Electrocoagulation (EC) is an electrolytic process that is used mostly for wastewater and industrial process water treatment. Due to its unique ability to remove contaminants such as emulsified oils, suspended solids and dissolved metals, electrocoagulation has become one of the fastest growing technologies in this area. There are various devices and systems that comprise the basic principle of electrocoagulation which I would like to explain in this article.
Objectives of advanced green technologies
Advanced green technologies (AGTs) refer to a group of practical methodologies and materials based, among others, on non-toxic chemical processes, clean energies, and environmental monitoring to slow down or correct the negative impact induced by human activities.
As copper continues to be a rich and desired resource for a variety of products such as electrical wire, building infrastructure, electronics and other technology alike, copper process plants have responded by striving to continuously optimize and capture as much copper as possible from their mining processes.
Mining processes have always looked for different ways to optimize their operations such as saving water, using less energy, and minimize on-site waste streams or tailings. Some of these optimizing techniques have included process water recycling from clarified tailings, transfering energy between solutions in heat exchangers, incorporating more gravity controlled flows between processes instead of using pumps, or recovering lost metal from waste streams.
Billions of litres of wastewater are treated every year in wastewater treatment plants around the world. This wastewater, both industrial and municipal, can contain various pollutants depending on the source. Wastewater may contain soap, waste products, food scraps, human waste, oils and in some cases, metals. The main goal of wastewater treatment is to preserve the environment and keep the pollutants out of rivers and oceans.
What is wastewater effluent?
Effluent is generally considered to be water pollution. According to Wikipedia effluent is an outflowing of water or gas from a natural body of water, or from a manmade structure. United States Environmental Protection Agency defines it as "wastewater - treated or untreated - that flows out of a treatment plant, sewer, or industrial outfall. Generally, refers to wastes discharged into surface waters". Wastewater is any water that is affected in quality by human impact on the environment.
Approximately 10 years ago copper became an important metal in semiconductor manufacturing. Copper offers much better conductivity and lower power consumption compared to aluminum for back end of line (BEOL) interconnects.
Usage of copper however produces a concentrated copper waste that contains hazardous chemicals like copper sulphate and sulphuric acid.
"I only feel angry when I see waste. When I see people throwing away things we could use."
– Mother Teresa
What is Metal Finishing?
Metal finishing is a type of surface finishing that can be defined as the deposition of a metallic coating onto a product either to enhance performance, function or aesthetic qualities while providing overall added value. While it's not obvious on a daily basis, many objects have been subjected to metal finishing for use in our normal lives. These include parts in a car, aircraft, fencing, medical and dental devices, industrial machinery or even beautiful pieces of art. The term finishing is based on the fact that it's normally the last step of the manufacturing process (save for any heat treatment).
Clean, fresh water is a luxury in many countries and is increasingly becoming a valuable commodity. Our society today is faced with the challenge of harnessing the power of advanced wastewater treatment technologies to preserve our precious water resources. Not only does this apply to municipal water treatment plants that work around the clock to make sure communities all over the world have access to clean, fresh water, but also in industrial processes to minimize usage and waste.
Many industrial processes in the automotive, textile, manufacturing, mining, oil & gas, and jewelry sectors are designed to reuse process water as much as possible. Even the most cleverly designed processes however require a 'bleed' or outlet to prevent the build up of impurities that can affect the quality of the finished product if not properly dealt with.
Presently only 20% of globally produced wastewater receives proper treatment.
- United Nations Educational, Scienctific, and Cultural Organization (UNESCO)