• Korean Chemical Engineering Research
• /
• v.52 no.2
• /
• pp.191-198
• /
• 2014

A semi-pilot hybrid system composed of a photocatalytic reactor and a biofilter was operated under various operating conditions in order to treat malodorous waste air containing both hydrogen sulfide and ammonia which are major air pollutants emitted from composting factories and many publicly owned treatment works (POTW). When both hydrogen sulfide and ammonia contained in malodorous waste air were treated simultaneously by a biofilter system, its performance of ammonia removal was much more poor than that by a biofilter system treating waste air containing only ammonia, unlike its performance of hydrogen sulfide removal. For semi-pilot hybrid system, the removal efficiencies of hydrogen sulfide and ammonia turned out to be ca. 83 and 65%, respectively. Therefore, for semi-pilot hybrid system, the removal efficiencies of hydrogen sulfide and ammonia was increased by ca. 4 and 30%, respectively, compared to those of semi-pilot biofilter system (control). In addition, the maximum elimination capacities of hydrogen sulfide and ammonia for semi-pilot hybrid system turned out to be ca. 60 and $37g/m^3/h$, respectively. These maximum elimination capacities of hydrogen sulfide and ammonia were estimated to be ca. 9.1% and ca. 23.3% greater than those for semi-pilot biofilter system (control), respectively. Therefore, the semi-pilot hybrid system contributed the enhancement of removal efficiency and the maximum elimination capacity of ammonia in a higher degree than that of hydrogen sulfide, compared to the semi-pilot biofilter system.

• Membrane and Water Treatment
• /
• v.14 no.2
• /
• pp.85-93
• /
• 2023

Membrane separation is widely used for several applications such as water treatment, membrane reactors and climate change. Cross-linked organic-inorganic hybrid polyvinylidene fluoride (PVDF) / Tetraethyl orthosilicate (TEOS) was adopted for the preparation of optimized hollow membrane (HFM) for membrane distillation or other low pressure separators for mechanical properties and permeability under varying pretreatment schemes. HFMs were prepared on semi-pilot membrane fabrication system. Novel adopted post-treatment schemes involved soaking in glycerol, magnesium sulphate (MgSO₄), sodium hypochlorite (NaOCl), and isopropanol for different durations. All fibers were characterized for morphology using a scanning electron microscope (SEM), surface roughness using atomic force microscope (AFM), elemental composition by examining Energy Dispersive Spectroscopy (EDS), water contact angle (CA°) and porosity. The performance of the fibers was evaluated for pure water permeation flux (PWF). Post-treatment with MgSO₄ gave the highest both tensile modulus and flux. Assessment of properties and performance revealed comparable results with other organic-inorganic separators, HF or flat. In spite of few reported data on post treatment using MgSO₄ in presence of TEOS, this proves the potential of low cost treatment without negative impact on other membrane properties. The flux is also comparable with hypochlorite which manifests substantial precaution requirements in actual industrial use.The relatively high values of flux/bar for sample treated with TEOS, post treated with MgSO₄ and hypochlorite are 88 and 82 LMH/bar respectively.