Improving Drinking Water Safety in Rural Communities: Experimental Removal of Bacterial Contamination Using Solar Disinfection and Natural Filtration Methods

Abstract

Unsafe drinking water remains a major health threat in rural communities. This paper compares experimental evidence for solar disinfection and natural filtration. It synthesizes published laboratory studies, field trials, and WHO evaluation reports from 1996 to 2024. The evidence shows that solar disinfection can produce large bacterial reductions when water is clear and sunlight is strong. Boyle et al. found complete inactivation for several vegetative bacteria under real sunlight, while spore-forming bacteria were harder to remove. Fontán-Sainz et al. showed that a 25-L compound parabolic collector reduced Cryptosporidium viability after eight hours, but turbidity slowed the process. Natural filtration also showed strong results. Stauber et al. reported a 97% geometric mean reduction in E. coli with a plastic biosand filter and a 60% reduction in diarrheal disease. Mwabi et al. found 2-4 log reductions with biosand and ceramic filters, and more than 5 log reduction with a silver-impregnated porous pot. The studies also show that filtration and solar disinfection work best together. Filtration lowers turbidity and improves sunlight transmission. Solar disinfection then adds disinfection without fuel or chemicals. The combined train is simple, low cost, and suited to rural settings. Its success still depends on training, water storage, and local climate. Keywords: solar disinfection, biosand filter, rural water safety, bacterial contamination, household water treatment.