Activated Carbon Services
At WRc we have established in-house capability to provide independent technical assessment of micro-contaminant removal by activated carbon, using batch isotherm tests for PAC and small-scale rapid column tests (RCTs) for GAC.
These laboratory scale tests offer a proven alternative to pilot plant trials for comparing GACs, and predicting full scale plant performance, within periods of only a few weeks. WRc has extensive experience in carrying out RCTs, and facilities for carrying out the tests on up to four GACs or suites of compounds in parallel.
The results from these tests can be used in the WRc GACman simulation model, to evaluate alternative designs and operating scenarios for full-scale GAC plant.
Micropollutant removal from water
The demand
With an ever-changing contaminant profile and evolving regulatory constraints, potable water treatment faces a constant challenge to find the most cost-efficient way to remove specific micro-contaminants. These can include pesticides, algal toxins, taste and odour compounds, and pharmaceuticals.
The method
Activated carbon is an effective and proven treatment for removal of natural and polluting micro-contaminants from water. Available as powdered carbon (PAC) or granular carbon (GAC). There are many suppliers, grades and carbon source materials, and the relative performance of GAC types can differ considerably depending on the nature of the water and contaminant.
The problem
A GAC bed would be expected to last at least a year, making pilot plant trials impractical and expensive for comparing GACs. The capital cost of activated carbon as well as the operating costs of regenerating the material when it is spent are significant. As a result, selection of the most cost-effective product for each application and the monitoring of residual capacity for part-spent GAC are vital tools in controlling those costs.
- Characterisation and condition assessment
- Physical analysis of virgin media or core samples
- Hydraulic performance of filter media utilising our pilot scale facilities
- Initial screening of GAC products by batch isotherm testing
- Leaching characteristics of GAC utilising our pilot scale facilities
- Generalised adsorption capacity (Iodine number tests)
- Contaminant specific adsorption capacity for GAC using continuous flow RCTs
- PAC selection and dose requirements using contaminant specific isotherm tests
- GAC performance modelling utilising WRc GACMan software