Aminomethylation of spruce tannins and their application as coagulants for water clarification

Tannins in mangrove plants in Segara Anakan Lagoon, Central Java, Indonesia

“…The total tannin has correlation with the biomass of barks, stems, and leaves (Hilmi et al 2019a;Taillardat et al 2018), carbon content, organic compound, and extractive matter. The results showed in Tables 5 and 6 suggest that R. apiculata, R. mucronata, S. alba, Xylocarpus moluccensis, Exoecaria agallocha, N. fruticans, and Heritiera littoralis have the potential to supply the raw materials of tannin industry (Bello et al 2020) Our data also showed that the total tannins in mangrove species bigger than those from black acacia, Acacia mearnsii, and other breeds which ranged between 25.57-97.89 mg g -1 (Li et al 2015;Nardeli et al 2019). Accordingly, Salar et al (2017), also mentioned that the potential of condensed tannins obtained from cultivars ranged between 40.96-99.91 mgCE/100 g, with coffee fruit at 0.402-1.46% (Patay et al 2016), and medicinal plants at 17.15-44.02% (Moura et al 2016).…”

Effects of Tree Harvesting Time and Tannin Cold-/Hot-Water Extraction Procedures on the Performance of Spruce Tannin Biocoagulant for Water Treatment

“…Condensed tannin is suitable for synthesizing cationic coagulants due to its nucleophilic characteristics [10,25]. As shown in Fig.…”

“…Several studies have confirmed that hot-water extraction is a viable method for the extraction of spruce tannin [10,[14][15][16], and tannin extracted with hot water from spruce bark has been proven suitable for synthesizing biocoagulants [8,10]. However, the main limitation in the application of spruce bark as a tannin source for tannin-based coagulants is the low tannin yield and the presence of a significant amount of co-extracted impurities such as sugars, minerals and phenolic non-tannin compounds [10,17]. The presence of impurities is not desirable during aminomethylation and could facilitate the production of competitive byproducts during the Mannich reaction [12].…”

“…Some notable practical applications of tannin biocoagulants in water treatment include the sequestration of heavy metals from surface water [6], decolouration of dye effluents [7], turbidity reduction of industrial process waters [8] and removal of humic substances from peat extraction runoff waters [9]. On the other hand, a significant difference in their coagulative performance due to variation in the chemical composition of tannins from various sources has also been widely reported [10][11][12]. Arismendi et al [12] aminomethylated Acacia mearnsii, Schinopsis balansae and Castanea sativa extracts and observed that the carboxyl or ester groups in Castanea sativa extracts tend to prohibit or slow down the reaction between the iminium ions and tannin phenols by deactivating the electrophilic characteristics of the aromatic ring in the tannin matrix.…”

“…Spruce is a common tree species in the Nordic countries and accounts for over 30 percent of forest resources in Finland [13]. Several studies have confirmed that hot-water extraction is a viable method for the extraction of spruce tannin [10,[14][15][16], and tannin extracted with hot water from spruce bark has been proven suitable for synthesizing biocoagulants [8,10]. However, the main limitation in the application of spruce bark as a tannin source for tannin-based coagulants is the low tannin yield and the presence of a significant amount of co-extracted impurities such as sugars, minerals and phenolic non-tannin compounds [10,17].…”