Advancement in nanomaterials for environmental pollutants remediation: a systematic review on bibliometrics analysis, material types, synthesis pathways, and related mechanisms.

Environmental pollution is a major issue that requires effective solutions. Nanomaterials (NMs) have emerged as promising candidates for pollution remediation due to their unique properties. This review paper provides a systematic analysis of the potential of NMs for environmental pollution remediation compared to conventional techniques. It elaborates on several aspects, including conventional and advanced techniques for removing pollutants, classification of NMs (organic, inorganic, and composite base). The efficiency of NMs in remediation of pollutants depends on their dispersion and retention, with each type of NM having different advantages and disadvantages. Various synthesis pathways for NMs, including traditional synthesis (chemical and physical) and biological synthesis pathways, mechanisms of reaction for pollutants removal using NMs, such as adsorption, filtration, disinfection, photocatalysis, and oxidation, also are evaluated. Additionally, this review presents suggestions for future investigation strategies to improve the efficacy of NMs in environmental remediation. The research so far provides strong evidence that NMs could effectively remove contaminants and may be valuable assets for various industrial purposes. However, further research and development are necessary to fully realize this potential, such as exploring new synthesis pathways and improving the dispersion and retention of NMs in the environment. Furthermore, there is a need to compare the efficacy of different types of NMs for remediating specific pollutants. Overall, this review highlights the immense potential of NMs for mitigating environmental pollutants and calls for more research in this direction.

Fabricated magnetic adsorption - Forward osmosis membrane hybrid system for hydroponic irrigation from rich arsenic-containing heavy metal water stream.

Solidification of soluble arsenic from extremely acidic water and direct use of recovery water have been the major challenges in global water management, with the urgent need for new treatment system development. Thus, magnetic adsorption - fertilizer drawn forward osmosis (FDFO) hybrid system with a novel adsorbent and fertilizer mixture to solve the drawbacks of each process was developed with the ultimate goals of metal removal and direct reuse for hydroponic irrigation. Magnetic metal-organic framework-based adsorbent (CMM) was synthesized with various promising capabilities, i.e., wide pH range efficiency, strong pH adjustment, good stability, fast adsorption (1 h), and oxidation (40 min), high capacity (175 and 126 mg/g for As(III), As(V)), strong magnetization (75 emu/g), complete separation by a magnet, excellent interference-tolerance and reusability. In the FDFO system, a massive water volume (50 times higher than the initial draw solution with suitable nutrients for hydroponics irrigation with acceptable NaCl levels was obtained for the first time up to now. However, low As(III) rejection (50%) required the FDFO process to improve more. After integrating with magnetic adsorption, nearly 100% of As was removed. The pH of feed solutions adjusted from extremely acidic to close to neutral conditions further solidified metal by precipitation and membrane separation processes, leading to almost no detection of metals in the final draw solution. Also, favorable nutrients and excellent reusability were obtained. This hybrid process would generally offer an environmentally sustainable and high efficiency for decontaminating As-containing heavy metal water for hydroponic irrigation.

Application of MnFe2O4 magnetic silica-covered ethylenediaminetetraacetic acid-functionalized nanomaterials to the draw solution in forward osmosis.

Forward osmosis (FO) is an emerging and promising water treatment technology. However, selection of an optimal draw solution (DS) is essential for efficient FO process operations. In this study, the potential of ethylenediaminetetraacetic acid (EDTA) functionalized SiO2-covered magnetic nanoparticles (MNPs) as DS in FO process were investigated. The MNPs were synthesized and characterized for their morphology, size distribution, magnetic behavior, and dispersibility. Investigations were carried out to determine the effects of DS concentration and MNPs type, utilizing bare, SiO2 covered, and EDTA coated MNPs at concentrations of 20, 40, and 60 g/L. Furthermore, water flux generation capability and rejection efficiency of octanoic acid (OC) was evaluated with EDTA-MNPs as DS in FO mode (active layer facing feed solution) and PRO mode (active layer facing draw solution). Our results showed that a maximum water flux of 9.59 ± 2 LMH in FO mode, and 11.104 ± 2 LMH in PRO mode was achieved using 60 g/L of EDTA-MNPs. Additionally, we investigated the reusability of the EDTA-coated MNPs and found that their recovery was higher than (>90%) with no aggregation. The stability of EDTA-MNPs was due to strong covalent linkages between their four carboxylate groups and the hydrophilic SiO2 surface layer, which resulted in steric hindrance and prevented their aggregation. Finally, we assessed the rejection efficiency of OC at different pH values and found that it was low (30-39%) at pH values below pKa and high (90-97%) at pH values above pKa. Owing to internal concentration polarization, the rejection of OC in FO mode was (10-20%) higher than in PRO mode. The findings demonstrate EDTA-coated MNPs have significant potentials as an effective DS in FO process .

