Ozonation as a Means to Optimize Biological Nitrogen Removal from Landfill Leachate

In this study, we investigate factors that can affect nitrification and denitrification in a moving bed biofilm system, treating partly stabilized landfill leachate. The optimization of biological treatment by means of controlled ozonation is additionally evaluated. Results obtained with a laboratory-scale, continuous-flow biofilm system suggest that nitrogen removal can be limited by the low influent biodegradable substrate concentrations, and that autotrophic nitrification can be adversely impacted by the high alkalinity buffer and ammonium/ammonia concentration. Our results suggest an optimum ozone dosage as high as 0.5 g/L O₃ can be required to effectively decrease the effluent soluble COD concentration and pH profile in the aerobic reactors, improve the biodegradable COD production from inert compounds, and induce chemical nitrification in the system. The specific cost of ozonation evaluated is 0.36–0.73 euro/m³ with 911 mg/L average effluent soluble COD measured in the biofilm system.     

Ozone Technology of German Industrial Enterprises

The FIGAWA study group Ozone constituted in 1972 under the chairmanship of G.E. Kurzmann includes the manufacturers of Ozone producing and water treatment plants as well as scientists working in this field, experts and project engineers. Approximately 90% of the market volume are represented in this group.

On the occasion of its 25th anniversary the study group presents a summary of the development in German ozone techniques. This summary is supposed to show the activities of the manufacturers and equipment firms as well as the prominent position of ozone application in many fields of water engineering. The following figures and illustrations show the increasing number of application possibilities for ozone where it is impossible to replace this with other technologies for ecological and economic reasons.     

Influence of Liquid Height to the Oxidation Process of Landfill Leachate by Using Ozone

The influence of liquid height on chemical oxygen demand (COD) of leachate was investigated. When 400 mL leachate was filled in a thick tube reactor (TTR) with height of 0.063 m, COD removal efficiency was 45.69%, while ozone dosage was 3.35 mg_O3/mg_COD. As leachate was filled in a slender tube reactor (STR) with a height of 0.815 m, removal efficiency was 51.81%, and ozone dosage was 3.12 mg_O3/mg_COD. The results indicated that COD removal efficiency increased with the height of liquid. It is believed that the liquid height increased hydraulic pressure and resulted in COD removal efficiency.     

Ozonation Of Leachates From Aged Domestic Landfills

Ozonation was evaluated as a treatment process for domestic landfill leachates. Bench-scale batch and continuous flow experiments depicted that the process is effective in color removal but considerably less effective in TOC and ammonia removal. The high buffer capacity of the leachate maintained relatively constant pH through the process. Biodegradability of the leachate as measured by BOD/COD also improved.     

天井洼垃圾渗滤液处理场调试方案研究

介绍了天井洼垃圾渗滤液处理场设计概况,并对处理场的调试和试运行进行了系统介绍,主要包括调试和试运行的前期准备工作,系统调试方案及过程、协调管理工作等方面。     

蜂巢石强化 UASB 反应器处理垃圾渗滤液研究

向厌氧系统中投加载体材料是提升反应器稳定性及厌氧效率的有效手段.本试验将蜂巢石投加到上流式污泥床反应器(UASB)中,研究其对垃圾焚烧发电厂渗滤液厌氧消化效率的影响及厌氧污泥中产甲烷菌群落结构的变化.试验结果显示,投加蜂巢石缩短了UASB污泥驯化时间,与未投加蜂巢石的反应器相比,CODCr去除率提前12天稳定达到85％以上;污泥形貌观察及粒径分布测试表明,蜂巢石作为固定微生物的载体能够有效加速污泥颗粒化进程,运行至第15天,投加蜂巢石的反应器中粒径大于0.2 mm的污泥占比53.17％,高于未投加蜂巢石反应器的31.92％,形成了更加密实、更大的颗粒污泥.当有机负荷逐步提升至28.77 kgCODCr/(m3·d)时,投加蜂巢石的反应器CODCr去除率仍稳定达到97％,所能承受的最大有机负荷是未投加蜂巢石反应器的2倍以上.高通量测序表明,有机负荷提升后,投加蜂巢石反应器中产甲烷丝菌(Methanosaeta)代替产甲烷杆菌(Methanobacterium)成为优势种属.     

