活性炭与KDF联用去除食用水重金属污染研究

发布时间：2018-02-02 14:16

本文关键词： KDF 活性炭重金属食用水吸附容量铜锌析出　出处：《湖南农业大学》2013年硕士论文　论文类型：学位论文

【摘要】：重金属常通过水体污染进入食物链,威胁着人们的饮水安全。一般食品工业用水量很大,因此一种高效、安全、可靠的净水系统亟需研究。本文在不同初始浓度、滤层高度、滤速等条件下研究活性炭与KDF联用净水系统对模拟水样中Cr6+、As3+、Cd2+的处理效果,筛选出既能够满足《生活饮用水卫生标准》,又能保证一定处理效率的最优净水条件。并以Cr6+为例,研究了系统在优化条件下净水的饱和吸附量及稳定性,通过试验分析该系统应用于轻度污染水体的处理效果,为活性炭与KDF联用净水系统在食品工业中的应用提供了理论依据和应用基础。主要结论如下：以GB5749-2006《生活饮用水卫生标准》中的限值为参考,试验条件下,活性炭对含As3+、Cd2+的模拟水样净化处理后,去除率低于50%,出水水质均存在超标的情况。当滤层高度110mm,初始浓度0.125mg/L,滤速25L/h-135L/h时,活性炭对Cr6+的去除效果较好,去除率在64.8%-84.8%,出水水质达标。而在初始浓度为0.25mg/L,滤层高度110mm时,只有滤速25L/h时,Cr6+的去除率达到82.8%,出水Cr6+浓度在限值范围内。其他条件下,去除率大多在70%以下,出水Cr6+浓度超标。因此,单独应用活性炭对水中Cr6+、As3+、Cd2+进行处理是远远不能满足食用安全要求的,存在较大的风险。尝试构建活性炭与KDF联用的净水系统,使其既达到处理效率高、运行成本低的目的,又绝对保证食用水安全,确定了未处理水的污染程度。在净水装置滤层高度110mm、滤速135L/h,进水Cr6+初始浓度0.25mg/L、Cd2+的初始浓度0.025mg/L时,系统对Cr6+和Cd2+的去除率分别为93.2%、82.0%；As3+的初始浓度0.025mg/L、装置滤层高度170mm和滤速135L/h时,去除率可达96.0%。固定净水装置滤层高度为110mm,滤速135L/h,初始Cr6+浓度0.25mg/L条件下,活性炭与KDF联用净水系统在保证出水Cr6+浓度不超出《生活饮用水卫生标准》的前提下,共处理模拟水样2160L。按系统滤柱的单位滤层高度计算,可知饱和吸附量为4.87g/m。如食品厂或家庭每天使用该系统净化10L水样,可安全使用200天以上。在水质情况良好的情况下,再结合反冲洗,使用寿命将会远大于200天。活性炭与KDF联用净水系统组成成分Cu2+、Zn2+的溶出是随着出水中Cr6+的浓度逐渐增大而逐渐减小,成反对应关系,两个浓度均在《生活饮用水卫生标准》所规定的1mg/L标准内,铜析出量远远小于锌析出量。固定滤层为110mm,滤速为135L/h,初始Cr6+浓度为0.25mg/L时,pH越高,铜、锌析出量越大,温度越高,铜锌析出量越大,适量的铜、锌是对人体健康有益的元素。优化条件下的活性炭与KDF联用净水系统应用于处理受重金属轻度污染地下水和地表水中,去除效果良好,经处理后的水样水质各项指标均能够达到《生活饮用水卫生标准》。
[Abstract]:Heavy metals often enter the food chain through water pollution, threatening the safety of drinking water. General food industry uses a large amount of water, so it is efficient and safe. Under the conditions of different initial concentration, height of filter layer and filtration rate, this paper studies the application of activated carbon and KDF in the treatment of Cr6 as _ 3 in simulated water samples. The treatment effect of Cd2, which can not only meet the sanitary standard of drinking water, but also guarantee the treatment efficiency, is the best condition of clean water. The Cr6 is taken as an example. The saturated adsorption capacity and stability of purified water under optimized conditions were studied and the treatment effect of the system applied to light polluted water was analyzed through experiments. The main conclusions are as follows: (1) this paper provides the theoretical basis and application basis for the application of the combined use of activated carbon and KDF in the food industry. With the reference of the limit of GB5749-2006, the activated carbon purifies the simulated water sample containing As3 and CD 2. When the filter height is 110 mm, the initial concentration is 0.125 mg / L, and the filtration rate is 25 L / h-135L / h. The removal efficiency of activated carbon to Cr6 is better, the removal rate is 64.8-84.8, the effluent quality is up to standard, and when the initial concentration is 0.25 mg / L, the filter height is 110mm. The removal rate of Cr 6 reached 82.8 at the filter rate of 25L / h, and the Cr6 concentration in the effluent was within the limit. Under other conditions, the removal rate was mostly below 70%. The concentration of Cr6 in effluent exceeds the standard. Therefore, the treatment of Cr6 As3 + CD2 in water by using activated carbon alone is far from meeting the requirements of edible safety, and there is a great risk. This paper attempts to construct a water purification system which is combined with activated carbon and KDF to achieve the purpose of high treatment efficiency and low operation cost, and to ensure the safety of edible water. The contamination degree of untreated water was determined. At the filter height of 110mm, filtration rate of 135L / h, the initial concentration of influent Cr6 was 0.25 mg / L. When the initial concentration of Cd2 was 0.025 mg / L, the removal rates of Cr6 and Cd2 were 93.2 mg / L and 82.0, respectively. When the initial concentration of As3 is 0.025 mg / L, the filter height is 170 mm and the filter speed is 135 L / h, the removal rate can reach 96.0%. The filter height of the fixed water purification unit is 110 mm, the filtration rate is 135 L / h, and the initial Cr6 concentration is 0.25 mg / L. The combined use of activated carbon and KDF ensures that the effluent Cr6 concentration does not exceed the sanitary standard of drinking water. According to the unit filter height of the filter column, the saturated adsorption capacity is 4.87 g / m. For example, the food factory or family uses the system to purify 10L water sample every day. Safe use more than 200 days. In the case of good water quality, combined with backwashing, the service life will be much longer than 200 days. The dissolution of Cu2 ~ (2 +) Zn _ (2), a component of water purification system combined with activated carbon and KDF, decreases with the increase of Cr6 concentration in the effluent, which is inversely related. Both concentrations were within the 1mg / L standard of drinking water hygiene standard, and the amount of copper released was much smaller than that of zinc. The fixed filter layer was 110 mm and the filtration rate was 135 L / h. When the initial concentration of Cr6 is 0.25 mg / L, the higher the pH, the higher the amount of copper and zinc, the higher the temperature, the higher the amount of copper and zinc. The proper amount of copper and zinc is beneficial to human health. Under the optimized conditions, the activated carbon combined with KDF water purification system was applied to treat groundwater and surface water polluted by heavy metals, and the removal effect was good. After treatment, all the indexes of water quality can reach the hygienic standard of drinking water.
【学位授予单位】：湖南农业大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：R123

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