Treatment of Gaseous Ammonia Emissions Using Date Palm Pits Based Granular Activated Carbon.

Muhammad Vohra

doi:10.3390/ijerph17051519

Abstract

The present work investigated the application of granular activated carbon (GAC) derived from date palm pits (DPP) agricultural waste for treating gaseous ammonia. Respective findings indicate increased breakthrough time (run time at which 5% of influent ammonia is exiting with the effluent gas) with a decrease in influent ammonia and increase in GAC bed depth. At a gas flow rate of 1.1 L/min and GAC column length of 8 cm, the following breakthrough trend was noted: 1295 min (2.5 ppmv) > 712 min (5 ppmv) > 532 min (7.5 ppmv). A qualitatively similar trend was also noted for the exhaustion time results (run time at which 95% of influent ammonia is exiting with the effluent gas). The Fourier Transform Infrared Spectroscopy (FTIR) findings for the produced GAC indicated some salient functional groups at the produced GAC surface including O–H, C–H, C–O, and S=O groups. Ammonia adsorption was suggested to result from its interaction with the respective surface functional groups via different mechanisms. Comparison with a commercial GAC showed the date palm pits based GAC to be having slightly higher breakthrough and exhaustion capacity.

Highlights

An exponential increase both in the human population and related industrial activities, in the past century, has caused a significant increase in air pollution
Several experiments were conducted at varying influent gaseous ammonia concentrations, using granular activated carbon (GAC) column lengths of 6 and 8 cm
This is somewhat different from the adsorption of benzene onto date palm pits (DPP) based GAC that showed a sharp breakthrough curve [24]

Summary

Introduction

An exponential increase both in the human population and related industrial activities, in the past century, has caused a significant increase in air pollution. Several stringent environmental regulations have been promulgated, which do require an appropriate treatment of gaseous emissions, including ammonia (NH3 ), considering the respective toxicity and environmental concerns [1,2,3]. Considering the respective toxicity and health concerns, various technologies have been employed for the removal of gaseous ammonia including bio-filters [3,13,16,17], catalytic systems [18] biological treatment [11], scrubbers [5] and other specific technologies such as nano-particles applications [4]. Activated carbon from different carbon-rich sources including wood [1], palm shell [25], and coal and coconut shell [26] has been used for gaseous ammonia treatment. The respective modification methods include oxidation [27], acids [28], inorganic-agents [29], ozone [30], ZnCl2 , HNO3 and (NH4 ) S2 O8 [26], and aluminum-zirconium poly-cations [15]

Methods

Results

Conclusion