Forward Black Liquor Acid Precipitation: Lignin Fractionation by Ultrafiltration

A Comprehensive Review on Pulp and Paper Industries Wastewater Treatment Advances

“…74 In this regard, the recovery of lignin fractions of low molar mass was examined by UF membrane, and the results showed that, despite the thick fouling layer formation, a 5 kDa membrane was able to retain up to 85% of the lignin from the feed solution, while 31% of the solids in the feed stream were permeated through the membrane. 75 However, a study using ZnO/PES UF membranes for the recovery of lignin and hemicellulose revealed that hemicellulose was recovered at 91% with a 78% volume reduction, while lignin was permeated through the membrane. 76 In another study, membrane fouling reduced UF performance by 80% due to low permeate flux, while the COD in the retentate samples increased rapidly during the first 10 h of filtration.…”

“…116,117 Iron hydroxides precipitate in acidic environments, and slight lignin solubilization may pose the most challenging barriers to Fenton-based processes. 75 In light of this, Fenton-based processes cannot be used for the treatment of acidic effluent generated by P&P bleaching units when the target pollutant is lignin.…”

“…Moreover, it was demonstrated that the optimum pH for obtaining higher COD and color removal was around 2.5–3.0 . The OH • radical’s tendency to deteriorate the structure of lignin makes Fenton-based processes suitable for the removal of lignin from P&P streams due to the high oxidation capacity as well as the pH independence of lignin at room temperature. , Iron hydroxides precipitate in acidic environments, and slight lignin solubilization may pose the most challenging barriers to Fenton-based processes . In light of this, Fenton-based processes cannot be used for the treatment of acidic effluent generated by P&P bleaching units when the target pollutant is lignin.…”

Bio-based platform chemicals synthesized from lignin biorefinery

“…Using MST as post-pretreatment to combine with solvent extraction may be conducive to membrane fouling mitigation because pretreatment can reduce the lignin molecular mass and solution complexity. 16,140 Importantly, lignin of low molar mass in lignin-lean black liquor (non-precipitating fraction after acid precipitation treatment of lignin) can be further effectively recycled. 16 Similarly, different fractions of lignin of different molecular masses can be obtained by applying a two-step process of first organosolv pretreatment, followed by UF.…”

Enhancing the compost maturation of deer manure and corn straw by supplementation via black liquor

“…However, because of the higher viscosity of black liquor from ash and lignin, the saccharification yield was low in samples with black liquor pretreatment. Lignin recovery from black liquor is another main utilization direction, but the cost of recycling is too high to industrial production [ 13 ]. Several researchers also reported the conversion of black liquor into polyhydroxyalkanoates (PHAs), biodiesel, hydrogen, biogas, and organic acid production [ [14] , [15] , [16] , [17] ].…”