Characterization of biocarbon-source recovery and microbial community shifts from waste activated sludge by conditioning with cornstover: Assessment of cellulosic compositions

Abstract

Most studies on the production of volatile fatty acids (VFAs) from waste activated sludge (WAS) digestion have focused on operating conditions, pretreatments and characteristic adjustments. Conditioning by extra carbon sources (ECS), normally added in a solid form, has been reported to be an efficient approach. However, this has caused considerable waste of monomeric sugars in the hydrolysate. In this study, the effects of two added forms (pretreated straw (S) and hydrolyzed liquid (L)) of cornstover (CS) on WAS acidification were investigated. To obtain different cellulosic compositions of CS, low-thermal or autoclaved assisted alkaline (TA or AA) pretreatments were conducted. The results showed that AA-L test achieved the highest VFAs value (653 mg COD/g VSS), followed by AA-S (613 mg COD/g VSS). These values were 12% and 28% higher, respectively, than that obtained in the TA-L and TA-S tests. Meanwhile, higher percentages of acetic acid were observed after AA pretreatment (~62% versus ~53% in TA). The added forms of CS played an important role in structuring the innate microbial community in the WAS, as shown by high-throughput sequencing and canonical correspondence analysis. The findings obtained in this work may provide a scientific basis for the potential implementation of co-digesting WAS with ECS simultaneously obtaining energy and high value-added products.

Microbial network of the carbonate precipitation process induced by microbial consortia and the potential application to crack healing in concrete

“…DNA was extracted from the sediments of three replicate flasks using a EZNA ® Soil DNA kit (Omega Bio-Tek, Inc., Norcross, GA, USA) and then pooled together. Amplicon liberates were constructed for pyrosequencing using bacterial fused primers 341 F and 805 R for the V3-V4 region of the 16S rRNA gene 19 . A common way to distinguish the products of a multiplex genotyping reaction is to incorporate specific nucleotide sequences, i.e., “barcodes”, into the allele-specific genotyping oligos.…”

Microbial community response and SDS-PAGE reveal possible mechanism of waste activated sludge acidification enhanced by microaeration coupled thermophilic pretreatment

“…Large amounts of WAS are produced from wastewater treatment plants (WWTPs), which contain high levels of organic matter, such as proteins and carbohydrates [2]. Taking the resource utilization of WAS into account, short-chain fatty acids (SCFAs) produced from the WAS fermentation process are attracting more interest as a crucial way to achieve biological carbon recovery [3], [4]. In addition, the SCFAs are raw materials for the synthesis of biodegradable plastics polyhydroxyalkanoates [5].…”

How Do Biocides That Occur in Waste Activated Sludge Affect the Resource Recovery for Short-Chain Fatty Acids Production

“…As shown in Figure (B), various anaerobic species showed lower abundance due to the presence of CHD and HTAB, such as the Acinetobacter , Sapropiraceae , Anaerolineaceae , and et al However, the dominant fermentative bacteria, which were expected to utilize various organic substrates for SCFAs generation, were highly enriched in reactors with CHD and HTAB exposure. For example, Bacteroides that contributed significantly to acetic and propionic acids production and Macellibacteroides that could metabolize carbohydrates with acetate as the main fermentation product were both increased in the biocides reactors. Acidaminobacter , which was reported to be involved in the sludge biological hydrolysis and organics fermentation for acetic and propionic acids production, , was found to be respectively 8.87% and 22.05% in the CHD and HTAB reactors, while it was only 0.08% in the control.…”