Aquatech Delivers an Advanced Effluent Treatment Plant for Leading Global Steel Manufacturer
| Challenge: | The complexity of toxic effluents, including chromium and zinc, poses a formidable challenge to the Cold Rolling Mill's commitment to environmental compliance and operational efficiency. |
| Solution: | Aquatech has developed an effluent treatment plant solution tailored to effectively address diverse effluent streams while also meeting stringent disposal standards. |
| Result: | The implementation of Aquatech's treatment system addresses the unique challenges presented by the steel plant's multi-effluent streams. |
This project profile details how a leading global steel producer navigates regulatory compliance and manages rising freshwater costs by incorporating a wastewater treatment system designed to meet the planned manufacturing expansion of its cold rolling mill.
Rolls of steel at a Cold Rolling Mill
A global steel producer is expanding its manufacturing capacity in India, a water-scarce region. This includes integrating a wastewater treatment system for its Cold Rolling Mill, which is critical for ensuring regulatory compliance and effectively managing rising freshwater costs. The priority is a reliable effluent solution that meets disposal regulations.
Challenge
The Cold Rolling Mill complex generates multiple effluent streams, some of which contain chromium and zinc, which are highly toxic and a major issue in steel manufacturing. Addressing fluctuating effluent characteristics in this plant presents a unique challenge to its efficient operation.
As a result, when designing the plant, it is critical to select construction materials for the equipment that can handle various effluent streams, whether acidic, alkaline, oily, or chromic. Additionally, the design must incorporate a robust energy-efficient scheme to reduce power consumption and meet the stringent disposal regulations.
Addressing these challenges is crucial for achieving and maintaining long-term operational consistency. We aim to design a treatment system that operates reliably, maintaining uninterrupted operations 24/7/365.
Solution
The steel plant generates different effluent streams, including waste concentrated alkaline water, waste diluted alkaline water, demineralized water mixed with detergent and oil, chromic wastewater, waste oily water, and various acidic wastes. Aquatech has developed a comprehensive, cost-effective effluent treatment plant solution tailored to effectively address these diverse streams while also meeting stringent disposal standards for biological oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), oil and grease, iron, chromium, and zinc.
The chromium-containing effluent stream is treated separately in batches to neutralize the chromium before being combined with the other streams for overall treatment. A floating-type oil skimmer is employed in the collection tank to remove free oil from all effluent streams.
Effluent Treatment Plant Process Flow Diagram
For streams with high oil and gas content, a multi-stage oil removal process is utilized, incorporating API, TPI, and dissolved air flotation (DAF) units. The API and TPI units are designed to operate at temperatures above 45°C (113°F). A post-separator tank extracts residual zinc from the mixed stream.
After removing oil, grease, zinc, and iron, the effluent stream is routed to biological treatment units to remove the remaining residues, BOD, and COD. Sludge generated from the oily, biological, and chromium streams is handled by separate filter presses. Recovered slope oil from these processes is repurposed as a resource within the main steel processing plant.
Treated Water Quality at the Outlet
Result
Aquatech’s effluent treatment system is designed to significantly reduce critical feed water parameters including BOD, COD, free oil, emulsified oil, zinc, and chromium. By effectively targeting these constituents, our solution not only addresses the unique challenges presented by multi-effluent streams of the steel plant but also reflects our commitment to environmentally friendly practices.