Modification of green algae harvested from the Persian Gulf by L-cysteine for enhancing copper adsorption from wastewater: Experimental data

Prewetting Electron Beam Irradiated and Native Sheep Wool Can Affect Their Sorptivity

In this work, the effect of prewetting native and electron beam-modified wool on the resulting sorption of Cu(II) from wool solutions was studied. The following conditions and combinations were applied: 6 mM and 50 mM solutions, prewetting time 0-24 h, contact time 1-24 h. The sorption results showed that wetting the wool before sorption from the low concentrated solution can fundamentally improve the efficiency of the separation process. The opposite result was achieved when applying a more concentrated solution; that is, prewetting slightly reduced the sorptivity. The reasons for such results are discussed. The application of these findings can be used to optimize the separation process in technological practice, however, will require solute specification.

Adsorption of heavy metals from the aqueous solution using activated biomass from Ulva flexuosa

The removal of various highly toxic heavy metals from wastewater environment is an important task to improve environment. The biosorption potential of cadmium, cobalt and zinc was evaluated using Ulva flexuosa biomass. The impacts of adsorbent dosage, pH of the medium, contact time, and agitation speed were analyzed. The maximum biosorption potential was reached at pH 4.0, 0.4 g initial biosorbent dosage, contact time 40 min and 30 mg/L initial metal concentration for cadmium, while the other factors were similar to zinc, except 35 min contact time (p < 0.01). The optimum absorption was pH 4, 0.6% adsorbent dosage, after 30 min contact time with the heavy metals and 40 mg/L cobalt concentration. Heavy metal removal efficiency was 94.8 ± 3.3%, 87.5 ± 2.3%, and 90.8 ± 1.4%, for cadmium, cobalt, and zinc, respectively (p < 0.01). The Langmuir constant (R²) was 0.980 for cadmium, 0.838 for cobalt and it was 0.718 for zinc. The present results revealed that the selected acid modified biomass was highly suitable for the adsorption of metal ions such as, Cd²⁺, Co²⁺ and Zn²⁺. The present work revealed the potential application of algal biomass for the removal of various heavy metals from the environment.

An Overview to the Health Benefits of Seaweeds Consumption

Currently, seaweeds are gaining major attention due to the benefits they give to our health. Recent studies demonstrate the high nutritional value of seaweeds and the powerful properties that seaweeds' bioactive compounds provide. Species of class Phaeophyceae, phylum Rhodophyta and Chlorophyta possess unique compounds with several properties that are potential allies of our health, which make them valuable compounds to be involved in biotechnological applications. In this review, the health benefits given by consumption of seaweeds as whole food or by assumption of bioactive compounds trough natural drugs are highlighted. The use of seaweeds in agriculture is also highlighted, as they assure soils and crops free from chemicals; thus, it is advantageous for our health. The addition of seaweed extracts in food, nutraceutical, pharmaceutical and industrial companies will enhance the production and consumption/usage of seaweed-based products. Therefore, there is the need to implement the research on seaweeds, with the aim to identify more bioactive compounds, which may assure benefits to human and animal health.

A Short Review on the Valorization of Green Seaweeds and Ulvan: FEEDSTOCK for Chemicals and Biomaterials

This short review analyzed the recent trend towards, progresses towards the preparation of chemicals of, and value-added biomaterials from marine macroalgae resources, especially green seaweeds and their derived ulvan polysaccharides for various applications. In recent years, ulvan both in pristine and modified forms has gained a large amount of attention for its effective utilization in various areas due to its unique physiochemical properties, lack of exploration, and higher green seaweed production. The pristine form of ulvan (sulfated polysaccharides) is used as a bio-component; food ingredient; or a raw material for the production of numerous chemicals such as fuels, cosmetics, and pharmaceuticals, whereas its modified form is used in the sector of composites, membranes, and scaffolds, among others, because of its physicochemical properties. This review highlights the utilization of green seaweed and its derived ulvan polysaccharides for the preparation of numerous chemicals (e.g., solvents, fuel, and gas) and also value-added biomaterials with various morphologies (e.g., gels, fibers, films, scaffolds, nanomaterials, and composites).

Effective adsorption of nickel (II) with Ulva lactuca dried biomass: isotherms, kinetics and mechanisms

This study aimed to evaluate the Ni²⁺ ions adsorption capability of Ulva lactuca. The isotherms, kinetics and mechanisms for the adsorption of Ni²⁺ from aqueous solution by Ulva lactuca were also investigated. Influencing factors including initial pH, initial Ni²⁺ concentration, biomass, contact time were examined. The results indicate that the maximum Ni²⁺ adsorption capacity of 38.28 mg/g was obtained at pH 5, initial Ni²⁺ concentration 250 mg/L, biomass dosage 0.5 g/L and contact time 30 min. The adsorption can be well fitted with Langmuir isotherm, and the kinetics were well described by the pseudo-second-order model. The parameters of thermodynamics verified that Ni²⁺ adsorption on Ulva lactuca was a spontaneous and endothermic process. Analyses of FT-IR, SEM-EDS and XPS indicate that carboxyl and hydroxyl groups on the surface of biomass are involved in Ni²⁺ adsorption. The dried biomass of Ulva lactuca can be a cost-effective and eco-friendly adsorbent for the removal of Ni²⁺ from wastewater.