【作者】 诸卫平；

【导师】 龙明华；

【作者基本信息】 广西大学 ， 作物栽培学与耕作学， 2013， 博士

【摘要】 水稻秸秆是最主要的农作物秸秆之一,焚烧农作物秸秆会产生烟雾和灰分。通过焚烧农作物秸秆获取草木灰作为农家肥进行农业生产,是我国传统农业的生产方式。至今,我国许多农村地区还保留着这种传统生产的方式。焚烧农作物秸秆的现象在我国广大农村地区依然普遍存在；露天焚烧农作物秸秆所产生的烟雾等污染物是多环芳烃(PAHs)的主要来源之一,由于PAHs对环境和人体造成的危害极大而引起世人对它的关注。本文对用焚烧水稻秸秆产生的烟雾和灰分中的PAHs种类及含量和亚硝酸盐含量进行分析,研究了水稻秸秆烟雾及其烟雾溶解液和稻草灰对蔬菜生长和品质及蔬菜体内PAHs种类及含量的影响,并初步探讨了几种中草药对用烟雾溶解液制成的人工模拟酸雨酸度的中和作用和对土壤中PAHs净化作用的效果。主要研究结果如下：1.将焚烧水稻秸秆产生的烟雾溶解于蒸馏水中,制成烟雾溶解液,烟雾溶解液呈酸性,其酸度随烟雾含量的增加而增强。烟雾溶解液和稻草灰中均含有萘、苊烯、菲、芴、苊、葸、荧蒽、芘、苯并(a)蒽、屈、苯并(b)荧葸、苯并(k)荧蒽、苯并(a)芘、茚并(1,2,3-c,d)芘及苯并(g,h,i)二萘嵌苯等15种PAHs,且稻草灰中还含有亚硝酸盐(以NaNO2计),含量为13.9mg/kg。烟雾溶解液中多数PAHs挥发或降解速度较快,尤其是苯并(b)荧葸、苯并(k)荧蒽、茚并(1,2,3-c,d)芘及苯并(g,h,i)二萘嵌苯等4种PAHs的挥发或降解速度特别快。2.在实验室条件下,研究了焚烧水稻秸秆产生的烟雾的不同的熏蒸时间(0、2、4、6、8h/d对豌豆芽生长、品质及其体内PAHs种类及含量的影响。结果表明：所有烟雾熏蒸的豌豆芽的株高均显著矮于CK,表明烟雾熏蒸明显抑制豌豆芽的伸长生长。烟雾熏蒸处理对豌豆芽的单株重没有明显的影响；所有烟雾熏蒸时间处理的豌豆芽体内的总糖和蛋白质含量均比CK的高,表明在一定的烟雾熏蒸时间内,烟雾熏蒸在一定程度上能提高豌豆芽体内的总糖和蛋白质的含量。豌豆芽体内粗脂肪含量随着烟雾熏蒸时间的增加而呈减少的趋势；所有烟雾熏蒸处理对豌豆芽粗纤维含量没有明显的影响；较短时间(2、4、6h/d)的烟雾熏蒸有利于豌豆芽体内可溶性固形物含量的提高,较长时间(8h/d)的烟雾熏蒸则抑制豌豆芽体内可溶性固形物的形成。所有烟雾熏蒸处理的豌豆芽中,都检测到15种PAHs,而在CK中只检测到7种PAHs的存在,豌豆芽体内的PAHs总含量和平均PAHs含量随烟雾熏蒸时间的增加呈增加的趋势,表明在烟雾熏蒸胁迫下,有利于豌豆芽对PAHs的吸收,最终导致豌豆芽内PAHs的积累,造成豌豆芽PAHs污染。3.在实验室和盆栽试验条件下,研究稻草灰不同施用量对绿豆芽(2、4、6、8g/盘)和菜心(90、180、270、360g/盆)生长、品质及其体内PAHs种类及含量的影响。结果表明：稻草灰施用量能在一定程度上促进绿豆芽的伸长生长,而抑制其增粗生长。随着稻草灰施用量的增大,一定程度上抑制了绿豆芽体内总糖的合成。在稻草灰处理的绿豆芽体内共检测出11种PAHs。稻草灰处理能使绿豆芽体内的菲、芴、苊、葸、荧葸、芘、苯并(a)葸及屈等含量显著增加,使绿豆芽受到PAHs的污染。稻草灰施用量对绿豆芽体内PAHs的总量有显著的影响,当稻草灰施用量为2g/盘时,绿豆芽吸收的PAHs总量最高(37.77μg/kg),而随着稻草灰施用量的增加,绿豆芽体内的PAHs总含量逐渐减少,但仍显著高于CK；稻草灰施用量一定程度上促进菜心的伸长生长,而抑制其增粗生长；随着稻草灰施用量的增大,一定程度上抑制了菜心体内总糖的合成。在稻草灰处理的菜心体内共检测出12种PAHs。稻草灰施用量对菜心体内PAHs的总含量有明显的影响,随着稻草灰施用量增加,菜心体内PAHs的总含量先升后降,当稻草灰施用量为360g/时,菜心体内PAHs的总含量仅为3.22μg/kg,明显低于CK (18.34μg/kg)。以上研究结果表明当土壤中的PAHs的总含量增大到一定限度时,反而阻碍了菜心对PAHs的吸收。4.在实验室和盆栽试验条件下,研究水稻秸秆烟雾溶解液浓度对绿豆芽和菜心生长、品质及其体内PAHs种类及含量的影响。结果表明：烟雾溶解液浓度对绿豆芽的生长没有显著影响。当用烟雾溶解液原液处理时,菜心单株重、根重及根冠比与CK呈显著性差异,烟雾溶解液浓度对菜心的茎径和株高无明显影响。所有烟雾溶解液浓度处理的绿豆芽的粗脂肪含量均比CK的高；烟雾溶解液不同浓度能一定程度地增加绿豆芽体内的粗纤维含量。烟雾溶解液浓度对绿豆芽的蛋白质和可溶性固形物等含量无显著影响；烟雾溶解液浓度对绿豆芽体内PAHs的总含量有显著影响,其中以2倍稀释液处理时,绿豆芽体内的PAHs总含量最高(5.96μg/kg)。烟雾溶解液浓度一定程度上抑制菜心体内总糖和粗脂肪的合成,烟雾溶解液不同浓度处理的菜心对各种PAHs的吸收量无明显规律。5.在实验室条件下,探讨了中草药对用烟雾溶解液制成的人工模拟酸雨的酸度中和作用和对土壤中PAHs净化作用的效果。对人工模拟酸雨酸度中和作用的试验表明,大青叶煎煮液对人工模拟酸雨的酸度有很好的中和作用,其处理从第0d开始,pH值(6.5)就明显高于CK的pH值(5.2),第4d时的pH值为7.1,达到中性水平,随后逐渐变成弱碱性,第8d到第40d,pH值均维持在7.8左右的弱碱性水平；板蓝根煎煮液对人工模拟酸雨的酸度不但没有中和作用,反而加剧了人工模拟酸雨的酸化,处理过后pH值反而降低,从第O d到第6d,pH值由4.6降到4.1；甘草煎煮液对人工模拟酸雨酸度的中和作用较板蓝根煎煮液的强,但比大青叶煎煮液的弱,且需要较长时间,效果缓慢,处理后40d,pH值才上升到中性状态。研究结果表明大青叶煎煮液能有效中和人工模拟酸雨的酸度,并在短时间内使人工模拟酸雨达到弱碱性状态,是改良和治理酸性土壤的途径之一。对土壤中PAHs净化作用的试验结果表明,在金银花煎煮液处理的土壤中,在被检测到的16种PAHs含量中,有11种PAHs均低于CK的含量,这11种PAHs总含量和平均PAHs含量都低于CK,且差异显著,16种PAHs总含量和平均PAHs含量比CK的低,但差异不显著；在丁香煎煮液处理的土壤中,在被检测到的15种PAHs中,有7种PAHs含量明显低于CK,这7种PAHs总含量和平均PAHs含量都比CK的低,且差异显著,16种PAHs总含量和平均PAHs含量比CK的低,但差异不显著。在蒸馏水浸泡处理的土壤中,除3种PAHs的含量低于CK外,其余13种PAHs的含量均等于或高于CK的含量,PAHs总含量和平均PAHs含量均高于CK。研究结果表明,金银花和丁香的煎煮液对土壤中的PAHs有明显的降解和净化作用,而蒸馏水的作用效果则不明显。本研究首次开展了利用中草药煎煮液对人工模拟酸雨的酸度的中和作用和对土壤中PAHs净化作用的研究,并发现有明显的效果,开启了综合治理土壤PAHs污染的新途径和新思路。更多还原

