Detoxification and Multi-Resource Recovery from Landfill Leachate

Lead Research Organisation: University of Sheffield
Department Name: Chemical & Biological Engineering

Abstract

Despite improved recycling infrastructure and public awareness, the UK still sends a staggering 17 million tonnes of municipal solid waste into landfill every year. This leads to the build up of leachate, the liquid which drains from a landfill site. Leachate contains trace chemicals, which can have strong contaminating effects on the environment, and therefore effective treatment methods are required. More to the point, however, ambitions for waste management should go beyond protection of human health and the environment, with conservation of energy and recovery of natural resources high on the agenda.

This translational project aims to demonstrate an integrated process for leachate treat went and resource recovery. It involves three innovations: a novel physical pre-treatment, enhanced treatment with adaptively evolved microbial consortia and resource recovery through efficient biomass harvesting, and hence, contributing to the UK circular economy. The outcomes cut across several NERC research priority themes e.g. 'sustainable use of natural resources' and 'environment, pollution and human health.'

Leachate can vary considerably in composition, depending on the age and type of waste within the landfill, containing both dissolved and suspended organic and inorganic material. Viridor Waste Management Ltd is the third largest waste management organisation in the UK, owning over 40 sites. Approximately half the sites use foul sewers to carry contaminated wastewater to a sewage works for treatment, the rest is either transported using tankers or released to surface waters. The total annual leachate production is 1,056,716 m3 and the operational costs vary between £4-£10 per m3 (e.g. disposal costs, energy or chemicals used).

The previous work includes isolation of natural microbial consortia from leachate, novel harvesting method development and estimation of potential resources recovered. The main translational activities in this project are to design and build a pilot scale photobioreactor that is fitted with all the innovations from previous NERC and non-NERC funded research. This will be installed by Varicon Solutions, TUOS Research Technician and staff at Viridor at a local landfill site (Erin). Pre-processed leachate will be fed into the photobioreactor and growth and operating parameters carefully monitored. The data will be used in a techno economic assessment for Viridor but also other end-users. An easy-to-use Resource Recovery calculator will also be created. The process will be filmed in time-lapse and used to make a video for marketing, knowledge exchange and educational purposes. Both the video and photobioreactor system will be demonstrated at a relevant Trade Show in late 2017/early 2018.

The ultimate aim is to demonstrate the progress of the NERC funded research up technology readiness levels with industrial, societal and environmental impact, together with economic benefits for the project partner and wider waste management community.

Planned Impact

Presently, the core of our infrastructure in regard to resource production as well as waste treatment relies on unsustainable means i.e. fossil fuels. A more viable approach is desperately required, where energy inputs are reduced or sourced renewably and resources are recycled. From this perspective, the most elegant template for engineering an ideal but complex system is a natural system where nothing is left unused; waste from one component is the resource for another. This project is inspired by a microfluidic device but also natural communities of microorganisms that form the basis of biological treatment of toxic waste. Biological treatment is often cheaper and more energy efficient than chemical and physical methods, but crucially, have reduced negative environmental impacts. The project is not solely focused on treatment but also on resource recovery and helping form a sustainable circular economy. By recovering resources from waste means efforts to gain resources by traditional energy intensive means can be reduced, for example, ammonia production by the Haber process or mining of metals. Microalgae will provide the mechanism for resource recovery and gain energy through photosynthesis, further confirming the sustainability of the approach.

The development of advanced engineering approaches and modifications to traditional landfill practice have been spurred on since the first European Directive in 1975 (Surface water 1975/440/EEC) where attempts have aimed to minimise the adverse impact of waste on the environment. However, the existence of contaminated leachate is an inevitable consequence of the process. Furthermore, regulatory standards (EU Urban Waste Water Directive 91/271/EEC) have become stricter. This project aims to develop an advanced and novel physical and biological based methodology that can be applied for treatment of a variety of wastes and therefore help achieve these standards.

The primary beneficiaries include the growing waste management industry. As well as more efficient and reduced cost of leachate treatment, the resources recovered can be used internally. For example, Viridor spend £25m per year on diesel and generating a liquid fuel from their waste would lower their demand for transportation fuel and overall carbon footprint. They also use heavy metals and recovering these would reduce purchasing costs.

