Our planet’s surface is predominantly composed of water but it is crucial to realize that we are disposing of waste material into these aquatic ecosystems. Essentially, we are tainting the very water that could serve our needs. However, the environmental repercussions of wastewater extend beyond just this aspect and harm the entire ecosystem wherein wildlife is also affected by this water pollution. There is an urgent need to take stringent action against water pollution from both household sewage and industrial wastewater.
Wastewater treatment procedures
The concept of wastewater treatment encompasses the intricate procedure of eradicating impurities found in wastewater, originating from sources like municipal sewage systems or diverse industrial operations. These meticulously engineered methods are crafted with the intention of elevating water quality and aligning with the stipulated benchmarks for effluent purity. Establishing a resolute and economically viable approach to wastewater treatment stands as the cornerstone for enhancing well-being and fostering ecological resilience.
Various government agencies such as the US Environmental Protection Agency and Environment & Climate Change Canada oversee wastewater management activities. The EPA mandates the preliminary treatment of industrial wastewater within production facilities before it is discharged into municipal sewer systems. Notably, the presence of oils and metals within wastewater poses a risk to municipal treatment plants, resulting in undesired pollutants discharged into freshwater bodies.
Semiconductor wastewater treatment
Copper has been massively used in electronic semiconductors, but the generation of copper-rich effluents from electroplating causes massive hazardous waste. This waste stream, laden with elevated levels of hydrogen peroxide, presents a major challenge as conventional on-site effluent treatment processes are unable to handle it effectively. Consequently, most semiconductor manufacturers resort to enlisting certified waste contractors to collect and treat these plating solutions offsite.
Remarkably, semiconductor manufacturers have spearheaded a proactive drive towards integrating metal recovery methodologies, notably through electrowinning, as a means of not only efficiently extracting copper, but also neutralizing hydrogen peroxide. While electrowinning technology has long been a stalwart in the mining & metals industry, its versatile applications are being utilized in wastewater treatment today.
Innovative electrowinning technology
In order to remove metal contaminants in wastewater, an electrowinning process is used where anodes and cathodes are placed in a solution that’s still or moving slowly. The direct current released at the anode causes metal ions to deposit on the cathode. Over a period, the metal decreases and if there are impurities in the solution, the metal’s purity drops.
Further, air bubbles are formed at the anode point in the conventional electrowinning processes. However, as these bubbles ascend to the anode’s surface, they rupture, thereby liberating sulfuric acid – a menacing element known as acid mist – into the atmosphere. This chemical poses an imminent threat to the well-being of facility employees, highlighting the need for stringent safety measures. Moreover, the corrosive nature of this acid mist drastically diminishes the longevity of crucial plant components.
An innovative electrowinning technology designed by emew corporation eliminates the scourge of acid mist. The emew process operates within a fully enclosed setup, containing all gases within its system. Notably, this self-contained design eliminates the necessity for supplementary ventilation, ushering in an unprecedented benchmark for Health, Safety, and Environmental performance. Benefits of emew technology include higher purity, better recovery, more efficiency, and lower costs.
With emew’s electrowinning technology, the solution moves quickly through a closed space, removing any places where the metal could run out and making the reclaimed metals purer. Each emew cell has a tube made of stainless steel that’s 150mm to 200mm wide. The anode goes through the middle of the tube and the inside of the tube acts as the cathode. While the solution goes from the bottom to the top of the cell, DC voltage creates an electric difference between the anode and cathode. After the metal has plated for the right amount of time, the cathode is harvested from the cell.
Cost-effectiveness of electrowinning technology
This novel electrowinning process comes at a high cost for manufacturers to integrate this metal recovery methodology in their waste management process. While the yield of marketable copper is quite low when compared to may the financial investment required for this novel electrowinning process, the substantial savings hitherto spent on external waste management contractors rationalize this venture.
There is a compelling case of a pioneering semiconductor manufacturer who implemented a compact electrowinning facility tailored for copper plating waste treatment and achieved a notable return on investment within a year. In addition, the company’s annual production of up to 60,000 lbs of saleable copper stands as a testament to the feasibility and efficacy of this endeavor. Furthermore, a striking outcome materialized as they successfully slashed their hazardous copper waste shipments by a staggering one million gallons annually.
Mining leachate treatment
Similarly, in the realm of copper mining, avenues can be explored to minimize the environmental repercussions of mining. Heap leaching technique is used in mines to recover copper from low-grade oxide deposits. As with any hydro-metallurgical process, there is an intrinsic need to bleed a portion of electrolyte for impurity control. Recovering high-grade saleable copper from such bleed streams using emew electrowinning technology decreases copper tenors returning to the heap, enhances leach efficiency and improves overall copper recovery from the heap.
Further, the integration of proven methodologies such as emew Ion Exchange, any leachate stemming from mining operations can be neutralized and ensure minimizing environmental harm. This process ensures the effective removal and oxidation of toxic substances, preventing their introduction into ecosystems. emewIX has innovated a a seamless 1-2 step solution tailored for copper mine waste challenges offers an array of transformative advantages. This synergistic approach resonates particularly for copper mines seeking augmented copper yield, optimized cash flows, and minimized ecological impacts.
