Determining major factors controlling phosphorus removal by promising adsorbents used for lake restoration: A linear mixed model approach

Abstract

Phosphorus (P) removal from lake/drainage waters by novel adsorbents may be affected by competitive substances naturally present in the aqueous media. Up to date, the effect of interfering substances has been studied basically on simple matrices (single-factor effects) or by applying basic statistical approaches when using natural lake water. In this study, we determined major factors controlling P removal efficiency in 20 aquatic ecosystems in the southeast Spain by using linear mixed models (LMMs). Two non-magnetic -CFH-12 and Phoslock- and two magnetic materials -hydrous lanthanum oxide loaded silica-coated magnetite (Fe-Si-La) and commercial zero-valent iron particles (FeHQ)- were tested to remove P at two adsorbent dosages. Results showed that the type of adsorbent, the adsorbent dosage and color of water (indicative of humic substances) are major factors controlling P removal efficiency. Differences in physico-chemical properties (i.e. surface charge or specific surface), composition and structure explain differences in maximum P adsorption capacity and performance of the adsorbents when competitive ions are present. The highest P removal efficiency, independently on whether the adsorbent dosage was low or high, were 85-100% for Phoslock and CFH-12, 70-100% for Fe-Si-La and 0-15% for FeHQ. The low dosage of FeHQ, compared to previous studies, explained its low P removal efficiency. Although non-magnetic materials were the most efficient, magnetic adsorbents (especially Fe-Si-La) could be proposed for P removal as they can be recovered along with P and be reused, potentially making them more profitable in a long-term period.

Ecotoxicity screening of novel phosphorus adsorbents used for lake restoration

“…Table 1. Main physic-chemical features of the P adsorbents used for this study. Concentrations (total and atomic surface) have been taken from Funes et al (2018).…”

“…In more detail, the underlying mechanism is that by one hand, MPs trap dissolved P with a minimal alteration in water quality (e.g. Funes et al, 2016Funes et al, , 2018 and on the other hand, P adsorbed on MPs can be desorbed, in basic solutions, and therefore recovered P can be eventually used as a fertilizer (Álvarez-Manzaneda et al, unpublished). Additional advantages of using MPs include: (i) high (18.83 mg P g -1 ) and fast (less than 1 h) maximum P adsorption capacity; (ii) their magnetic properties allows for recovery of MPs from solution by applying a magnetic separation gradient; (iii) the non-dependence on redox conditions of their P adsorption properties; (iv) their lower economic cost compared to other P adsorbents (e.g.…”

Passive Detection of Phosphorus in Agricultural Tile Waters Using Reactive Hybrid Anion Exchange Resins

“…The material should also allow the free passage of pore water and enable the recovery of the sorbed substances [21]. For the monitoring of DRP in agricultural waters using the passive sampling method, iron (oxyhydr)oxide coated anion exchange resin is an ideal adsorbent [22][23][24] since iron (oxyhydr)oxides can selectively and rapidly adsorb phosphate via inner-sphere complexation [25][26][27]. The objective of this study was to evaluate the passive sampling method using hybrid anion exchange resin bags to monitor the DRP loss in agricultural tile drainage water.…”

Synthesis, characterization and application of magnetic nanoparticles in the removal of copper from aqueous solution

“…In particular, magnetite nanoparticles are employed as adsorbents for the separation and removal of Zn(II) ions and other contaminants by the application of external magnetic field (Maity and Agrawal 2007;Shirsath and Shirivastava 2015). Magnetite nanoparticles are preferred in metal removal applications due to their nanosize, magnetic separation capability, simple synthesis and coating technique and surface modification (Yargeau 2012;Ratnayaka et al 2009;Funes et al 2018;Dias et al 2011;Lasheen et al 2017;Achla and Singh 2017;Ibrahim et al 2018). Magnetic nanoparticles also find applications in drug-targeting to improve the therapeutic potential of many water-insoluble and unstable drugs (Pedro et al 2003).…”