The contamination of water sources due to industrial wastes containing dyes and phenolic compounds has led to a decline in water quality. Water pollution causes adverse human health and environmental issues. Treating industrial wastewater before it enters water bodies using novel materials and innovative processes is crucial to achieving the United Nation’s Sustainable Development Goal (SDG) #6. These pioneering solutions hold the key to revitalizing our water bodies, preserving life, and paving the way for a cleaner, healthier world. This research focuses on offering cost-effective and sustainable solutions to environmental pollution, particularly from wastewater treatment. The adsorptive and catalytic properties of activated carbon in treating harmful organic compounds using adsorption and catalytic ozonation processes are the focus of the current work.
An inexpensive, and sustainable method to synthesize activated carbon (AC) from renewable waste biomass using an integrated furnace-microwave process is proposed. The biomass precursor sourced from thornbush, an environmentally nuisance, offers a renewable, cost-effective, and abundant source of raw material for the sustainable production of AC. The activated carbon prepared using the integrated activation method was superior to the conventional methods.
Further, the effect of phosphoric acid and potassium hydroxide as activating agents on the physicochemical properties of activated carbon was investigated. A sequential I-optimal experimental approach was used to optimize the integrated synthesis process. Comprehensive characterization of optimally synthesized activated carbons was performed using SEM, EDX, BET, FTIR, TGA, and point of zero charge analysis. Additionally, the effectiveness of the optimally synthesized activated carbons was assessed in treating 4-nitrophenol and real industrial wastewater in batch as well as continuous packed bed column.
The activated carbon was used as a catalyst in the advanced oxidation process using ozone for faster and more rapid degradation of pollutants in industrial wastewater. An airlift reactor was designed to enhance liquid circulation and activated carbon suspension, which led to intensified Chemical Oxygen Demand (COD) removal. The initial COD of 3000 mg/L in an industrial dye bath effluent could be reduced by 80% within 30 minutes in this reactor. The performance of the airlift reactor was much superior to that of the conventional semi-batch reactor and bubble column. The effect of feed concentration, catalyst dosage, pH, and ozone concentration on COD removal were investigated. The integrated treatment process carried out in the airlift reactor was optimized. The catalytic activity and reusability of catalysts in treating organic compounds is demonstrated.

Keywords: Prosopis juliflora; Activated carbon; Furnace-Microwave activation; Adsorption; Catalytic ozonation; Airlift reactor; Design of experiments; Industrial effluent treatment