As supply of natural resources such as water, energy and raw materials become increasingly finite, waste management technologies are emerging as a key area of focus for many industries.
Adding to that pressure are rising waste handling and disposal costs and new environmental regulations facilitating a shift away from landfill.
This all raises demand for innovative new methods of reducing waste generation through waste treatment and recycling.
The benefits of a circular economy based on sustainable industrial waste management has prompted companies to establish efficient collection and processing systems
Monika Chrusciak, energy and environmental research analyst, Frost & Sullivan
According to researcher Frost & Sullivan, new laws for industrial waste treatment are also helping to drive the industry, which it estimates will earn global revenues of $750bn by 2020.
“The benefits of a circular economy based on sustainable industrial waste management has prompted companies to establish efficient collection and processing systems, therefore fuelling market revenues,” says Monika Chrusciak, energy and environmental research analyst at Frost & Sullivan.
Smart collection and processing are particularly important in a scenario where mixed material industrial waste presents low economic value, says Chrusciak.
An example is the sludge that often results from treating wastewater.
A zero liquid discharge is what some within industry are beginning to aim for says David Martin, vice president of Nalco Water in Europe and MEA.
Nalco Water services a range of process industry sectors looking to minimise their water footprint.
This can be achieved through a number of means such as reuse from one application to another, and recycling.
“Companies are trying to be more responsible in the way they manage water, and by using less water you produce less waste,” he says.
While chemistry is evolving new ways to treat water, Martin says monitoring and automation technologies are allowing far more accurate responses from equipment to process fluctuations such as the flow rate.
This provides useful data and insights that allow operators to better reduce water footprint, he says.
As landfill solutions become more tightly regulated, manufacturers may also need to examine alternative methods for the disposal or treatment of sludge.
“Although legislators [in Europe] are very familiar with energy and carbon footprint issues, only now are they starting to look more closely at the waste element,” he says.
Companies are trying to be more responsible in the way they manage water, and by using less water you produce less waste
David Martin, vice president of Nalco Water in Europe and MEA
Companies must also consider the future availability of water when making investment decisions.
For this purpose, Nalco has developed a tool that allows them to establish a ‘shadow’ price of water supplies, reflecting its future cost for developing long-term strategies.
“When water is not as available, it means they can still continue to do what they are doing today,” says Martin.
There are also tightening regulations in regard to the disposal of wastewater says John Moroney, UK & Ireland business support manager at Hach.
“Water can either go via sewer to a local wastewater treatment works or to a receiving body of water like river or sea,” he says.
However, there are a lot more directives coming out of Europe to dictate conditions around this, he says.
Hach supplies instruments for quality or environmental testing activities across a range of process industries.
In the food and dairy industry, its technology is used for testing organic wastewater to remove nutrients and suspended solids.
For wastewater processes, its real time control solutions have been designed to either save energy or chemical consumption.
“For example, in the aeration process, you only need to add the correct amount of air according to the ammonium load. However, many [operators] over-aerate, which is less energy efficient,” says Moroney.
Using real time control, the system can react to fluctuating levels of ammonium by taking signals from an analyser that is measuring ammonium levels in water.
“This is put into an algorithm…and that then provides a set point to the operator’s aeration control system, allowing them to save energy.”
In the mix
Other Hach applications improve sludge management by managing the amount of polymer used in the mixture.
“The solids taken from the wastewater must be treated separately using a sludge processing plant,” says Moroney.
“It is thickened through a dewatering process and then dewatered to achieve the right concentration, so it can be disposed of by lorry, landfill or incineration.”
Between these two processes, the sludge can be digested, producing methane gas that in turn can be used to generate electricity. The amount of electricity generated depends on the gas yield, which depends on the stability of sludge concentration.
“To do you this, you must add chemicals (typically a polymer) to combine with solids to become thick enough. So you need to control the quantity in order to control the concentration of the sludge.”
The final treatment of water, often prior to its release to environmental watercourse, is another area of technology evolving in line with tightening environmental restrictions.
One of these is the new Priority Substances Directive – a list of micro-pollutants of priority concern that must be removed from discharge waters.
The final treatment of water, often prior to its release to environmental watercourse, is another area of technology evolving in line with tightening environmental restrictions
ATG UV has developed technology for the final treatment of wastewater streams to meet this directive.
This ultraviolet (UV) light technology is able to deactivate all known microorganisms for a range of industries including pharmaceutical, petrochemicals, the company says.
“In these industries UV light can be used for disinfection as an alternative to using chemicals,” says Paul Hennessey, oil & gas business manager at ATG UV.
This is because many industries, especially those offshore, want to reduce their use of chemicals.
“For the ultra-pure water used in steam generation, you can use high intensity UV light at 185nm to break down total organic carbon,” says Hennessey.
“The more pure the water, the less build-up on turbines and the chance of a blowout. Due to other equipment used in the process, chemicals often cannot be used.”
Ready for treatment
The oil and gas industries use a lot of produced water as a stimulation fluid for reinjection, says Hennessey.
But to re-inject water used in an oil or gas field, it must first be treated to get rid of any bacteria, residual chemicals and unwanted substances such as hydrocarbons and biocides.
These include sulfate-reducing bacteria (SRBs) which are generally dormant but can become highly active once in an anaerobic environment.
“You can cause significant damage to the reservoir and infrastructure if you don’t control the bacteria,” says Hennessey.
Another critical application is within the Blowout Preventer (BOP) Fluid used in safety valves used for subsea drilling – one of the things that failed in Deepwater Horizon incident.
“You have to keep that fluid sterile and free from particles because down at those pressures the BOP is like a Formula One engine where even the tiniest particle can create a problem,” says Hennessey.
Engineers at the University of Colorado Boulder have developed a wastewater treatment process that they say consumes carbon dioxide (CO2) emissions, and creates renewable energy as a by-product.
The new process, which they have named Microbial Electrolytic Carbon Capture (MECC), purifies wastewater using an electrochemical reaction that absorbs more CO2 than it releases.
Current wastewater treatment methods produce CO2 emissions by the burning of fossil fuels to power machinery, and decomposition of organic material also occurs within the wastewater.
The new process, which they have named Microbial Electrolytic Carbon Capture (MECC), purifies wastewater using an electrochemical reaction that absorbs more CO2 than it releases
MECC can use the natural conductivity of saline wastewater as the basis of an electrochemical reaction that absorbs CO2 from both the water and the air, the researchers say.
The reaction changes CO2 into stable mineral carbonates and bicarbonates that can be redeployed as a chemical buffer in the wastewater treatment cycle. The reaction will also release excess hydrogen gas, which may have potential use as energy for a fuel cell, the researchers say.
“This energy-positive, carbon-negative method could potentially contain huge benefits for a number of emission-heavy industries,” says Zhiyong Jason Ren, an associate professor of civil, environmental, and architectural engineering at CU-Boulder.