REMOVAL EFFICIENCY OF Ca<sup>2+</sup>, Mg<sup>2+</sup> FROM CONCENTRATED LEACHATE IN LANDFILL USING NaOH SOLUTION

XIAO Wangsong; WANG Huawei; SUN Yingjie; GONG Zhaoguo; WANG Yanan; FU Youxian; LIU Keqiong; SUN Zhiguo

doi:10.13205/j.hjgc.202208007

Volume 40 Issue 8

Nov. 2022

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Article Navigation > ENVIRONMENTAL ENGINEERING > 2022 > 40(8): 55-61

XIAO Wangsong, WANG Huawei, SUN Yingjie, GONG Zhaoguo, WANG Yanan, FU Youxian, LIU Keqiong, SUN Zhiguo. REMOVAL EFFICIENCY OF Ca2+, Mg2+ FROM CONCENTRATED LEACHATE IN LANDFILL USING NaOH SOLUTION[J]. ENVIRONMENTAL ENGINEERING , 2022, 40(8): 55-61. doi: 10.13205/j.hjgc.202208007

Citation:

XIAO Wangsong, WANG Huawei, SUN Yingjie, GONG Zhaoguo, WANG Yanan, FU Youxian, LIU Keqiong, SUN Zhiguo. REMOVAL EFFICIENCY OF Ca²⁺, Mg²⁺ FROM CONCENTRATED LEACHATE IN LANDFILL USING NaOH SOLUTION[J]. ENVIRONMENTAL ENGINEERING , 2022, 40(8): 55-61. doi: 10.13205/j.hjgc.202208007

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REMOVAL EFFICIENCY OF Ca²⁺, Mg²⁺ FROM CONCENTRATED LEACHATE IN LANDFILL USING NaOH SOLUTION

doi: 10.13205/j.hjgc.202208007

1. School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao 266033, China;
2. Qingdao Xiaojianxi Leachate Treatment Co., Ltd, Qingdao 266041, China;
3. Qingdao Jieyuan Environment Co., Ltd, Qingdao 266041, China

Received Date: 2021-09-08
Publish Date: 2022-11-08

Abstract

Abstract

In order to reduce and alleviate the corrosion and scaling of equipment during the evaporation process of concentrated leachate, the removal efficiency of Ca²⁺ and Mg²⁺ in concentrated leachate was investigated by the combination of alkali solution and compound reagents. The chemical composition and mineral characteristics of precipitates were analyzed by various methods. The influence of water quality parameters and scaling amount during the removal of Ca²⁺ and Mg²⁺ were also explored. The results showed that: 1) when the volume addition ratio of 7.5 mol/L NaOH was 3%, the Ca²⁺ and Mg²⁺ were effectively removed after 60 min of reaction, and the removal efficiencies were 89.49% and 98.45% respectively, but the sedimentation performance was poor under this condition; 2) when NaOH combined with diatomite and Ca(OH)₂ was used, the sedimentation performance of precipitates was significantly improved, and the removal efficiency of Ca²⁺ and Mg²⁺ were not significantly affected. The sedimentation ratio was 36.84% when 1% Ca(OH)₂ was added, significantly lower than single NaOH solution of 75.61%. 3) according to the analysis of chemical composition and mineral characteristics of precipitates, the main minerals were Mg(OH)₂, Mg₅(CO₃)₄(OH)₂·4H₂O, NaCl and KCl; 4)the simulated experiment for evaporation of raw concentrated leachate and supernatant showed that the amount of scaling after alkali treatment was lower than that of raw concentrated leachate when pH was adjusted to 5.0.
- landfill,
- concentrated leachate,
- Ca²⁺、Mg²⁺,
- removal efficiency,
- mineralogical properties

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