Volatile fatty acid (VFA) yield from sludge anaerobic fermentation through a biotechnological approach

Photoconverting waste amphiphiles at the mild air–water interface into easily separable value-added products

“…where ΔG 0 water represents the standard-state free energy of solvation of the organic molecule, which can be calculated by the difference of E (single point energy) in water and vacuum. 53,69 The use of eqn (1) implies that the liquid phase provides an ideally dilute solution, and as a consequence, K is the Henry's law constant (referred to as H cp , eqn (2). The Henry's law constant calculated by using eqn (1) is dimensionless, and the conversion to SI units, mol m −3 Pa −1 , is made by division with R × T. R is the universal gas constant, R = 8.314462618 J K −1 mol −1 ) and T is the temperature (298.15 K).…”

“…Amphiphiles substances are substances with a hydrophilic group at one end and a hydrophobic group at the other end, 1 such as fatty acids, 2 fatty alcohols, 3 fatty amines, and fatty aldehydes. On the one hand, these substances are widely present in nature.…”

Volatile Fatty Acid Production from Organic Waste with the Emphasis on Membrane-Based Recovery

“…An HRT of approximately 8-20 days is typically needed as a minimum HRT for methanogens. Thus, keeping HRT for a shorter period would drastically wash out methanogens [51,90]. Additionally, Strazzera et al (2018) [74] revealed that acetic acid was the main product under a short HRT, whereas propionic acid was the predominant product under a higher HRT.…”

“…Previous studies found that the HRT varied based on the type of substrate and operating conditions. Moreover, it should be noted that a higher HRT requires a larger reactor, which is linked to higher functional costs [90].…”

Soft Sensor for VFA Concentration in Anaerobic Digestion Process for Treating Kitchen Waste Based on SSAE-KELM

“…Particularly, volatile fatty acid (VFA) is the key quality indicator for the stable operation of the anaerobic digestion process. Specifically, excessive accumulation of VFA would inhibit the activity of methanogens; it would acidify the system under no effective monitoring and timely treatment, severely influencing the stability of digestion process [2]. Therefore, timely and effective monitoring of VFA concentration is crucial to ensure the stable operation of the anaerobic digestion process.…”