Many people including scientists, consumers, regulators, investors, and business and government leaders believe that climate change is a result of human-caused environmental harm, and its price tag is becoming too high to ignore. Managing wastewater is a significant challenge and companies produce both hazardous and non-hazardous wastewater as a result of their manufacturing and production systems. How industries manage waste can affect the environment, and in turn their financial health. Today, there is a growing urgency around climate protection that is increasing pressure for environmental accountability in all business decisions. The liquid waste management market generates a large revenue globally owing to rising number of manufacturing activities that result in the generation of toxic chemicals.
What is Liquid Waste Management?
Liquid waste is defined as industrial or household liquid waste such as wastewater, fats, oil or grease, cleaning fluids or pesticides, or the by-products of manufacturing processes, that may be hazardous or potentially harmful to human health or the environment.
Types of industrial waste include – inorganic wastewater, organic wastewater, RCRA wastewater with heavy metals or organics, non-hazardous wastewater, oil and water mixtures, CERCLA hazardous wastewater, TSCA, and RCRA/TSCA and non-TSCA PCB wastewater.
Liquid waste management is a procedure to prevent discharge of pollutants to the drain system or water bodies as a result of creation, collection, and disposal of hazardous or non-hazardous liquid material. This treatment process efficiently deals with all types of liquid waste, resulting in salvageable metals and oils, and clean water that can be reused in other operations or returned to the water cycle.
Sources of liquid waste include residential areas – that are domestic and over populated, commercial and industrial areas, and through natural disasters like flood, earthquake, tsunami, etc.
Liquid Waste Disposal and Treatment
Proper treatment and disposal of liquid waste is essential. Improper disposal of liquid waste can inflict immense damage on the surrounding environment and can disrupt the balance of aquatic ecosystem, destroy natural habitats, and cause biodiversity loss. They can contaminate the groundwater and surface water sources in which humans and animals rely for various purposes.
There are general regulatory requirements relating to waste, additional regulations apply to generating, storing, transporting, treating and disposing of hazardous and liquid wastes.
Wastewater pre-treatment is a critical step in getting water ready for a traditional wastewater treatment facility where it can be safely reintroduced back to the environment.
Depending on specific wastewater, pre-treatment solutions can help minimize demand on local publicly owned treatment plants (POTWs), recover oil for fuel blending, recover solids for compost or energy recovery, remove contaminants unsuitable for traditional wastewater treatment.
Wastewater treatment involves the following process:
- Removal of contaminants like oil, dissolved solids and metals, etc., by physical and chemical treatment (chemical oxidation and reduction, acid/base neutralization, chemical precipitation of metals, flocculation, carbon adsorption, stabilization through encapsulation, oil/water separation)
- Biological water treatment
- Evaporation (where water is boiled off and remaining solids are sent for composting or energy generation)
- Destroying wide range of waste streams and contaminants with the help of Liquid Direct Injection technology (treatment at very high temperatures)
- Turning organic waste streams into renewable energy by anaerobic digester facilities
The sewage treatment involves four processes – collection and pumping, preliminary treatment, primary treatment, and secondary treatment.
Some disposal methods involve – dewatering (pumping the liquid waste into a sturdy bag that removes the water, leaving only solid waste), sedimentation (similar to dewatering, it separates water from solid waste using gravity instead of centrifugal force to pull the two states of matter apart), composting (removing the water from the waste, leaving behind organic matter and turning them into organic fertilizer using natural microorganisms), root-zone treatment (a complex method that sends liquid waste through a sedimentation tank and then through various additional filtration processes), and solidification (involves adding binding agents to wastewater until the waste forms a compact, rigid, easily disposable solid).
No single disposal technique is most effective for every case. When choosing a liquid waste disposal method, it is important to consider certain aspects in mind. Some of the few considerations are – solid formation and stability, land space, waste quantity, necessary treatment, well and surface water sources, water table level, and relative costs of disposal technologies.
Wastewater treatment infrastructure has grown slowly over the past decades. Many of the treatment plants currently in operation are having a difficult time to keep up with the amount of liquid waste that is being generated, which results in over-spill into lakes and rivers. The global liquid waste management market is expanding significantly. To protect the environment and help industries run sustainably, it is important to manage liquid waste with expertise.