克氏原鳌虾壳聚糖生产过程中废液处理工艺研究

Study on Wastewater Treatment Process during Chitosan Production with Procambarus clarkii

[目的]探讨克氏原鳌虾壳聚糖生产过程中废液处理的无公害化工艺。[方法]以当地小龙虾的头胸甲为原料提取壳聚糖过程中所产生的废液为研究对象,研究废液处理工艺的效果。[结果]用脱钙后的酸性废液和脱酰基后的废碱液按体积比2.5∶1.0进行中和,回收钙质效果好,去Ca（OH）2后的碱性废液稀释至9%,可作脱蛋白之用;将含蛋白废碱液的pH值调节为3.0-4.0,可回收大量蛋白;将脱钙洗涤废酸液和脱蛋白洗涤废碱液按照1.0∶1.2的体积比混合后,pH值为7.5,可直接排放;氧化脱色废液与还原漂白废液以体积比3.4∶1.0、氧化脱色水洗废液与还原漂白水洗废液以体积比2.8∶1.0的比例混合,可消除废液中残留的高锰酸钾和亚硫酸钠,回收氧化锰沉淀,达到安全排放的标准。[结论]采用该工艺对废液综合处理后可节约化学试剂50%以上,达到无污染废液目的。

[Objective] The study aimed to discuss the non-pollution process during chitosan production with Procambarus clarkii.[Method] Taking the wastewater produced in extracting the chitosan with the carapace of local as the raw material as the research objective,the effects of treatment process for 3 kinds of wastewater was studied.[Result] The calciums almost were reclaimed when the acidic waster liquid after eliminating calciums was neutralized with the alkaline waste liquid after eliminating acetyls according to the proportion of 2.5∶1.0 vol and the alkaline waste liquor after removing Ca（OH）2 could be diluted to 9%,which could be used for removing protein in carapace.The protein in waste liquid could be recovered when the pH of the alkaline waste liquid containing protein was adjusted to 3.04.0.The waste liquid could be discharged directly when the washing waste liquid after removing the calcium was mixed with the alkaline waste liquid after removing the protein according to the proportion of 1.0∶1.2 vol with the pH of 7.5.When the oxidized and decolorized waste liquid was mixed with the deoxidized bleach waste liquid according to the proportion of 3.4∶1.0 vol and the oxidized and decolorized washing waste liquid was mixed with the deoxidized bleach waste liquid according to the proportion of 2.8∶1.0,the remained potassium permanganate and sodium sulfite in discolored waste liquid could be eliminated,which could produce the deposition of MnO2 and reached the standard of safe drainage after deposition.[Conclusion] The comprehensive treatment on the waster liquid by the process in the study could save the chemical reagent by more than 50%,which reached the purpose of non-pollution waste liquid.