Study of Enteromorpha polysaccharides as a new-style coagulant aid in dye wastewater treatment

Durable hydrophobic Enteromorpha design for controlling oil spills in marine environment prepared by organosilane modification for efficient oil-water separation

Hydrophobic and oleophilic materials are attractive candidates for efficient oil collection due to their excellent oil-water separation. However, the most of currently reported oil adsorption materials are limited resources or require complicated preparation steps, which causes high energy consumption and not be practical for large-scale application. Herein, we report a facile strategy to modify the wettability of Enteromorpha from hydrophilic to hydrophobic, which not only greatly reduces energy consumption but also shows the outstanding capacity for oil-water separation with the maximum adsorption capacities is 11.4 g/g and the contact angle reaches 137°. The successful modification of the Enteromorpha is achieved by grafting n-octyltriethoxysilane on the surface of the pristine Enteromorpha. The hydrophobic and superoleophilic Enteromorpha guarantee adequate voids in the fibrous bundles only for oil adsorption and the oil floating on the seawater is removed by the formation of hydrogen bonding between oil and modified Enteromorpha. By optimizing test, the optimal adsorption conditions are adsorption time of 60 min, oil-water ratio of 1:10 and pH of 7. Our reported hydrophobic organosilane modified Enteromorpha will open a new avenue to control marine oil pollution and suppress the damage of Enteromorpha to the marine ecology system.

Enteromorpha polysaccharide-zinc replacing prophylactic antibiotics contributes to improving gut health of weaned piglets

This research aimed to study whether Enteromorpha polysaccharide-zinc (EP-Zn) can act as an alternative to antibiotics in weaned piglet feeds. Two hundred and twenty-four weaned piglets from 14 pens were randomly assigned into 1 of 2 groups according to their body weight and litter size (7 pens/group). The piglets in the antibiotics group were fed with olaquindox at 400 mg/kg and enduracidin at 800 mg/kg basal diet, and piglets in the EP-Zn group were fed with EP-Zn at 800 mg/kg basal diet. One piglet per pen was selected to collect samples after 14 d of feeding. Results showed that EP-Zn supplementation significantly increased the plasma anti-oxidants level compared with the antibiotics group. However, a nonsignificant difference was observed in growth performance between treatment groups. Additionally, the intestinal tight junction (TJ) protein expression and the histopathologic evaluation data showed that EP-Zn contributed to improving intestinal development. Further, piglets in the EP-Zn group had a lower level of intestinal inflammation-related cytokines including IL-6 (P < 0.001), IL-8 (P < 0.05), IL-12 (P < 0.05) and tumor necrosis factor-α (TNF-α) (P < 0.001), and showed an inhibition of the phosphorylation nuclear transcription factor-kappa B (p-NF-κB) (P < 0.05) and total NF-κB (P < 0.001) level in the jejunal mucosa. Taken together, it is supposed that EP-Zn, to some extent, would be a potent alternative to prophylactic antibiotics in improving the health status of weaned piglets.

Intestinal Anti-Inflammatory Effects of Selenized Ulva pertusa Polysaccharides in a Dextran Sulfate Sodium-Induced Inflammatory Bowel Disease Model

The purpose of this study was to examine the alleviative effects of selenized polysaccharides from Ulva pertusa (ulvan-Se) on inflammatory bowel disease (IBD) in mice. The dextran sulfate sodium (DSS)-induced IBD mouse model was used to explore the protective effects of ulvan-Se on the intestinal mechanical and immune barrier. At doses less than 1208 mg/kg·bw ulvan-Se showed no significant damage to Institute of Cancer Research (ICR) mice in an acute toxicity test. The results showed that DSS destroyed the mechanical barrier, which includes epithelial cells, while ulvan-Se promoted mRNA expression of tight junction proteins (zonula occludens protein 1, occludin, and claudin-1) and inhibited the infiltration of white blood cells into the intestines. At 100 mg/kg·bw, ulvan-Se enhanced the antioxidant capacity of mice more effectively than the 50 mg/kg·bw ulvan-Se. Furthermore, ulvan-Se improved the intestinal immune barrier by increasing immunoglobulin A and immunoglobulin M, while regulating the levels of interleukin (IL)-1β, interferon-γ, and IL-4. Oral administration of ulvan-Se also suppressed tumor necrosis factor-α, IL-1β, IL-6, and cyclooxygenase-2 mRNA expression mediated by the nuclear factor kappa B pathway. Taken together, our findings reveal that ulvan-Se could be used as a potential alternative supplement for reducing intestinal inflammation in IBD.