【Abstract】 Rice straw is one of the most important crop residues. The phenomenon of burning crop residues is widespread in most vast rural areas of China. Organic pollutants generated from burning crop residues are a major source of polycyclic aromatic hydrocarbons (PAHs). PAHs aroused the world’s attention because of their harm to environment and human health. In this dissertation, the harmful substances in the artificial simulated acid rain and rice straw ash had been detected. Meanwhile, the effects of the smoke, the artificial simulated acid rain, and ash from burning rice straw on growth, quality, and PAHs contents of vegetable crops were studied. Lastly, the effects of the neutralization of three Chinese herbal decoctions to acid rain and purification of two Chinese herbal decoctions to PAHs in soil were evaluated in laboratory. The main results of the study are summarized as follows.1. The smoke from burning rice straw was dissolved in water and made into smoke dissolved liquid(or artificial simulated acid rain). The harmful substances in smoke dissolved liquid and rice straw ash had been detected. The results showed that fifteen kinds of PAHs including naphthalene,acenaphthylene,phenanthrene,fluorene,acenaphthene, anthracene,fluoranthene,pyrene,benzo(a)anthracene,chrysene,benzo(b)fluoranthene,benzo(k) fluoranthene,benzo(a)pyrene,indeno(1.2.3-c.d)pyrene and benzo(g, h, i)perylene were found in smoke dissolved liquid and rice straw ash. And some nitrite (NaNO2) with the concentration of13.9mg/kg were discovered in the rice straw ash. Furthermore, the acidity of smoke dissolved liquid increased with enhance of smoke content. In addition, most of the PAHs in smoke dissolved liquid volatilized easily and degraded fast, and especially benzo (b) fluoranthene, benzo (k) fluoranthene, indeno (1.2.3-c.d) pyrene and benzo (g, h, i) perylene did much fast. 2. Effects of the different rice straw burning smoke fumigation time (0,2,4,6,8h/d) on growth, quality, and PAHs of peas were studies in laboratory. The results showed that the smoke fumigation time showed no effect on fiber content of pea sprouts. Smoke fumigation had no significant effect on plant weight of pea sprouts.Rice straw burning smoke fumigation (2,4,6,8h/d) obviously inhibited the elongation growth of pea, but could increase the content of total sugar and protein compared with control treatment(0h/d). Crude fat content of pea sprouts decreased with increasing the smoke fumigation time. The less time of smoke fumigation (2,4,6h/d) could improve soluble solids content of the pea sprouts, and more time (8h/d) showed the inhibition on the formation of soluble solid. The results of polycyclic aromatic hydrocarbons (PAHs) contents of pea sprouts detected showed that a total of15kinds of PAHs pollutants were