Exploring the Efficacy of Ulva lactuca in Industrial Wastewater Treatment: A Sustainable Approach

ABSTRACT

The toxic and persistent organic and inorganic elements in oil refinery effluents, such as heavy metals, dyes, and phenolic compounds, significantly release harmful pollutants into water bodies. Refinery wastewater treatment  is  essential  to  meeting  the  growing  water  demand  and  safeguarding  downstream  users  from  health hazards. Marine algae are one of the most popular adsorbents and biofilters for treating industrial effluent, and they have many advantages over other materials. These include being readily available in large quantities, having various  functional  groups  (such  as  carboxyl,  hydroxyl,  sulfate,  and  phosphate),  inexpensive,  and  being environmentally acceptable. In this research, green seaweed, “Ulva lactuca,” was naturally found in the batch treatment of refinery wastewater in the most efficient, cost-effective, and environmentally friendly way, utilizing limited resources.  The  surface  morphological  characterizations  of  the  seaweed  before  and  after  treatment  are carried out using Scanning Electron Microscopy (SEM). A series of batch experimental studies were carried out to  remove  organics  from  refinery  wastewater  by varying  the  effluent  solution pH,  mixing  time,  stirring  speed, algae  dosage,  and  effluent  solution  temperature.  The study mainly focused on determining parameters like Chemical Oxygen demand COD), Total Dissolved solids (TDS), Total Suspended solids (TSS), Turbidity, and Dissolved oxygen before and after treatment. The study demonstrates that the optimal efficiency of the treatment process occurs at a pH of 6, with 90 minutes of stirring time, a dosage of 0.8-1 g of Ulva lactuca, a stirring speed of 60-140 RPM, and a solution temperature of 35°C. The experimental results of the present study demonstrate that  green  seaweed,  Ulva  lactuca,  is  an  eco-friendly  and  cost-effective  biosorbent  for  effectively  removing contaminants from refinery effluent. Ulva lactuca exhibited excellent pollution removal efficiency, significantly reducing chemical oxygen demand, dissolved oxygen, turbidity, dissolved solids, and suspended matter.