三乙胺废水资源化处理技术研究

发布时间：2018-08-18 19:01

【摘要】：三乙胺是具有较高产品价值的化工原料,工业用途十分广泛。实际工业生产过程中排放的三乙胺废水,具有毒性大、浓度高、难降解等特点,对生态环境和人类健康有很大的危害。因此,研究探讨经济、有效的废水处理方法和回收技术具有重要的现实意义。本文对山东某阻燃剂工厂生产过程中产生的三乙胺废水,采用蒸馏回收法,离子交换树脂法和Fenton氧化法相结合进行试验研究,以期为处理实际废水中的三乙胺提供理论指导。蒸馏法可以将沸点较低的三乙胺分离出并资源化回收,可有效的降低废水中的COD。采用蒸馏方法处理阻燃剂苯氧基四溴双酚A碳酸酯齐聚物(RDT-7)车间产生的,含高浓度三乙胺的合成水洗水和精馏排放水。实验结果表明废水pH的变化对蒸馏效果有较大的影响,pH值越大COD去除率越高。合成水洗水经蒸馏法蒸馏出总水样的10%后,90%的剩余水样的COD由原来的13200mg/L降至170mg/L,COD的去除率达到98%,釜液中三乙胺由原来的8432mg/L降至26mg/L。精馏排放水经蒸馏法蒸馏出总水样的10%后,90%的剩余水样的COD由原来的9300mg/L降至173mg/L,COD的去除率达到98%,釜液中三乙胺由原来的6310mg/L降至15mg/L。由静态吸附实验可知,在室温,pH为11.5,反应时间为2h的条件下,0.500 g RX01型树脂对初始浓度为1500 mg/L的模拟三乙胺废水有较强的吸附效果,三乙胺去除率能达到99%,树脂的静态饱和吸附量为145 mg/g；静态吸附条件下,阳离子对树脂吸附三乙胺过程有较大影响,阳离子浓度越高,竞争吸附作用力越强,树脂吸附三乙胺的吸附量越低,相等浓度条件下,阳离子影响效果的顺序为Ca2+Mg2+K+Na+。树脂吸附热力学研究表明：Langmuir吸附模型更能准确的描述RX01型离子交换树脂对三乙胺的吸附过程,热力学常数为ΔG°0, ΔH°0, ΔS°0,表明三乙胺在RX01上的吸附过程是自发进行,且伴随着熵增加的吸热过程。动力学研究结果表明,准二级动力学模型能更好的描述树脂吸附交换过程,计算测得的表观活化能Ea为78.3 KJ/mol,说明了树脂吸附三乙胺为化学吸附,颗粒扩散为主要控速步骤。由动态吸附实验可知,当废水pH值为11.5,吸附柱高径比5.37,吸附流速为60 BV/h的条件下,20 mL(约为20.6 g湿树脂)树脂处理浓度为1500 mg/L的三乙胺废水,最终穿透点在70 BV,前70 BV的出水中,三乙胺质量浓度非常低,小于3 mg/L,三乙胺去除率可达99.5%。动态脱附过程中,以2mol/L的HCl溶液为脱附剂,脱附剂流速为1 BV/h、出水体积为4 BV时,三乙胺的脱附率达94.8%,浓缩倍数为17.5；在最优动态吸附-脱附条件下重复进行10次实验,树脂吸附量没有明显下降,且各项吸附性能稳定。采用离子交换树脂,对蒸馏处理后的实际废水馏出液进行吸附。实验结果表明：当馏出液中三乙胺初始质量浓度为1372mg/L,选择60 BV/h流量进行动态吸附,40BV为穿透体积,此条件下出水三乙胺浓度小于10 mg/L,去除率可达99.2%以上；动态脱附过程中,以2 mol/L的HC1溶液为脱附剂,脱附剂流速为1 BV/h、出水体积为4 BV时,三乙胺的脱附率达92.5%,浓缩倍数为10；RX01型树脂处理实际废水馏出液有较好的去除效果。Fenton氧化法对含有低浓度三乙胺的釜液处理效果较好,在pH值为3.0,H202投加量10mg/L,n(Fe2+):n(H2O2)为1：5,反应2h后,废水在pH为8.0时反应沉淀后,溶液中三乙胺浓度降至2.23 mg/L,去除率90.2%,满足三乙胺排放标准3 mg/L要求。
[Abstract]:Triethylamine is a kind of chemical raw material with high product value and has a wide range of industrial uses. The wastewater discharged from the actual industrial production process has the characteristics of high toxicity, high concentration and difficult degradation, which is harmful to the ecological environment and human health. Therefore, it is necessary to study the economical and effective wastewater treatment methods and recovery technologies. In this paper, the triethylamine wastewater from a fire retardant factory in Shandong Province was studied by distillation recovery method, ion exchange resin method and Fenton oxidation method in order to provide theoretical guidance for the treatment of triethylamine in actual wastewater. The COD in wastewater can be effectively reduced by recycling. The synthetic washing water and distillation effluent containing high concentration triethylamine produced in the flame retardant phenoxytetrabromobisphenol A carbonate oligomer (RDT-7) workshop are treated by distillation. The experimental results show that the change of wastewater pH has a great influence on the distillation effect, and the higher the pH value, the higher the COD removal rate. After 10% of the total water sample is distilled by distillation, COD of 90% of the remaining water sample is reduced from 13200 mg/L to 170 mg/L, COD removal rate is 98%, triethylamine is reduced from 8432 mg/L to 26mg/L. After 10% of the total water sample is distilled by distillation, COD of 90% of the remaining water sample