Study on the preparation of chitosan-pumice floating composite material for removing algae and its performance and mechanism of removing algae
-
摘要: 鉴于江河湖库有害藻华现象频发，目前较多使用的是高效絮凝剂与天然粘土矿物联合除藻，但存在着用量大、淤泥多、使底泥增厚、沉下去的藻类仍会伺机爆发等缺点，无法达到令人满意的除藻效果。本文使用轻质漂浮矿物浮石作为载体，制备一种不产生底泥的壳聚糖/浮石浮上式复合除藻材料，以铜绿微囊藻为受试对象，研究了物料配比、投加量、藻悬液pH、反应时间等因素对其絮凝除藻性能的影响，对复合除藻材料的表面形貌及成分进行了SEM和XRF表征，并通过Zeta电位方法探讨了该材料的除藻机制。结果表明：其最佳制备和使用条件为：壳聚糖/浮石配比为10∶1，当藻悬液pH为7，100 mL藻悬液中投加复合除藻材料6 g，反应时间180 min时，复合材料对浊度(NTU)去除率最高为94%，对叶绿素Chlorophyll a(Chl-a)的去除率可达98%；其性能优良的原因在于，该材料的表面凹凸不平，表面积大，且其Zeta电位为正值，极易与带负电的藻发生吸附絮凝和电荷中和，使藻细胞不断聚集形成大絮体，表现出良好的除藻效果。Abstract: In view of the frequent occurrence of harmful algal blooms in rivers, lakes and reservoirs, high-efficiency flocculants and natural clay minerals are commonly used to remove algae, but there are some problems, such as large amounts of clay minerals, silt and thickening of sediments. The sunken algae will still wait for an opportunity to erupt and other shortcomings, unable to achieve a satisfactory algae removal effect. In this paper, a lightweight floating mineral pumice was used as a carrier to prepare a chitosan-pumice floating composite algae-removing material that does not produce sediment. With microcrystal aeruginosa as the test object, the material ratio, dosage, the effect of pH and reaction time of the algae suspension on its flocculation and algae removal performance, the surface morphology and composition of the composite algae removal material were characterized by SEM and XRF, and the algae removal mechanism of the material was discussed by Zeta potential measurement. The results show that the optimal preparation and use conditions are: chitosan-pumice ratio is 10∶1, the pH of the algae suspension is 7, 100 mL of the algae suspension is added 6 g of the composite algae-removing material, and the reaction time is 180 minutes, the maximum removal rate of the composite material for turbidity (NTU) is 94%, and the removal rate for Chlorophyll a (Chl-a) can reach 98%; the reason for its excellent performance is that the surface of the material is uneven, large surface area, and its Zeta potential is positive. It is easy to adsorb and flocculate and neutralize the charge with negatively charged algae, causing the algae cells to continuously aggregate to form large flocs, showing a good floating algae removal effect.
-
图 1 壳聚糖/浮石配比对叶绿素(Chl-a)和浊度(NTU)去除率影响
Figure 1. Effect of chitosan pumice ratio on Chlorophyll a (Chl-a) and turbidity (NTU) removal rate
图 2 浮石 (a)、壳聚糖/浮石复合材料 (b) 的SEM图像(50.0 k)
Figure 2. SEM images of pumice (a), chitosan/pumice composite (b) (50.0 k)
图 3 壳聚糖/浮石复合材料投加量 (a)、藻悬液pH值 (b) 及反应时间 (c) 对絮凝除藻效果的影响
Figure 3. Effects of chitosan/pumice composite dosage (a), pH value of algae suspension (b) and reaction time (c) on algae removal by flocculation
图 4 浮石投加量 (a)、壳聚糖 (b) 投加量及其3种材料的最佳投加量 (c) 对铜绿微囊藻的絮凝效果
Figure 4. Flocculation of Microcystis aeruginosa with pumice dosage (a), chitosan dosage (b) and the best dosage of three materials(c)
图 5 壳聚糖/浮石复合材料再生后对铜绿微囊藻的去除效果
Figure 5. Removal effect of microcystis aeruginosa after regeneration of chitosan/pumice composite
图 7 装置组与市售除藻剂除藻效果比较
Figure 7. Comparison of algal removal effect between device group and commercial algal removal agentt
图 8 pH值 (a)、壳聚糖/浮石配比 (b)、浮石及壳聚糖/浮石复合材料投加量 (c) 对Zeta电位的影响
Figure 8. Effects of pH value (a), ratio of chitosan pumice (b), dosage of pumice and chitosan/pumice composites (c) on Zeta potential.