Indeed, any industries related to water use including water companies, fisheries and tourism would see indirect impact of this research as treated leachate will reduce the chances of contamination of nearby ground and surface water. This includes recreational water use, e.g. fishing, water sports, swimming, boat clubs etc. Regulatory bodies such as the Environment Agency would benefit from improved water surface characteristics near landfill leachates, and land/water body owners such as the Canal and River Trust and Natural England will also feel the value.

Ultimately, the detoxification of leachate will benefit the natural environment, wildlife and society and increase the opportunity to achieve "good ecological status" (National UK Ecosystem Assessment by Defra). Currently, 95% of municipal solid waste (450-500 million tonnes) is disposed of annually Worldwide in landfills and this continuously contaminates surface and ground water. Furthermore, one tonne of landfill is estimated to generate about 125 m3 of greenhouse gases (65% CH4, 34% CO2) contributing to approximately 20% of the Worlds anthropogenic methane production and hence manmade global warming.

Finally, companies with expertise in photobioreactor technology required to cultivate the algal microbial communities will benefit from the knowledge created here.
 
Title Project short film "Engineering microbial consortia for resource recovery from waste" 
Description South Yorkshire's Film Makers Network produced a fantastic short film on this project which has been disseminated via several media channels and received lots of attention. 
Type Of Art Film/Video/Animation 
Year Produced 2018 
Impact Potential new industrial and academic collaborators. Invited speaker to Algae Tech conference (Munich September 2018). 
URL https://www.youtube.com/watch?v=h51Pw_7kZJw
 
Description We have methods to engineer the biology of microbial communities to not only improve existing industrial processes but add in extra functionality, such as resource recovery from waste. Previously the focus has been to control microbes by manipulating process parameters, e.g. temperature, mixing, aeration etc. but now we can select which microbes are there and for a specific purpose.

We have since won money from DASA (Ministry of Defence) to apply our research to "decarbonise the military" with a £300K one year grant.

The work was also published in Biology journal .

South Yorkshire's Film Makers Network produced a film of our research called Engineering microbial consortia for resource recovery from waste
https://www.youtube.com/watch?v=h51Pw_7kZJw
Exploitation Route We have submitted a new paper that succinctly shows a low cost, speedy method to identify keystone microbial species in waste sources and thereby construct a synthetic ecosystem for industry.
Sectors Agriculture, Food and Drink,Chemicals,Energy,Environment,Healthcare,Manufacturing, including Industrial Biotechology

URL https://www.youtube.com/watch?v=h51Pw_7kZJw
 
Description South Yorkshire Film Makers network have produced a 7 minute film of the project Funding through DASA (Ministry of Defence) to apply to their waste streams We will be providing similar solutions to the Indian Government and local Indian companies after winning the Urban UK India competition
First Year Of Impact 2021
Sector Environment,Manufacturing, including Industrial Biotechology
Impact Types Societal,Economic

 
Description Defence and Security Accelerator (DASA)
Amount £300,000 (GBP)
Organisation Ministry of Defence (MOD) 
Sector Public
Country United Kingdom
Start 03/2021 
End 03/2021
 
Description Engineering Microbial Consortia for Industry
Amount £18,443 (GBP)
Funding ID EP/S020705/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 12/2018 
End 05/2019
 
Description UKRI Interdisciplinary Centre for Circular Chemical Economy
Amount £4,436,401 (GBP)
Funding ID EP/V011863/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 01/2021 
End 12/2024
 
Description Greening Tinsley Project 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact We teamed up with Live Projects and had 12 architects working with us for 6 weeks. In the time, several workshops for school children were held as well as the design and build of an outdoor photobioreactor showing the merits clean air and the problems with traffic pollution. The final event was an open day at recently closed school, the Victorian era build was closed due to high levels of toxic pollution from the local M1.
Year(s) Of Engagement Activity 2018
URL http://www.liveprojects.org/2018/greening-tinsley/