Recovery of volatile fatty acids using forward osmosis: Influence of solution chemistry, temperature, and membrane orientation.

This study investigates the suitability of forward osmosis (FO) for recovery of volatile fatty acids (VFAs) from anaerobic digesters (ADs) and identifies the conditions favorable for commercially viable maximum recovery of VFAs. The recovery efficiency of VFAs is evaluated using a polyamide (PA)-based thin-film composite (TFC) membrane. The pH (3, 5, 7, and 9), temperature (20 °C and 40 °C), and membrane orientation (active-layer [AL]-facing FS and AL facingDS) were changed, and water flux, reverse salt flux (RSF), rejection rate, and concentration factor (CF) were evaluated for five VFAs. The water flux and RSF were higher at a higher pH, temperature and in AL-DS mode. A low rejection rate of 23-36% and a CF of 0.20-1.90 were observed at a pH below the pKa due to the solubility of molecular VFAs, while rejection rates was 80-97% and concentration increase by 1 to 4.8-fold at a pH above the pKa values were achieved due to deprotonation of VFAs and changes in membrane surface charges. With an equal increase in temperature of FS and DS from 20 to 40 °C, the rejection rate decreased by almost 20%. While with a transmembrane temperature change, a decrease in rejection rate of 20% was observed compared with baseline experiments due to decreases in viscosity and high diffusivity. In AL-DS mode, VFAs were rejected at a rate of almost 20% lower than that in AL-FS mode due to internal concentration polarization and membrane properties. These findings provide useful information on the factors that can influence optimal recovery rates of VFAs.

Phytochemical composition, antilipidemic and antihypercholestrolemic perspectives of Bael leaf extracts.

BACKGROUND: In recent times, focus on plant research has improved all over the world and essential parts of plants provide bioactive compounds in human diet. The bael (Aegle marmelos) has enormous traditional uses in the treatment of chronic diarrhea, dysentery, peptic ulcers and as a laxative. The main focus of this study was characterization of bael leaf extract for its bioactive constituents, antihypercholestrolemic and antilipidemic perspectives. METHODS: After proximate composition of bael powder, the aqueous extract of bael leaf was used for phytochemical profiling (alkaloids, total phenolic content and total flavonoid content). Afterwards, normal rats group G0 was administrated basal diet while G1 and G2 normal rat groups were fed diets containing bael leaf extract 125 mg and 250 mg, respectively for consecutive 60 days. In a similar way, hyperlipidemic rats group Gh0 was administrated basal diet while Gh1 and Gh2 hyperlipidemic rat groups were fed diets containing bael leaf extract 125 mg and 250 mg, respectively for consecutive 60 days. The blood drawn on day 0, day 30 and day 60 was analyzed for serum parameters, such as total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides concentration and free and ester cholesterol. RESULTS: Bael leaf powder is a rich source of crude fiber (14.50 ± 0.10 g/100 g). Aqueous extract of bael leaf contains alkaloids (15.58 ± 0.05 mg/g), flavonoids (64.00 ± 0.05 mg/g), phenolics (30.34 ± 0.01 GAEmg/g). From the In vivo studies, the lowest weight gain was observed in group G2 and in Gh2 as compared to control of both groups. The decrease in serum TC for G1-15.06%, G2-17.27% while in Gh1-22.46% and Gh2-34.82% after day 60, respectively. The maximum decrease was observed in group G2 (- 14.33%) and in Gh2 (- 24.79%) for triglycerides after 60 days. For HDL-cholesterol, significant increase (11.20%) in G2 and (49.83%) in Gh2 was observed of after 60 days. A trend in decrease of serum LDL-cholesterol in G2 (- 9.63%) and in Gh2 (- 44.65%) was also observed at day 60, and - 19.05% and - 30.06% decrease was noted in G2 and Gh2, respectively and decreasing trend was observed in free and total cholesterol - 22.30% and - 81.49% for groups G2 and Gh2 after day 60. CONCLUSIONS: The results of the present study demonstrated that the extract contents of bael leaf provide protective role against hypercholesterolemic and hyperlipidemic conditions.

