【作者】 王玉；

【导师】 蒋金辉；

【作者基本信息】 华中师范大学 ， 水生生物学， 2016， 硕士

【摘要】 环境内分泌干扰物会严重影响生物的生存发展,其污染已成为亟待解决的重要问题,特别在水生生态系统中。环境内分泌干扰物的种类很多,本研究以其中常见的有机污染物为对象,并将其分成两大类,一类具有生物降解特性如壬基酚(NonylPhenol,NP)和双酚F(4,4’-Dihydroxydiphenylmethane,BPF),研究其在自然水体中的光解及生物(微生物及沉水植物体系)降解转化,为阐明该类污染物在自然环境中的归趋奠定基础,同时也为生物修复该类污染水体提供理论依据；另一类则在自来水中常见,包括内分泌干扰物的卤代物TCBPA(Tetrachlorobisphenol-A)和难降解污染物BPS(4,4’-Sulfonyldiphenol),研究其在活性炭体系中的吸附特性及机制,评估采用活性炭吸附为主要工艺家庭滤水壶对该类污染物的去除效率,为在家庭末端去除该类污染物、保障人体健康提供技术支持。通过比较采自武汉市的南湖、东湖和紫阳湖的湖水在无菌条件下对NP、BPF的降解能力,结果发现天然水体中存在促进光解的物质,且相比BPF,NP更容易发生光解。当原位微生物群落保留时,南湖水、东湖水和紫阳湖水中NP的去除率分别提高了72.7%、41.1%和25.6%,BPF的去除率分别提高了10.3%、2.1%和9.7%,表明自然水体中均普遍存在能具有去除NP和BPF能力的微生物。选择南湖水和东湖水,当微生物群落交换后,微生物的存在仍能显著促进了水体中NP的去除,东湖水体中的微生物使南湖水中NP的去除率提高了40.1%,而南湖水体中的微生物使东湖水中NP的去除率提高了57.2%；而当微生物群落交换后,东湖微生物的存在使南湖水中BPF去除效率提高了44.2%,显著高于东湖微生物原位实验中微生物的作用(约2.1%),表明环境改变会影响微生物对污染物的去除效率。通过限氧实验发现,南湖水体中NP的去除效率没有显著影响,但BPF的去除效率影响显著,表明相比NP,微生物对BPF对去除更依赖于氧气条件。NP和BPF的混合胁迫不会减少水体中NP的去除,但是会显著减少BPF的去除,表明NP可能会影响水体中对BPF去除有作用的微生物群落。沉水植物体系(均采自武汉植物园)可以高效去除水体中的NP和BPF,特别是金鱼藻(Ceratophyllum demersum),8天时对NP和BPF的去除率均超过了95%。通过抗生素抑制附生细菌后,沉水植物对NP的降解转化效率在8天内基本无明显变化,表明沉水植物体系中对NP的降解转化贡献以植物为主,附生细菌群落贡献较小。沉水植物金鱼藻、狐尾藻(Myriophyllum spicatum)降解转化NP的速度非常迅,特别是金鱼藻,0-1天为其快速反应阶段,1天去除率达到90%±0.8%。沉水植物对NP的植物积累也较小,表明通过植物积累沿食物链放大的环境风险较小。通过粗酶降解实验发现,过氧化物酶可能与沉水植物降解转化NP和BPF有关粉末状活性炭对BPS和TCBPA有较强的吸附能力,吸附平衡的时间分别为50min和120min,其吸附动力学都符合准二级吸附动力学模型(R2BPS=0.9998, R2TCBPA=0.9987)。Langmuir吸附等温线能较好描述粉末状活性炭对BPS的吸附过程,最大饱和吸附量为83.3mg/g。对TCBPA来说Freudlich等温方程拟合较好,最大饱和吸附容量为92.9mg/g。BPS、TCBPA的吸附反应均为放热反应(△HBPS=-14.61kJ/mol,△HTCBPA==-18.06kJ/mol),高温不利于吸附的进行。增加pH以及添加腐殖酸都会降低活性炭的吸附BPS、TCBPA的能力。傅里叶红外光谱实验结果表明,羟基、氨基可能是活性炭吸附BPS过程中的主要作用官能团。滤水壶吸附实验结果表明中可知,有些滤水壶并不能有效去除水体中的BPS,可能是因为流量控制工艺不佳导致。采用活性炭联合其他污染物去除工艺如超滤的滤水壶更可以有效去除水体中的BPS。所以建议选择流量控制稳定、且有多种工艺联合的滤水壶更为安全。综合以上两个方面研究,表明自然水体中的微生物及沉水植物体系均可以通过生物作用显著影响水中内分泌干扰物的环境归趋,且利用沉水植物修复该类污染水体极具可能性；利用活性炭可以有效去除自来水中的内分泌干扰物,从而在末端减少人体对污染物的暴露,保障人体健康。更多还原

