School of Energy Resources and Environmental Engineering, Egypt-Japan University of Science and Technology (E-Just), P.O. Box 179, New Borg El Arab City, Alexandria, 21934, Egypt.
Bioprocess Biosyst Eng. 2011 Aug;34(6):767-76. doi: 10.1007/s00449-011-0528-9. Epub 2011 Feb 26.
Grey wastewater (GW) treatment via down-flow hanging sponge (DHS) system was the subject of the study. The reactor was operated at different hydraulic retention times (HRTs) of 11.7, 5.8 and 2.9 h, corresponding to organic loading rates (OLRs) of 1.9, 3.6 and 6.8 kgCOD/m3 day, respectively. The results obtained revealed that decreasing the HRT from 11.7 to 2.9 h negatively affected on the performance of the DHS system. COD(total), COD(soluble), COD(particulate) and detergent removal efficiency were reduced from 96 ± 2.4 to 90 ± 2.3%, from 83 ± 10 to 69 ± 8%, from 98 ± 2 to 94 ± 3% and from 96 ± 12 to 88 ± 6.9%, respectively. However, the removal efficiency of the distinguished COD fractions and detergent remained unaffected when decreasing the HRT from 11.7 to 5.8 h. The DHS system provided a removal efficiency of 95 ± 1% for COD(total), 79 ± 8% for COD(soluble), 98 ± 2 for COD(particulate) and 94.7% for detergent at an HRT of 5.8 h. Based on these results, it is recommended to operate such a system at an HRT of 5.8 h and OLR not exceeding 3.6 kgCOD/m3 day for producing an effluent quality complying for reuse in unrestricted irrigation purposes. The removal of TKj-N and nitrification efficiency in the DHS system was significantly affected by increasing the OLR from 1.9 to 3.6 kgCOD/m3 day and from 3.6 to 6.8 kgCOD/m3 day. At an OLR of 1.9 kgCOD/m3 day, the DHS system removed 80 ± 12% of TKj-N and 91 ± 22% of ammonia which is significantly higher than that at an OLR of 3.6 (58.5 ± 13%) and 6.8 kgCOD/m3 day (26.8 ± 16%). Similar results were recorded for the removal of total coliform (TC), viz., the efficiencies dropped for TC from 99.8 ± 0.2 to 99.4 ± 0.8% and from 99.4 ± 0.8 to 90.0 ± 7.6%, respectively. DHS profile results showed that the major part of COD was removed in the upper portion of the system while the nitrification process was taken place in the lower part of the DHS system at OLR of 1.9 kgCOD/m3 day and HRT of 11.7 h.
采用下流式悬挂式海绵（DHS）系统对灰水（GW）进行处理。该反应器在不同水力停留时间（HRT）为 11.7、5.8 和 2.9 h 下运行，相应的有机负荷率（OLR）分别为 1.9、3.6 和 6.8 kgCOD/m3·天。结果表明，将 HRT 从 11.7 小时降低到 2.9 小时会对 DHS 系统的性能产生负面影响。COD（总）、COD（可溶性）、COD（颗粒状）和洗涤剂去除效率分别从 96±2.4%降低到 90±2.3%、从 83±10%降低到 69±8%、从 98±2%降低到 94±3%和从 96±12%降低到 88±6.9%。然而，当 HRT 从 11.7 小时降低到 5.8 小时时，区分 COD 分数和洗涤剂的去除效率不受影响。当 HRT 为 5.8 小时时，DHS 系统对 COD（总）的去除效率为 95±1%，对 COD（可溶性）的去除效率为 79±8%，对 COD（颗粒状）的去除效率为 98±2%，对洗涤剂的去除效率为 94.7%。基于这些结果，建议在 HRT 为 5.8 小时且 OLR 不超过 3.6 kgCOD/m3·天时运行该系统，以产生符合无限制灌溉用途再利用的出水质量。在 DHS 系统中，TKj-N 的去除和硝化效率受到 OLR 从 1.9 增加到 3.6 kgCOD/m3·天和从 3.6 增加到 6.8 kgCOD/m3·天的显著影响。在 OLR 为 1.9 kgCOD/m3·天时，DHS 系统去除了 80±12%的 TKj-N 和 91±22%的氨，这明显高于 OLR 为 3.6（58.5±13%）和 6.8 kgCOD/m3·天时（26.8±16%）。总大肠菌群（TC）的去除也有类似的结果，TC 的效率从 99.8±0.2%下降到 99.4±0.8%，从 99.4±0.8%下降到 90.0±7.6%。DHS 剖面图结果表明，在 OLR 为 1.9 kgCOD/m3·天和 HRT 为 11.7 小时时，大部分 COD 是在系统的上部去除的，而硝化过程是在 DHS 系统的下部进行的。
