EFFECTS OF BACTERIA SOLUTION PHYSICAL PROPERTIES ON SPRAYING DISTRIBUTION WITH VARIOUS TYPES OF NOZZLES

Over two billion tons of municipal solid waste is generated annually worldwide, with 33% not environmentally safely managed. Bacillus subtilis with Tryptic Soy Broth (TSB) culture media has been proposed as a precipitate solution to help accelerate waste decomposition. Given the sheer size of waste landfill, the solution is to be sprayed from a nozzle system attached to a drone. This study aims to experimentally study the effects of the physical properties of the bacteria solution on spraying distribution with various types of nozzles including spiral, full cone and flat fan. A test chamber is constructed to conduct the experiments where a nozzle is positioned over an array of 15x15 square containers for collecting the dispensed liquid. An investigation of bacteria density was besides conducted with purpose to study bacteria densities in the different position under the spray area. The results show that when spraying the bacteria with culture media, the coverage is significantly reduced due to culture media viscosity. Using statistical methods, different nozzles exhibit various characteristics of bacteria spray deposition patterns. Wider spray angles result in lower density of bacteria deposition. The contribution of this study is the experimental data of flow uniformity coefficient and spray pattern of bacterial solution which can be further researched into drone flight control manual for waste disposal purposes.