Mineral Sulphur Hot Springs

Tiered Approach to Successful Construction of Sulfate Rich Water Passive Treatment System

J. Robinson  SLR Consulting Limited, UK

I. Andrews  SLR Consulting Limited, UK

J. Dodd  SLR Consulting Limited, UK

L. Josselyn  Linkan Engineering, US

J. Gusek  Linkan Engineering, US

E. Clarke  St Gobain Limited, UK

 

Abstract

A passive sulfate reduction system with iron scrubbers was identified as the most viable option for treatment of elevated sulfate within leachate from an old landfill and bench scale trials were established in 2019 at the site to test the theory. This included the use of Biochemical Reactor (BCR) with different proportions of wood chips, straw, manure, limestone, and biochar to culture sulfate reducing bacteria.  In addition the concept of ‘bugs on booze’ was trialled, using Fix Bed Anaerobic Bioreactor (FBAR), where alcohol added to enhance the sulfate reducer activity.  In total three BCRs and two FBARs were set up for this stage of the assessment.  The resulting treated leachate was then passed through different iron media types (haematite, magnetite and iron filings) to remove sulfide generated by the bacteria, with an aerobic wetland used to polish the effluent. The use of sand filters was also implemented to aid the treatment. The success of the bench scale project led to a pilot scale system being constructed and monitored in Spring 2020, the results of which confirm the success of the bench scale testing and provides useful insights into management of the system particular in winter months. The COVID crises has had its impact but the system has operated continuously and will run through 2021.

Keywords: passive treatment, sulfate reduction, biochemical reactor, wetland, pilot plant

 

As a technical leader in the field of geochemistry Jamie Robinson has over 30 years’ experience in the prediction and treatment of metalliferous mine drainage and designs passive treatment technologies globally.  He has developed a geochemical modelling approach to predicting the quality of pit lakes formed as part of mine closure schemes. Jamie predicts water quality as part of feasibility studies for proposed mining schemes and at closure.  This has included gold mines in Europe, Chile, Ireland, Canada, USA  and Australia. Jamie has studied epithermal gold deposits in Chile including understand the formation geochemistry. Jamie has developed a variety of innovative and award-winning investigation and remediation techniques for the assessment and mitigation of soil and groundwater contamination. This work has led to over twenty publications in the scientific community. Jamie has lectured in Australia and UK and is an examiner for the Specialist in Land Condition (SiLC) qualification and a scrutineer for the Royal Geological Society. Jamie also acted as an external examiner for Strathclyde University and Glasgow University.  Jamie is currently acting as a Qualified Person on a number of large-scale restoration projects in the UK and was awarded the status of Suitably Qualified Person (through the National Quality Mark Scheme) in 2017.  Jamie has also acted as Expert Witness in the UK regarding to hydrogen cyanide vapor risks to humans and for a proposed gold mine in the UK.