Phosphogypsum as a novel modifier for distillers grains biochar removal of phosphate from water.

A novel biochar composite was fabricated via the pyrolysis of distillers grains treated phosphogypsum for phosphate removal from water. Batch adsorption experiments were performed on the adsorption characteristics of phosphate. Effects of pyrolysis temperature, solution pH, the dosage of adsorbent, ambient temperature on phosphate adsorption were also investigated. The results demonstrated that the optimum initial solution pH for phosphate adsorption was 6.0, and high pyrolysis temperature was favorable for phosphate adsorption. The optimal dosage of biochar was 1.25 g L-1. A pseudo-second-order kinetic model can well explain the adsorption kinetics, indicative of the energetically heterogeneous solid surface of the composite. The maximum phosphate adsorption capacity of the phosphogypsum modified biochar obtained from Langmuir isotherm reached 102.4 mg g-1 which was almost five times that of distillers grains biochar alone (21.5 mg g-1). The mechanism is mainly attributed to electrostatic adsorption, surface precipitation and ligand exchange. The ideal adsorption performance indicated that biochar supported phosphogypsum can be used as high-quality adsorbent for phosphate removal in wastewater treatment.

Enhanced removal of hexavalent chromium by engineered biochar composite fabricated from phosphogypsum and distillers grains.

Two kinds of industrial wastes (distillers grains and phosphogypsum) were used as raw materials to produce a new biochar composite for Cr(VI) removal in water. The influencing factors including pyrolysis temperature, dosage, initial solution pH as well as contacting time were explored. The adsorption kinetics, isotherms, and thermodynamics of two biochars were conducted. The results show that the adsorption of Cr(VI) by biochar is related to pH. The ideal pH was 3.0 and the adsorbed Cr(VI) decreases as the pH increases. The Cr(VI) adsorption process conformed to the pseudo-second-order equation. Phosphogypsum modified (PM)-biochar is well described by the Freundlich model. The maximum adsorption capacities of distillers grains (DG)-biochar and PM-biochar on Cr(VI) were 63.1 and 157.9 mg g-1, respectively. The thermodynamic analysis indicates that the Cr(VI) adsorption occurs spontaneously which is an endothermic process. This study provided an alternative way for Cr(VI) removal from water.

Dietary supplementation with soybean oligosaccharides increases short-chain fatty acids but decreases protein-derived catabolites in the intestinal luminal content of weaned Huanjiang mini-piglets.

The improvement of gut health and function with prebiotic supplements after weaning is an active area of research in pig nutrition. The present study was conducted to test the working hypothesis that medium-term dietary supplementation with soybean oligosaccharides (SBOS) can affect the gut ecosystem in terms of microbiota composition, luminal bacterial short-chain fatty acid and ammonia concentrations, and intestinal expression of genes related to intestinal immunity and barrier function. Ten Huanjiang mini-piglets, weaned at 21 days of age, were randomly assigned to 2 groups. Each group received a standard diet containing either dietary supplementation with 0.5% corn starch (control group) or 0.5% SBOS (experimental group). The results showed that dietary supplementation with SBOS increased the diversity of intestinal microflora and elevated (P < .05) the numbers of some presumably beneficial intestinal bacteria (e.g., Bifidobacterium sp, Faecalibacterium prausnitzii, Fusobacterium prausnitzii, and Roseburia). Soybean oligosaccharide supplementation also increased the concentration of short-chain fatty acid in the intestinal lumen, and it reduced (P < .05) the numbers of bacteria with pathogenic potential (e.g., Escherichia coli, Clostridium, and Streptococcus) and the concentration of several protein-derived catabolites (e.g., isobutyrate, isovalerate, and ammonia). In addition, SBOS supplementation increased (P < .05) expression of zonula occludens 1 messenger RNA, and it decreased (P < .05) expression of tumor necrosis factor α, interleukin 1ß, and interleukin 8 messenger RNA in the ileum and colon. These findings suggest that SBOS supplementation modifies the intestinal ecosystem in weaned Huanjiang mini-piglets and has potentially beneficial effects on the gut.