两性离子角蛋白对皮革废水的絮凝及絮体的回用

Flocculation of Leather Wastewater by Amphoteric Keratin and Recycle of the Flocs

以3-氯-2-羟丙基三甲基氯化铵(CTA)、氯乙酸钠和皮革厂废牛毛提取的角蛋白为原料,制备了一种两性离子角蛋白,探究了其对皮革染色加脂废液的絮凝作用,考察了投加量、p H值及絮凝时间对CODCr(采用重铬酸钾为氧化剂测出的化学需氧量)和总Cr去除率的影响。结果表明:两性离子角蛋白的投加量为0.5 g/L、p H=4、絮凝时间为4 h时,絮凝效果最好,废液中的CODCr从18 840 mg/L降至3 600 mg/L,总Cr质量浓度从19.023 mg/L降至1.277 mg/L,脱色率达87.5%。将回收的絮体经过处理后应用于铬鞣坯革的填充,并进行坯革厚度、抗张强度、断裂伸长率的测定及纤维结构的观测,结果表明:坯革填充絮体后,坯革增厚率达7.32%,与未填充的空白坯革相比,抗张强度从9.25 MPa提高到12.90 MPa,断裂伸长率从39.62%提高到57.90%,同时,絮体能够对皮革纤维起到良好的分散作用。

A new amphoteric keratin was synthesized by copolymerization of 3-chloro-2-hydroxypropyl trimethyl ammonium chloride（ CTA）,sodium chloroacetate and keratin extracted from the wasted ox hair in tannery. Subsequently,the flocculating performance on dyeing and fatliquoring wastewater from leather making process was investigated. Meanwhile,the influence of dosage of amphoteric keratin,p H value,and flocculating time on the removal rate of chemical oxygen demand（ CODCr） and total chromium（ Cr） was investigated. The results indicated that the prepared amphoteric keratin had a good flocculating effect on dyeing and fatliquoring wastewater and an obvious decolorization effect. The removal rate of CODCrdecreased from 18 840 mg / L to 3 600 mg / L,and the removel rate of total chromium decreased from 19. 023 mg / L to 1. 277 mg / L,and decolorization rate reached 87. 5% with a flocculant dosage of 0. 5 g / L at p H 4 for 4 h. Finally,the flocs obtained were used as leather filling materials,and the thickness of the filled leather,leather tensile strength,elongation at break was tested,And the fiber structure was characterized by scanning electron microscopy（ SEM）. The results showed that the thickening rate of the filled leather was 7. 32%,the tensile strength increases from 9. 25 MPa to 12. 90 MPa,and the elongation at break increases from 39. 62% to 57. 90% compared unfilled leather. Additionally,this flocculant exhibited a good dispersion effect on leather fiber.