CST Wastewater Solutions managing director Michael Bambridge explains that while the volume of beer being produced remains constant, there is now far greater concentration in the industry on the disposal of waste produced in the water-intensive production process.
Despite an overall decline in alcohol consumption, waste management challenges in brewing beer still exist, as overall beer production has remained fairly constant as a result of the near doubling of the population.
It’s a far cry today from 50 years ago, when Australians topped the world for beer consumption at 190 litres a head for adults – and New Zealanders weren’t far behind, on 180 litres.
Under the impact of health campaigns, low-alcohol beers, alternative tipples, and lifestyle changes wrought by public good campaigns, overall beer consumption in terms of total alcohol consumed per capita, has roughly halved.
Australia now no longer makes the top 10 beer drinking nations by volume now – that distinction goes to the Czech Republic – while Australia and New Zealand are about in 17th and 27th place respectively.
CST’s wastewater technologies range from advanced filtration and liquid-solid separation used by craft breweries and other food and beverage producers, right up to Global Water & Energy anerobic digestion technologies that produce more than 50 million cubic metres a year of wastewater effluent, from which typically 90-99 per cent of organic contamination (contained oxygen deficit, or COD) has been removed. Using anerobic digestion to produce biogas from waste, the technologies use this energy to feed heat processes, generate local electricity and replace fossil fuels. Installations typically offer ROI times of 5-7 years before going on to contribute to operators’ bottom lines after they have fully paid for themselves.
The advanced filtration and liquid-solid separation technologies are particularly relevant to craft brewers, of which there are some 700 in Australia and 150 in New Zealand.
Bambridge says that craft brewers globally are very aware of sustainability, and there is a major push among all brewers – including the large brewers which own many of the craft operations – to make their operations more sustainable.
“The best brewers are becoming sustainability leaders, recycling their wastewater, and ensuring wastewater returned to the environment goes back at a higher quality than when it was taken from the environment (up to 99 per cent COD removed). Importantly, solid waste produced during brewing is being re-routed from scarce, expensive, and hazardous landfill to on-site dewatering, compaction and recycling to reduce the impacts on water tables in Australia and New Zealand, where clean-green credentials are increasingly important to a social license to operate.”
“Reducing waste from brewing operations (and any food and beverage process) produces benefits that can pay for themselves in increasingly short ROI cycles,” said Bambridge.
First line of defence
A first line of defence in a brewer’s WWTP is the screening in headworks that precede downstream wastewater treatment. This headworks stage is where organic and non-organic detritus is screened out of the inlet water, so as to help prevent environmental spills, and to ensure water quality processes downstream can function reliably and at their highest levels.
A Rotary Drum Screen is an ideal first line of defence in these applications, because it can capture floating solids that would otherwise flow through a wastewater treatment plant, potentially causing costly equipment damage and blockages.
CST’s Australian-manufactured Rotary Drum Screens have outstanding 0.5-3mm or finer screening at high flows, typically up to 2,000 litres per second. The capacity to screen down to 0.5mm means the screens are not only protecting processes downstream, but doing the local environment a major service by removing plastic nanoparticles that are emerging as a major environmental issue.
The screens are designed with all components located above the wastewater flow, which simplifies maintenance, with routine servicing possible without removing the drum. No mechanical components come into contact with screened solids, so there is no opportunity for premature wear from solids impacting internal workings of the screen.
“Not only does local manufacture deliver a more robust and low-maintenance product – and better whole-of-lifecycle value – but it places the customer next to the source of supply for spare parts, future extensions, and retrofits to boost performance long-term,” said Bambridge.
The switch to local production also enables us to offer full stainless-steel products with world-respected standards of Australian metals engineering, replacing carbon steel components and further improving corrosion resistance in harsh local environments.
Avoiding landfill waste
Avoidance waste going to landfill is also a rapidly expanding priority. As boutique craft breweries proliferate throughout Australia and New Zealand, their operators are very conscious of the environmental and sustainability credentials they present to their buyers and local communities, which extends beyond outstanding taste of the product into how it is made in a sustainable manner that appeals to the majority under-50 age groups who buy the distinctive products.
Landfill facilities are increasingly scarce and costly, because of the environmental issues including potential water table issues of which Governments are keenly aware. Even getting waste to these facilities is expensive – transport alone can be $200 a ton – and then there are the OH&S hazards of loading sticky heavy waste, and the environmental hazards of spills onto public roads.
Bambridge says drier, lighter and more compact waste – which can be more easily recycled – is increasingly becoming the responsible and cost-effective alternative to landfill.
One of CST’s highly effective solutions to dewatering and wase management is the KDS Multidisc Roller system which requires no wash water, while capturing 90-99 per cent of solids. KDS units can handle 310kg of dry solids an hour. They are engineered to overcome the limitations of technologies such as screw presses, belt presses and centrifuges typically employed by small-to-medium applications to treat the sludge produced by their operations.
“One larger craft brewer with which we are involved (which cannot be named for contractual reasons) has cut is solids waste volume by 90 per cent by weight and volume through using advanced KDS dewatering technology, as a primary treatment. This produces dry, healthier, and lighter material that is easier to recycle and far less harmful to health and water tables than the wet, sticky, and hard-to-handle solids waste that are often part of the brewing process,” said Bambridge.
The dryness achieved on volumes of four cubic metres of wastewater an hour was complemented by the KDS’ reduced polymer usage of 10 litres a month, with filtrate being recycled for treatment in the on-site sequencing batch reactor (SBR).
“Not only does this compact dryness cut the amount of process waste that might otherwise go to landfill – thereby reducing risk to water table leakage – but also it curtails the need for trucks emitting fossil fuel to transport it by public roads to specialised and expensive waste management centres.”
“The KDS technology – which is used in Australia and New Zealand to reduce the environmental impacts of food, beverage, agricultural, and municipal projects – produces dry output that is ready for recycling into fertiliser or for other uses.”
KDS applications also include thickening and dewatering of Dissolved Air Flotation (DAF) sludge – a very common wastewater application – a process in which the KDS achieves solids capture of 95-99 per cent sludge at a dryness of 15-20 per cent. Waste activated sludges are typically 15-18 per cent dryness. This high quality, Japanese-manufactured technology uses minimal energy, consuming as little as 0.06kW hr of electricity.
The technology is also available in a skid-mounted version, making it highly suitable for municipal and remote industrial worksite waste handling, where its cost-effectiveness and low-maintenance operation is a major advantage particularly where engineering support may be far distant.
This whole-of-lifespan value, as distinct from a race to the bottom on sticker price, is a mature engineering approach in meeting and continuing to meet users’ tasks that vary from place to place, day-to-day and week-to-week as loads on the system change.
“Our engineering approach is not one-size-fits-all, because one size (or type) does not. Our horizontal in-channel rotary drum screening technology, for example, is built from the outset to be both robust and adaptable, not to be cheaper up front, but to transfer cost and problems down the line,” said Bambridge.
