A critical review on selenium removal capacity from water using emerging non-conventional biosorbents.

Anthropogenic-driven selenium (Se) contamination of natural waters has emerged as severe health and environmental concern. Lowering Se levels to safe limits of 40 µg-L-1 (recommended by WHO) presents a critical challenge for the scientific community, necessitating reliable and effective methods for Se removal. The primary obectives of this review are to evaluate the efficiency of different biosorbents in removing Se, understand the mechanism of adsorption, and identify the factors influencing the biosorption process. A comprehensive literature review is conducted to analyze various studies that have explored the use of modified biochars, iron oxides, and other non-conventional biosorbents for selenium removal. The assessed biosorbents include biomass, microalgae-based, alginate compounds, peats, chitosan, and biochar/modified biochar-based adsorbents. Quantitative data from the selected studies analyzed Se adsorption capacities of biosorbents, were collected considering pH, temperature, and environmental conditions, while highlighting advantages and limitations. The role of iron impregnation in enhancing the biosorption efficiency is investigated, and the mechanisms of Se adsorption on these biosorbents at different pH levels are discussed. A critical literature assessment reveals a robust understanding of the current state of Se biosorption and the effectiveness of non-conventional biosorbents for Se removal, providing crucial information for further research and practical applications in water treatment processes. By understanding the strengths and limitations of various biosorbents, this review is expected to scale-up targeted research on Se removal, promoting the development of innovative and cost-effective adsorbents, efficient and sustainable approaches for Se removal from water.

Xiaoliu Pingyi Pecipe Inhibits Lung Pre-Metastatic Niche Formation and Prevents Myeloid-Derived Suppressor Cells Recruitment.

BACKGROUND: Metastasis, a leading cause of cancer-related deaths, involves complex mechanisms. The premetastatic niche (PMN) is a crucial contributor to this process. Myeloid-derived suppressor cells (MDSCs) play an important role in PMN formation and promote tumor progression and metastasis. The Xiaoliu Pingyi recipe (XLPYR), a traditional Chinese medicine, is effective in preventing postoperative recurrence and metastasis in cancer patients. OBJECTIVE: This study investigated the effects of XLPYR on MDSCs recruitment and on the expression of PMN markers and elucidated the mechanisms involved in the prevention of tumor metastasis. METHODS: C57BL/6 mice were subcutaneously injected with Lewis cells and treated with cisplatin and XLPYR. Tumors were resected after 14 days after the establishment of a model of lung metastasis, and tumor volume and weight were measured. Lung metastases were observed 21 days after resection. MDSCs in the lung, spleen, and peripheral blood were detected by flow cytometry. Western blotting, qRT-PCR and ELISA were used to detect the expression of S100A8, S100A9, MMP9, LOX, and IL-6/STAT3 in premetastatic lung tissue. RESULTS: XLPYR treatment inhibited tumor growth and prevented lung metastasis. Compared to mice without subcutaneous tumor cell transplantation, the model group had an increased proportion of MDSCs, higher expression of S100A8, S100A9, MMP9, and LOX in the premetastatic lung. XLPYR treatment reduced the proportion of MDSCs, S100A8, S100A9, MMP9, and LOX expression, and downregulated the IL-6/STAT3 pathway. CONCLUSIONS: XLPYR may prevent MDSCs recruitment and reduce the expression of S100A8, MMP9, LOX, and IL6/STAT3 in premetastatic lung tissue, thus reducing lung metastases.

Recovery of nitrogen and phosphorus in wastewater by red mud-modified biochar and its potential application.

A large amount of wastewater containing nitrogen, phosphorus, and fluorine produces in the production of phosphate fertilizer. In this study, to simultaneously recover nitrogen and phosphorus from phosphorus-containing wastewater and realize the resource utilization of red mud and rape straw, red mud-modified rape straw biochar (RM/RSBC) was prepared by facile one step, and the physicochemical properties were characterized by Zeta potential, SEM-EDS, BET specific surface area (SSA), FTIR, XRD, and XPS. The adsorption performance and mechanisms of ammonium and phosphate onto RM/RSBC were explored through static, fixed-bed column adsorption, and practical wastewater experiments. The results showed that pH = 3.0 and 8.0 were favorable for the removal of phosphate and ammonium, respectively. The main adsorption mechanisms of ammonium and phosphate were the interaction between ammonium and surface functional groups and surface precipitation, respectively. The removal efficiencies of ammonium and phosphate by fixed-bed column adsorption mainly depended on the addition amount of RM/RSBC, the concentration of ammonium and phosphate, and the flow rate. The results of the germination experiment showed that adding > 0.5 wt% of RM/RSBC loaded with ammonium and phosphate promoted the growth of mung beans. This study shows that RM/RSBC can not only recover ammonium and phosphate in wastewater, but also realize the resource utilization of red mud and rape straw.

Release characteristics of phosphate from ball-milled biochar and its potential effects on plant growth.

Ball-milled biochar could potentially supply phosphorus, an essential element for plant growth. To realize resource reuse and phosphorus recovery, three feedstocks (rice straw, distillers grains, and Eupatorium adenophorum) were used to prepare ball-milled biochar to evaluate its release characteristics of phosphorus and potential effects on germination and growth. The results showed that the phosphate release performance of ball-milled distillers grains biochar (DM) at 300 and 600 °C was better than that of other biochars ball-milled for 12 h. The DM prepared at 600 °C and incubated for 12 (DM-12) or 24 h (DM-24) had the best phosphate release capacity. The solution with pH 3.0 was beneficial to the release of phosphate from DM-12. The pseudo-second-order model could better fit the phosphate release of DM-12. A germination and seedling growth experiment suggested that adding 2.5 wt% DM-12 was beneficial to the height of mung beans. This study shows that DM-12 can be used as a slow-release fertilizer for the growth of mung beans, which provides a new way for resource utilization of distillers grains and phosphorus-rich biochar.