癸二酸生产废水处理工艺的研究？ 摘 要 癸二酸是一种重要的有机化工原料，广泛应用于生产工程塑料、添加剂、人 造香料等方面。目前的生产工艺中，每生产 1 吨癸二酸，需排放约 30 吨废水， 废水中含有的主要杂质为硫酸钠、癸二酸、苯酚以及其他一些脂肪酸。这样的废 水直接排放，不仅污染环境，对水生物、农作物、土壤都会带来严重的影响，而 且也是资源的极大浪费。因此，本文采用多效蒸发和树脂吸附相结合的工艺处理 废水，以降低废水苯酚含量和回收其中的硫酸钠作为本文的两个研究重点，为工 业生产提供基础工艺数据。 采用简单蒸馏模拟多效蒸发过程， 实验中加入碱抑制苯酚挥发。 考察 ph 值、 过滤次数对工艺过程及硫酸钠纯度的影响，并确定了最佳的操作条件为：预处理 中 ph 值调至约为 10.00，常温过滤与热过滤相结合以除去更多脂肪酸杂质。在 此工艺条件下可得纯度为 98.86%的硫酸钠。 经过上述工艺处理后，废水中苯酚含量降至40~50mg/l，但仍不满足排放标 准，因此用树脂吸附做进一步处理。实验采用 nka-ⅱ crosslinked polystyrene 大孔树脂，通过静态实验研究吸附交换时间、温度、ph 值、树脂用量以及废水 含盐量等因素的影响，结果表明温度越高树脂的吸附能力越低；废水的 ph＜7 时，高 ph值有利于吸附反应的进行；所用树脂量越多，吸附反应进行得越快。 另外，废水中含盐量在 1 %~ 6 %的范围内，含盐量越高，树脂的脱酚效果越好。 通过动态吸附实验研究流速的影响，确定适宜的工艺条件为：温度=25℃，ph=6， 流速=4ml/min，但由于工厂的特殊要求，在实际操作中我们选择温度为 40℃。 另外还着重研究了树脂吸附交换的热力学和动力学，得出用 langmuir- freundlich 模型最为准确的结论；以三参数方程描述该吸附交换过程，求得不同 温度下 nka-ⅱ crosslinked polystyrene 树脂吸附交换苯酚的标准自由能变以及 不同吸附交换量下的吸附交换焓变。由此从理论上证明了该过程是放热过程，且 以物理吸附为主，颗粒扩散为主控步骤。对实验数据进行拟合，发现该吸附动力 学符合二级反应动力学过程，属于颗粒扩散控制。 关键词： 癸二酸，含酚废水，蒸发，树脂吸附，动力学过程 abstract the sebacic acid is a kind of important organic material which can be widely used to produce the plastics, additive and spicery and so on. each ton production of sebacic acid will produce 30 tons effluent in present process. what the wastewater contain are sodium sulphate, sebacic acid, phenol and other fatty acids. the effluence of this kind of wastewater not only pollutes the environment, seriously destroys hydrophyte, crops and soil, but also loses the resources which are contained in the wastewater. therefore, multiple-effect evaporation and resin adsorption was used to treat the wastewater in order to reducing the concentration of phenol and reclaiming sodium sulphate in the wastewater. the research result can provide the basic data for industrial scale process. differential distillation process is used to simulate multiple effect evaporation process. sodium hydroxide is added to suppress volatilization of phenol and ensure the purity of condensate. the effects of ph values and filtration times on the treatment process and the purity of sodium sulphate are investigated. the results show that the optimum technology condition is, ph of wastewater is adjusted to 10.00 before evaporation, and both normal temperature filtration and high temperature filtration are used in order to remove fatty acids as more as possible. the purity of sodium sulphate can reached 98.86% under this condition. after the above technology process, the concentration of phenol in condensate can be reduced to 40~50 mg/l, which is still higher than the effluence standard in our country. so nka-ⅱ crosslinked polystyrene resin was used to adsorb remained phenol in condensate. effects of time, temperature, ph value, dosage of resin and the concentration of sodium sulphate on adsorption behavior are investigated in the static adsorption experiment. the results demonstrate that the higher temperature, the lower adsorption capacity, the higher ph value and the more dosage of resin, the better adsorption effect. furthermore, the concentration of sodium sulphate between 1% and 6% is good for the adsorption process. the optimum technology determined by dynamic adsorption experiment is : temperature is 25℃，ph value is 6, and the velocity of flow is 4ml/min, but considered the special need of plant, 40℃ is chosen as the best condition in the practical operation. furthermore, thermodynamic and kinetics of the adsorption process is studied. langmuir-freundlich isotherm models are the best to simulate the adsorption. three-parameter equilibrium is used to describe the adsorption process and the standard g δ and h δ is concluded under various temperatures. as a result, this heat liberation and physical adsorption process are approved. at the same time, the conclusion of article diffusion is approved as the main control process. a two-order adsorption kinetics equation was developed for the process, and relevant parameters are regressed. in addition, results show that the process in controlled by the particle diffusion, i,e. pdc. key words：sebacic acid, phenolic wastewater, evaporation, resin adsorption, kinetic 查看更多
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