Project Lead(s): Guillermo Villa
Arsenic exposure is a public health problem of particular concern to many developing countries.
In countries such as India, China, Pakistan, Argentina and Peru, the levels of arsenic in ground water are often above the permissible limits of 10μgL-1.
The team's goal was to design and build intradomiciliary filters for treating drinking water contaminated with arsenic that would be suitable for rural communities in Peru, using zerovalent iron encapsulated in chitosan gel.
Chitosan traps arsenic and can be easily obtained from crustaceans in the Peruvian sea.
Chitosan-iron is a stable molecule and traps arsenic under varying pH levels and the presence of other ions.
The team synthesized chitosan extracted from chitin of squid pens and obtained nanometric zerovalent iron. They then stabilized the iron in biopolymer chitosan.
Biosorbent surface analysis was then conducted by scanning electronic microscopy, followed by assessment of the removal capacity of the biosorbent in water from the Sama River, where the team carried out the trials.
Finally, the team designed and constructed a filtration system and assessed its removal capacity using surface water, also from the Sama River. They also took urine samples from the population and analyzed them for arsenic.
The team found that the synthesized material, based on chitosan and zerovalent iron, was highly efficient in removing arsenic from drinking water, with average concentrations of 22.61 ug/L following the filtration process.
No noticeable reduction of arsenic levels in urine was observed, possibly due to other sources of arsenic contamination (such as food and soil).
In order to observe a reduction of arsenic urinary levels from an exposed population, the team feels it will be necessary to carry out an intervention study for a period greater than six months.
Knowledge of the project was disseminated in conferences.