is reduced from 9300 mg/L. The removal rate of COD reached 98% at 173 mg/L and triethylamine was reduced from 6310 mg/L to 15mg/L. The static adsorption experiment showed that 0.500 g RX01 resin had a strong adsorption effect on the simulated triethylamine wastewater with initial concentration of 1500 mg/L at room temperature, pH 11.5 and reaction time 2 h. The removal rate of triethylamine could reach 99% and the resin had a good adsorption effect. Static saturated adsorption capacity is 145 mg/g; under static adsorption conditions, cations have a greater impact on the resin adsorption process of triethylamine. The higher the cation concentration, the stronger the competitive adsorption force, the lower the resin adsorption capacity of triethylamine. Under the same concentration, the order of cations effect is Ca2+Mg2+K+Na+. Adsorption thermodynamics study of resin The results show that Langmuir adsorption model can describe the adsorption process of triethylamine on RX01 ion exchange resin more accurately. The thermodynamic constants are G 0, H 0 and S 0, indicating that the adsorption process of triethylamine on RX01 is spontaneous and accompanied by the increase of entropy. The adsorption and exchange process of resin was described, and the apparent activation energy Ea was 78.3 KJ/mol. It was shown that the resin adsorption of triethylamine was a chemical adsorption and the particle diffusion was the main speed-controlling step. The resin was used to treat the wastewater containing 1 500 mg/L triethylamine. The final penetration point was 70 BV. The mass concentration of triethylamine in the effluent of the first 70 BV was very low, less than 3 mg/L. The removal rate of triethylamine was 99.5%. In the dynamic desorption process, the flow rate of the desorbent was 1 BV/h, and the volume of the effluent was 4 BV. The removal rate of triethylamine reached 94.5%. The adsorption capacity of the resin was not significantly decreased and the adsorption performance was stable. The ion exchange resin was used to adsorb the distillate of the distillation wastewater. The results showed that the initial concentration of triethylamine in the distillate was 1372 M. G/L, selected 60 BV/h flow rate for dynamic adsorption, 40 BV for the penetration volume, the concentration of effluent triethylamine under this condition is less than 10 mg/L, removal rate can reach 99.2%; in the dynamic desorption process, 2 mol/L HC1 solution as desorbent, desorbent flow rate is 1 BV/h, effluent volume is 4 BV, the desorption rate of triethylamine is 92.5%, concentration times is 10; The Fenton oxidation process has a good effect on treating the distillate of wastewater containing low concentration of triethylamine. The concentration of triethylamine in the solution is reduced to 2.23 mg/L and the removal rate is 90.2% when the pH value is 3.0, the dosage of H202 is 10 mg/L, the dosage of n (Fe2+): n (H2O2) is 1:5 and the reaction time is 2 h. Three ethylamine emission standard 3 mg/L requirements.
【学位授予单位】：华东理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X783

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