Contribution to the Society
The iron and steel sector is frequently seen as one of the primary drivers of a country's economic and technological development. Globalization and industrialization have fueled huge expansion in the past. Global crude steel output totaled 89.6 million metric ton in 2015. Steel consumption is increasing across all industries, and so is water consumption. In India, for example, making a metric ton of steel necessitates 60 m3 of water.
Unfortunately, steel and metal production is also linked to large-scale pollution. Processes, cooling, descaling, and dust cleansing all need water. However, only a little amount of water is really consumed, with the majority being reused or released. Fresh water is typically utilized for processing and cooling, while seawater is typically used after pretreatment in once-through cooling systems.Water cannot be totally remedied for reclamation using traditional treatment methods, but newer techniques such as membrane separation offer significant promise.Hazardous substances such as benzene toluene xylene (BTX) and polycyclic aromatic hydrocarbons (PAH), cyanide, ammonia, thiocyanate, phenols, and cresols can be found in typical steel industry waste streams. These compounds present challenges for treatment.
Treatment Process Involved
Treatment stages can include many different technologies.Physical separation, which might include gravity settling, screening, and oil removal, are commonly used in primary stages, but membrane technology is also now a good alternative to traditional separation.In the steel industry, water recovery entails cooling and desalinating water to manage salt content in circulation systems, as well as reducing fresh water consumption and outflow while enhancing steel quality and equipment service life. Membrane separation, chemical treatments, reverse osmosis, and ultrafiltration can be combined to achieve a high level of contaminant removal and deliver reusable effluents that are easier on equipment, more environmentally friendly, and more cost-effective than discharging untreated water into the environment.
RO In Steel and Metal Industry
Consumers may be familiar with reverse osmosis (RO) from under-sink water treatment systems, but RO is employed in a wide range of applications and scales. Reverse osmosis can purify unusable water to the point that it's almost completely free of health and esthetic concerns.To understand how reverse osmosis works, it's necessary to first grasp what osmosis is. Osmosis is the molecular kinetic energy-driven movement of liquids through a semi-permeable membrane. It is, for example, the process by which cells in biological systems move water.Reverse osmosis, on the other hand, uses pressure to drive liquid through a semi-permeable membrane. Water molecules pass easily across a reverse osmosis membrane due to their tiny size, whereas minerals and pollutants with larger molecules are halted. Membranes are made up of a number of materials, the most common of which are ceramics and polymers.
Reverse osmosis is utilized in a variety of applications, including ice production, hemodialysis, saltwater desalination, CIP water recovery, manufacturing, and effluent water reuse (RO ranked first among technologies amenable to water reuse in a recent study of water industry specialists). RO is widely used alongside other treatment methods such as dissolved air flotation (DAF), disc filtration, ultrafiltration, UV treatment, and advanced oxidation processes as one step of treatment. Treatment systems featuring a RO component may require extensive customization to fit specific supplies and meet regulatory requirements.
High-rejection, low-pressure, heat-sanitized, and fouling-resistant membranes are the four types of membranes utilized in RO. In RO, fouling is a recurring issue. Because scale can accumulate on membranes, conditioning feed water and flushing membranes is routine practice to extend membrane life and prevent clogging, deterioration, or encrustation.