A Study on the Removal of Copper (II) from Aqueous Solution Using Lime Sand Bricks

Xiaoran Zhang,Kaihong Song,Ziyang Zhang,Shimin Guo,Junfeng Liu,Chaohong Tan,Haiyan Li

doi:10.3390/app9040670

Abstract

Heavy metals such as Cu(II), if ubiquitous in the runoff, can have adverse effects on the environment and human health. Lime sand bricks, as low-cost adsorbents to be potentially applied in stormwater infiltration facilities, were systematically investigated for Cu(II) removal from water using batch and column experiments. In the batch experiment, the adsorption of Cu(II) to bricks reach an equilibrium within 7 h and the kinetic data fits well with the pseudo-second-order model. The sorption isotherm can be described by both the Freundlich and Langmuir model and the maximum adsorption capacity of the bricks is 7 ± 1 mg/g. In the column experiment, the best removal efficiency for Cu(II) was observed at a filler thickness of 20 cm, service time of 12 min with a Cu(II) concentration of 0.5 mg/L. The Cu(II) removal rate increases with the increasing bed depth and residence time. The inlet concentration and residence time had significant effects on the Cu(II) removal analyzed by the Box–Behnken design (BBD). The Adams-Bohart model was in good agreement with the experimental data in representing the breakthrough curve. Copper fractions in the bricks descend in the order of organic matter fraction > Fe-Mn oxides fraction > carbonates fraction > residual fraction > exchangeable fraction, indicating that the lime sand bricks after copper adsorption reduce the long-term ecotoxicity and bioavailability to the environment.

Highlights

With the rapid development of urbanization, the increase of impervious areas has interrupted the water infiltration channel, which has greatly increased the rainfall runoff and peak discharge [1].The heavy metals in urban stormwater runoff mainly come from automobile exhaust, industrial smoke and fossil fuel combustion, dust and various metal facilities
Characterization of the Lime Sand Bricks area of bricks was a bit higher compared to chitosan of 1.05 m2 /g [21] and perlite of 1.66 m2 /g [22]
The lime sand bricks were systematically investigated as potential filter materials for the removal of Cu(II) from aqueous solutions using static batch experiments and fixed bed continuous column experiments

Summary

Introduction

The heavy metals in urban stormwater runoff mainly come from automobile exhaust, industrial smoke and fossil fuel combustion, dust and various metal facilities. Heavy metals such as copper, zinc and lead are common components in stormwater runoff and usually with relatively high concentrations. Excessive intake of heavy metals in the human body may irritate the mucous membranes, leading to liver and kidney damage, capillary damage and central nervous system problems [2]. When the concentration is above the threshold level, it can cause anemia and gastrointestinal discomfort Infiltration facilities such as permeable pavements could remove pollutants in urban runoff to some extent. The removal of heavy metals in runoff is mainly through the interception of pores in the media. Improving the adsorption capacity of the pavement system medium towards pollutants has a positive effect on reducing the water quality risks

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