图 9 铜绿微囊藻絮凝显微镜观察图(10×40倍)
Figure 9. Microscopic observation of Microcystis aeruginosa (10×40 time) ((a) Original state diagram of Microcystis aeruginosa suspension; (b) State diagram of Microcystis aeruginosa suspension after adding chitosan flocculation reaction; (c) State diagram of Microcystis aeruginosa suspension after adding composite reaction; (d) State diagram of Microcystis aeruginosa suspension after adding composite 180 min)
-
[1] 宋靖珂, 王学江, 王佳忆, 等. 漂浮型Ag2CrO4/g-C3N4/TiO2可见光催化材料除藻性能[J]. 复合材料学报, 2021, 38(6):1914-1921.SONG Jingke, WANG Xuejiang, WANG Jiayi, et al. Algae rem oval performance of floating Ag2CrO4/g-C3N4/TiO2 visible light catalytic material[J]. Acta Materiae Compositae Sinica,2021,38(6):1914-1921(in Chinese). [2] WANG S K, WANG F, HU Y R, et al. Magnetic flocculant for high efficiency harvesting of microalgal cells[J]. ACS Applied Materials & Interfaces,2014,6(1):109-115. [3] YUAN Z, WEN Y L, LI J L, et al. Harvesting Chlorella vulgaris by magnetic flocculation using Fe3O4 coating with polyaluminium chloride and polyacrylamide[J]. Bioresource Technology,2015,198:789-796. doi: 10.1016/j.biortech.2015.09.087 [4] YANG Z, SHANG Y, LU Y, et al. Flocculation properties of biodegradable amphoteric chitosan-based flocculants[J]. Chemical Engineering Journal,2011,172(1):287-295. doi: 10.1016/j.cej.2011.05.106 [5] 张文轩, 杨琥, 程镕时, 等. 壳聚糖改性絮凝剂絮凝性能的研究[J]. 高分子通报, 2010(4):49-54.ZHANG Wenxuan, YANG Hu, CHENG Ronshi, et al. Study on flocculation performance of chitosan modified flocculant[J]. Polymer Bulletin,2010(4):49-54(in Chinese). [6] 邹华, 潘纲, 阮文权. 壳聚糖改性粘土絮凝除藻的机制探讨[J]. 环境科学与技术, 2007, 25(6):8-9, 13. doi: 10.3969/j.issn.1003-6504.2007.06.004ZOU Hua, PAN Gang, RUAN Wenquan. Mechanism of algae removal by chitosan modified clay[J]. Environmental Science and Technology,2007,25(6):8-9, 13(in Chinese). doi: 10.3969/j.issn.1003-6504.2007.06.004 [7] 靳晓光, 张洪刚, 潘纲. 阳离子化壳聚糖改性黏土絮凝去除藻[J]. 环境工程学报, 2018, 12(9):2437-2445. doi: 10.12030/j.cjee.201803110JIN Xiaoguang, ZHANG Honggang, PAN Gang. Algae removal by cationic chitosan modified clay[J]. Journal of Environmental Engineering,2018,12(9):2437-2445(in Chinese). doi: 10.12030/j.cjee.201803110 [8] GURBUZ F, CODD G A. Microcystin removal by a naturally-occurring substance: pumice[J]. Bulletin of Environmental Contamination and Toxicology, 2008, 81(3): 323–327. [9] 张洁. 秸秆分解产物光致过氧化氢对铜绿微囊藻抑制效能研究[D]. 重庆: 重庆大学, 2016.ZHANG Jie. Study on the inhibition effect of straw decomposition product photoinduced hydrogen peroxide on Microcystis aeruginosa[D]. Chongqing: Chongqing University, 2016(in Chinese). [10] 严群, 韩冬雪, 汪宏, 等. 藻类生长期对改性蛭石絮凝除藻的影响[J]. 环境工程学报, 2017, 11(3):1621-1626. doi: 10.12030/j.cjee.201511114YAN Qun, HAN Dongxue, WANG Hong, et al. Effect of algae growth period on algae removal by modified vermiculite flocculation[J]. Journal of Environmental Engineering,2017,11(3):1621-1626(in Chinese). doi: 10.12030/j.cjee.201511114 [11] 杨磊, 张高科, 汤丹丹, 等. 壳聚糖改性红壤去除铜绿微囊藻[J]. 