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This study assesses the efficiency of various physico-chemical, biological and other tertiary methods for treating leachate.
An evaluation study on the treatability of the leachate from methane phase bed (MPB) reactor indicated that at an optimum
hydraulic retention time of 6 days, the efficiency of the reactor in terms of biological oxygen demand (BOD) and chemical
oxygen demand (COD) removal was 91.29 and 82.69%, respectively. Recycling of the treated leachate through the municipal solid
waste layers in the leachate recycling unit (LRU) resulted in a significant increase in the biodegradation of organics present
in the leachate. Optimum BOD and COD removal efficiencies were achieved at the third recycle; additional recycling of the
leachate did not produce any significant improvement. Physico-chemical treatment of the leachate demonstrated that alum and
lime (Option 2) were more economical than coagulants lime and MgCO3. A cost analysis of the economics of the various treatments revealed that the alternative treatment consisting of a MPB bed
followed by a LRU and aerated lagoon is the most cost-effective treatment. However, the alternative consisting of a MPB followed
by the LRU and a soil column, which is slightly more costly, would be the most appropriate treatment when adequate land is
readily available. 相似文献
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回灌对垃圾填埋初期渗滤液化学需氧量的影响 总被引:4,自引:0,他引:4
通过模拟柱实验 ,研究了回灌对垃圾填埋场初期渗滤液 CODCr的影响。研究结果表明 ,模拟降雨雨水的渗入且无渗滤液回灌的参照柱 ,其渗滤液出水 CODCr最高 ,一般在 70 0 0 0 mg/L 左右 ;模拟渗滤液原液回灌 ,从第 4周起因脂肪酸的积累导致渗滤液的 p H低于 6,从而抑制了微生物的生化反应 ;模拟好氧生物处理后渗滤液的回灌 ,能加速垃圾层 CODCr的溶出和甲烷化阶段的建立 ,且此时渗滤液的 CODCr变化规律符合指数方程 ;当垃圾层建立甲烷化阶段后 ,回灌 CODCr在 2 0 0 0 0 m g/L 左右的渗滤液 ,仍可促使垃圾中有机物迅速转化为气态物 相似文献
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Tarek Abichou Morton A. Barlaz Roger Green Gary Hater 《Waste management (New York, N.Y.)》2013,33(10):2006-2014
The Outer Loop landfill bioreactor (OLLB) in Louisville, KY, USA has been the site of a study to evaluate long-term bioreactor performance at a full-scale operational landfill. Three types of landfill units were studied including a conventional landfill (Control cell), a new landfill area that had an air addition and recirculation piping network installed as waste was being placed (As-Built cell), and a conventional landfill that was modified to allow for liquids recirculation (Retrofit cell). During the monitoring period, the Retrofit, Control, and As-Built cells received 48, 14, and 213 L Mg?1 (liters of liquids per metric ton of waste), respectively. The leachate collection system yielded 60, 57 and 198 L Mg?1 from the Retrofit, Control, and As-Built cells, respectively. The head on liner in all cells was below regulatory limits. In the Control and As-Built cells, leachate head on liner decreased once waste placement stopped. The measured moisture content of the waste samples was consistent with that calculated from the estimate of accumulated liquid by the liquid balance. Additionally, measurements on excavated solid waste samples revealed large spatial variability in waste moisture content. The degree of saturation in the Control cells decreased from 85% to 75%. The degree of saturation increased from 82% to 83% due to liquids addition in the Retrofit cells and decreased back to 80% once liquid addition stopped. In the As-Built cells, the degree of saturation increased from 87% to 97% during filling activities and then started to decrease soon after filling activities stopped to reach 92% at the end of the monitoring period. The measured leachate generation rates were used to estimate an in-place saturated hydraulic conductivity of the MSW in the range of 10?8 to 10?7 m s?1 which is lower than previous reports. In the Control and Retrofit cells, the net loss in liquids, 43 and 12 L Mg?1, respectively, was similar to the measured settlement of 15% and 5–8% strain, respectively (Abichou et al., 2013). The increase in net liquid volume in the As-Built cells indicates that the 37% (average) measured settlement strain in these cells cannot be due to consolidation as the waste mass did not lose any moisture but rather suggests that settlement was attributable to lubrication of waste particle contacts, softening of flexible porous materials, and additional biological degradation. 相似文献