Dr Liping Pang is a Science Leader in the Environmental Science Group at ESR's Christchurch Science Centre.
Liping earned her PhD in Civil Engineering from the University of Canterbury and an MSc in Earth Sciences from the University of Waikato.
Liping's expertise is in experimental investigations into and modelling contaminant transport in porous media, particularly subsurface microbial transport.
In recent years, Liping has initiated multidisciplinary research into developing a new class of surrogates using biomolecule-modified particles to mimic pathogen transport and removal in water systems. So far, surrogates for Legionella pneumophila, Cryptosporidium parvum and rotavirus have been developed. Results from a preliminary validation study involving the novel Legionella biopolymer surrogate suggest it is promising for studying Legionella mobility and persistence in engineered water systems. The rotavirus surrogate has been validated in coastal sand aquifer media, in unmodified and hydrophobically modified quartz sand, and in stony alluvial soils under on-site wastewater applications. The Cryptosporidium surrogate has been validated in alluvial sand, and overseas researchers have also validated the surrogate in granular limestone aquifer media and in a pilot-scale water treatment plant. Working with Invercargill City Council, the Cryptosporidium surrogate was used to determine the relative protozoan removal efficiencies of rapid sand filters and point-of-use filters typically used in New Zealand.
Liping and her co-workers have also developed novel synthetic DNA tracers for tracking water contamination. So far, 20 different DNA markers, each with a unique identifier, have been developed. These tracers can be used either as free DNA or encapsulated DNA within biopolymer microparticles. Working with Environment Canterbury and Waikato regional council, these DNA tracers have been validated in surface water, groundwater and soil. Both free and encapsulated DNA tracers were easily detected at a distance of at least 1 km in a stream.
By analysing a large body of published data from field experiments, Liping has established an extensive database of microbial removal rates for a wide range of soils, vadose zones, and aquifer media under different environmental conditions. This database is widely used internationally to analyse water contamination risks, determine safe setback distances, and select suitable sites for land disposal of wastewater and sludge.
Liping’s other research includes
- Colloid-associated virus and phosphorus transport and bacteria-facilitated heavy metal transport in groundwater
- Modelling bacteria and virus leaching through intact soil lysimeters under effluent irrigation and microbial transport in groundwater
- Modelling nanoparticle transport in soils
- Modelling the cumulative impact of septic tanks on groundwater quality
- Determining setback distances for drinking-water wells based on transport of enteric viruses
- Evaluating the impact of on-farm livestock disposal on groundwater microbial quality
- Modelling pesticide leaching through soils and their transport in groundwater
- Studying the attenuation and transport of heavy metals, nitrate and phosphorus in aquifers
Liping has led 3 Marsden-, 2 HRC- and 1 MBIE Smart Ideas-funded projects, and she has been a key researcher on many FRST/MBIE programmes. She has a wide network of international collaborators.