found in the pea sprouts which were fumigated by different smoke fumigation time and7kinds of PAHs found in the pea sprouts which were not fumigated by any smoke fumigation,AHs and average PAHs in pea sprouts decreased with increasing the smoke fumigation time, indicating that the PAHs pollutants were easily absorbed by pea sprouts in continuous rice straw smoke fumigation stress, eventually leading to the accumulation of toxic substances in the pea body, resulting in the PAHs of contamination of vegetable crops leading PAHs polluting.3. Effects of different dosages of rice straw ash on growth, quality, and PAHs of mung bean sprout and Chinese flowering cabbage were studies in laboratory. The results showed that rice straw ash could promote elongation of mung bean sprout and flowering Chinese cabbage and inhibit stem diameter to some extent. Along with the increase of dosages of straw ash, straw ash inhibited the synthesis and accumulation of total sugar in mung bean sprout and flowering Chinese cabbage. Dosages of rice straw ash could increase the conents of PHE、FLU、ACE、ANT、FLT、PYR、BaA and CHR in mung bean sprout significantly,polluting mung bean sprout.11and12kinds of PAHs in mung bean sprout and flowering Chinese cabbage which were treated by rice straw ash were detected, respectively. Different dosages of rice straw ash have different effects on total PAHs in mung bean sprout and flowering Chinese cabbage. The content ofAHs was highest (37.77μg/kg) when the mung bean sprout was treated by the dosage of2g rice straw ash per pot. But with the dosage of rice straw ash increasing (from2to8g/pot), theAHs in mung bean sprout decreased (from37.77to11.15μg/kg). Along with increasing dosages of straw ash (from90to360g/pot), theAHs in flowering Chinese cabbage rose at the beginning (22.24μg/kg) and then fell (from24.91to3.22μg/kg). The contents ofAHs in flowering Chinese cabbage under the treatment in straw ash of360g/pot were3.22μg/kg,which were lower than CK(18.34μg/kg) significantly. The above results showed that the PAHs pollutants were not easily absorbed by the plant when the concentration of PAHs in the soil increased to a certain amount. The absorbing of every PAH between mung bean sprout and flowering Chinese cabbage had no obvious rule.4. The effects of different concentrations of rice straw smoke dissolved liquid on growth, quality and PAHs content of mung bean sprouts and flowering Chinese cabbage were researched by pot experiments in laboratory. The results showed that different concentrations of the smoke dissolved liquid did not affect on the morphology, protein and soluble solids content of the mung bean sprouts but increased the crude fat and crude fiber content in plants. It also increased the PAHs content in plants. The PAHs content was the highest (5.96μg/kg) under the added2-fold dilution of smoke dissolved solution. The