard detergent solution and subsequently washed in a water bath. The dirt removal was evaluated through colorimetric measurements. The total color differences ΔE of the samples were measured with respect to an uncontaminated fabric, before and after each washing cycle. The percentage of ΔE variation obtained was calculated and correlated to the dirt removal. The results showed that the US transducers enhanced the dirt removal and temperature was the parameter most influencing the US efficiency on the cleaning process. Better results were obtained at a lower process temperature.

Spouted beds appear to go through a revival, testified by a very recent and comprehensive book on the topic (Epstein & Grace, 2011). This renewed interest arises by implementing new concepts in scaling-up spouting contactors and devising potential applications to high temperature processes, noticeable examples being given by pyrolysis and gasification of biomass, kinetically controlled drying of moist seeds to guarantee the requested qualities and polymer upgrading processes.

This paper presents the results from an extensive experimentation on polyester chips heating, crystallization and upgrading in three different size spouted bed units: a cylindrical 0.15 m diameter × 1.3 m tall, a 0.35 m square-based × 2.1 m tall parallelepiped and a sextuple multi-spouting 0.7 × 1.05 m2 demonstration reactor for solid state post-polymerization. The first apparatus was finalized to measuring several process operating variables (maximum gas temperature at the inlet, overall heat transfer coefficient and particle agglomeration tendency); the second unit provided the hydrodynamical data necessary to scale-up the system, insert into a PET upgrading process of 30 ton/day operating capacity and partially replace a bubbling fluidized bed heating/crystallizing unit. The ultimate goal of the project consisted in intensifying the process design by saving gas compression and thermal energy. The hydrodynamical findings of the squared modular unit were compared against several existing correlations: Manurung's equations for the maximum pressure drop and the pressure drop at stable spouting required a minimal alteration; Mathur and Gishler's equation properly fitted the experimental minimum spouting velocity. The continuously operating multiple spouting apparatus showed that regulating the solids level was an issue mainly due to the very large particle throughput, if related to the mixing efficiency of each module; reciprocal interference between spouted bed cells was manifested

A continuous autothermal two-stage pyrolysis/partial combustion process has been tested at the bench scale. Coal (or oil shale) up to 5 kg/h is fed to a spouted bed pyrolyzer in which the volatiles are driven off for tar recovery. Part of the resulting char is passed to a spouted bed partial combustor which produces the hot flue gas to provide heat and a spouting medium in the pyrolyzer. The two reactors are placed in a compact vertical configuration. The process is tested on two coals of different rank, and on oil shale. The effect of prime operating variables on yield are established and a number of operating modes demonstrated.

A capacitive balance that is able to work in the severe environment of a freeze-drying process has been conceived, constructed and tested. The influence of temperature variations had to be taken into account: a model of the instrument which makes use of the temperature of several components measured by three thermocouples was developed to correct the frequency signal generated by the device and to convert it into mass; the model parameters were identified by a least-squares method from blank lyophilisation runs. This balance offers the possibility of optimising the freeze-drying process through the accurate investigation of the process kinetics.