SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Zhihong Yin,Liandong Zhu,Xiaowen Shi,Francesco G. Gentili,Yohanes Kristianto Nugroho
Flocculation is one of the promising methods for harvesting microalgae. In this study, a series of grafted cationic chitosan-cyclodextrin composite flocculants (CTS/β-CDs) with different structural properties were prepared from chitosan and cyclodextrin. The results showed that the harvesting efficiency of CTS/β-CD-1 for C. vulgaris reached 99.91%. The chain type of polymeric flocculants with moderate graft chain lengths (L = 10–20) and tighter branched chain density distribution (D = 1.0–1.8) was favorable for C. vulgaris harvesting. The addition of CTS/β-CDs caused the discrete C. vulgaris cells to be flocculated and aggregated, and the reorganization of particles resulted in larger particles after flocculation, improving the dewatering performance of microalgae flocs. CTS/β-CDs had no significant inhibitory effect on the extraction of lipids, proteins and carbohydrates, and did not affect the extraction and quality of fatty acid methyl esters, and the re-cultivation experiments of the harvested water showed that chitosan-based flocculant was able to effectively reduce the cost of microalgae harvesting. Electrostatic interactions and bridging were the main harvesting mechanisms between CTS/β-CD-1 and C vulgaris . E-DLVO modeling suggested that flocculation is mainly a result of electrostatic and acid-base interactions when the distance between particles is small. At higher pH, the harvesting efficiency of CTS/β-CD-1 with C. vulgaris decreased. The study contributes to a better understanding of the structure–activity relationship between the structural characteristics of flocculants and the harvesting performance.
研究领域:
生物技术
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2019
·
IF 7.015
Rui Huang,Zhiquan Liu,Boyin Yan,Yaqiong Li,Huarui Li,Dongmei Liu,Peng Wang,Fuyi Cui,Wenxin Shi
To tailor low-biofouling membranes remains one of the most problematic issues in filtration for microalgae harvesting. The aim of this study is to develop a high negatively charged and hydrophilic membrane to reduce membrane fouling via bioinspired design and Layer-by-layer (LBL) self-assembly technique for the application in microalgae harvesting. Bioinspired adhesive based on the polydopamine and polyethylenimine (PDA/PEI) composite was first linked onto the neutrally charged PC membrane substrates, then the poly-(styrenesulfonate) (PSS)/poly-(diallyldimethylammonium chloride) (PDADMAC) layers were uniformly assembled by electrostatic attraction. The resultant highly negatively charged and hydrophilic PC membranes exhibit a zeta potential of -66.1 mV and a water contact angle of 26°. Moreover, the modified membranes present a high average flux (133.1 L m 2 h -1 ·bar -1 ) in 1-h microalgae filtration, a high algae retention (~100%) as well as a high flux recovery rate (over 94%). Meanwhile, the resultant membranes exhibit excellent chemical stability in high salty solutions, the low pH solutions and tolerance to long-time running in DI water. The combination of bioinspired construction method and LBL self-assembly technique could be expected to be a universal way to endow neutrally charged materials with highly negative or positive surface charge for various applications.
研究领域:
环境科学
·
材料科学
·
生物工程
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Dian Dai,Mingxiang Qv,Dongyang Liu,Chunming Tang,Wei Wang,Qirui Wu,Zhihong Yin,Liandong Zhu
Magnetic harvesting of microalgae depends on the interface interactions between microalgal cells and flocculants, and thus it is important to find a reasonable evaluation method understand these interface interactions. In this effort, we discussed the formation mechanism and pH regulation of microalgae magnetic harvesting via magnetic chitosan (Fe 3 O 4 @SiO 2 -CS) synthesized by a micro-emulsion method. The flocculation performances and mechanisms during the harvesting of microalgae by the novel flocculant were evaluated. The synthesis process and structure were determined by XRD, FT-IR, SEM and XPS, and the results indicated that Fe 3 O 4 @SiO 2 -CS was successfully prepared. The collection efficiency of 96.52 % was achieved for Chlorella vulgaris within 3 min using Fe 3 O 4 @SiO 2 -CS with the Fe 3 O 4 @SiO 2 and CS mass ratio of 1:3 under pH 1.0. Moreover, this study introduced the two-dimension fractal dimension and extended Derjaguin-Landau-Verwey-Overbeek (E-DLVO) model to evaluate the harvesting performances and mechanisms of Fe 3 O 4 @SiO 2 -CS. Experimental results showed that a strong electrostatic interaction was formed under acidic conditions between Fe 3 O 4 @SiO 2 -CS and microalgae cells with D 2 = 1.82 (fractal dimension value). The hydrophobic tryptophan-like amino acid was observed in the slime-extracellular polymeric substances (S-EPS) secreted by microalgae. S-EPS was found to be a significant substance to promote harvesting performance when the system was neutral or alkaline. This work provides deeper insights into microalgae harvesting by Fe 3 O 4 @SiO 2 -CS as well as reasonable mechanisms to illustrate the interaction of Fe 3 O 4 @SiO 2 -CS and microalgae under different pH values.