Structure characterization of low molecular weight sulfate Ulva polysaccharide and the effect of its derivative on iron deficiency anemia

Sulfate Ulva polysaccharide with low molecular weight was prepared by enzymatic method and name SUE. The structural characterization of SUE and the effect of its derivative SUE-iron (III) on iron deficiency anemia were studied. Results showed SUE with molecular weight of 178 kDa were consisted of 57.9% rhamnose, 12.1% glucose, 16.3% glucuronic acid, and 13.7% xylose. The backbone contained (1 → 3, 4)-linked rhamnose, (1 → 4)-linked xylose, (1 → 6)-linked glucose and sulfate substitution was at C-3 of rhamnose. Due to high contents of sulfate group (23.7 ± 1.1%) and uronic acid, SUE-iron (III) with 20.3% iron content was synthesized. In order to evaluate the effects of SUE-iron (III) supplementation, an IDA animal model was created. After iron supplement administration, the SUE‑iron (III) showed effective effect on returning hemoglobin, red blood cells, serum iron, and erythropoietin to the normal levels. The hematological index of rats showed no difference from that in positive group. Besides, SUE-iron (III) is beneficial to alleviate inflammatory damage caused by IDA. These suggest that SUE-iron (III) might be exploited as safe and effective new iron supplement.

Synthesis of a Cationic Polyacrylamide under UV Initiation and Its Flocculation in Estrone Removal

A ternary cationic polyacrylamide (CPAM) with the hydrophobic characteristic was prepared through ultraviolet- (UV-) initiated polymerization technique for the estrone (E1) environmental estrogen separation and removal. The monomers of acrylamide (AM), acryloyloxyethyl-trimethyl ammonium chloride (DAC), and acryloyloxyethyl dimethylbenzyl ammonium chloride (AODBAC) were used to synthesize the ternary copolymer (PADA). Fourier transform infrared spectroscopy (FT-IR), 1H nuclear magnetic resonance spectroscopy (1H NMR), thermogravimetry/differential scanning calorimetry (TG/DSC), and scanning electron microscopy (SEM) were employed to characterize the structure, thermal decomposition property, and morphology of the polymers, respectively. FT-IR and 1H NMR results indicated the successful formation of the polymers. Besides, with the introduction of hydrophobic groups (phenyl group), an irregular and porous surface morphology and a favorable thermal stability of the PADA were observed by SEM and TG/DSC analyses, respectively. At the optimal condition (pH = 7, flocculant dosage = 4.0 mg/L and E1 concentration = 0.75 mg/L), an excellent E1 flocculation performance (E1 removal rate: 90.1%, floc size: 18.3 μm, and flocculation kinetics: 22.69×10-4 s−1) was acquired by using the efficient flocculant PADA-3 (cationic degree = 40%, and intrinsic viscosity = 6.30 dL·g−1). The zeta potential and floc size analyses were used to analyze the possible flocculation mechanism for the E1 removal. Results indicated that the charge neutralization, adsorption, and birding effects were dominant in the E1 removal progress.

Simultaneous removal of nano-ZnO and Zn2+ based on transportation character of nano-ZnO by coagulation: Enteromorpha polysaccharide compound polyaluminum chloride

It is confirmed that nano-ZnO (nZnO) has impact on environment and is considered as heavy metal pollutants. It is a new technology that applies coagulation process to simultaneous removal of the nanoparticles and heavy metals. Environmental chemical behavior of ZnO in water, such as the dispersion, aggregation, sedimentation, and dissolution of releasing metal ions, has been systematically studied in this paper. The result shows that three kinds of nZnO state such as compacted sediment, suspended, and released is separately 36.54 %, 40.61 %, and 22.86 %. Enteromorpha polysaccharide (Ep) was used together with polyaluminum chloride (PAC) in surface water purification. In order to study the mechanism of simultaneous removal of residual nZnO particles and Zn²⁺, coagulation process was further applied in this study. The evolution of flocs size, strength, and recovery ability and fractal structure due to Ep addition was systematically studied in this paper. Results indicated that PAC-Ep was efficient in removing nZnO and Zn²⁺, which leads to more than 95 % particles, 50-60 % natural organic matter (NOM) removed, and 35 % of resolved heavy metal ion adsorbing-chelation. Ep was an efficient coagulant aid in enhancing performance of coagulation and generating flocs with bigger sizes, faster growth rates, and higher recovery abilities. Additionally, the flocs formed by PAC-Ep presented a much looser structure than flocs formed only by PAC. Graphical abstract ᅟ.

