Advanced Energy Ltd., Zagreb, Croatia.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2011;46(12):1338-45. doi: 10.1080/10934529.2011.606423.
This paper provides the information on the optimum conditions of the treatment process of the boat pressure washing wastewater (BPWW) by the combination of the ozonation and electrochemical (EC) methods developed on the laboratory and pilot plant scale. The initial effluent was highly enriched in heavy metals and elevated levels of organic contaminants. The concentrations of V, Cr, Fe, Cu, Zn, TOC, and COD exceeded the upper permissible limits of 22, 20, 6, 112, 17, 4, and 2 times, respectively. The main mechanisms of the organic matter destruction were the ozone oxidation and the indirect oxidation with chlorine/hypochlorite formed by the anodic oxidation of chloride already present in the wastewater. The heavy metal removal was forced by the coagulation/flocculation using Fe(2+), Fe(3+), and Al(3+) ions released into the treated solution by electrochemical corrosion of the sacrificial stainless steel and aluminum electrodes. At the optimum conditions obtained with the pilot plant, the removal efficiencies of the parameters V, Cr, Fe, Ni, Cu, Zn, Pb, TOC, and COD were 100.00 %, 99.35 %, 99.51 %, 87.31 %, 99.83 %, 99.65 %, 100.00 %, 88.46 %, and 76.28 %, respectively. All the parameters in the final effluent were in agreement with regulated values. The advantages of this system compared to its physico-chemical counterparts are as follows: (1) no need for the external addition of flocculating agents since they are electrochemically generated inside the treatment tank; (2) minimal pH changes during the treatment process not requiring pH adjustment by acids/basis; (3) a significantly lower amount of sludge since only Fe and Al ions were released in the solution; (4) flocs formed by the electrocoagulation can be easily separated by the filtration due to their higher stability, lower content of the bound water and larger surface compared to chemical flocs; (5) the final EC effluent is clear, colourless and odourless, containing the less total dissolved solids and organics, thence more suitable for the reuse compared to the one obtained by the standard chemical treatment.
本文提供了在实验室和中试规模上开发的臭氧氧化和电化学（EC）方法联合处理船用压力清洗废水（BPWW）的最佳条件信息。初始废水富含重金属和高浓度有机污染物。V、Cr、Fe、Cu、Zn、TOC 和 COD 的浓度分别超过 22、20、6、112、17、4 和 2 倍的上限允许限值。有机物破坏的主要机制是臭氧氧化和间接氧化，间接氧化是由废水中已存在的氯离子的阳极氧化形成的氯/次氯酸盐。重金属的去除是通过电化学腐蚀牺牲不锈钢和铝电极释放到处理溶液中的 Fe(2+)、Fe(3+)和 Al(3+)离子进行混凝/絮凝来强制进行的。在中试工厂获得的最佳条件下，V、Cr、Fe、Ni、Cu、Zn、Pb、TOC 和 COD 的去除效率分别为 100.00%、99.35%、99.51%、87.31%、99.83%、99.65%、100.00%、88.46%和 76.28%。最终废水中的所有参数均符合规定值。与物理化学处理方法相比，该系统的优势在于：(1) 无需外部添加絮凝剂，因为它们是在处理罐内电化学产生的；(2) 处理过程中 pH 值变化极小，无需用酸/碱进行 pH 调节；(3) 由于仅在溶液中释放 Fe 和 Al 离子，因此产生的污泥量明显减少；(4) 由于电絮凝形成的絮体具有更高的稳定性、更低的结合水含量和更大的表面积，因此比化学絮体更容易通过过滤分离；(5) 与标准化学处理相比，EC 最终出水清澈、无色、无味，总溶解固体和有机物含量较低，因此更适合再利用。
