Advanced Water Management Centre (AWMC), The University of Queensland, St. Lucia, QLD 4072, Australia; CRC for Water Sensitive Cities, PO Box 8000, Clayton, Victoria 3800, Australia.
Advanced Water Management Centre (AWMC), The University of Queensland, St. Lucia, QLD 4072, Australia.
Water Res. 2015 Mar 15;71:150-9. doi: 10.1016/j.watres.2014.12.044. Epub 2015 Jan 5.
Dosage of iron salt is the most commonly used method for sulfide control in sewer networks but incurs high chemical costs. In this study, we experimentally investigate the feasibility of using iron rich drinking water treatment sludge for sulfide control in sewers. A lab-scale rising main sewer biofilm reactor was used. The sulfide concentration in the effluent decreased from 15.5 to 19.8 mgS/L (without dosing) to below 0.7-2.3 mgS/L at a sludge dosing rate achieving an iron to total dissolved inorganic sulfur molar ratio (Fe:S) of 1:1, with further removal of sulfide possible by prolonging the reaction time. In fact, batch tests revealed an Fe consumption to sulfide removal ratio of 0.5 ± 0.02 (mole:mole), suggesting the possible occurrence of other reactions involving the removal of sulfide. Modelling revealed that the reaction between iron in sludge and sulfide has reaction orders of 0.65 ± 0.01 and 0.77 ± 0.02 with respect to the Fe and sulfide concentrations, respectively. The addition of sludge slightly increased the total chemical oxidation demand (tCOD) concentration (by approximately 12%) as expected, but decreased the soluble chemical oxidation demand (sCOD) concentration and methane formation by 7% and 20%, respectively. Some phosphate removal (13%) was also observed at the sludge dosing rate of 1:1 (Fe:S), which is beneficial to nutrient removal from the wastewater. Overall, this study suggests that dosing iron-rich drinking water sludge to sewers could be an effective strategy for sulfide removal in sewer systems, which would also reduce the sludge disposal costs for drinking water treatment works. However, its potential side-effects on sewer sedimentation and on the wastewater treatment plant effluent remain to be investigated.
铁盐投加是控制污水管网中硫化物最常用的方法，但会产生较高的化学成本。本研究通过实验考察了利用富铁饮用水处理污泥控制污水中硫化物的可行性。采用实验室规模上升式主管污水生物膜反应器。在不投加污泥的情况下，出水硫化物浓度从 15.5-19.8mgS/L 降低到 0.7-2.3mgS/L 以下，当污泥投加量达到铁与总溶解无机硫摩尔比（Fe:S）为 1:1 时，硫化物去除率进一步提高，通过延长反应时间还可能进一步去除硫化物。实际上，批次试验表明铁消耗与硫化物去除摩尔比为 0.5±0.02(mole:mole)，表明可能发生了涉及硫化物去除的其他反应。模型表明，污泥中铁与硫化物的反应对铁和硫化物浓度的反应级数分别为 0.65±0.01 和 0.77±0.02。如预期的那样，污泥的添加略微增加了总化学需氧量（tCOD）浓度（约增加 12%），但降低了可溶解性化学需氧量（sCOD）浓度和甲烷生成量，分别降低了 7%和 20%。在污泥投加量为 1:1（Fe:S）时，还观察到了一些磷酸盐去除（13%），这有利于从废水中去除营养物质。总的来说，本研究表明，向污水中投加富铁饮用水污泥可能是一种有效去除污水系统中硫化物的策略，同时也可以降低饮用水处理厂的污泥处置成本。然而，其对污水沉降和污水处理厂出水的潜在副作用仍有待进一步研究。