Perspectives on the feasibility of using microalgae for industrial wastewater treatment

Although microalgae can serve as an appropriate alternative feedstock for biofuel production, the high microalgal cultivation cost has been a major obstacle for commercializing such attempts. One of the feasible solution for cost reduction is to couple microalgal biofuel production system with wastewater treatment, as microalgae are known to effectively eliminate a variety of nutrients/pollutants in wastewater, such as nitrogen/phosphate, organic carbons, VFAs, pharmaceutical compounds, textile dye compounds, and heavy metals. This review aims to critically discuss the feasibility of microalgae-based wastewater treatment, including the strategies for strain selection, the effect of wastewater types, photobioreactor design, economic feasibility assessment, and other key issues that influence the treatment performance. The potential of microalgae-bacteria consortium for treatment of industrial wastewaters is also discussed. This review provides useful information for developing an integrated wastewater treatment with microalgal biomass and biofuel production facilities and establishing efficient co-cultivation for microalgae and bacteria in such systems.

Coagulation behavior and floc characteristics of a novel composite poly-ferric aluminum chloride-polydimethyl diallylammonium chloride coagulant with different OH/(Fe3+ + Al3+) molar ratios

In this paper, flocculating performance and mechanisms of a new composite coagulant, poly-ferric aluminum chloride-polydimethyl diallylammonium chloride (PFAC-PD) with different OH^-/(Fe³⁺ + Al³⁺) molar ratios, were investigated for humic acid (HA)-kaolin synthetic wastewater treatment. The impact of OH^-/(Fe³⁺ + Al³⁺) molar ratios on the removal efficiencies of turbidity and dissolved organic carbon, specific UV absorbance, coagulation mechanisms and dynamics was explored during the coagulation process using composite coagulants. The coagulation experimental results revealed that the composite coagulants with lower OH^-/(Fe³⁺ + Al³⁺) molar ratio exhibited better coagulation efficiency. When OH^-/(Fe³⁺ + Al³⁺) molar ratio of the composite coagulant was 1.5, adsorption-bridging played a dominant role in coagulating HA-kaolin synthetic wastewater. The floc growth rate and floc size, increased with increasing OH^-/(Fe³⁺ + Al³⁺) molar ratio and the highest peak height of the size distribution was obtained by PFAC-PD with OH^-/(Fe³⁺ + Al³⁺) = 1.5. Also, the composite coagulants with higher OH^-/(Fe³⁺ + Al³⁺) molar ratio formed more compact flocs, as reflected by the higher fractal dimension value. The flocs coagulated by PFAC-PD with basicity value of 1.0 gave strong strength and good recoverability.

Development of a magnetic coagulant based on Moringa oleifera seed extract for water treatment

In this work, to evaluate the effectiveness of the coagulation/flocculation using a natural coagulant, using Moringa oleifera Lam functionalized with magnetic iron oxide nanoparticles, producing flakes that are attracted by an external magnetic field, thereby allowing a fast settling and separation of the clarified liquid, is proposed. The removal efficiency of the parameters, apparent color, turbidity, and compounds with UV254nm absorption, was evaluated. The magnetic functionalized M. oleifera Lam coagulant could effectively remove 90 % of turbidity, 85 % of apparent color, and 50 % for the compounds with absorption at UV254nm, in surface waters under the influence of an external magnetic field within 30 min. It was found that the coagulation/flocculation treatment using magnetic functionalized M. oleifera Lam coagulant was able to reduce the values of the physico-chemical parameters evaluated with reduced settling time.

Purification and characterization of polysaccharides degradases produced by Alteromonas sp. A321

Two different degradases from Alteromonas sp. A321 for polysaccharides from Enteromorpha prolifera (DPE-L and DPE-P) were purified to homogeneity. The molecular weights of purified DPE-L and DPE-P were 75.2 and 102.5 kDa, respectively, and their internal sequences were analysed by LC-MS-MS. The enzymes exhibited an optimum temperature of 30-40 °C (DPE-L) and 35-45 °C (DPE-P), an optimum pH of 7.0 (DPE-L) and 6.0 (DPE-P). DPE-P was highly stable in the presence of EDTA and 1,10-phenanthroline while DPE-L was inhibited by 1,10-phenanthroline. The Km values of DPE-L and DPE-P were 2.93 mg/ml and 0.31 mg/ml and the Vmax values were 6.11 μmol/min/ml and 2.88 μmol/min/ml, respectively. Results of HPLC and ESI-MS analyses showed that enzymatic products were: Rha1(SO3H)1, Rha1(SO3H)1Gluc1, Rha2(SO3H)2Gluc1, and Rha3(SO3H)3Gluc1Xyl1 by DPE-L, and Glu2, Glu3, plus Glu4 by DPE-P, respectively. Thus DPE-L and DPE-P can be used to produce oligosaccharides which potentially revealed more of structure of polysaccharides from E. prolifera.