壳聚糖季铵盐改性河沙去除铜绿微囊藻的研究

摘要

The chitosan quaternary ammonium salt (HTCC) was prepared by the reaction of chitosan with 2,3-epoxypropyltrimethylammonium chloride (GTA).The river sand modified by HTCC was used for treating Microcystis aeruginosa.The results showed that the flocculating ability of HTCC modified sand was more remarkable.(1) The highest algae removal ratio was reached (99.50％) when the dosage of HTCC and river sand was 7.5 mg/L and 0.500 g/L respectively,the density of algae was 9.5 × 106 cells/mL,the temperature was about 25 ℃ and the pH of al gae was about 8.(2) Compare with HTCC alone,the river sand were critical for speeding up the kinetic processes of flocculation and sedimentation of algal floes.(3) The modified river sand has a wide scope of application of the pH that the removal ratio was significant in the range of pH 7-12.(4) The modified river sand was suitable for Microcys tis aeruginosa in the summer of the water temperature was 25 35 ℃.(5) The effective storage time of HTCC-modified river sand should not exceed 10 days in 2-8 ℃.(6) The HTCC has a lower risk of ammonia dissolution rate and the maximum ratio was 1.77％.%以2,3环氧丙基三甲基氯化铵和壳聚糖为原料制备了水溶性的壳聚糖季铵盐(HTCC),利用HTCC对河沙进行改性,并用于铜绿微囊藻的处理.结果表明:(1)在HTCC用量为7.5 mg/L、预处理河沙用量为0.500 g/L的最佳条件下制备得到的HTCC改性河沙(简称改性河沙)对铜绿微囊藻具有良好的降藻效果,当藻密度为9.5×106个/mL、水温25℃左右、藻液pH为8左右时,降藻率达到最高(99.50％).(2)改性河沙的加入能大大缩短絮体形成及沉降的时间,压实絮体,减少其上浮.(3)改性河沙具有较宽的pH适用范围(7～12).(4)改性河沙适宜在水温为25～35℃的夏季对铜绿微囊藻进行降藻.(5)改性河沙悬浊液在2～8℃下存放不宜超过10d.(6) HTCC的氨氮溶出率较低(最高为1.77％),氨氮溶出风险较低.