Efficient removal of phosphorus in bioretention system by sludge pyrolysis residue
- PDF / 1,439,510 Bytes
- 9 Pages / 595.276 x 790.866 pts Page_size
- 37 Downloads / 181 Views
ORIGINAL PAPER
Efficient removal of phosphorus in bioretention system by sludge pyrolysis residue Guowen Yu & Beiping Zhang & Xiejuan Lu & Jia Li & Jingwen Chen & Jiaolan Zuo
Received: 7 December 2013 / Accepted: 14 May 2014 # Saudi Society for Geosciences 2014
Abstract Phosphorus (P) removal in a bioretention system has been highly variable. In this study, we investigated the potential application of sludge pyrolysis residue, which was prepared from sludge pyrolysis, for adsorption of P from a bioretention system. Kinetics result suggested that the P adsorbed on sludge pyrolysis residue was faster than that of two soils, and both the surface and intraparticle diffusion were the rate-controlling steps for the adsorption. All adsorption isotherms were highly nonlinear and fitted well by the Langmuir model in comparison to the Freundlich model. The maximum adsorption capacity of P by sludge pyrolysis residue reaches 1,250 mg/kg at an initial concentration of 100 mg/L. Batch adsorption experiments and postadsorption characterization results indicated that the adsorption was mainly controlled by both the precipitation and surface deposition mechanisms. The presence of Al, Fe, and Ca in sludge pyrolysis residue can facilitate the P adsorption. The release of P adsorbed on sludge pyrolysis residue is negligible because of a strong interaction between P and Al, Fe, and Ca in sludge pyrolysis residue. The findings of this study suggested that sludge pyrolysis residue could be used as an optimal filter medium to improve the removal performance of P in a bioretention system.
Keywords Phosphorus . Adsorption . Sludge pyrolysis residue . Soils . Bioretention system
G. Yu : B. Zhang (*) : X. Lu : J. Li : J. Chen : J. Zuo School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan, People’s Republic of China e-mail: [email protected] G. Yu e-mail: [email protected]
Introduction Phosphorus (P) is a limiting nutrient for the growth of organisms and plants and is an indicator of surface water quality (Almeelbi and Bezbaruah 2012; Abdalla and Khalifa 2013; Khan et al. 2013). Excessive P from both point and nonpoint sources into natural waters is known to cause eutrophication which is occurring throughout the world (Smith 2003; Penn and Warren 2009; Bhargava and Sheldarkar 1993; Ozacar 2003). Dissolved phosphate of ∼0.02 mg/L is considered to have potential that leads to profuse algal growth in waters (USEPA 1995). Accelerated eutrophication not only affects the aquatic ecosystems but also indirectly hinders the economic progress. The combined costs were approximately $2.2 billion annually as a result of eutrophication in US freshwaters (Dodds et al. 2008). It is therefore of great importance to develop effective technologies to remove phosphate from runoff and natural water bodies. Bioretention systems have the potential to retain most applied P when appropriate materials are used (Davis et al. 2006; Hsieh and Davis 2005). Bioretention is an urban stormwater best management practic
Data Loading...
