Assessment of Nutritional Value of Single‐Cell Protein from Waste‐Activated Sludge as a Protein Supplement in Poultry Feed

Abstract

The amount of protein wasted through sludge in Gauteng, South Africa, amounts to 95 000 metric tonne/yr, with the order of magnitude of the national protein requirement of approximately 145 000 metric tonne/yr. Waste-activated sludge (WAS) from wastewater treatment plants (WWTPs) that treat domestic wastewater contains protein in a ratio of 2:1 against fishmeai. This protein source has not been utilized because of the high content of toxic heavy metals and other potential carcinogenic pollutants in the sludge, in this study, a pretreatment method of modified aqua regia dilute acid wash was used to lower the metal content by approximately 60%. However, this resulted in a 33% loss of amino acids in the acid-washed WAS. A feed substitution test in poultry with different fishmeal-sludge ratios (0%, 25%, 50%, 75%, and 100% WAS as percent substitution of fishmeai) showed no impact of sludge single-cell protein (SCP) on mortality rate. However, sludge substitution in the feed yielded weight gains and cost savings up to 46%. Water Environ. Res., 84, 2106Res., 84, (2012.

The Relationship of Physicochemical Properties to the Antioxidative Activity of Free Amino Acids in Fenton System

“…Namely, Glu, Gly, Asp, and Ser are the most abundant in river waters, whereas Gly, Ser, Ala, Lys, Glu, and His are most abundant FAA in seawater. , All these FAA, except Lys and His, showed weak AA in the Fenton system. In addition, analyses of FAA pools in wastewater have shown a similar trend of prevalence of FAA that are not prone to Fenton-provoked oxidation, such as Ser, Gln, and Thr, and Glu, Ala, and Gly …”

“…In addition, analyses of FAA pools in wastewater have shown a similar trend of prevalence of FAA that are not prone to Fenton-provoked oxidation, such as Ser, Gln, and Thr, 44 and Glu, Ala, and Gly. 45 Cys and HCY exhibited different redox properties. The reaction of HCY with HO • gave rise exclusively to thiyl radical (HCY-S • ), which was not the case with Cys.…”

Valorization of Wastes From Agrofood and Pulp and Paper Industries Within the Biorefinery Concept: Southwestern Europe Scenario

“…Nevertheless, these practices are associated with environmental problems. Alternatively, sludge can be used for the elaboration of ecoblocks brick made from recycled materials as activated sludge [20], for the production of activated biochar to remove organic micropollutants [21], for the biogas production [22], and for animal feed as protein supplementation source [23]. On the other hand, solid wastes contain low humidity and have a considerable heating value.…”

Production of Bioagent for Calcium-Based Biocement

“…It is known that hydrolyzed activated sludge can be used for cultivation of different microorganisms [28,29]. There was attempt to use activated sludge, produced on wastewater treatment plant, for growth of ureaseproducing bacteria Sporosarcina pasteurii ATCC 11859 [26].…”

“…However, these media are expensive for the large scale applications. Waste activated sludge from wastewater treatment plants (WWTPs) that treat domestic wastewater contains organic matter, N, P, K, and other nutrients [28]. Hydrolyzed activated sludge was proposed for cultivation of different microorganisms: yeasts (Candida, Hansenula, etc.…”