Effect of saline water ionic strength on phosphorus recovery from synthetic swine wastewater

2022 ◽  
Vol 113 ◽  
pp. 81-91
Author(s):  
Zhipeng Zhang ◽  
Bing Li ◽  
Filicia Wicaksana ◽  
Wei Yu ◽  
Brent Young
Minerals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 231 ◽  
Author(s):  
Malibongwe Manono ◽  
Kirsten Corin ◽  
Jenny Wiese

Previous studies speculate that hydroxo species present in flotation pulps at pH > 9, particularly those of polyvalent cations, selectively adsorb onto gangue minerals. Such species supposedly enhance the depressive action of carboxymethyl cellulose (CMC) onto gangue via an acid-base interaction between the positively charged mineral surface and the negatively charged CMC molecule. Thus, the hydrophilicity of gangue minerals is enhanced, preventing the dilution of the concentrate. However, as there is little evidence to support these claims for complex process waters of increasing ionic strength, it is important to investigate. Adsorption data and mineral surface charge analyses provide a fundamental understanding of how electrolytes and their ionic strengths affect gangue mineral-depressant adsorption. It is strongly anticipated that decoupling these effects will allow process operators to tailor their process water quality needs towards best flotation operating regimes and, in the long run, effect closed water circuits. Thus, using talc as a proxy for naturally floatable gangue common in sulfidic Cu–Ni–PGM ores, this work investigates the influence of the ionic strength of process water on the adsorption of CMC onto talc for a perspective on how saline water in sulfidic ores would affect the behavior and therefore management of floatable gangue. In the presence of CMC, the microflotation results showed that the rate of talc recovery decreased with increasing ionic strength of process water. Increases in ionic strength resulted in an increase in the adsorption of CMC onto talc. Talc particles proved to have been more coagulated at higher ionic strength since the settling time decreased with increasing ionic strength. Furthermore, the zeta potential of talc particles became less negative at higher ionic strengths of process water. It is thus proposed that increases in the ionic strength of process water increased the zeta potential of talc particles, enhancing the adsorption of CMC onto talc. This in turn created a more coagulated nature on talc particles, increasing their hydrophilicity and thereby retarding floatability.


2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Hailong Fan ◽  
Jiahui Wang ◽  
Zhen Tao ◽  
Junchao Huang ◽  
Ping Rao ◽  
...  

Abstract Electrostatic interaction is strong but usually diminishes in high ionic-strength environments. Biosystems can use this interaction through adjacent cationic–aromatic amino acids sequence of proteins even in a saline medium. Application of such specific sequence to the development of cationic polymer materials adhesive to negatively charged surfaces in saline environments is challenging due to the difficulty in controlling the copolymer sequences. Here, we discover that copolymers with adjacent cation–aromatic sequences can be synthesized through cation–π complex-aided free-radical polymerization. Sequence controlled hydrogels from diverse cation/aromatic monomers exhibit fast, strong but reversible adhesion to negatively charged surfaces in seawater. Aromatics on copolymers are found to enhance the electrostatic interactions of their adjacent cationic residues to the counter surfaces, even in a high ionic-strength medium that screens the electrostatic interaction for common polyelectrolytes. This work opens a pathway to develop adhesives using saline water.


2010 ◽  
Vol 176 (1-3) ◽  
pp. 1083-1088 ◽  
Author(s):  
Zhi-Long Ye ◽  
Shao-Hua Chen ◽  
Shu-Mei Wang ◽  
Li-Feng Lin ◽  
Yi-Jun Yan ◽  
...  

2017 ◽  
Vol 9 (10) ◽  
pp. 1845 ◽  
Author(s):  
Qiming Wang ◽  
Tao Zhang ◽  
Xinyue He ◽  
Rongfeng Jiang

2018 ◽  
Vol 78 (8) ◽  
pp. 1642-1651 ◽  
Author(s):  
Dongyuan Chu ◽  
Zhi-Long Ye ◽  
Shaohua Chen ◽  
Xiaojing Xiong

Abstract Struvite (MgNH4PO4·6H2O) crystallisation is a promising approach for phosphorus recovery from swine wastewater. Currently, intensive pig feeding has made heavy metals (HMs) extensive in swine wastewater; therefore, significant amounts of HMs have been detected in struvite recovery products. In this study, the HM residues in the struvite products recovered from stirred and fluidised bed reactors were investigated. The results showed that Zn, Mn, and Cu were the most abundant elements in swine wastewater (1,175.3 ± 178.0, 745.4 ± 51.5, and 209.3 ± 54.4 μg L−1, respectively). The HMs, especially Zn (97.0%) and Cu (96.8%), were mainly distributed in the total suspended solids (TSS) of the swine wastewater. Redundancy analysis revealed that the HMs in the struvite products harvested from the fluidised bed reactor were mainly attributable to the aggregation of dissolved matters, because most TSS were elutriated through fluidisation. In contrast, the HMs in the struvite products harvested from the stirred reactor mainly originated from the TSS, which complexed with the HMs, and co-precipitated and settled with the struvite products. Furthermore, chemical fractionation of the HM species confirmed that the presence of HMs in the struvite products was mainly attributable to metal precipitation and organic aggregation.


2017 ◽  
Vol 313 ◽  
pp. 1633-1638 ◽  
Author(s):  
Zhi-Long Ye ◽  
Yujun Deng ◽  
Yaoyin Lou ◽  
Xin Ye ◽  
Jianqiao Zhang ◽  
...  

2006 ◽  
Vol 54 (8) ◽  
pp. 247-255 ◽  
Author(s):  
H. Harada ◽  
Y. Shimizu ◽  
Y. Miyagoshi ◽  
S. Matsui ◽  
T. Matsuda ◽  
...  

Interest in phosphorus recovery from urine diverted from faeces has been growing recently. Phosphorus in urine can be precipitated out as struvite (MgNH4PO4•6H2O) with addition of magnesium salt under alkaline conditions. Struvite formation, however, should be more well understood for its practical application. We predicted the struvite formation with a development of a new equilibrium model. The model considered the formation of eight different kinds of precipitates, including struvite, with effects of ionic strength and temperature. In addition, experiments on struvite formation in urine were conducted for the model validation. The model prediction of struvite formation had good agreement with the experimental results. The optimum pH to form struvite was predicted to be 9.4–9.7. In order to precipitate 99% of phosphate in urine with 1.5 fold Mg concentration to PO4-P, the pH value was necessary to be more than 8.1 based on the model prediction.


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