Feasibility of Using Drinking Water Treatment Residuals as a Novel Chlorpyrifos Adsorbent

Abstract

Recent efforts have increasingly focused on the development of low-cost adsorbents for pesticide retention. In this work, the novel reuse of drinking water treatment residuals (WTRs), a nonhazardous ubiquitous byproduct, as an adsorbent for chlorpyrifos was investigated. Results showed that the kinetics and isothermal processes of chlorpyrifos sorption to WTRs were better described by a pseudo-second-order model and by the Freundlich equation, respectively. Moreover, compared with paddy soil and other documented absorbents, the WTRs exhibited a greater affinity for chlorpyrifos (log Koc = 4.76-4.90) and a higher chlorpyrifos sorption capacity (KF = 5967 mg(1-n)·L·kg(-1)) owing to the character and high content of organic matter. Further investigation demonstrated that the pH had a slight but statistically insignificant effect on chlorpyrifos sorption to WTRs; solution ionic strength and the presence of low molecular weight organic acids both resulted in concentration-dependent inhibition effects. Overall, these results confirmed the feasibility of using WTRs as a novel chlorpyrifos adsorbent.

Removal of chlorpyrifos from waste water by wheat straw-derived biochar synthesized through oxygen-limited method

“…frog and sh. Zhao et al 7 has found that the residual of drinking water treatment material can effectively adsorb chlorpyrifos in water with respect to paddy soil, which contains iron, aluminium hydroxide minerals and humic materials. Chishti et al used microorganisms to degrade chlorpyrifos in water.…”

Aging of aluminum/iron-based drinking water treatment residuals in lake water and their association with phosphorus immobilization capability

“…Besides P, the DWTRs used in this study were also found to have high adsorption capability for hydrogen sulfide and chlorpyrifos. The adsorption capacities for hydrogen sulfide were approximately 14e15 mg g À1 (Wang and Pei, 2012), and the affinity (log Koc) for chlorpyrifos were 4.76e4.90 (Zhao et al, 2013).…”

“…In fact, the DWTRs have been demonstrated non-hazardous according to the toxicity characteristic leaching procedure assessment method used by the US Environmental Protection Agency (Wang et al, 2014a). The DWTRs are amorphousness, have a high specific surface area, and also have a strong adsorption capability for many contaminants, e.g., phosphorus (P) (Makris et al, 2005b;Oliver et al, 2011), hydrogen sulfide (Wang and Pei, 2012), perchloric acid (Makris et al, 2006a), arsenic (Makris et al, 2006b;Gibbons and Gagnon, 2011), chromium (Zhou and Haynes, 2011), lead (Zhou and Haynes, 2011;Putra and Tanaka, 2011), mercury (Hovsepyan and Bonzongo, 2009), and selenium (Ippolito et al, 2009), as well as organic pollutants (Zhao et al, 2013;Punamiya et al, 2013). Based on these attributes, DWTRs have also been used for environment remediation, typically for P pollution control.…”

Use of Fe/Al drinking water treatment residuals as amendments for enhancing the retention capacity of glyphosate in agricultural soils

“…The obtained correlation coefficients (R 2 ) were within the range of 0.91-0.99. Glyphosate sorption isotherms for TJ and SD soils with and without Fe/Al WTR amendment are of type L (n < 1), implying that glyphosate sorption sites will decrease with increasing glyphosate sorption Zhao et al (2013). b pH determined in aqueous slurry with soil/water ratio of 1:2.5. and the gradual saturation of potential sorption sites (Giles et al, 1960).…”