Application of Regression Analysis for Ozone and Catalytic Ozonation of Organic Compounds from Landfill Leachate with Ceramic Raschig Rings and Natural Manganese Ore

Treatment of landfill leachate could be improved by adding ceramic raschig rings and manganese ore as catalysts for ozonation. Regression analysis were carried out to assess effects of parameters (pH, reaction time, the amount of H₂O₂, the surface area of ceramic raschig rings and the amount of manganese ore) on removing organic compounds from landfill leachate by ozone alone, peroxone, ozone/ceramic raschig rings, peroxone/ceramic raschig rings, ozone/manganese ore and peroxone/manganese ore. Results showed that parameters of reaction time, the amount of H₂O₂ and the amount of manganese ore were the high effects on removal of organic compounds from landfill leachate, following by pH paremeter. Ceramic raschig rings did not have significant effect on color, COD and TOC removal.     

The Ecoclear® Process. Results from Full-Scale Installations

Ecoclear® a heterogeneous catalytic ozonation process, has been in commercial operation since 1992 at an ozone consumption of 1.7 kg ozone per kg COD removed. Chlorinated hydrocarbon concentrations in contaminated groundwater are reduced to less than 10 μg/L. A second full scale installation was commissioned early in 1996 for leachate treatment. It is incorporated in the Biomembrat®-Plus process, a combination of biological treatment, nanofiltration and catalytic ozonation, at an ozone consumption of less than 1.0 kg ozone per kg COD removed.     

Mono- and diesters from o-phthalic acid in leachates from different European landfills

Leachates from 17 different landfills in Europe were analysed with respect to phthalates, i.e. phthalic acid diesters (PAEs) and their degradation products phthalic acid monoesters (PMEs) and ortho-phthalic acid (PA). Diesters are ubiquitous and the human possible exposure and potential to human health and environment has put them in focus. The aim of this study was to elucidate whether monoesters and phthalic acid could be traced in landfill leachates and in what concentrations they may be found. The results showed that phthalates were present in the majority of the leachates investigated. The monoesters appeared from 1 to 20 microg/L and phthalic acid 2-880 microg/L (one divergent value of 19 mg phthalic acid/L). Their parental diesters were observed from 1 to 460 microg/L. These observed occurrences of degradation products, of all diesters studied, support that they are degraded under the landfill conditions covered by this study. Thus, we have presented strong evidences to conclude that microorganisms in landfills degrade diesters released from formulations in a variety of products, including polyvinyl chloride (PVC) species.     

The effect of phosphate application on the mobility of antimony in firing range soils

Chemical and biogenic sources of phosphate are commonly accepted in situ treatment methods for immobilization of lead (Pb) in soil. The metalloid antimony (Sb), commonly associated with Pb in the environment, exists as either a neutral species or a negatively charged oxyanion. Antimony is used in the manufacture of bullets as a hardening agent, constituting approximately 3% of the bullet mass. Technological solutions to reduce the migration of metals from small arms firing range (SAFR) soils for environmental compliance purposes must be robust with respect to multi-component systems containing both cationic and anionic contaminants. The effect of varying physico-chemical soil properties on Sb mobility post-firing was assessed in this study for six soil types using common analytical protocols and methods related to regulatory criteria. The sands (SM and SP) demonstrated the greatest Sb solubility in post-firing leachate samples and therefore were selected to evaluate the effects of five commercially available stabilization amendments on Sb mobility. Enhanced Sb leaching was experimentally confirmed in the phosphate-treated soils compared to both the untreated control soil and the sulfur-based amendment, and thus suggests competition for negative sorption sites between Sb and phosphate. However, the 5% Buffer Block® calcium phosphate amendment did not exhibit the same enhanced Sb release. This can be attributed to the inclusion of aluminum hydroxide in the amendment composition. Technologies are needed that will adequately immobilize Pb without mobilizing oxyanions such as Sb. Further research will be required to elucidate binding mechanisms and redox conditions that govern the mobility of Sb on SAFRs.