【作者】 田洪磊；

【导师】 田呈瑞；

【作者基本信息】 陕西师范大学 ， 食品科学， 2006， 硕士

【摘要】 我国一些主要苹果产区存在的重金属污染问题,主要原因是工业废水对灌溉水质的污染造成金属离子在果实中的富集,且苹果果实存在对Cu²⁺、pb²⁺、Cd²⁺优先富集的特点。在人们食品安全意识不断提高,及苹果鲜果、浓缩苹果汁金属离子更严格含量标准提出的情况下,依据所建立的苹果质量安全预警系统的要求,本文探讨了苹果果实中重金属富集的规律及苹果汁重金属离子去除的方法,力图为所建立的苹果质量安全预警系统中的快速反应体系提供信息服务。 甜菜渣是甜菜制糖工业的主要废弃物,除部分用作动物饲料外,未能有效利用。其中含有20%左右的粗纤维,经过适当的提取工艺,低温干燥,基团改性后可得吸附性强的鳌合/离子交换纤维。本论文就是利用改性甜菜纤维研究其对金属离子的吸附性能。以甜菜纤维具有吸附阳离子性能为基础,引入离子交换性能强的巯基,制备高吸附型巯基甜菜纤维,为控制果汁中的微量元素含量提供方法,同时为甜菜渣的综合利用开辟了新的途径。 本文主要研究:苹果对重金属富集规律;原料粒度、提取温度、提取时间、液料比、盐酸液浓度对甜菜纤维提取率的影响,确定最佳的提取条件,获得了甜菜纤维的最佳脱色方法:并根据纤维素和硫代乙醇酸在乙酸酐和乙酸介质中发生酯化反应合成SC的原理,得出了巯基甜菜纤维制备的最佳工艺参数;以Cu²⁺、pb²⁺、Cd²⁺、As²⁺为对象,分析研究了巯基甜菜纤维对重金属离子的静态、动态吸附性能及其可再生性;初步研究了甜菜纤维对苹果汁重金属离子的吸附效果,以期能为苹果的安全生产提供理论依据和数据支持。试验结果表明: （1）洛川无公害苹果示范区土壤重金属含量变化较大,依元素不同而异,其中w(Cd²⁺)变化较大,变异系数为38.89%;w(pb²⁺)、w(Cu²⁺)变化程度次之,变异系数为34.20%、25.58%;w(As²⁺)变化最小,变异系数为22.26%,重金属含量在各土样之间存在较大的差异性,反映了果园管理的不同对果园土壤质量产生了明显影响。 （2）在4种重金属中As²⁺污染最为严重,平均污染指数为0.65,Cd²⁺污染次之,平均污染指数为0.60,pb²⁺、Cu²⁺重金属污染较轻,综合污染指数均小于1,土壤重金属污染程度较轻,表明洛川无公害苹果示范园区土壤达到国家无公害苹果生产的标准,但其中某些样点污染指数有趋近于1的趋势,应该引起该区果园管理者的注意。更多还原

