Removal of ammonia by biofilters with straight and wavy lamellar plates

Abstract

The aim of the study was to evaluate the performance of two newly developed plate-type biofilters in treating air contaminated with ammonia vapour at different inlet air temperatures (24, 28, and 32 °C). The biofilters had two different structures, straight lamellar plates (SLP) and wavy lamellar plates (WLP), with both having a built-in capillary system for humidifying the packing material made of synthetic hydrophilic fibres and wood fibre. In the packing material of the biofilters, different types of microorganisms were used, including bacteria, micromycetes and yeast. The efficiency of ammonia removal from the air using the biofilters with the two different plate types was investigated. The treatment efficiency of air-containing ammonia vapour reached 81.0–85.2% and 84.2–87.0% in biofilters with SLP and WLP, respectively. The highest ammonia treatment efficiency was obtained in the biofilter with WLP at 28 °C with 87.0% of ammonia being removed. The latter removal efficiency was obtained when a large population of the microorganisms was present with 1.0 ± 0.2 × 107, 1.0 ± 0.5 × 107 and 1.6 ± 0.1 × 109 CFU/g of micromycetes, yeast and bacteria, respectively. The results also demonstrated that at different temperatures of polluted air, different microorganisms predominated in the packing material of the biofilters.