Pomegranate peel as a new low-cost adsorbent for ammonium removal

Abstract

Since adsorption is one of the best ammonium removal methods, great efforts have been made to identify new low-cost and efficient adsorbents from agricultural waste and by-products due to their abundant availability, low-cost and eco-friendly advantages, in addition to the possibility of recycling ammonium back into agricultural processes. In this study, a series of batch experiments were performed to detect new bio-adsorbents for ammonium ions removal. Among the materials tested, pomegranate peel powder showed a high affinity to adsorb ammonium ions and, furthermore, available information on ammonium adsorption by this biomaterial is still missing from the literature. First, pomegranate peel powder was characterized by the determination of different parameters such as zeta potential, iodine number, Fourier-transform infrared spectroscopy analysis, scanning electron microscopy, particle size distribution and porosity. Then, the impact of various parameters, such as pH, contact time, stirring speed, adsorbent dose and adsorbate concentration in the adsorption process, was investigated. The highest ammonium removal capacity was obtained at pH = 4 using 400 mg of pomegranate peel powder and a stirring speed of 150 rpm for an initial concentration of ammonium of 30 mg/L. The system (adsorbent, adsorbate and solution) reached equilibrium after 2 h and the data fit well with the Langmuir model with a maximum monolayer adsorption capacity of 6.18 mg/g, while kinetics were well described by the pseudo-second-order model. These results introduce pomegranate peel powder as a promising bio-adsorbent to remove and recover ammonium from aqueous solutions.

Effect of Acid Flow Rate, Membrane Surface Area, and Capture Solution on the Effectiveness of Suspended GPM Systems to Recover Ammonia

“…These technologies include reverse osmosis [16], air-stripping using stripping towers and acid absorption [17], zeolite adsorption through ion exchange [18], coprecipitation with phosphate and magnesium to form struvites [19], use of bio-adsorbents, and gas-permeable membranes (GPM) [20]. Traditional processes suffer from some limitations: reverse osmosis requires high pressure; air stripping towers and zeolite adsorption techniques require manure pre-treatment; precipitation of struvites not only requires the use of additives but may also interfere with equipment performance and lead to increased maintenance costs [20]; and research is still lacking on the reusability of ammonium-loaded bio-adsorbents as bio-fertilizers or even bio-compost [21,22]. On the other hand, GPM technology has a low energy consumption (0.18 kWh•kg NH 3 −1 ), requires a small working pressure, does not require pre-treatment of effluents, does not need the addition of any alkaline reagent [23,24], and does not drastically disturb the operation of the livestock activity, which can all be regarded as interesting advantages.…”

Adsorption and coagulation in wastewater treatment – Review

“…Several natural adsorbents have been studied for pollutants removal from wastewater. For instance, Bellahsen et al (2021) applied natural adsorbents from the banana peel, compost, bark, wheat husk, wheat bran, sugar beet pulp, and pomegranate peel for the adsorption of ammonium. The result shows pomegranate peel powder (PPP) could achieve 97% removal, however, other materials showed a negative and low adsorption ability.…”

Zinc adsorption from aqueous solution using lemon, orange, watermelon, melon, pineapple, and banana rinds

“…First, the lemon, orange, watermelon, melon, pineapple, and banana rinds (1 kg fruit rind for each fruit) were peeled, washed with cold tap water then by pure water and dried in an oven at 105 °C for 24 h. Next, the dried rinds were milled and sieved to less than 180 μm particle size. Finally, the produced rind dust was preserved in polyethylene bags at room temperature (22+0.5 °C) (Khan et al 2017;Bellahsen et al 2021).…”