【Abstract】 Some apples’ area in our country were polluted badly by heavy metal ions, its dominating causation which leads to heavy metal ions’ cumulation in apples is that irrigative water is polluted by industrial waste water.Furthermore, apples can adsorb some heavy metal ions preferentially. We studied on enrichmented law of heavy metal ions in apples and using sugar-beet residue to remove the deleterious metal ions from apple juice, with people’s increasing requirement to the fruit juice security, the stricter standard for metal ions and the pre-warning system of apples’ safety.especially for the harmful metal ions will be put forward. So, it is necessary to look for a method to get rid of metal ions suited to continuous manufacture.The thesis’ disquisitive contents are: the enrichmented law of heavy metal ions in apples;the generative method of the sulfohydryl sugar-beet fiber;the sulfohydryl sugar beet fiber’s capability of static state adsorption and dynamic adsorption for Cu²⁺、 Pb²⁺ 、 Cd²⁺、 As²⁺;the effect of adsorption of the sulfohydryl sugar-beet fiber on heavy metal ions in apple juice. Consequently, we can provide theoretics-gist and data- sustain for apples’ safe production.The results of the work were listed as follows:（1）The change of heavy metal ions’ contents is distinct in the soil of social in-effects of pollution. Thereinto, the content’s range of Cd²⁺ is in evidence compare to others, its aberrance- coefficient is 38.89%, the content’s range of Pb²⁺、 Cd²⁺、 Cr²⁺ take second place, and theirs aberrance-coefficient are 34.20%、 30.30%、 25.58% respectively, the content’s range of As²⁺ is the least, and its aberrance-coefficient is22.26%,which show that heavy metal ions’ contents in various samples are different.（2）The polluted degree of As²⁺ is the most grievous in above 4stirps of heavy metal ions, The polluted degree of Cd²⁺ take second place, and theirs average polluted exponents are 0.65 and 0.60 respectively, the rest are on the small side. But the general polluted exponent of heavy metal ions in the orchard is less than 1, the quality of soil in the orchard accords with state standard, nevertheless, some edaphic amples’ pollutedexponents have the trend to 1. Therefor the culturist should pay attention to the pollution of heavy metal ions.（3） the contents of Cu2"\ Pb2+% As2+ in apples are different observably, the maximal content is 3.2⁶.7 times as the minimum ones, the contents of Cd2+ is 15.0 times as the minimum one. The collective aberrance-coefficient changes in the rage of 35.94% 75.94%. All apples amples’ polluted exponents are less than 1.Herein to, the polluted exponent of Cu2+ is upper correspondingly, the polluted exponent of Pb2+ is lower correspondingly.（4）Apples have different adsorptive ability, the order is:u（Cd2+）>u（Cu2+）>u（As2+） >u（Pb2+）, the experimental results showed that Apples have powerful adsorptive ability to Cd2+,but the adsorptive ability to Pb2+ is feeblish.（5） The sugar beet fiber was distilled by chemic method, the factors have different order, which is reaction temperature, hydrochloric acid concentration, stuff ratio, reaction time, stuff granularity. The best condition of grafting reaction was stuff granularity 40 M, reaction temperature 80V, reaction time 160min, stuff ratio 14/1, hydrochloric acid concentration 0.3%.（6） The sugar beet fiber was decolored by H2O2, the decoloring temperature was the most important, H2O2 additive quantity and the decoloring time secondly, pH of liquor lastly, The best condition of technics was H2O2 additive quantity 4%,the decoloring temperature 50 °C, the decoloring time 4h, pH=6.0.（7）The primary and secondary order of the factors among the produnction of SC is: the acidity of reaction-system, the reaction time, the reaction temperature, the stuff ratio, The best condition of reaction conditions was the stuff ratio 5:l（mL/g）, the acidity of reaction-system 0.3%, the reaction temperature 50°C, the reaction time 18h,in this condition the most content of SH is 2.0%.（8）The results of the experimentation about SC static state adsorption show that the sulfohydryl sugar beet fiber have better capability to Cu2\ Pb2\ Cd2\ As2+, the adsorption time , the additive quantity of sulfohydryl sugar beet fiber, pH and the adsorption temperature influence adsorption effect completely, especially, pH and the adsorption temperature are more important than others.（9）The adsorption effect increase gradually with the increasing of pH, when pH was 4.0, the adsorption effects were most comparatively, the adsorption effect of Pb + was the best, 82%;its of As2+ was the least, 27.7%, the fitting pH was 4.0;when theadsorption temperatures were 40°C .. 53°C, the cleaning effects on Cu2\ Pb2\ Cd2+ were better with relation to temperature, their maximal rats of adsorption were 87.3% n 93.7% .. 83.4%;when the adsorption time was 80min, the cleaning effects on As was on the small side,its maximal rats of adsorption was 33.8%. the fitting temperature was 40X2.（10）The sulfohydryl sugar beet fiber’s static state adsorption action for single hydronium, such as Cu2-\ Pb2+% Cd2\ As2+ ,has better pertinency with Langmuir and Freundlich models, adsorption capability for single hydronium: Pb2+) > Cd2+ >Cu2+ >As2+;the total adsorption capability: Cu2+ >Pb2+ >Cd2+ >As2+,in addition, its adsorption for Cu2+ satisfy with linearity adsorption model.（ll）The sulfohydryl sugar beet fiber’s static state adsorption action for mixed hydroniums, such as Cu2+% Pb2+> Cd2+, has better pertinency with Langmuir and Freundlich models accordingly. But dynamic adsorption action for As2+ has bad pertinency with Langmuir and Freundlich models, which show that the other hydroniums influence on the adsorption for As2*, in the mixed liquor, adsorption capability for single hydronium: Cu2+ >Pb2+ >Cd2+ >As2+;the total adsorption capability: Pb2+>Cd2+>Cu2+>As2+.（12）The sulfohydryl sugar beet fiber’s dynamic adsorption action for hydroniums is better, its capacitance is great, it can take a long time to approach adsorption balance, adsorption capability for hydronium: Cu2+ >Pb2+ >Cd2+ >As2+,which is consistent with the results of static state adsorption experimentation.（13）Cleaning the hydroniums’ saturated adsorption columniations .which dealed with Cu2\ Pb2+> Cd2+andAs2+ liquor whose concentration was 30.0//g/mL, When the velocity of flow in columniations is lO.OmL/min, the cleaning effect is better;when the additive quantity HC1 whose concentration was 0.4mol/L reached 900mL, the cleaning curve trend to mild estate, the rate of cleaning was 45%⁵3%.The regeneration effect of SC was better.（14）The results of the sulfohydryl sugar beet fiber’s adsorption effect showed that:(Dthe adsorption temperature 30°C, getting 2.5g SC to deal with 35mL apple juice, in which the hydroniums （Pb2+> Cu2+） concentrations were 0.8 mg/kg and 8.0 mg/kg respectively, the sugar content was 15.3Brix,the sulfohydryl sugar beet fiber got saturation after 5h, its best elimination rats of Cu2+and Pb2+were 84.6% and 74.2% respectively.?the adsorption temperature 30°C,the rage of adsorption time 30¹80min, theelimination rats of Pb2* in apple juice were obvious, the adsorption got saturation after 180min, its best elimination rats of Cu2+and Pb2+were 85.6% and 75.4% respectively;the rage of adsorption time 30³00min, the adsorption velocity of Cu2+ in apple juice were better, the adsorption got saturation after 300min.?ranging between 30 and 65 °C, The sulfohydryl sugar beet fiber’s adsorption effect gathered head gradually with the temperature raising. The rate of adsorption effect for Pb2+ changed in evidence in the rage of 30³7°C, adsorption got balance after 37°C.The degree of adsorption took the balance, the adsorption effect of Cu2+ was better than its of Pb2+,the rage of adsorption rats were 79.6%⁹0.5%.（4） hydroniums concentration connected on the adsorption effect in apple juice nearly, when the Pb2+ and Cu2+hydroniumsconcentrations were 0.2 rag/kg and l.Omg/kg respectively, the competition among hydroniums was less owing to low hydroniums concentration, the removal efficiency approximated of adsorption about Pb2+ could get 95.3%. Cu2+could get 97.1%.更多还原