TY  - JOUR
A1  - Wang, Hao
A1  - Wang, Xue-jiang
A1  - Wang, Wei-shi
A1  - Yan, Xiang-bo
A1  - Xia, Peng
A1  - Chen, Jie
A1  - Zhao, Jian-fu
T1  - Modeling and optimization of struvite recovery from wastewater and reusing for heavy metals immobilization in contaminated soil
JF  - Journal of chemical technology & biotechnology
N2  - BACKROUND: Few studies have been carried out to connect nutrients recovery from wastewater and heavy metals immobilization in contaminated soil. To achieve the goal, ammonia nitrogen (AN) and phosphorus (P) were recovered from rare-earth wastewater by using the formation of struvite, which was used as the amendment with plant ash for copper, lead and chromium immobilization. RESULTS: AN removal efficiency and residual P reached 95.32 +/- 0.73% and 6.14 +/- 1.72mgL(-1) under optimal conditions: pH= 9.0, n(Mg): n(N): n(P)= 1.2: 1: 1.1, which were obtained using response surface methodology (RSM). The minimum available concentrations of Cu, Pb and Cr (CPC) separately reduced to 320.82 mg kg(-1), 190.77 mg kg(-1) and 121.46 mg kg(-1) with increasing immobilization time at the mass ratio of phosphate precipitate (PP)/plant ash (PA) of 1: 3. Humic acid (HA) and fulvic acid (FA) were beneficial to immobilize Cu, both of which showed no effect or even a negative effect on Pb and Cr immobilization.
KW  - precipitation
KW  - experimental design
KW  - immobilization
KW  - heavy metals
KW  - environmental remediation
Y1  - 2016
U6  - https://doi.org/10.1002/jctb.4931
SN  - 0268-2575
SN  - 1097-4660
VL  - 91
SP  - 3045
EP  - 3052
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Wang, Hao
A1  - Wang, Xuejiang
A1  - Wang, Weishi
A1  - Su, Yinglong
A1  - Zhao, Jianfu
T1  - Reuse of a phosphorus recovery product (struvite/palygorskite) from nutrient wastewater for copper remediation in aqueous solution and soil
JF  - Geoderma : an international journal of soil science
N2  - In this study, a phosphorus recovery product, struvite palygorskite (S-PAL), obtained from nutrient-rich wastewater by using MgO modified palygorskite was applied for copper remediation in aqueous solution and contaminated soil to achieve waste recycling. The effects of contact time, initial pH, initial Cu(II) concentration and reaction temperature on Cu(II) adsorption in aqueous solution were intensively testified. Pseudo-second-order model was able to properly describe Cu(II) adsorption kinetics by using palygorskite (PAL) and S-PAL, and S-PAL exhibited higher adsorption amount (106.27 mg/g) than PAL (8.46 mg/g) at pH of 4. Cu(II) adsorption on PAL and S-PAL could be well fitted by Freundlich isotherm and Langmuir isotherm, respectively. The calculated thermodynamic parameters indicated that Cu(II) adsorption onto PAL and S-PAL were spontaneous and endothermic. A 28-day soil incubation experiment was conducted to evaluate the effects of PAL and S-PAL with three different rates (1%, 5% and 10% w/w) on Cu immobilization in contaminated soil. In the immobilization test, Cu extracted by 0.01 mol/L CaCl2 after seven days incubation significantly decreased with increasing rate of PAL and S-PAL. BCR sequential extraction results showed the significant decrease of acid soluble Cu and a concomitant increase of the residual fraction of Cu after S-PAL and PAL addition. XRD patterns of soil samples after treatment by PAL and S-PAL showed the formation of Cu0.6Mg1.3Si2O6 and Cu-3.04(PO4)(2)OH0.08 center dot 2H(2)O, which indicated that silanol groups and phosphate exhibited affinity for Cu in the soil.
KW  - palygorskite
KW  - struvite
KW  - adsorption
KW  - copper immobilization
KW  - waste reuse
Y1  - 2020
U6  - https://doi.org/10.1016/j.geoderma.2019.113955
SN  - 0016-7061
SN  - 1872-6259
VL  - 357
PB  - Elsevier Science
CY  - Amsterdam [u.a.]
ER  -