A simple and highly efficient approach towards the degradation of methylene blue and study the impact of degraded water on seed germination of cicer arietinum

Abstract

The scarcity of fresh air, drinking water, and soil is a matter of serious concern worldwide owing to the presence of organic pollutants in the environment. The organic dye, such as methylene blue (MB) have enormous toxic effects on the environment and human health. Therefore, the degradation of non-biodegradable dyes is very important to reduce toxicity in water and-a step towards waste water management systems. This paper focuses on the degradation of non-biodegradable MB dye using carbon quantum dots (CQDs). CQDs were synthesized by a microwave irradiation method using citric acid and L-cysteine as precursor and confirmed by X-Ray Diffraction (XRD), Raman Spectrum, Fourier Transform Infrared Spectroscopy (FTIR) and Energy Dispersive x-ray (EDX) spectroscopy techniques. The optical properties of the synthesized CQDs of 2.56 nm, were investigated by UV-visible spectroscopy technique and the absorption peak appeared at 340 nm which corresponding to n → π * transition. In photoluminescence (PL) spectra analysis, the highest emission peak was obtained at 440 nm when excited at 345 nm. The synthesized CQDs were used for the dye degradation of MB in distilled water and degradation percentage was calculated and found to be 99.17% in 90 min under UV light irradiation. Also, studied the impact of degraded water in seed germination of Cicer arietinum (black gramme) and calculated the seed germination growth rate in degraded water was found to be 15%–20% more than the seed germination growth rate in MB containing dye water.

Keywords

• carbon quantum dots (CQDs)
• photocatalytic activity
• methylene blue dye