排序方式: 共有52条查询结果,搜索用时 15 毫秒
1.
2.
壳聚糖絮凝剂在活性污泥调理中的应用 总被引:14,自引:1,他引:14
研究了自制的壳聚糖絮凝剂在活性污泥调理中的应用,通过污泥比阻、上清液剩余浊度、泥饼含水率及沉降性能等的测定,重点分析了活性污泥脱水的pH范围、絮凝剂投量和壳聚糖分子量及其脱乙酰度对调理效果的影响,并与絮凝剂聚丙烯酰胺(PAM)和聚合氯化铝(PAC)作了比较,在此基础上还进行了双絮凝剂两段法处理污泥的初步探索。研究发现,壳聚糖作为活性污泥调理剂,投量(干污泥质量百分比)在0.8%~1.2%,pH值在5~8时即有较好的调理效果,与PAM效果基本相当,接近于8%~16%的PAC;壳聚糖相对分子量在30×10~4左右,脱乙酰度在70%左右时有较好的调理效果;双絮凝剂两段法处理污泥,在同等用量时效果好于单絮凝剂一段法。 相似文献
3.
4.
Nugraha E. Suyatma Alain Copinet Lan Tighzert Veronique Coma 《Journal of Polymers and the Environment》2004,12(1):1-6
Biodegradable film blends of chitosan with poly(lactic acid) (PLA) were prepared by solution mixing and film casting. The main goal of these blends is to improve the water vapor barrier of chitosan by blending it with a hydrophobic biodegradable polymer from renewable resources. Mechanical properties of obtained films were assessed by tensile test. Thermal properties, water barrier properties, and water sensitivity were studied by differential scanning calorimeter analysis, water vapor permeability measurements, and surface-angle contact tests, respectively. The incorporation of PLA to chitosan improved the water barrier properties and decreased the water sensitivity of chitosan film. However, the tensile strength and elastic modulus of chitosan decreased with the addition of PLA. Mechanical and thermal properties revealed that chitosan and PLA blends are incompatible, consistent with the results of Fourier transform infrared (FTIR) analysis that showed the absence of specific interaction between chitosan and PLA. 相似文献
5.
壳聚糖是一种天然高分子聚合物,被广泛地作为絮凝剂用于水处理过程。探讨了壳聚糖的三种絮凝机理。在水处理中,其絮凝性能的发挥受到pH值、壳聚糖的投加量、壳聚糖的分子量以及壳聚糖的脱乙酰度等因素的影响。 相似文献
6.
Agata Szygua Eric Guibal María Ario Palacín Montserrat Ruiz Ana Maria Sastre 《Journal of environmental management》2009,90(10):2979-2986
Chitosan (a biopolymer) is an aminopolysaccharide that can be used for the treatment of colored solutions by coagulation–flocculation (as an alternative to more conventional processes such as sorption). Acid Blue 92 (a sulfonic dye) was selected as a model dye for verifying chitosan's ability to treat textile wastewater. A preliminary experiment demonstrated that chitosan was more efficient at color removal in tap water than in demineralized water, and that a substantially lower concentration of chitosan could be used with tap water. Dye removal reached up to 99% under optimum concentration; i.e., in terms of the acidic solutions and the stoichiometric ratio between the amine groups of the biopolymer and the sulfonic groups in the dye. The flocs were recovered and the dye was efficiently removed using alkaline solutions (0.001–1 M NaOH solutions) and the biopolymer, re-dissolved in acetic acid solution, was reused in a further treatment cycle. 相似文献
7.
We compared the efficacy of matrix based fertilizers (MBFs) formulated to reduce NO3-, NH4+, and total phosphorus (TP) leaching, with Osmocoate 14-14-14, a conventional commercial slow release fertilizer (SRF) and an unamended control in three different soil textures in a greenhouse column study. The MBFs covered a range of inorganic N and P in compounds that are relatively loosely bound (MBF 1) to more moderately bound (MBF 2) and more tightly bound compounds (MBF 3) mixed with Al(SO4)3H2O and/or Fe2(SO4)3 and with high ionic exchange compounds starch, chitosan and lignin. When N and P are released, the chemicals containing these nutrients in the MBF bind N and P to a Al(SO4)3H2O and/or Fe2(SO4)3 starch-chitosan-lignin matrix. One milligram (8000 spores) of Glomus intradices was added to all formulations to enhance nutrient uptake. In all three soil textures the SRF leachate contained a higher amount of NH4+, NO3- and TP than leachate from all other fertilizers. In all three soils there were no consistent differences in the amount of NH4+, NO3- and TP in the MBF leachates compared to the control leachate. Plants growing in soils receiving SRF had greater shoot, root and total biomass than all MBFs regardless of Al(SO4)3H2O or Fe2(SO4)3 additions. Arbuscular mycorrhizal infection in plant roots did not consistently differ among plants growing in soil receiving SRF, MBFs and control treatments. Although the MBFs resulted in less plant growth in this experiment they may be applied to soils growing plants in areas that are at high risk for nutrient leaching to surface waters. 相似文献
8.
Dos Santos HH Demarchi CA Rodrigues CA Greneche JM Nedelko N Slawska-Waniewska A 《Chemosphere》2011,82(2):278-283
It was reported the adsorption of As(III) on the surface of the chitosan-Fe-crosslinked complex. Theoretical correlation of the experimental equilibrium adsorption data for As(III)/Ch-Fe system is best explained by the non-linearized form Langmuir-Freundlich isotherm model. At optimum conditions, pH 9.0, the maximum adsorption capacity, calculated using the Langmuir-Freundlich isotherm model was 13.4 mg g−1. The adsorption kinetics of As(III) onto Ch-Fe are described by the pseudo-first-order kinetic equation. The results of the Mössbauer spectroscopy showed that there is no redox process on the surface of the adsorbent. 相似文献
9.
Ryo?ShojiEmail author Takanori?Miyazaki Takashi?Niinou Mikio?Kato Hiroshi?Ishii 《Journal of Material Cycles and Waste Management》2004,6(2):142-146
We have successfully prepared a bead-type adsorbent from two materials with different adsorption characteristics. Heavy metals were removed by greatly swollen egg shell membrane-conjugated chitosan beads. The egg shell membrane accumulated and removed precious metal ions from a dilute aqueous solution with a high affinity in a short contact time. Experiments suggested that chitosan beads could take up gold ions with great capacity and selectivity by conjugation with egg shell membrane. Under certain conditions, the selective removal of gold and copper in a mixture of gold and copper ions by egg shell membrane-conjugated chitosan beads was 100% and 2%, respectively. Egg shell membrane-conjugated chitosan beads can be seen as a promising material to recover gold in wastewater from various industries, such as electroplating. 相似文献
10.
This work explores the feasibility of using chitosan (CS)-sodium alginate (SA) crosslinking gel to reinforce dry water (DW) composites. The stability and fire extinguishing efficiency of the DW powder are investigated. Compared to ordinary DW material, water loss rate of the modified DW composite is decreased, and its pressure resistance and stability are significantly increased. Moreover, it possesses higher fire extinguishing efficiency than conventional dry powder. Fire extinguishing mechanism and gel formation mechanism are proposed. The improvement in stability has great significance for the storage and transportation of DW materials. These results demonstrate the ability to create a fully green and renewable crosslinking gel capable of endowing high stability to DW material. This work provides a novel solution to improve the stability of DW materials, which will have great application prospect in fire suppression of some flammable hazardous chemicals. 相似文献