Shon H K, Vigneswaran S, Kim In S, Cho J, Kim G J, Kim J B, Kim J H
Faculty of Engineering, University of Technology, Sydney, P.O. Box 123, Broadway, NSW 2007, Australia.
Environ Sci Technol. 2007 Feb 15;41(4):1372-7. doi: 10.1021/es062062g.
Sludge disposal is one of the most costly and environmentally problematic challenges of modern wastewater treatment worldwide. In this study, a new process was developed, which has a significant potential for lower cost of waste disposal, protection of the environment and public health, and yield of economically useful byproducts. Titanium oxide (TiO2), which is the most widely used metal oxide, was produced from the wastewater sludge generated by the flocculation of secondary wastewater with titanium tetrachloride (TiCl4). Detailed analyses were conducted to compare TiCl4, ferric chloride (FeCl3), and aluminum sulfate (Al2(SO4)3) flocculation. Removal of organic matter and different molecular sizes by Ti-salt flocculation was similar to that of the most widely used Fe- and Al-salt flocculation. The mean size of Ti-, Fe-, and Al-salt flocs was 47.5, 42.5, and 16.9 microm, respectively. The decantability of the settled flocs by TiCl4 coagulant was similar to that by FeC13 coagulant and much higher than that of Al2(SO4)3. The photocatalyst from wastewater (PFW) produced by TiCl4 flocculation was characterized by X-ray diffraction, BET surface area, scanning electron microscopy/energy dispersive X-ray, transmission electron microscopy, photocatalytic activity, and X-ray photoelectron spectroscopy. The resulting PFW was found to be superior to commercial TiO2 (P-25) in terms photocatalytic activity and surface area. The PFW as also found to be mainly doped with C and P atoms. The atomic percentage of the PFW was TiO(1.42)C(0.44)P(0.14).
污泥处置是全球现代污水处理中成本最高且对环境造成问题最多的挑战之一。在本研究中，开发了一种新工艺，该工艺在降低废物处置成本、保护环境和公众健康以及生产经济上有用的副产品方面具有巨大潜力。二氧化钛（TiO₂）是使用最广泛的金属氧化物，它由用四氯化钛（TiCl₄）对二级废水进行絮凝产生的废水污泥制得。进行了详细分析以比较TiCl₄、氯化铁（FeCl₃）和硫酸铝（Al₂(SO₄)₃）的絮凝效果。钛盐絮凝去除有机物和不同分子大小物质的效果与使用最广泛的铁盐和铝盐絮凝效果相似。钛盐、铁盐和铝盐絮凝体的平均大小分别为47.5、42.5和16.9微米。TiCl₄凝聚剂沉淀后的絮凝体的沉降性能与FeC1₃凝聚剂相似，且远高于Al₂(SO₄)₃。通过X射线衍射、BET比表面积、扫描电子显微镜/能量色散X射线、透射电子显微镜、光催化活性和X射线光电子能谱对TiCl₄絮凝产生的废水光催化剂（PFW）进行了表征。结果发现所得的PFW在光催化活性和表面积方面优于商业TiO₂（P - 25）。还发现PFW主要掺杂有C和P原子。PFW的原子百分比为TiO(1.42)C(0.44)P(0.14)。