环境工程学报, 2015, 9(8):3745-3750. doi: 10.12030/j.cjee.20150825YANG Lei, ZHANG Gaoke, TANG Dandan, et al. Removal of Microcystis aeruginosa from chitosan modified red soil[J]. Journal of Environmental Engineering,2015,9(8):3745-3750(in Chinese). doi: 10.12030/j.cjee.20150825 [12] UMMALYMA S B, MATHEW A K, PANDEY A, et al. Harvesting of microalgal biomass: Efficient method for flocculation through pH modulation[J]. Bioresource Technology,2016,213:216-221. doi: 10.1016/j.biortech.2016.03.114 [13] VU H P, NGUYEN L N, LESAGE G, et al. Synergistic effect of dual flocculation between inorganic salts and chitosan on harvesting microalgae Chlorella vulgaris[J]. Environmental Technology & Innovation,2020,17:1-8. [14] PEI H Y, MA C X, HU W R, et al. The behaviors of Microcystis aeruginosa cells and extracellular microcystins during chitosan flocculation and flocs storage processes[J]. Bioresource Technology,2014,151:314-322. doi: 10.1016/j.biortech.2013.10.077 [15] RASHID N, REHMAN S U, HAN J I. Rapid harvesting of freshwater microalgae using chitosan[J]. Process Biochemistry,2013,48(7):1107-1110. doi: 10.1016/j.procbio.2013.04.018 [16] CHUA E T, ELTANAHY E, JUNG H, et al. Efficient harvesting of nannochloropsis microalgae via optimized chitosan-mediated flocculation[J]. Global Challenges,2019,3(1):1-7. [17] PRADANA Y S, KUSUMASTUTI Y, RAHMA F N, et al. Chitosan flocculation-sedimentation for harvesting selected microalgae species grown in monoculture and mixed cultures[J]. Chemical Engineering Transactions,2017,56:1549-1554. [18] GREGORY J, BARANY S. Adsorption and flocculation by polymers and polymer mixtures[J]. Advances in Colloid & Interface Science,2011,169(1):1-12. [19] YANG R, LI H, HUANG M, et al. A review on chitosan-based flocculants and their applications in water treatment[J]. Water Research,2016,95:59-89. doi: 10.1016/j.watres.2016.02.068 [20] WANG T, YANG W L, HONG Y, et al. Magnetic nanoparticles grafted with amino-riched dendrimer as magnetic flocculant for efficient harvesting of oleaginous microalgae[J]. Chemical Engineering Journal,2016,297:304-314. doi: 10.1016/j.cej.2016.03.038 [21] YUAN Y, ZHANG H, PAN G. Flocculation of cyanobacterial cells using coal fly ash modified chitosan[J]. Water Research,2016,97:11-18. doi: 10.1016/j.watres.2015.12.003 [22] CHENG Y S, ZHENG Y, LABAVITCH J M, et al. The impact of cell wall carbohydrate composition on the chitosan flocculation of Chlorella[J]. Process Biochemistry,2011,46(10):1927-1933. doi: 10.1016/j.procbio.2011.06.021 [23] BEACH E S, ECKELMAN M J, CUI Z, et al. Preferential technological and life cycle environmental performance of chitosan flocculation for harvesting of the green algae neochloris oleoabundans[J]. Bioresource Technology,2012,121:445-449. doi: 10.1016/j.biortech.2012.06.012 [24] DONG C L, CHEN W, CHENG L. Flocculation of algal cells by amphoteric chitosan-based flocculant[J]. Bioresource Technology,2014,170:239-247. doi: 10.1016/j.biortech.2014.07.108 -
下载:
点击查看大图
计量
- 文章访问数: 826
- HTML全文浏览量: 379
- PDF下载量: 39
- 被引次数: 0
