Treatment of Combined Acid Black 48 and Coffee Wastewater by Low-Cost Adsorbents

Abstract

Removal of synthetic dyes from wastewater is essential both from the environmental and human health point of view. A small concentration of synthetic dyes can reduce water transparency and consequently influence photosynthesis and alter aquatic ecosystems. Acid black 48 is an Azo dye that falls under the category of synthetic dyes used in the textile industry. With dyes, coffee wastewater has high chemical oxygen demand (COD) that can affect dissolved oxygen (DO) in surface waters. A mixture of wastes in surface waters creates a need to investigate the efficiency of existing treatment methods and optimize them. Adsorption using activated carbon is a conventional method used to remove dyes and heavy metals from wastewater. Industries prefer efficient and economical treatment methods to meet challenging effluent standards regarding COD, BOD, and intensity of color. The adsorption process was optimized using low-cost adsorbents in the current study, including peanut hull and onion peel, to treat a binary mixture of acid black 48 and coffee wastewater. After adsorption, microfiltration was used to remove any suspended solids from the wastewater solution. The performance of combined treatment processes for the color removal of the binary mixture was analyzed and compared using transmittance and absorbance. Treatment efficiency of adsorption using low-cost adsorbents was compared with powdered activated carbon. Apart from absorbance and transmittance, non-purgeable organic carbon (NPOC) values were analyzed to determine organic carbon removal in the combined binary wastewater. Experimental results indicated that Langmuir isotherm was the best fit for a binary mixture with an optimum dosage of 1.2 g using onion peel. The regression coefficient value was 0.82, and the uptake was 58.13 mg of binary mixture per 1 g of onion peel. The effective pH for maximum uptake of acid black 48 using onion peel for adsorption was 5.7. The increasing dosage of low-cost adsorbents adsorption improved in removing binary waste of dyes and coffee waste from wastewater. Adsorption using onion peel improved adsorbent performance up to 1.2 g dosage and steadily decreased beyond that. The adsorption capacity of onion peel was comparatively higher than the peanut hull based on the linear fit.

Comparison of dye wastewater treatment methods: A review

“…Coagulation and flocculation treatment processes have been used to remove color and organic pollutants from dye wastewaters [25,26]. Low cost adsorbents have been used to remove color from various dye containing wastewaters [27,28,29,30]. One type of low cost adsorbents is agriculturally based adsorbents, which have been employed for decolorization of dye containing combined wastewaters [31,32].…”

Estudo Cinético Da Fotólise Direta De Corantes Alimentícios E Têxteis Em Fotoreator De Fluxo

“…No entanto, em conjunto com o grande desenvolvimento de produtos e serviços, determinadas atividades industriais produzem resíduos tóxicos, compostos muitas vezes por materiais orgânicos concentrados com coloração intensa. Tais substâncias são denominadas como corantes, sendo utilizados em diversas áreas como: farmacêutica, têxtil, alimentícia, celulose, couro e tintas (BENJELLOUN et al, 2021, CRINI et al, 2019MITTAL, 2020;PAMULA;HUNG;PAUL, 2020). Além disso, os corantes apresentam uma gama de aplicações de alta tecnologia, a citar: biomédicas, células solares, impressão a laser, terapia fotodinâmica entre outras (GRČIĆ et al, 2014).…”