Treatment of metal-contaminated wastewater: A comparison of low-cost biosorbents

Abstract

This study aimed to identify some optimum adsorption conditions for the use of low-cost adsorbent, seaweed (Ascophyllum nodosum), sawdust and reed plant (Phragmites australis) root, in the treatment of metal contaminated wastewater for the removal of cadmium, chromium and lead. The effect of pH on the absorption capacity of each of these biosorbents was found to be significant and dependent on the metal being removed. Post-adsorption FTIR analysis showed significant binding activities at the nitro NO groups site in all biosorbents, especially for lead. Competitive metal binding was found to have possibly affected the adsorption capacity for chromium by A. nodosum more than it affected sawdust and P. australis root. Adsorption is believed to take place mainly by ion exchange particularly at low pH values. P. australis root exhibited the highest adsorption for chromium at pH 2, cadmium at pH 10 and lead at pH 7. A. nodosum seaweed species demonstrated the highest adsorption capacity of the three biosorbents used in the study, for cadmium at pH 7 and for lead at pH 2. Sawdust proved to be an efficient biosorbent for lead removal only at pH 7 and 10. No significant effect of temperature on adsorption capacity was observed, particularly for cadmium and lead removal.

Saw-sedge Cladium mariscus as a functional low-cost adsorbent for effective removal of 2,4-dichlorophenoxyacetic acid from aqueous systems

“…It also contains oxygen, which was not detected directly by this method. C. mariscus mainly consists of carbon and hydrogen (48.0 and 7.1 % respectively), similarly to other sorbents of plant origin (tea grounds, the seaweed Ascophyllum nodosum, sawdust, and the grass Phragmites australis- Akunwa et al 2014;Foroughi-Dahr et al 2015). The presence of nitrogen (0.9 %) can be explained by the occurrence of amide and amine groups in the material structure, which was also confirmed by further analysis of the FTIR spectra.…”

Acid modified jackfruit wood sawdust as biosorbent for the removal of Fe(II) from aqueous solutions

“…wood sawdust is biomass which mainly consist of cellulose (40 -50%), hemicellulose (20 -40%) and lignin (20 -40%) [16]. Wood sawdust is biowaste from wood industry and its accumulation generate pollution and health problem [17]. In Indonesia, the yield of sawmill industry waste is around 50 -60 %, and about 15 -20% consist of wood sawdust.…”

Comparison of multiple regression analysis using dummy variables and a NARX network model: an example of a heavy metal adsorption process

“…In recent years, researchers have increasingly turned their attention to the adsorption process due to its advantages, such as the use of low‐cost adsorbents, easy application, simplicity of equipment, efficiency and environmental friendliness mostly because adsorbents can be derived from a wide variety of materials, and natural, synthetic and waste products (Akunwa et al . ; Visa & Chelaru ). Generally, an adsorbent is considered to be low‐cost if it requires little processing, is abundant in nature or is obtained as a by‐product or waste material from various industries including clays, zeolites, coal, fly ash, peat, siderite, agriculture and charcoal (Rađenović et al .…”

“…There are numerous studies concerning the removal of heavy metal contamination from aqueous systems, and a number of methods have been described in the literature including precipitation as hydroxides, electro-dialysis, coagulation-sedimentation, reverse osmosis, ion-exchange, ultra-filtration and adsorption (Bhat et al 2015;Javadian et al 2015). In recent years, researchers have increasingly turned their attention to the adsorption process due to its advantages, such as the use of low-cost adsorbents, easy application, simplicity of equipment, efficiency and environmental friendliness mostly because adsorbents can be derived from a wide variety of materials, and natural, synthetic and waste products (Akunwa et al 2014;Visa & Chelaru 2014). Generally, an adsorbent is considered to be lowcost if it requires little processing, is abundant in nature or is obtained as a by-product or waste material from various industries including clays, zeolites, coal, fly ash, peat, siderite, agriculture and charcoal (Radenović et al 2011).…”