To design a treatment system that effectively removes high levels of organic pollutants from industrial wastewater in a cost-effective and environmentally sustainable manner, we can consider the following steps:1. Preliminary treatment: The first step involves screening and sedimentation to remove large solid particles and debris from the wastewater. This can be achieved using bar screens, grit chambers, and sedimentation tanks.2. Primary treatment: In this stage, we can use oil-water separators, such as gravity-based separators, coalescing plate separators, or hydrocyclones, to remove oils and greases from the wastewater. These methods are relatively simple, cost-effective, and can remove a significant portion of the pollutants.3. Secondary treatment: To further remove organic pollutants, we can employ biological treatment processes, such as activated sludge systems, trickling filters, or constructed wetlands. These processes use microorganisms to break down and consume the organic pollutants, converting them into less harmful substances like carbon dioxide, water, and biomass. This method is environmentally friendly and can achieve high removal efficiencies.4. Tertiary treatment: For cases where even higher removal efficiencies are required, advanced treatment methods can be used. These may include adsorption using activated carbon, membrane filtration, or advanced oxidation processes AOPs such as ozonation, Fenton's reaction, or photocatalysis. These methods can be more expensive but are highly effective in removing residual organic pollutants.5. Sludge management: The treatment process will generate sludge, which contains the removed pollutants and biomass. Proper sludge management is essential to ensure environmental sustainability. This can involve dewatering, stabilization, and disposal or resource recovery through methods like anaerobic digestion, composting, or incineration with energy recovery.6. Monitoring and control: Regular monitoring of the treatment system's performance is crucial to ensure its effectiveness and compliance with environmental regulations. This can involve sampling and analysis of influent and effluent wastewater, as well as process control measures to optimize the treatment system's operation.By combining these steps and selecting the most appropriate technologies based on the specific characteristics of the wastewater and the desired treatment objectives, we can design a cost-effective and environmentally sustainable treatment system to remove high levels of organic pollutants from industrial wastewater.