plant weight, root weight and root to shoot ratio of flowering Chinese cabbage showed significant difference with the control but showed no significant effect on the stem diameter and plant height under original smoke dissolved solution treamment. Smoke dissolved solution could inhibit the synthesis of total sugar and crude fat to some extent in flowering Chinese cabbage and increased the crude fiber content in mung bean sprouts. The PAHs content in different treated plants showed no apparent regularity.5. The effects of the neutralization of three Chinese herbal decoctions to artificial simulated acid rain acidity(made from smoke dissolved solution) and purification of two Chinese herbal decoctions to PAHs in soil were evaluated in laboratory, the results showed that the Indigowoad leaf boiled liquid could effectively neutralize artificial simulated acid rain acidity in a short time, the pH value of artificial simulated acid rain increased from6.5in the beginning to7.1on the fourth day after artificial simulated acid rain treated by Indigowoad leaf boiled liquid,which were all higher than CK. The pH value of artificial simulated acid rain remained weak alkaline level after the eighth day. Isatis root boiled liquid had no effect on neutralization of artificial simulated acid rain acidity, and could exacerbate acidity of artifical simulated acid rain on the contrary from the beginning to the fortieth day, the pH value getting down from4.6to4.1. The effect of the neutralization of licorice boiled liquid to artificial simulated acid rain acidity was very weak and slow, the pH of artificial simulated acid rain treated by licorice boiled liquid after40days later rose to a neutral state. This study showed that the Indigowoad leaf boiled liquid could effectively neutralize artificial simulated acid rain acidity in a short time, which was one of the effective measures for the improvement and management of acid soils.The honeysuckle and clove boiled liquid show obvious effect on degradation and purification of PAHs in the soil, but distilled water is not conducive to degradation of PAHs in the soil. The contents of Σ11PAHs in the soil soaked by honeysuckle boiled liquid and the conents of Σ7PAHs in the soil soaked by clove boiled liquid were all lower than those of CK significantly,and the conents of Σ16PAHs in the soil soaked by honeysuckle and clove boiled liquid were all lower than those of CK insignificantly. Such as the contents of most kinds of PAHs in the soil soaked by distilled water were higher than those of CK. Their contents of the ΣAHs and average PAHs were higher than those of CK. It was first reported that plant decoction was used to study on degradation and purification of PAHs pollutions in the soil, which opened up new ways and new ideas for the comprehensive management of soil pollution in the present studies.更多还原