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Published on: April 9, 2016
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Removal efficiency of dissolved organic matter from secondary effluent by coagulation-flocculation processes
Natália Rodrigues Guimarães1, Fabiane Dörr2, Rodrigo de Oliveira Marques1
1Hydraulic and Environmental Engineering Department, Polytechnic School of University of São Paulo, São Paulo, São Paulo, Brazil.
Summary
This study evaluated coagulants for removing organic compounds in wastewater effluent. Iron chloride achieved the highest removal efficiency, showing potential for optimizing water reuse strategies.
Area of Science:
- Environmental Science
- Water Treatment Engineering
Background:
- Wastewater reuse is crucial for conserving drinking water resources.
- Biological treatment converts organic matter into complex effluent matrices.
- Residual organic compounds in treated wastewater require efficient removal.
Purpose of the Study:
- To assess the efficacy of various coagulants in removing dissolved organic carbon (DOC) from treated wastewater.
- To analyze the impact of coagulation-flocculation on the molecular weight distribution of effluent organic matter.
- To evaluate the role of zeta potential (ZP) in the coagulation process.
Main Methods:
- Coagulation-flocculation using iron chloride, aluminum sulfate, and polyaluminum chloride (PAC).
- Measurement of dissolved organic carbon (DOC) concentrations.
- Size exclusion chromatography (SEC) coupled with mass spectrometry (MS) for molecular weight analysis.
- Zeta potential (ZP) measurements.
Main Results:
- DOC removal efficiencies: up to 45% with iron chloride, 38% with aluminum sulfate, and 31% with PAC.
- Zeta potential did not show a determining role in organic matter removal.
- SEC-MS detected alterations in the molecular weight distribution of effluent organic matter post-treatment.
Conclusions:
- Iron chloride demonstrated superior performance in DOC removal compared to aluminum sulfate and PAC.
- SEC-MS is a valuable tool for characterizing effluent organic matter and optimizing treatment processes.
- Coagulation-flocculation effectively modifies the molecular characteristics of organic matter in wastewater effluent.
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