REDUCTION OF COD FROM REACTIVE DYE WASTE WATER
Vansita Suthar
INTRODUCTION.
Due to the scarcity of water resources, it is crucial to safeguard public health and well-being. One way to achieve this is by enforcing stringent regulations on the discharge of wastewater effluents to minimize the introduction of harmful substances into water bodies. Furthermore, there is a growing trend to reduce total solids (TS) in wastewater and repurpose them for industrial applications. The treatment of wastewater to a high standard has expanded the potential uses while reducing negative impacts on freshwater ecosystems.
Currently, the main environmental issue in wastewater treatment is related to dye effluents. This is because the textile industry consumes a substantial amount of water, resulting in wastewater that contains unused colours and their constituents. Dye-containing wastewater produced by the textile sector is extremely toxic and poses severe challenges for wastewater treatment facilities. Textile effluents contain high levels of colour, TDS, and hazardous metals, which have reduced the ability of contaminants to self-degrade in wastewater. Numerous techniques, such as chemical oxidation, coagulation and adsorption processes, as well as biological processes, are employed to remove dye using traditional methods, but none of these are sufficient on their own to remove dye from wastewater. For instance, biological processes are unsuitable for decolourization of dyes since the majority of the colours are inorganic and harmful to the process microorganisms. Activated carbon is effective for treating soluble colours, while coagulation is better suited for insoluble dyes but not for soluble ones. Due to the product of their degradation, most dyes in particular reactive dyes cause serious environmental problems. Due to the complicated structure and refractory nature of dyes, the degradation of colours from textile effluent is exceedingly hard. Wastewater produced in textile manufacturing plants may contain both natural and synthetic pollutants, the composition of which depends on the production techniques employed. Several parameters are commonly used to evaluate the characteristics of textile wastewater, such as Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD), Suspended Solids (SS), Dissolved Solids (DS), pH, Chloride, Sodium, and others. The quality of textile wastewater is determined by these parameters, and it is important to take them into account when selecting appropriate treatment methods to ensure that the environment is not adversely impacted.
