The removal of dyes from textile wastewater: a study of the physical characteristics and adsorption mechanisms of diatomaceous earth

The feasibility of using diatomite for the removal of the problematic reactive dyes as well as basic dyes from textile wastewater was investigated. Methylene blue, Cibacron reactive black and reactive yellow dyes were considered. Physical characteristics of diatomite such as pH(solution), pH(ZPC), surface area, Fourier transform infrared, and scanning electron microscopy were investigated. The surface area of diatomite was found to be 27.80 m(2) g(-1) and the pH(ZPC) occurred around pH of 5.4. The results indicated that the surface charge of diatomite decreased as the pH of the solution increased with the maximum methylene blue removal from aqueous solution occurring at basic pH of around (1011). Adsorption isotherms of diatomite with methylene blue, hydrolysed reactive black and yellow dyes were constructed at different pH values, initial dye concentrations and particle sizes. The experimental results were fitted to the Langmuir, Freundlich, and Henry models. The study indicated that electrostatic interactions play an important role in the adsorption of dyes onto diatomite. A model of the adsorption mechanism of methylene blue onto diatomite is proposed. (C) 2003 Elsevier Ltd. All rights reserved.

Textile wastewater treatment using granular activated carbon adsorption in fixed beds

This work involved the treatment of industrial wastewater from a nylon carpet printing plant which currently receives no treatment and is discharged to sea. As nylon is particularly difficult to dye, acid dyes are required for successful coloration and cause major problems with the plant's effluent disposal in terms of color removal. Granular activated carbon Filtrasorb 400 was used to treat a ternary solution of acid dyes and the process plant effluent containing the dyes in a fixed-bed column system. Experimental data were correlated using the bed depth service time (BDST) model to previously published work by the authors for single dye adsorption. The results were expressed in terms of the BDST adsorption capacity, in milligrams of adsorbate per gram of adsorbent, and indicated that there was a 12-25% decrease iri adsorption capacity in the ternary system compared to the single component system; This reduction has been attributed to competitive adsorption occurring in the ternary component system. Dye adsorption from the process plant effluent showed an approximate 65% decrease in adsorption capacity compared to the ternary solution system. This has been attributed to interference caused by the other colorless textile effluent pollutants found in the process wastewater. A chemical oxygen demand analysis on these components indicated that the dyes accounted for only 14% of the total oxygen demand.

The effect of feeder type and change of feeder type on growing and finishing pig performance and behaviour

Reduced feed intake and hence lower growth rates commonly occur when the environment of the pig changes, e.g. at weaning and when pigs are moved from growing accommodation to finishing accommodation. It is hypothesised that if environmental factors, such as feeder type, remain the same in the weaning and finishing accommodation this 'growth check' may be reduced. A total of 640 pigs in 32 pens of 20 pigs per pen were used to investigate the effects of two feeder types and changing or not changing the feeder type at 10 weeks of age on growth performance and behaviour in the periods from 4 to 10, 10 to finish (22) and from 4 to finish (22) weeks of age, respectively. The two feeder types tested were a 'wet and dry' single-space (S) feeder and a 'dry' multi-space feeder (M).

TEXTILE TECHNOLOGIES IN CONCRETE ENVIRONMENTS."

Girli Concrete is a cross disciplinary funded research project based in the University of Ulster involving a textile designer/ researcher, an architect/ academic and a concrete manufacturing firm.
Girli Concrete brings together concrete and textile technologies, testing ideas of
concrete as textile and textile as structure. It challenges the perception of textiles as only the ‘dressing’ to structure and instead integrates textile technologies into the products of building products. Girli Concrete uses ‘low tech’ methods of wet and dry concrete casting in combination with ‘high tech’ textile methods using laser cutting, etching, flocking and digital printing. Whilst we have been inspired by recent print and imprint techniques in architectural cladding, Girli Concrete is generated within the depth of the concrete’s cement paste “skin”, bringing the trades and crafts of both industries together with innovative results.
Architecture and Textiles have an odd, somewhat unresolved relationship. Confined to a subservient role in architecture, textiles exist chiefly within the categories of soft furnishings and interior design. Girli Concrete aims to mainstream tactility in the production of built environment products, raising the human and environmental interface to the same specification level as the technical. This paper will chart:
The background and wider theoretical concerns to the project.
The development of Girli Concrete, highlighting the areas where craft becomes
art and art becomes science in the combination of textile and concrete
technologies.
The challenges of identifying funding to support such combination technologies,
working methods and philosophies.
The challenges of generating and sustaining practice within an academic
research environment
The outcomes to date