Phytopreventive antihypercholesterolmic and antilipidemic perspectives of zedoary (Curcuma Zedoaria Roscoe.) herbal tea.

BACKGROUND: Metabolic syndrome is an increasingly prevalent problem, not only in industrialized developed countries, but in developing countries as well. The modern healthcare to reduce the dysfunction of metabolic syndrome is burdened with great problems of unsafe medicines and certain degree of side effects. Medicinal plants and derived component products are becoming increasingly popular in modern society as natural alternatives to synthetic multiple drugs for the treatment of hypercholesterolemia and hypertriglyceridemia. The present research work was carried out to evaluate the zedoary (Curcuma zedoaria Roscoe.) herbal tea (ZHT) for antihypercholestrolemic and antilipidemic perspectives in discerning consumers. METHODS: Zedoary rhizome dried powder (ZRDP) after proximate composition analysis was used to prepared ZHT samples as T1 (500 mg ZRDP), T2 (1 g ZRDP) and T3 (1.5 g ZRDP) in 200 mL boiling water for 5 minutes, respectively. ZHT samples were characterized for total phenolic compounds (TPC), DPPH inhibition, total flavonoids, color tonality (L*, a* and b* value), pH, acidity, total soluble solids (TSS) and sensory acceptance. Thirty mild-hypercholestrolemic male human volunteers were randomly allocated to three groups (G1, G2 and G3) and each group consisting of 1o mild-hypercholestrolemic male human subjects. The volunteers were assigned ZHT samples for consecutive two months. The blood drawn for day 0, day 30 and day 60 after an overnight 12 h fast was analyzed for serum parameters such as total cholesterol (TC), high-density lipoprotein cholesterol (HDL-cholesterol), low-density lipoprotein cholesterol (LDL-cholesterol) and triglycerides (TG) concentration. RESULTS: The ZRDP possessed abundantly the crude protein (13.5 ± 0.68 %), total dietary fiber (21.86 ± 0.71 %), acid detergent fiber (13.22 ± 0.44 %), neutral detergent fiber (18.68 ± 0.53 %) and mineral contents. Highest TPC, DPPH inhibition and total flavonoids values were observed 9.74 ± 0.64 (mg GAE/g DW), 47.28 ± 1.62 (%) and 17.12 ± 0.75 (QE mg/g), respectively in T3. L* value was significantly (p ≤ 0.05) low for T3 samples. In contrast, a* value and b* value was significantly (p ≤ 0.05) higher for T3 when compared with T1 and T2. T3 samples showed lower pH (5.13 ± 0.13) and higher acidity (0.25 ± 0.08) values than T1 (5.64 ± 0.25, 0.17 ± 0.05) and T2 (5.42 ± 0.21, 0.21 ± 0.06), respectively. Similarly, an increasing trend in TSS contents was observed. Sensory scores assigned to color, flavor, aroma and overall acceptability attributes varied in a quite narrow range for all ZHT samples. The lowest evaluation scores were recorded for T3 samples. The G3 showed the more reduction in body weight and BMI during efficacy study as compared to G1 and G2. The decrease in serum TC for G1, G2 and G3 on day 60 was observed 9 %, 14 % and 17 %, respectively when compared with reference value at day 0. The consumption of T3 resulted in significant increase (6.8 %) of HDL-cholesterol after two months. A trend in decrease of serum LDL-cholesterol (5.6 %) and TG (12.5 %) was also observed after consumption of T3 at day 60. CONCLUSIONS: The results of the present study conclude that the strong phenolic contents and radical scavenging activity of zedoary rhizome have protective role against hypercholesterolemic and lipidemic conditions.