Numerically Optimized Effects of Contact Time Factor of Pulverized and Modified Bio-Adsorbents on Nitrogen Removal Rates in Industrial Wastewater

Abstract

This study investigated the effect of contact time of two agricultural wastes (cassava peels and ripe plantain peels) used as bio-adsorbents that were modified with base and acids to ascertain their ability to absorb nitrogenous compounds from hospital and abattoir wastewater. The absorbents were prepared using standard procedures into powdered forms and a portion was modified with acid and base respectively. Fourier Infrared spectroscopy was used on the prepared absorbents to determine the organic and functional groups present. Each modified bio-adsorbents was used to inoculate each of the 250 ml flasks containing the wastewater sample. Contact was allowed to be made for 14 hours and the nitrogen removal rate was measured and recorded. The Nitrogen concentration in the wastewater was determined using Ultra-violent spectroscopy. Response surface optimization was used to investigate the effect of contact time on the nitrogen removal rate. Models were generated to analyze the interactions between variables at optimum conditions. The results showed that the bio-adsorbents have the ability to remove nitrogen from wastewater. The nitrogen percentage removal recorded was 57%, 81%, and 77%, 55%, 91% ,and 78% respectively. The R2 from ANOVA was seen to be 96.5%, 97.9%, 97.9%, 98.2%, and 99.7%, and 97.9% repectively. Experimental results were best fitted into linear and quadratic polynomial models. The optimum conditions having desirability of 0.964 showed that the time of 13.558 hrs. The values obtained are a good indicator that the bio adsorbents used in this should be considered by the chemical industries in the process of absorbent design and production.