【作者】 刘文；

【导师】 吴巍；

【作者基本信息】 东南大学 ， 劳动卫生与环境卫生学， 2020， 硕士

【摘要】 近年来,由于人类活动的频繁增加,使得湖库水域过量的营养盐输入,从而加速了水体的富营养化并导致了蓝藻水华的暴发,而蓝藻水华及其产生的副产物会严重影响水生动植物的生存以及人类的健康。到目前为止,国内外许多学者对蓝藻水华的治理展开了研究,但是绝大部分治理措施仅限于水体中的蓝藻,忽视了底泥表层的蓝藻休眠体,故仅适用作应急措施。液电技术(也称液中高压脉冲放电技术)有着节能环保等特点,能产生一系列物理、化学、机械等效应,并且能够作用于污泥、破碎岩石。因此,本课题在实验室条件下优化液电技术处理参数,探讨液电技术抑制底泥表层越冬藻休眠体复苏生长的可行性;初步探讨液电技术在处理底泥表层越冬藻休眠体的过程中对水生生物的影响;并在实验室处理参数优化研究的基础上,使用液电技术处理太湖底泥表层野生藻休眠体,分析其对野生藻休眠体的除藻抑藻效果及水质改善情况。所得结果结论如下:(1)自主构建了液中高压脉冲放电装置,在实验室研究的条件下,探讨了工作电压(8k V、10 k V、12 k V、14k V)、作用深度(3cm、6cm、9cm、12cm)、作用时间(3min、6min、9min、12min)对模拟底泥表层越冬藻休眠体的除藻抑藻效果,优化了处理参数。结果表明:在工作电压14k V、作用深度6cm、作用时间12min的条件下,底泥表层的藻休眠体去除率为81.60%,复苏49天后水体中的铜绿微囊藻抑制率达到95.51%,藻毒素水平未测出。可以认为在铜绿微囊藻处于越冬阶段时,采用液电除藻技术可以有效去除底泥表层越冬的藻休眠体,抑制其复苏生长。(2)以部分水生生物为研究对象,初步探讨了液电技术在处理底泥表层越冬藻休眠体的过程中对水生生物的影响。结果表明:在14k V的工作电压下处理5min,14天后铜绿微囊藻的抑制率达到99.29%,而小球藻浓度几乎未改变;在电极距离底泥表层6cm的位置使用14k V的工作电压处理12min,锦鲤鱼、淡水单孔蚓、中华圆田螺三种水生生物的体表、形态学未见明显异常,处理后第7天各组的MDA、SOD水平基本一致。提示本实验条件下液电技术在处理越冬藻休眠体的过程中对水生生物并未造成严重危害。(3)取太湖梅梁湾冬季底泥表层野生藻休眠体及原位湖水,使用液电技术对其进行处理,分析其对野生藻休眠体的除藻抑藻效果及水质改善情况。结果表明:液电技术对底泥表层太湖野生藻休眠体复苏生长的抑制率达到了93.47%,并且处理组的TN、TP、COD降解效果均明显优于对照组。说明液电技术不仅可以抑制甚至防止蓝藻水华的暴发,对于水质的改善也能起到一定的效果。更多还原

【Abstract】 The excessive input of nutrients in lakes and reservoirs has accelerated the eutrophication of water bodies and promoted the outbreak of cyanobacteria blooms because of the frequent increase of human activities in recent years.Cyanobacteria blooms and their by-products seriously affect water the survival of vivid plants and human health.So far,many scholars at home and abroad have carried out researchs on the control of cyanobacteria blooms,but most of the control measures are limited to cyanobacteria in the water body,ignoring the dormant cyanobacteria in the surface layer of the sediment,so they are only suitable for emergency.The liquid-phase high-voltage pulse discharge technology(referred to as electrohydraulic technology,ET)has the characteristics of energy saving and environmental protection,which can produce a series of physical,chemical,and mechanical effects,and can act on sludge and broken rocks.Therefore,we optimize the processing parameters of ET under experimental conditions,and exploreed the feasibility of using ET to inhibit the resuscitation of dormant algal in the surface layer of sediment,then we evaluated the effect of ET on aquatic organisms in the process,and analyzed the effect of ET on algae removal and algae suppression and water quality improvement by treating dormant body of wild algae in Taihu Lake based on the optimization of the best processing parameters in the laboratory.The results obtained are as follows:(1)We constructed a high-voltage pulse discharge device in liquid independently,and investigated the effects of working voltage(8 k V,10 k V,12 k V,14 k V),working depth(3cm,6cm,9cm,12cm)and working time(3min、6min、9min、12min)on the algae-removing and algae-reducing effects of overwintering dormant algae on the surface of simulated sediment under the conditions of laboratory research.The results show that under the optimal conditions of operating voltage of 14 k V,action depth of 6cm,and an action time of 12 min,the removal rate of dormant algal in the surface layer of the sediment was 81.60%,and the inhibition rate of Microcystis aeruginosa reached 95.51% after 49 days of recovery,and the algal toxin was not detected.It can be considered that when Microcystis aeruginosa is in the wintering stage,the use of ET can effectively remove the wintering dormant algal in the surface layer of the sediment,and inhibit its recovery.(2)Taking some aquatic organisms as research objects,the effects of ET on aquatic organisms in the process of treating wintering dormant algal in the surface layer of sediment were preliminarily discussed.The results show that the inhibiton rate of Microcystis aeruginosa was 99.29% after 14 days of treatment at an operating voltage of 14 k V for 5 min,and the chlorella was almost unchanged.Meanwhile,there were no obvious abnormalities in the surface and morphology of the three aquatic organisms including koi fish,freshwater monoporous earthworm and Chinese round snail.Moreover,the MDA and SOD levels of the groups were basically the same on the 7th day after treatment when the electrode was treated with an operating voltage of 14 k V for 12 min at a distance of 6 cm from the surface of the sediment,These results show that the ET has not caused serious harm to aquatic organisms in the process of wintering dormant algal under our experimental conditions.(3)The wild dormant algal and in-situ lake water in the surface sediments of Meiliang Bay in Taihu Lake in winter were taken and treated with ET to analyze its algae-removing effect and water quality improvement of the wild dormant algal.The results showed that the inhibition rate of Taihu Lake’s wild algae treated by the ET reached 93.47%,and the degradation of TN,TP,and COD in the treatment group was significantly lower than that in the control group.Our findings show that the ET can not only inhibit or prevent the outbreak of algae blooms,but also effectively improve water quality.更多还原