酒精废水培养浮萍的影响因素及浮萍产沼气优化研究

发布时间：2018-06-15 10:13

本文选题：浮萍 + 生物量积累　；参考：《江南大学》2017年硕士论文

【摘要】：近几十年,世界各国,尤其中国等发展中国家,面临的环境污染和资源短缺(水、食品和能源)问题越来越严峻。其中,酒精生产行业产生了大量的废水,此类废水中含有丰富的营养物质(蛋白质、无机盐等),经过厌氧处理、好氧处理、厌氧与好氧相结合等技术处理后,虽然有机污染物得到一定的去除,但废水中仍存在一定量的营养类污染物(例如N、P)。如果未经进一步处理排入自然水体,将会造成严重的水体污染(如水体富营养化),进而影响环境和人类健康。而浮萍作为一种水生植物,可利用废水中的营养物质进行生物量积累,在净化废水的同时,采收的浮萍生物质可通过厌氧生物技术转化为沼气能源,具有一定的环境与经济效益。本文以浮萍为研究对象,进行酒精废水中生长的影响因素和其厌氧消化的条件研究。首先,在实验室(光照培养箱)条件下,进行酒精废水培养浮萍的可行性研究,确定浮萍生长的适宜稀释倍数;研究温度、pH、光照强度、CO_2通入方式对浮萍生物量积累的影响,确定生长的最佳条件。并在室外(周转箱)条件下,研究接种密度和采收周期对浮萍生长、浮萍成分以及对废水的处理效果。其次,将采收的浮萍和剩余污泥作为底物,进行厌氧消化产沼气研究,确定产沼气的最佳条件,以期为工程应用提供理论指导。主要研究结果有:1、当稀释酒精废水10倍时,浮萍生物量增大为0.60 g,相对生长率(RGR)为0.041g/(g·d);高于湖水组的0.032 g/(g·d),低于Hoagland培养液组的0.060 g/(g·d),表明酒精废水可以培养浮萍。在实验室条件下,浮萍生物量积累的最适条件为:温度20.0℃,pH为7.00,光照为4000 lux,CO_2通入方式为两天通一次、一次1min;通过多项式回归分析可知,获得浮萍最大增长量的适宜温度、pH和光照强度分别为19.3℃、6.73和4366 lux。2、在室外培养条件下,确定了接种密度为149 g/m2时,能够获得浮萍最大相对生长率、C含量、N含量和蛋白质含量(以干重计),分别为0.091 g/(g·d)、417.60 mg/g、45.60 mg/g和285.00 mg/g;浮萍对废水中TN、TP、NH_4~+-N、SCOD的去除效率相差不大,最大去除率分别为49%、79%、82%、38%;确定了采收周期为3天时,所得浮萍RGR最大,为0.088 g/(g·d),结束生物量比初始生物量增加了1倍,高于实验室条件下的浮萍增量。表明室外培养进一步促进了浮萍生物量的积累;而且浮萍除吸收利用废水中的N、P等营养元素外,还可吸附、去除其中的金属元素,更好的净化水体,。3、浮萍单独厌氧消化的底物产气量为157 mL/gVS,表明浮萍具有生产沼气的能力;将其与剩余污泥混合厌氧消化,其总产气量实际值为2963 mL,比计算值2669 mL提升了11%,且甲烷占比为56.93%,表明两者存在互补优势,混合后可以提高系统的产沼气能力。浮萍经热碱处理后厌氧消化的甲烷产量为1817 mL,比未处理组增大8%,且预处理组前18天的总产气量高于未处理组;18天后,其日产气量低于未处理组,表明浮萍经过预处理后,更多可利用的物质在反应前期被利用产气,加速了产气速度,提高了甲烷产量。浮萍与剩余污泥混合厌氧消化时,接种物与底物最适比为1:1,产气量为169 m L/gVS,总沼气产量、总甲烷产量及甲烷占沼气百分比均最优,分别为3309 mL、1883 mL和56.93%,TS、VS去除率最大,分别为26.44%、36.63%。4、pH、VFAS、NH_4~+-N、SCOD、营养物质浓度及酶活等指标的测定分析,表明浮萍与剩余污泥混合厌氧消化,混合体系在水解酸化阶段pH值迅速降低后可以较快回升,且适宜产甲烷的pH(6.50-7.50)时间较长;整个反应过程,NH_4~+-N浓度处于400 mg/L范围内,并未出现氨抑制现象;淀粉酶活在水解阶段活性较强,水解碳水化合物产生糖类,用于后续发酵利用;脱氢酶活受pH影响,在水解阶段和产甲烷阶段活性均较强,此阶段微生物活性较强且营养物质充足。5、浮萍与剩余污泥在5 L的小试反应器中混合厌氧消化,在5 gVS/(L·d)负荷下运行时,最高的日产甲烷量和日产沼气量分别为2569 mL和4678 mL。
[Abstract]:In recent decades, all countries in the world, especially China and other developing countries, are facing more and more serious problems of environmental pollution and shortage of resources (water, food and energy). Among them, a large number of wastewater has been produced in the alcohol production industry, which contains rich nutrients (protein, inorganic salts, etc.), after anaerobic treatment, aerobic treatment, anaerobic and good. Although organic pollutants have been removed by the technology of oxygen binding, there is still a certain amount of nutrient pollutants (such as N, P) in the wastewater. If untreated into natural water, it will cause serious water pollution (such as water eutrophication), and then affect the environment and human health. The duckweed is a kind of water. The plant can use the nutrients in the waste water to accumulate the biomass. While purifying the wastewater, the collected duckweed biomass can be transformed into the biogas energy by anaerobic biotechnology. This paper takes the duckweed as the research object, and carries out the influence factors of the growth of the alcohol wastewater and the anaerobic digestion bar. First, under the conditions of the laboratory (light culture box), the feasibility study of the cultivation of duckweed in alcohol wastewater was carried out to determine the suitable dilution multiple of the Duckweed growth. The effects of temperature, pH, light intensity and CO_2 on the accumulation of duckweed were studied, and the optimum conditions for the growth of duckweed were determined. Under the conditions of outdoor (Zhou Zhuanxiang), the inoculation was studied. Density and harvest cycle on Duckweed growth, duckweed composition and treatment effect on wastewater. Secondly, the duckweed and residual sludge as substrates are used as substrates for anaerobic digestion and biogas production to determine the optimum conditions for biogas production to provide theoretical guidance for engineering applications. The main results are as follows: 1, when the diluted alcohol wastewater is 10 