Engineered macroalgal and microalgal adsorbents: Synthesis routes and adsorptive performance on hazardous water contaminants.

Colourants, micropollutants and heavy metals are regarded as the most notorious hazardous contaminants found in rivers, oceans and sewage treatment plants, with detrimental impacts on human health and environment. In recent development, algal biomass showed great potential for the synthesis of engineered algal adsorbents suitable for the adsorptive management of various pollutants. This review presents comprehensive investigations on the engineered synthesis routes focusing mainly on mechanical, thermochemical and activation processes to produce algal adsorbents.

Adsorptive removal of cationic methylene blue and anionic Congo red dyes using wet-torrefied microalgal biochar: Equilibrium, kinetic and mechanism modeling.

This study aims to investigate the adsorption behavior of cationic and anionic dyes of methylene blue (MB) and Congo red (CR) onto wet-torrefied Chlorella sp. microalgal biochar respectively, as an approach to generate a waste-derived and low-cost adsorbent. The wet-torrefied microalgal biochar possessed microporous properties with pore diameter less than 2 nm.

Batch and dynamic adsorption of lysozyme from chicken egg white on dye-affinity nanofiber membranes modified by ethylene diamine and chitosan.

Adsorption of lysozyme on the dye-affinity nanofiber membranes was investigated in batch and dynamic modes. The membrane matrix was made of electrospun polyacrylonitrile nanofibers that were grafted with ethylene diamine (EDA) and/or chitosan (CS) for the coupling of Reactive Blue 49 dye. The physicochemical properties of these dye-immobilized nanofiber membranes (P-EDA-Dye and P-CS-Dye) were characterized microscopically, spectroscopically and thermogravimetrically.

Utilisation of environmentally friendly okara-based biosorbent for cadmium(II) removal.

Heavy metals released by various industries are among the major pollutants found in water resources. In this research, biosorption technique was employed to remove cadmium (Cd) from an aqueous system using a novel biosorbent developed from okara waste (OW), a residue from soya bean-based food and beverage processing. Characterisation results revealed that the OW biosorbent contained functional groups such as hydroxyl-, carboxyl- and sulphur-based functional groups, and the surface of the biosorbent was rough with multiple fissures which might be the binding sites for the pollutant.

Surface grafting techniques on the improvement of membrane bioreactor: State-of-the-art advances.

Membrane bioreactor (MBR) is regarded as the state-of-the-art technology in separation processes. Surface modification techniques play a critical role in improving the conventional membrane system which is mostly hydrophobic in nature. The hydrophobic nature of membranes is known to cause fouling, resulting in high maintenance costs and shorter lifespan of MBR.

Multistage optimizations of slow pyrolysis synthesis of biochar from palm oil sludge for adsorption of lead.

This research investigated the removal of lead (Pb) by a novel biochar derived from palm oil sludge (POS-char) by slow pyrolysis. Multistage optimizations with central composite design were carried out to firstly optimize pyrolysis parameters to produce the best POS-char for Pb removal and secondly to optimize adsorption conditions for the highest removal of Pb. The optimum pyrolysis parameters were nitrogen flowrateof30mLmin, heating rateof10°Cmin, temperatureof500°C and timeof30min.

Biochar potential evaluation of palm oil wastes through slow pyrolysis: Thermochemical characterization and pyrolytic kinetic studies.

This research investigated the potential of palm kernel shell (PKS), empty fruit bunch (EFB) and palm oil sludge (POS), abundantly available agricultural wastes, as feedstock for biochar production by slow pyrolysis (50mLmin N at 500°C). Various characterization tests were performed to establish the thermochemical properties of the feedstocks and obtained biochars. PKS and EFB had higher lignin, volatiles, carbon and HHV, and lower ash than POS.