改性壳聚糖絮凝剂处理印染废水的研究

研究了用壳聚糖与丙烯酰胺接枝共聚物做为絮凝剂对印染废水的絮凝处理,并与壳聚糖进行了絮凝效果比较,结果表明,其絮凝效果明显好于壳聚糖,在pH值为5～8范围内,PAC和接枝共聚物浓度分别为400mg·L-1和100mg.L-1时,其对印染废水的色度和COD去除率分别为最好,达到95.92%和76%。     

壳聚糖处理水中三氯甲烷的研究

壳聚糖包裹活性炭等经戊二醛交联形成颗粒，以其作为吸附材料吸附处理饮用水中三氯甲烷，有良好的吸附效果。     

壳聚糖三元接枝高分子絮凝剂对垃圾渗滤液生化处理出水的絮凝研究

采用壳聚糖三元接枝高分子絮凝剂(CAS)与聚合氯化铝(PAC)、磷酸镁铵沉淀法(MAP法)复配处理中山市老虎坑垃圾渗滤液生化处理出水.絮体粒径分布测试、絮体形态结构分析和Zata电位测定结果表明,CAS与PAC复配,可充分发挥CAS架桥和PAC电荷中和的协同作用,强化混凝过程,使细小的凝聚体形成体积庞大的絮状沉淀物,并在沉降过程中,网捕水体中的胶体颗粒,显著提高混凝效果.CAS和PAC的投加对NH4 -N脱氮的贡献甚微.采用MAP法与CAS、PAC复配,当投加量分别为50mg/LCAS、500 mg/LPAC、856 mg/LMgCl2·6H2O、1509 mg/LNa2HPO4·12H2O时,出水COD、色度分别小于300 mg/L、30倍,NH4 -N降至2 mg/L左右.     

壳聚糖与甲壳素对废水生物处理的强化作用研究

将壳聚糖溶液和甲壳素固体应用于SBR生物反应器处理有机废水。通过平行实验，对多项污染指标进行比较，证实了壳聚糖和甲壳素对废水生物处理的强化作用。研究还表明，壳聚糖与甲壳素强化生物处理的作用原理不同，壳聚糖是通过改善污泥的菌胶团结构强化生物处理，而甲壳素是作为微生物的生长载体强化生物处理。     

Binding of heavy metal contaminants onto chitosans--an evaluation for remediation of metal contaminated soil and water

The binding efficiency of chitosan samples for Ag(+), Cd(2+), Cu(2+), Pb(2+) and Zn(2+) has been evaluated in order to consider their application to remediate metal contaminated soil and water. The sorption behaviour of metal ions was assessed using a batch technique at different contact time and initial metal concentration with different background electrolytes. The kinetics followed a pseudo-second-order model, while the equilibrium data correlated well with the Freundlich and Langmuir isotherm models. For example, the maximum sorption capacity (Q) for chitosan was estimated as 1.93 mmol/g for Ag(+), 1.61 mmol/g for Cu(2+), 0.94 mmol/g for Zn(2+), 0.72 mmol/g for Cd(2+) and 0.64 mmol/g for Pb(2+). Covalent interaction between metal ions and functional groups (amino and hydroxyl) of the chitosans was the main binding mechanism. Ion exchange is not an important process. Chitosan and cross-linked chitosans were able to bind metal ions in the presence of K(+), Cl(-) and NO(3)(-). The nature of Cl(-) and NO(3)(-) ions did not affect Zn(2+) binding by the chitosans. Even at 11x dilution, the chitosans were able to retain metal ions on their surfaces.     

Asenic removal from groundwater using granular chitosan-titanium adsorbent

Arsenic(As) contamination poses an urgent environmental risk, and its removal from groundwater remains a challenge due to the lack of efficient adsorbents. Herein, a novel granular chitosan-titanium(CS-Ti) adsorbent was fabricated by the sol-gel method. Batch experiments show that As(V) adsorption on CS-Ti followed the pseudo-second-order kinetic model, and the adsorption isotherm conformed to the Freundlich model with the correlation coefficient of 0.99. In situ FTIR spectra revealed that the C...     

Solvent-free mechanochemical mild oxidation method to enhance adsorption properties of chitosan

• Solvent-free chitosan oxidation is obtained by rapid mechanochemical reaction. • Different oxidants induce very diverse physicochemical changes on chitosan. • Oxidized chitosan with persulfate or percarbonate has improved adsorption capacity. • Uptake on oxidized chitosan with persulfate is 125-fold faster than on pristine one. Oxidation has been profitably utilized to improve some properties of chitosan. However, only solvent-based oxidation procedures have been proposed so far, which are hardly feasible at industrial scale in an economic way because of product recovery cost. In this study, a solvent-free, rapid, and effective oxidation method is proposed. It is based on direct solid-state reaction between chitosan and oxidant powder in a mechanochemical reactor. Results prove that by short high energy ball milling (<3 h) it is possible to achieve diverse physicochemical modifications employing different reagents. Apart from polysaccharidic chain shortening, persulfate provokes high amorphization and induces formation of ketonic groups; percarbonate heightens deacetylation degree, preserving in part crystallinity; calcium peroxide merely deprotonates amino groups and increases amorphization degree. Adsorption tests with the azo-dye reactive red 2 show that adsorption capacity of chitosan co-milled with persulfate (974 mg/g milled product), which is the best performing adsorbent, is twice that of pristine chitosan, while adsorption rate is outstandingly boosted (125 times).     

Influence of zeta potential on the flocculation of cyanobacteria cells using chitosan modified soil

Using chitosan modified soil to flocculate and sediment algal cells has been considered as a promising strategy to combat cyanobacteria blooms in natural waters. However, the flocculation efficiency often varies with algal cells with different zeta potential (ZP) attributed to different growth phases or water conditions. This article investigated the relationship between ZP of Microcystis aeruginosa and its influence to the flocculation efficiency using chitosan modified soil. Results suggested that the optimal removal efficiency was obtained when the ZP was between − 20.7 and − 6.7 mV with a removal efficiency of more than 80% in 30 min and large floc size of > 350 μm. When the algal cells were more negatively charged than − 20.7 mV, the effect of chitosan modified soil was depressed (< 60%) due to the insufficient charge density of chitosan to neutralize and destabilize the algal suspension. When the algal cells were less negative than − 6.7 mV or even positively charged, a small floc size (< 120 μm) was formed, which may be difficult to sink under natural water conditions. Therefore, manipulation of ZP provided a viable tool to improve the flocculation efficiency of chitosan modified soil and an important guidance for practical engineering of cyanobacteria bloom control.     

壳聚糖及其衍生物在废水处理中的研究进展

天然高分子絮凝剂壳聚糖具有原料丰富、无毒、易于生物降解、价廉等优点 ,受到了国内外众多研究者的重视和开发应用。本文扼要介绍了国内近年来天然高分子絮凝剂壳聚糖及其改性产品在废水处理中的研究和应用情况。     

新型冠醚交联壳聚糖的吸附性能

合成３,５－二叔丁基－二苯并１４－冠－４双氯代乙酸酯冠醚,然后使之与壳聚糖发生反应制备成壳聚糖－３,５－二叔丁基－二苯并１４－冠－４双乙酸酯冠醚,经元素分析,ＦＴ－ＩＲ红外光谱分析和Ｘ－射线粉末衍射分析表征了结构。