The removal of ammonia from contaminated water by using various solid waste biosorbents

Abstract

Water is an essential natural resource for sustaining life and it is not free everywhere. Ammonia (NH3) in drinking water may be beneficial or harmful depending on their concentration in water. NH3 is colorless, pungent gas composed of nitrogen and hydrogen. The acute exposures to high levels of ammonia have also been associated with diseases of the lower airways and interstitial lung. Ammonia occurs naturally and is produced by human activity. It is an important source of nitrogen which is needed by plants and animals. The removal of ammonia from contaminated water by treatment with biosorbents is one of the most effective methods. Biosorption is a simple, economical and environment-friendly method for removal of ammonia from water. Every biosorbent had different physical, chemical and biological properties for removal of ammonia by biosorption from the water. The order of percentage removal of ammonia from water by using three different biosorbents was as follows: Orange peels> Coconut wire waste> Tea waste. The optimum sorption was obtained at basic pH is 4, dosage is 3.9gm, contact time is 60min, temperature is 30°C and agitation speed is 60rpm. In the SEM and XRD characterization observed that the particle size and crystallite size of orange peels biosorbent was 2.54µm and 3.02nm respectively with the end-centered cubic structures. In the FTIR analysis of orange peels biosorbents observed that the O-H, C-H, alkynes with -C=C- stretch, carbonyls, amines and aromatics group peaks are presence. In the BET characterization observed that orange peels biosorbents has a higher surface area (45.42m2/g) and pore volume (0.512cm3/g) as compared to other biosorbents. In orange peels biosorbents observed that the presence of heterogeneous surface with non-uniform distribution of heat adsorption and the adsorption process is multilayer. In the regeneration process observed that the reusing of orange peels biosorbent continuously for three times the adsorption capacity of ammonia from water reduced by 100 to 93.32%. This procedure can be made economical by regenerating and reusing of the biosorbent after removing the ammonia from water.