研究领域:
环境科学
·
生物技术
✓ 已验证
产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2019
·
IF 6.669
Yuxi Liu,Wenbiao Jin,Xu Zhou,Song-Fang Han,Renjie Tu,Xiaochi Feng,Paul D. Jensen,Qilin Wang
In this work, a novel flocculation process by using nano-Fe 3 O 4 coated with polyethyleneimine (Fe 3 O 4 @PEI) as magnetic seeds was developed to harvest the microalgae cultivated in urban sewage. Experiment results indicated that the harvest efficiency of Chlorella pyrenoidosa (0.5 g/L) was 98.92 ± 0.41% under the optimal conditions of Fe 3 O 4 @PEI dose of 20 mL/L, flocculation time of 20 min, and stirring speed of 800 rpm (3 min), while that of Scenedesmus obliquus (0.4 g/L) was 98.45 ± 0.35% under a Fe 3 O 4 @PEI dose of 16 mL/L, flocculation time of 15 min, and stirring speed of 730 rpm (3 min). Moreover, the process did not reduce the lipid content of microalgae and quality of biodiesel. After microalgae harvest, Fe 3 O 4 @PEI could be recovered by ultrasonication, re-wrapped with polyethyleneimine and reused to reduce operational cost.
研究领域:
环境科学
·
生物技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Cleaner Production
·
2021
·
IF 9.297
Wenqi Qin,Siqi Zhang,Shujuan Yang,Feilin Lin,Qichang Zhou,Houkui Gong,Xinyu Zhao,Furui He,Yang Zhou,Yuhong Feng,Gaobo Yu,Yuanyuan Liu,Jiacheng Li
Microalgae have been known as a promising sustainable resource for bioenergy cleaner production. Herein, a series of highly dispersible novel magnetic quaternary ammonium cationic surfactants (Fe 3 O 4 @DQn, n = 1, 2, 3) for the efficient harvesting of oleaginous Chlorella pyrenoidosa ( C. pyrenoidosa ) have been investigated. The Fe 3 O 4 @DQn capture microalgae process can be divided into a three-step operation (i.e., flocculation , separation, and recycle). For harvesting C. pyrenoidosa , the Fe 3 O 4 @DQn has both a high recovery efficiency (>98.4%) and a short flocculation time (2 min). In addition, the reused Fe 3 O 4 @DQ2 can maintain a high recovery efficiency (92.31%) with five cycling times. Moreover, the N -[3-(Trimethoxysilyl)propyl]ethylenediamine (TMPED) amount and the pH value both have a positive influence on the C. pyrenoidosa harvesting. It is worth noting that the dual effect of quaternary ammonium cationic surfactant, strong positively charged and hydrophobic properties, leads to a higher harvesting efficiency of microalgae. Furthermore, the results of particle size distribution and turbiscan stability index (TSI) show that a higher specific surface area, a smaller polydispersity index and TSI value of the Fe 3 O 4 @DQn can make a more excellent adsorption and dispersion properties. Finally, the Fe 3 O 4 @DQn might provide a promising high cost-performance to harvesting of oleaginous microalgae due to the better economic viability.
研究领域:
生物技术
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Zhihong Yin,Shuangxi Li,Dan Hu,Zhuo Li,Ruoyu Chu,Chenchen Liu,Xinzhu Li,Jiangjun Hu,Liandong Zhu
As an environmentally friendly bioflocculant, chitosan has a great application potential in the field of microalgae harvesting due to its biocompatibility. In this work, three different inorganic clay minerals (kaolin, montmorillonite, and diatomite) were selected to prepare chitosan-clay composite materials (CTS/KAL, CTS/MML and CTS/DTE) as flocculants to harvest microalgae cells. The harvesting capacities of CTS/KAL, CTS/MML and CTS/DTE were accordingly 97.37%, 97.81% and 98.34% for microalgae cells under the dosage of 60 mg/L, microalgae concentration of 0.923 g/L, settling time of 30 min and pH of 10. CTS/DTE showed excellent harvesting performance for microalgae cells, mainly due to the enhancement of charge neutralization, sweeping and bridging effects. Based on the phenomenological theory, the second-order polynomial model was used to analyze the influences of different external factors on the microalgae harvesting efficiency. A reasonable performance relationship between CTS-clays for harvesting of microalgae cells and external factors was established. The analysis of carbohydrates, proteins, and fatty acids of microalgae biomass collected by CTS/KAL, CTS/MML, CTS/DTE and centrifugation showed that the harvesting of CTS-clay did not influence the properties of biomass. The experimental results of water resource recycling and re-cultivation after microalgae harvesting by CTS/KAL, CTS/MML and CTS/DTE exhibited that the growth rates of 50% circulating medium + 50% fresh BG11 culture medium were accordingly 2.512, 2.466 and 2.572 times higher than those of 100% circulating medium. It is concluded that chitosan-clay composite materials are efficient and environmentally friendly flocculants with a great applicable potential in microalgae harvesting.
研究领域:
环境科学
·
生物技术
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）