Water is an essential substance used in daily life. According to the UNESCO World Water Assessment Programme (WWAP), every year, 100 million people, 1 million sea birds and 1 lakh marine mammals die each year from water pollution [1]. Water is highly contaminated by industrial sludge, heavy metals, pesticides, organic dyes and other chemicals. Water pollution causes various diseases in humans. Even a tiny amount of dyes can affect the quality of water. The textile and paper industries emit many dye wastes during the colouring process [2]. Methylene blue is a heterocyclic aromatic dye that appears blue due to its oxidation and colourlessness during reduction. Methylene blue causes rapid heartbeat, hallucinations, fever, nausea, vomiting, diarrhea and loss of coordination. Methylene blue dye is non-biodegradable and causes many health problems and environmental pollutions [3]. Traditional methods cannot effectively decompose methylene blue. Photocatalysis is the only process that completely degrades dye without any sludge or by-products. Because it is widely used to treat dye molecules due to its being inexpensive, environmentally friendly, and because no sludge was eventually observed [4]. Activated carbons are widely used as an active material to degrade methylene blue because of their large surface area and porous structure. Activated carbon is used in various applications from the environment, wastewater treatment, mercury removal, water purification, and gas purification to energy storage, super-capacitor and battery [5]. Rice husk [6], Wheat straw [7], Corncob [8]. Hazelnut shells, walnut shells and peanut shells [9], egg shells [10] and Coconut shells [11] were used in agricultural biomass-derived activated carbon. Activated carbon is synthesized using various synthesis processes such as Pyrolysis, physical activation, and chemical activation. The physical activation process requires high temperature and pressure to convert carbon. Chemical activation can be accomplished in a single step by performing out the thermal decomposition of raw material with chemical reactions. Chemical activation processes are carried out with acidic reagents, ZnCl2, H3PO4, HCL, and H2SO4 or with essential reagents such as KOH, K2CO3, NaOH, and Na2CO3. Due to their high stability and capacity of electronic transmission, carbonaceous materials are an ideal candidate for stabilizing hybrid systems and inducing photocatalytic energy.
Zhang et al., 2021 [12] reported that the carbon stalk derived hydrothermally treated activated carbon for the photodegradation of methylene blue removal and achieved a degradation efficiency of 99.4 % at 150 mg/L concentration methylene blue. Nizam et al., 2021 [13] reported that rubber seed and shell derived activated carbon for cationic methylene blue removal. The π-π interaction and hydrogen bonds cause methylene blue removal. Wang et al., 2020 [14] obtained activated carbon by using phosphoric acid as an activation agent by the integrated corncob hydrothermal carbonization technique. Activated carbon showed a surface area of 480 m2/g. The dye removal capacity of activated carbon increased from 41–82%. Emrooz et al., 2020 [15] prepared Azolla-derived micro and mesoporous activated carbon to remove methylene blue. In this current report, Jasmine flower-mediated activated carbon provides 94 % maximum degradation efficiency at the end of 120 min. The observed results were compared with previous reports. The hydrothermal carbonization technique is one of the straightforward, most environmentally friendly, time management, and energy-efficient processes for integrating nanoparticles. The primary purpose of this research is to develop a low-cost, high-performance absorbent at a shallow temperature Lin et al., 2021 [16]. The activation agent NaOH helps to improve the surface area and enhances photocatalytic activity.
In this present work, we aim to synthesis using simple and conventional carbon, an inexpensive hydrothermal carbonization technique using jasmine flower as a biomaterial. The catalytic activity of activated carbon by decomposing methylene blue dye under UV irradiation. In addition, the biological activities of activated carbon at different annealing temperatures were tested against various microbial pathogens.