Coal fly ash as adsorptive material for treatment of a real textile effluent: operating parameters and treatment efficiency

Abstract

The experimental results performed after the application of one single-stage treatment by sorption onto coal fly ash are evaluated in order to decolorize a real textile effluent of a private company specializing in manufacturing of cotton fabrics (i.e., sorption performance applied for a real textile effluent collected after the fabric dyeing, rinsing, and final finishing steps). The experiments are focused on studying the effect of initial textile effluent pH, adsorbent dose, temperature and adsorption time, considered as operating parameters of sorption process for high pollutant removals (e.g., organic pollutants as dyes, phenols, polymeric, and degradation compounds), and decoloration. The results indicate high values of decoloration degree (55.42-83.00%) and COD removal (44.44-61.11%) when it is worked at pH ≤2 with coal ash dose of 12-40 g/L, temperature higher than 20-25 °C, and continuous static operating regime (with an initial agitation step of 3-5 min). The treated textile effluent fulfills the quality demand, and is recyclable, inside reused or discharged after a stage of neutralization (standard pH of 6.5-8.5 for all textile effluent discharges). Also, the final effluent is able to follow the common path to the central biological treatment plant (i.e., a centralized treatment plant for all companies acting in the industrial site area with mechanical-biological steps for wastewater treatment) or may be directly discharged in the nearly watercourse.

Industrial Cellolignin Wastes as Adsorbent for Removal of Methylene Blue Dye from Aqueous Solutions

“…The Hazen color index represents the conversion of absorbance measured at 456 nm to Hazen units (HU) (i.e., an absorbance of 0.069 at 456 nm corresponds to 50 HU) (Zaharia and Suteu 2012b). The limits of HU units imposed by environmental legislation are < 200 in surface water and < 50 UH in sewage systems (Anjaneyulu et al 2005;Zaharia 2008).…”

“…The advantages and disadvantages of each technique have been extensively reviewed (Anjaneyulu et al 2005;Zaharia and Suteu 2012b;Latif et al 2010;Suteu et al 2009;Han et al 2011;Hubbe et al 2012;Salleh et al 2011;).…”

“…In this process, a substance (soluble dye) from the liquid phase (wastewater) is transferred to the surface of a solid, highly porous material (adsorbent), to which it binds physically or chemically (Zaharia and Suteu 2012b). The adsorption technique is preferable to other wastewater treatment techniques in terms of efficiency, low cost, simplicity, ease of operation, and inactivity towards toxic substances.…”

“…Moreover, the specific advantage of this method is that the adsorbent can be chosen from a large variety of materials. The selection of an adsorbent is based on the following requirements: high selectivity and capacity of adsorption, favorable kinetic features, physico-chemical stability, mechanical strength, ease of regeneration, and availability at low cost (Zaharia and Suteu 2012b). Unconventional low cost materials are used more and more as adsorbents in dye-containing wastewater as alternatives to conventional adsorbents, such as activated carbon or synthetic polymers, in order to avoid several disadvantages related to the latter (high cost, difficulties in preparation and/or regeneration, pollution resulting from their manufacture).…”

Preparation of rice husk carbon-clinoptilolite composite adsorbent for color removal from real textile wastewater: Effects of operating conditions

“…Accordingly, various type of adsorbents have been studied and tested for the removal of dye waste water including coal fly ash [5], bituminous coal [6], rattan [4], rubber tire [7] rice husk [8] and natural clay [9].…”