Effect of Reactive Black 5 azo dye on soil processes related to C and N cycling

Abstract

Azo dyes are one of the largest classes of synthetic dyes being used in textile industries. It has been reported that 15–50% of these dyes find their way into wastewater that is often used for irrigation purpose in developing countries. The effect of azo dyes contamination on soil nitrogen (N) has been studied previously. However, how does the azo dye contamination affect soil carbon (C) cycling is unknown. Therefore, we assessed the effect of azo dye contamination (Reactive Black 5, 30 mg kg−1 dry soil), bacteria that decolorize this dye and dye + bacteria in the presence or absence of maize leaf litter on soil respiration, soil inorganic N and microbial biomass. We found that dye contamination did not induce any change in soil respiration, soil microbial biomass or soil inorganic N availability (P > 0.05). Litter evidently increased soil respiration. Our study concludes that the Reactive Black 5 azo dye (applied in low amount, i.e., 30 mg kg−1 dry soil) contamination did not modify organic matter decomposition, N mineralization and microbial biomass in a silty loam soil.

Ligninolytic enzymes in Basidiomycetes and their application in xenobiotics degradation

“…High concentration of azo dyes can cause skin and mucous membrane ulcerations, respiratory tract irritation, nasal septum perforation, dermatitis, hemorrhage, diarrhea and vomiting. When released to surrounding waterbodies these dyes impair the quality of aquatic life, increase the chemical and biological oxygen demand (COD and BOD), reduce photosynthesis and favor toxicity [156,157]. The presence of the color reduces the oxygen levels and additionally hinders the treatment of these waters.…”

Acid modification of lignocellulosic derived material for dye and heavy metals removal: A review

“…Textile dyes are also poisonous, mutagenic, and carcinogenic agents that persist as pollutants in the environment and span entire food chains, causing biomagnification, in which species at higher trophic levels show higher levels of contamination than their prey [63,64]. Specifically, 15-50% azo dyes do not bind effective during fabric dyeing, which are eventually released into the water bodies [65]. These dyes have a negative effect to soil microbial communities and consequently affect the germination and growth of plants [65,66].…”

A critical review on advances in the practices and perspectives for the treatment of dye industry wastewater

“…Hence, they lead harmful effects on ecosystem [14]. Various reports are available which shows harmful effects of azo dyes on plants (plant growth and germination) [15][16][17][18].…”