Water Remediation Using Calcium Phosphate Derived From Marine Residues

Abstract

The processing of natural resources in marine and freshwater ecosystems, directly operated by industries related to maritime sector, contributes annually to several million tons of waste. The reuse and economic recovery of this waste would be very desirable and profitable, either economically or environmentally. In this work, the remediation of hazardous divalent metal ions from aqueous solutions using biological apatites derived from marine residues was addressed. The biological apatite (calcium phosphate particles) was produced by heat treatment of fish bones. Experimental sorption studies of kinetics and equilibrium of the metal ions as well as an evaluation of competitive sorption behavior for lead immobilization were carried out in batch operation mode. The efficiency and mechanisms of lead sorption on two different particle sizes of calcium phosphate from aqueous solution were investigated. The results showed a high adsorption capacity of the biosorbent for Pb 2+ (above 370 mg/g ads. ), in opposition to Cd 2+ and Zn 2+ . For the case of low initial concentrations of the metal ion, reducing the biosorbent particles size increases the sorption rate. It was possible to verify that lead immobilization proceeds with a rapid surface complexation of the lead on the sorption sites before partial dissolution of calcium phosphate and formation of pyromorphitelike compounds. By the selectivity experiments, performed using binary systems-Pb/Cd and Pb/Znit was evidenced a competitive process between the divalent ions, which leads to a considerable decrease on the adsorption capacity of the adsorbent material for all the metals.

Biogenic Calcium Phosphate from Fish Discards and By-Products

“…The powder obtained could also be used as precursor material for nanoparticle production [46] that could also be incorporated into sunscreen creams [47], or directly used in filters for the treatment of polluted water [48]. This biphasic material could be converted into coatings for implants by means of the pulsed laser deposition technique [49] that improves the osseointegration of dental and orthopaedic implants.…”

Assessment of physiological and biochemical responses, metal tolerance and accumulation in two eucalypt hybrid clones for phytoremediation of cadmium-contaminated waters

“…Cadmium has been recognised as one of the most hazardous metals for the environment, due to its ubiquitous nature, non biodegradability, high toxicity to biota even at low concentrations and high solubility in water (Da Silva et al, 2012;Xie et al, 2013). Moreover, Cd presence in the soil is of special concern due to its high mobility in the plant-soil system, leading to accumulation in edible tissues in large quantities and thus posing a serious threat to human beings through the food chain (Monteiro et al, 2008;Fu et al, 2011).…”

Morphophysiological Responses, Heavy Metal Accumulation and Phytoremoval Ability in Four Willow Clones Exposed to Cadmium Under Hydroponics

“…Among heavy metals, cadmium (Cd) is one of the most hazardous due to its ubiquitous nature, non-biodegradability, high toxicity to biota even at low concentrations and high solubility in water (Da Silva et al 2012 ;Xie et al 2013 ). Although Cd is not an essential element for plants, it can be readily taken up and accumulated by many plants, representing a possible way to enter the food chain (Prasad 1995 ;Astolfi et al 2004 ).…”