Many businesses produce liquid waste. These can range from by-products of industrial processes through to something as simple as used dishwater in pop up kitchens at festivals or sporting events. All of these need to be disposed of in the correct manner – so what are the different types of liquid waste and how should businesses effectively handle and dispose of them?
Examples of Liquid Waste
There are so many different types of liquid waste, it is impossible to list them all here. These range from the incredibly benign to the exceptionally toxic and hazardous. Each of them has to be treated in a different way – hence businesses need to be aware of the type of waste they are going to be producing and should have procedures in effect to deal with such waste.
- Wastewater – This is often known as sullage – it is a water that is not clean, but does not contain human waste. Examples of sullage include rainwater, used dishwater, drain water etc. This is usually disposed of into the drainage system - however this may not always be possible due to the remote nature of some sites.
- Used Oils and Fats – Often created in large kitchens or take away shops, used oils and fats are those that have become dirty and contaminated during the cooking process and have to be disposed of in a special manner. These cannot simply be poured down the drains as they can lead to large problematic blockages in the sewers.
- Engine Oils and Lubricants – Many car shops and repair centres use a large amount of fluids and mineral oils that are used in cars and their engines, such as brake fluid and lubricants. When spent, these are considered to be liquid waste and have to be disposed of in the correct fashion.
- Chemical Solutions – In many industrial chemical processes, a number of different chemical solutions are produced as by products. These can range from inert salt solutions through to highly acidic and dangerous liquids. Each one will have its own rules concerning the disposal and workers who come into contact with such liquids will need special training in how it is to be handled.
Storing Liquid Waste on Site
Sometimes it is necessary to store liquid waste on a business site. In these instances special barrels should be used that are clearly marked with the appropriate hazard warnings for the liquid. Once a barrel is used for one type of liquid waste it should never be used to store a different type of waste due to reactions that could occur within the barrel. If barrels are used to store dangerous waste, such as acids and other chemical solutions, then they must themselves be contained within a special built up area known as a bund. This is a walled enclosure that will contain any kind of spill from a broken barrel. Hence there are very specific guidelines about how bunds must be constructed and the amount of barrels that can be put into them. Bunds are not just used for small barrels either – if you go to a large liquid waste processing unit where huge amounts of liquid waste are stored then they’ll often be a large walled bund that will surround the containers, ready to impede the flow of liquid in the event of an accident.
Removal of Liquid Waste from Site
In most cases businesses will need to employ a third party company who can take liquid waste off your site. It may be that the waste has a value and can be recycled as is often the case with many different types of cooking fats and oils and companies may even pay a small amount to collect this off your site – there are examples on the internet of businesses that will offer small cash bonuses for your cooking oil. These collections agencies use staff that have been trained in the dangers of handling different types of liquid waste and are insured against accidents. When they have collected the waste this is taken to a central processing plant where it is treated and separated into usable parts.
Liquid Waste Treatments
There are a number of ways in which different types of liquid waste can be treated, which vary on the type of waste and it’s component parts. Some of the most common include:
- Recycling – Certain chemical solutions can be sent to treatment centres where they’re mixed with other reagents, turning them into new chemical compounds that can be reused in different industry sectors. It’s also possible for some oils and fats to be cleaned and re-sold or used in the production of bio-fuels.
- Centrifugation – This is the process of separating two liquids in a centrifuge. The more dense liquid will move towards the outside of the machine, whilst the less dense liquid will move towards the axis, allowing the waste processing unit to extract one chemical solution from another.
- Belt Press Thickening – If you need to process sludge then belt press thickening will allow you to remove the water from viscous, mud-like liquids and leave behind solid cakes of substance that can be disposed of further.
- Natural Processing – In recent years there has been a strong move towards natural liquid processing, for certain types of human created liquid wastes, where the liquid is put through a large amount of different size grit particles that can remove the larger waste particles. There have even been schemes for natural land processing units in India, where plants and algae are used to remove impurities from the water.
There are so many different types of liquid waste that it is impossible to create a one size fits all strategy to deal with every single kind of waste a business might produce. It is always necessary for any business that produces such waste to create a viable strategy for storing, removing and treating their waste when they set up their business model. The most important thing for such companies to remember is that tipping any liquid waste other than dishwater or rainwater into the local drainage system is illegal and carries large penalties, so a system for dealing with liquid waste has to be ready from the get go.