【Abstract】 Environmental endocrine disruptors, which have negative effect on development of organisms, have caused severe problems around the world, especially in aquatic ecosystems. There are many kinds of pollutants included. In this research, organic endocrine disruptors were selected for tests, including NP (NonylPhenol) and BPF (4,4’-Dihydroxydiphenylmethane) representing for a kind of pollutants that can be biodegraded according to early reports, and TCBPA (Tetrachlorobisphenol-A) and BPS (4,4’-Sulfonyldiphenol) representing for a kind of pollutants frequently detected in tap water. Photolysis and bio-degradation and bio-transformation of NP and BPF by micoorganisms in water column and submerged macrophytes were investigated, in order to illustrate the environmental destination of these pollutants and explore the potential in the bio-remediation of contaminated water. Adsorption experiments of TCBPA and BPS by activated carobon were also undertaken to declare the patterns, influencing factors and machanisms involved, and the effective of household water filters (based on the adsorption of activated carbon) was compared and essessed, whose results will be much beneficial to the removal of such pollutants for health protection in houses.Photolysis of NP and BPF was greater in autoclaved natural water including Nanhu Lake, Donghu Lake and Ziyanghu Lake comparing to that in ultrapure water, implying substances enhanced the process in natural water. Photolysis of NP was easier than that of BPF. Indigenous microorganisms can greatly enhanced the removal of NP in water, which was 72.7%,41.1% and 25.6% greater for Nanhu Lake, Donghu Lake and Ziyanghu Lake, repectively. And they can also greatly increased the removal of BPF in water, which was 10.3%,2.1% and 9.7% of increase, respectively. Such results indicated that microorganisms which can removing these pollutants were popular in natural water. After exchanging the microorganisms in water column between Nanhu Lake and Donghu Lake, the removal of NP in Nanhu Lake water was still 40.1% of increase due to the microorganisms from Donghu Lake water, while the removal of NP in Donghu Lake water was still 57.2% of increase due to the microorganisms from Nanhu Lake water, indicating the effect of microorganisms. After exchanging the microorganisms in water column, microorganisms from Donghu Lake increased the removal of BPF in Nanhu Lake water by 44.2%, which was significantly greater than the indigenous microorganisms in Donghu Lake (about 2.1%), which suggesting that environmental factors can greatly affect the pollutant removal. Effect of microorganisms on BPF removal demanded more oxygen than that on NP removal, because oxygen limiting greatly decreased the BPF removal while showed no significance on NP removal. Mixed pollutions showed great effect on BPF removal but no significant effect on NP removal. It may be caused by the negative effect of NP on microorganisms removing BPF.Submerged macrophytes which are pickted from wuhan botanical garden can effectively remove NP and BPF in water, especially Ceratophyllum demersum which showed over 95% of removal for both NP and BPF in 8 days. Plants, instead of epiphytic bacteria, may contribute the most to degradation and transformation of NP, because no significant difference showed after inhibition of epiphytic bacteria by antibiotics during the 8 days of experiments. Submerged plants showed great ability in biodegradation and biotransformation of NP, like Ceratophyllum demersum and Myriophyllum spicatum, especially C. demersum which can degradate 90%±0.85% of NP in one day. Meanwhile, slight bioaccumulation of NP was found in plants, which will be great in decreasing the environmental risks of such pollution through food chains. Peroxidase may take the role in the degradation process for both NP and BPF.Powdered activated carbon can effectively removing BPS and TCBPA from water by adsorption. The patterns both fitted well with pseudo-second-order model (R2BPS=0.9998, R2TCBPA=0.9987), which was fast at the first stage and reached the equilibration at 50 min and 120 min, respectively. Langmuir isotherm model was more suitable to explain the adsorption of BPS by activated carbon, while Freudlich isotherm model was more suitable for TCBPA adsorption. The calculated maximum adsorption capacity is 83.3 mg/g and 92.91 mg/g for BPS and TCBPA, respectively. Both adsorption process were exothermic (△HBPS=-14.61 kJ/mol,△HTCBPA=-18.06 kJ/mol). Hence the adsorption effectivity both decreased at higher temperature. Increase in pH, or addition with humic acid can greatly decrease the adsorption of BPS and TCBPA by activated carbon. Hydroxy and amino groups were the main functional groups based on Fourier transform infrared spectroscopy analysis. Some household water filters (based on the adsorption of activated carbon) can’t effectively remove the BPS based on the results.It may be caused by the flow control. Household water filters using adsorption technology by activated carbon combined with other like ultrafiltration will be more effective in BPS removal. Therefore, it was recommended to choose water filters with combined technologies and stable flow control for the health protection.From all the results above, microorganisms in water and submerged macrophytes can greatly affect the environmental destination of organic endocrine disruptors in natural water, and submerged macrophtes have great potential in phyto-remediation of contaminatd water by such pollutants. At the meantime, those pollutants can be effectively removed from tap water by adsorption with activated carbon, which will decrease the exposure of people to such pollutants, in other words, ensure the public health.更多还原