Biosorption of Heavy Metal by Algae Biomass in Surface Water

Abstract

Discharging wastewater containing heavy metals of Cu, Pb, Zn and Cd into water bodies can cause toxicity in plants and aquatic animals and some of them will be unable to survive except algae. Wastewater treatment method to remove heavy metal contaminants includes chemical precipitation, ion exchange, membrane, filtration, adsorption using activated carbon. However, these methods are either expensive or have other disadvantages such as high energy consumption and inefficiencies when existing heavy metals are at trace concentration. Biosorption using algae biomass can be an alternative method to eliminate heavy metals. The objective of the project is to investigate the capability of Marine Algae (MA) and Freshwater Algae (FA) biomass in adsorbing heavy metals of Cu, Pb, Zn and Cd from water medium using synthetic water and industrial water. MA and FA were obtained from the eastern coast of Pulau Ubin and local fish farm respectively. After being fully washed with deionised water, dried in a furnace for 105˚C, they are grinded to pass 1 mm 2 of siever. MA and FA were characterised using FTIR to determine their functional groups. An industrial water was collected from industrial discharge from metal factories in northern side of Singapore. Effect of adsorption time, adsorbent concentration, and pH were studied. The result showed that FA and MA had a higher capability in adsorbing a total metal of about 40 ppm level from an industrial water, or 4 times than synthetic water concentration, at the same adsorbent dosage of 50 mg. In conclusion, the presence of various functional groups, hydroxyl, carboxylic and amine groups, in all MA and FA samples had enabled the algae biomass to adsorb heavy metals of Cu, Pb, Cd and Zn from synthetic and industrial water. Due to their biosorptive properties and fast adsorption capability, algae could be a potential method for cleaning up surface water or post-treatment of wastewater and minimise the cost of eutrophication.

Statistical optimization for cadmium removal using Ulva fasciata biomass: Characterization, immobilization and application for almost-complete cadmium removal from aqueous solutions

“…The optimum pH of adsorbing cadmium from water medium using synthetic water and industrial water was at pH 11. Also the optimum pH for adsorption of heavy metals for marine algae also lies between pH 5 - pH 10 54 , where the maximum cadmium removal was recorded at pH 5 39 .…”

Current knowledge and future perspectives of the use of seaweeds for livestock production and meat quality: a systematic review

“…However, it should be remarked that the utilization of macroalgae in animal feeds presents some concerning issues, namely the uptake of metals by macroalgae from the surrounding water (Utomo et al, 2016). The levels of arsenic, mercury, lead, cadmium, aluminium and nickel in dried macroalgal biomass were reported to be substantial due to bioaccumulation of these elements from water (Chen et al, 2018;Morais et al, 2020), with highest concentrations of aluminium (554 mg/kg) and lowest of mercury (0.0370 mg/kg) (Chen et al, 2018).…”

Review of Heavy Metal Adsorption Processes by Several Organic Matters from Wastewaters

“…This value improves by 39.4% with 50% of water fed back, while it produces 93% better results when all water is fed back [85][86][87][88][89]106]. One of the most notable advantages of using microalgae in our current study is that producing it is not dependent on freshwater, and it can be done using contaminated water just as well [90].…”