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A new and cost-effective adsorbent N-TRAP, made from waste wood-shavings and anaerobically digestion biosolids and impregnated with H2SO4, was applied for the ammonia removal from air stream and biogas with high efficiency and effectiveness. Bearing a 75–80 and 65wt.% sulfuric acid, the N-TRAPs mediated with wood shavings and biosolids showed the maximum ammonia adsorption capacity of 260–280 and 230mgg−1, respectively. Gas temperatures (20 and 60°C) and moisture content (100% relative humidity) had no significantly negative effect on ammonia capture performance when temperature in the fixed-bed column was kept equalled to or slightly above the feed gas temperature. The pressure drop increased significantly when NH3 began to break through the N-TRAP stripper due to the formation of ammonium sulfate blocking the vacuum space of packed adsorbent. At last, an alternative N-TRAP filter bed design was proposed to resolve the problem of pressure drop evolution. [Copyright &y& Elsevier]

Abstract: In this study, powdered activated carbon (PAC) was used to remove polyvinyl alcohol (PVA) from the aqueous PVA solution. The adsorption kinetics has been studied pertaining to various initial PVA concentration and PAC dosage. The rates of adsorption were found to conform to the second-order kinetics with good correlation. Boyd plot confirmed that external mass transfer was the rate-limiting step in the sorption process. The adsorption isotherm obtained resembled with H-type of isotherm, which indicated a high affinity of the solute for the sorption sites. The Freundlich model appeared to fit the isotherm data better than the Langmuir model. The thermodynamic parameters such as ΔH°, ΔS° and ΔG° were evaluated from the slope and intercept of linear plot of log K c against (1/T)×1000. The change in entropy (ΔS°) and heat of adsorption (ΔH°) of PAC was estimated as 1.45kJmol−1 K−1 and 365kJmol−1, respectively. The free energy of the adsorption at all temperatures was negative indicating a spontaneous process. The maximum PVA removal of 92% was obtained at a pH of 6.3 and contact time of 30min for an adsorbent dose of 5g/L. [Copyright &y& Elsevier]

A new and cost-effective adsorbent N-TRAP, made from waste wood-shavings and anaerobically digestion biosolids and impregnated with H(2)SO(4), was applied for the ammonia removal from air stream and biogas with high efficiency and effectiveness. Bearing a 75-80 and 65 wt.% sulfuric acid, the N-TRAPs mediated with wood shavings and biosolids showed the maximum ammonia adsorption capacity of 260-280 and 230 mg g(-1), respectively. Gas temperatures (20 and 60 degrees C) and moisture content (100% relative humidity) had no significantly negative effect on ammonia capture performance when temperature in the fixed-bed column was kept equalled to or slightly above the feed gas temperature. The pressure drop increased significantly when NH(3) began to break through the N-TRAP stripper due to the formation of ammonium sulfate blocking the vacuum space of packed adsorbent. At last, an alternative N-TRAP filter bed design was proposed to resolve the problem of pressure drop evolution.