times the duckweed, duckweed The biomass increased to 0.60 g and the relative growth rate (RGR) was 0.041g/ (G. D), which was higher than the 0.032 g/ (G. D) of the lake water group. It was lower than the 0.060 g/ (G D) in the Hoagland culture group. It showed that the alcohol wastewater could cultivate the duckweed. Under the laboratory conditions, the optimum condition for the accumulation of duckweed was 20, 7 and 4000. Two days, one time and one 1min; by polynomial regression analysis, the optimum temperature for the maximum growth of duckweed was obtained. PH and light intensity were 19.3, 6.73 and 4366 lux.2 respectively. Under the outdoor culture conditions, the maximum relative growth rate of duckweed, C content, N content and protein content were obtained when the inoculation density was 149 g/m2. 0.091 g/ (g / D), 417.60 mg/g, 45.60 mg/g and 285 mg/g, respectively, and the removal efficiency of duckweed in wastewater TN, TP, NH_4~+-N, SCOD was not significant, the maximum removal rate was 49%, 79%, 82%, 38% respectively. When the harvest period was 3 days, the duckweed was 0.088 g/ (0.088), and the end biomass increased by 1 times higher than the initial biomass. The duckweed increment under laboratory conditions indicates that outdoor culture further promotes the accumulation of duckweed biomass; besides, the duckweed can also absorb and use the N, P and other nutrient elements in the wastewater to remove the metal elements and purify the water body better,.3, and the anaerobic digestion of the duckweed is 157 mL/gVS, indicating that the duckweed is alive. The capacity of biogas production; the actual gas production was 2963 mL, which was 11% and 56.93% compared with the calculated value of 2669 mL, which showed that there was a complementary advantage, which could improve the methane production capacity of the system. The methane production of the anaerobic digestion of duckweed was 1817 mL, compared with that of no place. The total gas production of the group was 8% higher than that in the untreated group for the first 18 days of the pretreatment group, and the daily gas output of the group was lower than that of the untreated group. It showed that after the duckweed was pretreated, more available substances were used to produce gas at the early stage of the reaction, accelerating the gas production rate and increasing the methane production. The inoculum was inoculated when the duckweed was mixed with the remaining sludge in the anaerobic digestion. The optimum ratio of the substrate to the substrate is 1:1, the gas yield is 169 m L/gVS, the total methane production, the total methane production and methane percentage are the best, and the maximum removal rate of 3309 mL, 1883 mL and 56.93%, TS, VS, respectively, is 26.44%, 36.63%.4, pH, VFAS, NH_4~+-N, SCOD, nutrient concentration and enzyme activity, indicating that duckweed and residual sludge In the mixed anaerobic digestion, the mixture system can quickly recover after the pH value of the hydrolysis acidification stage, and the pH (6.50-7.50) time suitable for methane production is longer. The whole reaction process, the concentration of NH_4~+-N is within the range of 400 mg/L, and no ammonia inhibition occurs; the activity of amylase in the hydrolysis stage is stronger, and the hydrolytic carbohydrates produce carbohydrates. The activity of dehydrogenase was affected by pH, and the activity of dehydrogenase was stronger in the hydrolysis stage and methanogenic stage. The activity of the microorganism was stronger and the nutrient substance was sufficient.5. The duckweed and the remaining sludge were digested in the 5 L small test reactor, and the highest daily methane production and the daily biogas content were found under the load of 5 gVS/ (L. D). Don't be 2569 mL and 4678 mL.
【学位授予单位】：江南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S216.4;X703

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