scholarly journals Implementation of Modified Acacia Tannin by Mannich Reaction for Removal of Heavy Metals (Cu, Cr and Hg)

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 352 ◽  
Author(s):  
Lorena Lugo ◽  
Alison Martín ◽  
John Diaz ◽  
Alejandro Pérez-Flórez ◽  
Crispin Celis
Keyword(s):  
Heavy Metals ◽  
Mannich Reaction ◽  
Industrial Wastewater ◽  
Oxygen Demand ◽  
Direct Mercury Analyzer ◽  
Removal Of Heavy Metals ◽  
Mercury Analyzer ◽  
Flocculation Process ◽  
Different Levels ◽  
Different Doses

The modified tannin by Mannich reaction was investigated for wastewater treatment. The removal of heavy metals, such as copper, chromium and mercury, in industrial wastewater was evaluated through the coagulation–flocculation technique, using modified Acacia tannin (MAT) as a coagulant agent. The successful tannin modification was evaluated by infrared spectopometry (FTIR), nuclear magnetic resonance (NMR); monitoring the removal of heavy metals was performed by atomic absorption (AA) and a direct mercury analyzer (DMA). Additionally, the parameters of water quality, total suspended solids (TSS), turbidity and chemical oxygen demand (COD) were assessed. Different doses of MAT were evaluated (375 ppm, 750 ppm, 1250 ppm and 1625 ppm) and three different levels of pH (4, 7 and 10). The highest percentages of removal obtained were copper 60%, chromium 87%, mercury 50%–80%, COD 88%, TSS 86% and turbidity 94%, which were achieved with the dose of 375 ppm of MAT at pH 10. The coagulation–flocculation process with the modified Acacia tannin is efficient for the removal of conventional parameters and for a significant removal of the metals studied.

scholarly journals Evaluation of Fresh Water Actinomycete Bioflocculant and Its Biotechnological Applications in Wastewaters Treatment and Removal of Heavy Metals

2019 ◽  
Vol 16 (18) ◽  
pp. 3337 ◽  
Author(s):  
Mayowa Oladele Agunbiade ◽  
Carolina Pohl ◽  
Esta Van Heerden ◽  
Oluwaseun Oyekola ◽  
Anofi Ashafa
Keyword(s):  
Heavy Metals ◽  
Oxygen Demand ◽  
Optical Emission ◽  
Dairy Wastewater ◽  
Polyaluminum Chloride ◽  
Flocculating Activity ◽  
Wastewaters Treatment ◽  
Removal Of Heavy Metals ◽  
Health Related ◽  
Rdna Analysis

This study evaluated the potential of a biopolymeric flocculant produced by Terrabacter sp. isolated from Sterkfontein Dam, South Africa. Microbial flocculants aid the aggregation of suspended solutes in solutions, thus, suggesting its alternative application to inorganic and synthetic organic flocculants, which are associated with health-related problems. The 16S rDNA analysis revealed the bacteria to have 98% similarity to Terrabacter sp. MUSC78T and the sequence was deposited in the Genbank as Terrabacter sp. with accession number KF682157.1. A series of experimental parameters such as bioflocculant dosage, cations concentrations, pH, and application of the purified bioflocculant in wastewaters treatment were investigated. In the presence of glucose as a sole carbon source, Ca2+ as cation at pH 8, the optimal flocculating activity attained was 85%. Optimum bioflocculant dosage of 0.5 mg/mL was able to remove chemical oxygen demand (COD), biological oxygen demand (BOD), suspended solids (SS), nitrate, and turbidity in dairy wastewater. In addition, the tested bioflocculant exhibited higher flocculating efficiency as compared to polyaluminum chloride, polyethylenime, and alum. Inductible coupled plasma optical emission spectroscopy (ICP-OES) analyses confirmed significant removal of 77.7% Fe, 74.8% Al, 61.9% Mn, and 57.6% Zn as representatives of heavy metals from treated dairy wastewater. Fourier transform infrared spectroscopy (FTIR) indicated the presence of carboxyl, hydroxyl, and amino groups in the purified bioflocculant which could be responsible for flocculation. Findings from this study showed the prospect of the studied bioflocculant as an alternative candidate in wastewater treatment and remediating of heavy metals.

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