【作者】 高鹏；

【导师】 王应军；

【作者基本信息】 四川农业大学 ， 环境工程， 2011， 硕士

【摘要】 本文选择了我国水华的优势藻种铜绿微囊藻(Microcystis aeruginosa)作为实验材料,分别采用海藻酸钠(SA)和聚乙烯醇(PVA)为固定化载体对铜绿微囊藻进行固定化实验,采用正交试验的方法确定两种包埋剂包埋固定化铜绿微囊藻的最佳条件,通过模拟污水试验研究了两种载体的固定化方法在不同影响条件下对氮磷的去除效果,并采用最佳包埋条件下的固定化铜绿微囊藻处理畜禽养殖废水,研究固定化铜绿微囊藻在实际污水中的生长及对实际污水中氮磷等营养元素的去除效果。研究结果如下.(1)正交试验以成球情况、机械强度、传质时间以及对NH4+-N和TP的净化能力为指标,考察包埋剂浓度、交联剂浓度、交联时间和包埋量等因素对上述指标的影响,从而确定海藻酸钠凝胶藻球的适宜包埋条件是：3%的海藻酸钠溶液,5%CaCl2溶液,2h交联时间,1：1的包埋量(海藻酸钠v：藻液v)；而聚乙烯醇凝胶藻球的适宜包埋条件是：10%聚乙烯醇-0.5%海藻酸钠溶液,交联剂为饱和硼酸-2%CaCl2的混合溶液,12h交联时间,1：2的包埋量(聚乙烯醇-海藻酸钠v：藻液v)。在此条件下固定的铜绿微囊藻球具有较高的生物活性、较好的强度以及传质性能。(2)通过模拟污水试验研究两种载体(海藻酸钠和聚乙烯醇)的固定化方法在不同影响条件下对氮磷的去除效果。研究表明将光强控制在25001ux-30001ux,温度为25℃、pH为8左右时最适合包埋固定化铜绿微囊藻去除污水中的氮磷；采用高密度藻珠(5×106)、将凝胶藻珠与污水比例控制在10%-14%的范围内、污水中氮磷比的范围在5：1-10：1内,对模拟污水中的氮磷的去除效果较好。(3)将铜绿微囊藻固定在海藻酸钠(SA)和聚乙烯醇(PVA)中,对不同浓度的畜禽污水进行净化,研究其对实际污水中TN,NH4+-N,TP,PO43-P和COD的净化效率以及净化过程中铜绿微囊藻的生长、叶绿素a含量的变化,并与未固定的铜绿微囊藻进行对照比较实验,同时还研究了固定化藻细胞对污水pH值的影响及藻细胞的溢出量。研究结果表明,实际污水经过6d的净化处理,固定化铜绿微囊藻细胞对氮磷的去除效果明显高于悬浮藻细胞,对于不同浓度的畜禽污水,SA凝胶藻颗粒对各物质的平均去除率都要高于PVA凝胶藻颗粒；与悬浮藻相比,最终固定化藻细胞的数量和叶绿素a含量都高于悬浮藻细胞的数量和叶绿素a含量,在试验后期PVA凝胶藻球中的藻细胞数量和叶绿素a含量高于SA凝胶藻球；试验开始后水中的pH值不断的增大,最后趋于平稳,最终稳定在9左右；从试验开始SA胶球的藻细胞泄漏量一直大于PVA藻球的泄漏量,到了实验后期,SA胶球的藻细胞泄漏量几乎达到了PVA的两倍,这说明PVA固定的藻球具有更好的强度。更多还原

【Abstract】 Microcystis aeruginosa as a kind of dominant specie on algal bloom from China was chosen for experimental material in this dissertation, SA and PVA as the immobilized carrier were experimented for immobilized Microcystis aeruginosa respectively. The author adopted orthogonal experiment to determine the optimum condition of using SA/PVA to imbed and immobilize Microcystis aeruginosa. By means of experimental simulation wastewater, this dissertation made in-depth research on the efficiency of SA/PVA removing N、P in different kinds of involved factors. Also, the optimum imbedding condition of immobilizing Microcystis aeruginosa was adopted to dispose the wastewater from livestock farm, and this dissertation investigated the growth of immobilized Microcystis aeruginosa and the efficiency of SA/PVA removing N and P in the practical wastewater.This orthogonal experiment was indexed by balling, mechanical strength, transferring time and the ability to purify NH4+-N/TP; and factors influencing the above indexes were investigated, including the concentration of imbedding agent, the concentration of cross-linker, the time of cross linkage, the imbedding proportion and so on. Consequently, the optimum imbedding condition based on SA gelatin balls was obtained, i.e., the concentration of imbedding agent:3% SA; the concentration of cross-linker:5% CaCl2;the time of cross linkage:2h; the imbedding proportion:1:1(VSA:VAlga); and also the optimum imbedding condition based on PVA gelatin balls was obtained, i.e., the concentration of imbedding agent:10% PVA-0.5% SA; the concentration of cross-linker:mixture solvent of saturated boric acid and 2% CaCl2; the time of cross linkage:12h; the imbedding proportion: 1:2(VPVA-SA:VAlga)-Under the above conditions, immobilized Microcystis aeruginosa had better performance on biological activity, mechanical strength and transfer.By means of experimental simulation wastewater, this dissertation made in-depth research on the efficiency of SA and PVA removing N、P in different kinds of involved factors. The results indicated that the configuration, i.e., illumination:2500lux-3000lux; temperature:25℃; pH:8, was best fit for immobilized Microcystis aeruginosa removing N、P in the simulation wastewater; and the configuration, i.e., high density gelatin(5×106); the proportion of gelatin balls to wastewater:10%-14%; the proportion of N/P in the wastewater:5:1-10:1, was better for removing N、P in experimental simulation wastewater.By means of immobilizing Microcystis aeruginosa on SA/PVA and purifying different concentration of wastewater from livestock farm, the author studied on the removal rate for TN, NH4+-N, TP, PO43-P and COD, the growth of Microcystis aeruginosa in the purifying process and the change of Chlorophyll a content. Meanwhile the author drawed a parallel between immobilized and non-immobilized Microcystis aeruginosa, and studied on the influence on pH from immobilized gelatin cells and their leakage. The results indicated that after six days of purification for wastewater, immobilized Microcystis aeruginosa had better effect on removing N、P than suspended algae obviously; for different concentration wastewater from livestock farm, the average removal rate of SA to each involved component was higher than PVA; Compared with suspended algae, the amount of immobilized algae and the content of Chlorophyll a were higher; In the later period of experiment, the amount of algae and the content of Chlorophyll a about PVA were higher than S A; pH had been increasing in the early days, leveled off and reached 9 finally; At the beginning, the leakage of SA gelatin cells kept greater than PVA gelatin cells, and finally the leakage of SA gelatin cells almost reached the double of PVA, which showed that immobilized algae by PVA had higher strength.更多还原