Treatment Of Sanitary Landfill Leachate Research Articles

Characteristics of Nitrogen Removal from Old Landfill Leachate by Sequencing Batch Biofilm Reactor

Municipal landfill leachate is a high strength wastewater characterized by high concentrations of organics and ammonia and potentially containing toxic materials. The paper reports the results of a laboratory scale investigation aimed at evaluating the effectiveness of mature municipal landfill leachate treatment by a biological stage (used SBBR as a biological treatment) to study the nitrogen removal capabilities for treatment of sanitary landfill leachate containing high ammonia concentration. The monitored sample taken from the Chang Sheng bridge landfill site in Chongqing city-China, has its concentrations of COD, BOD5 and NH3-N about 1650, 75 and 1100 mg L-1 respectively. The results showed that after two months long period of domestication and one month period of stability, the ammonia nitrogen removal efficiency reached to 99% in the SBBR reactor, at nitrogen loading rate 0.51 kg TN m-3 per day and HRT was 9 hrs, met to Chinese standards for discharge.

Tratamento de lixiviado de aterro sanitário por processo oxidativo avançado empregando reagente de Fenton

O objetivo deste trabalho foi o de analisar a viabilidade técnica do tratamento de lixiviado de aterro sanitário por processo oxidativo avançado (POA) empregado reagente de Fenton. Os ensaios foram executados no Aterro Sanitário de Belo Horizonte, onde o processo foi realizado em batelada, com capacidade de produção de 1000L, usando um reator de mistura simples. Os resultados mostraram elevada eficiência na remoção de poluentes orgânicos, onde as remoções de DQO foram superiores a 46%, com média em torno de 61%, sendo a maior remoção alcançada de 75%, a qual demandou a menor quantidade de reagente e menor tempo de agitação e conseqüentemente menor custo de operação. Estes resultados sugerem que não haverá comprometimento ao transpor este tratamento para uma escala real, e que este processo poderá ser realizado como tratamento preliminar.

Treatment of Landfill Leachate by a Combined Anaerobic Fluidized Bed and Zeolite Column System

The use of a combined anaerobic fluidized bed and zeolite fixed bed system in sanitary landfill leachate treatment was investigated. Anaerobic treatability studies were successfully performed in the anaerobic fluidized bed reactor. The chemical oxygen demand (COD) removal was attained up to 90% with increasing organic loading rates as high as 18gCOD∕Lday after 80days of operation. Good biogas production yield (Ygas) of 0.53L biogas per gram removed COD with methane (CH4) content of 75% was obtained. The attached biomass concentration increased along the column height from bottom to top, and its mean value was found 6,065mg∕L after 100days of operation. The anaerobically treated landfill leachate was further treated by a zeolite fixed bed reactor. While excellent ammonia removal (>90%) was obtained with the untreated zeolite, the regenerated zeolites showed higher performance. Consequently, this combined anaerobic and adsorption system is an effective tool to remove high COD and high ammonia in landfill leachate.

Treatment of Sanitary Landfill Leachate Using a Combined Anaerobic Fluidized Bed Reactor and Fenton's Oxidation

Sanitary Landfill leachate treatment by a combined anaerobic fluidized bed reactor and Fenton's oxidation was investigated. Anaerobic treatability studies were performed in a pilot-scale fluidized bed reactor using the typical quartz sand media. The anaerobic fluidized bed reactor (AFBR) attained chemical oxygen demand (COD) removal efficiencies of 80–90% and stable biogas production yield of 0.54 L biogas/g CODrem with increasing organic loading rates (OLRs) within the range 2 and 15 kg COD/m3-day. Anaerobically pretreated landfill leachate was further treated by Fenton's oxidation to decompose the refractory organic and inorganic components in the leachate and optimum operation conditions for two different organic loadings (2 and 4 kg COD/m3-day) were examined. An optimum pH of 2.5 and an optimum H2O2 dosage of 1,200 mg/L, for the OLR of 2 kg COD/m3-day, yield a COD removal of 85%. The results have clearly indicated that landfill leachate treatment by a combined AFBR and Fenton's Oxidation system is an appropriate treatment option to enhance the COD removal efficiency.

Treatment of Sanitary Landfill Leachate Using a Combined Anaerobic Fluidized Bed Reactor and Fenton's Oxidation

Sanitary Landfill leachate treatment by a combined anaerobic fluidized bed reactor and Fenton's oxidation was investigated. Anaerobic treatability studies were performed in a pilot-scale fluidized bed reactor using the typical quartz sand media. The anaerobic fluidized bed reactor (AFBR) attained chemical oxygen demand (COD) removal efficiencies of 80–90% and stable biogas production yield of 0.54 L biogas/g CODrem with increasing organic loading rates (OLRs) within the range 2 and 15 kg COD/m3-day. Anaerobically pretreated landfill leachate was further treated by Fenton's oxidation to decompose the refractory organic and inorganic components in the leachate and optimum operation conditions for two different organic loadings (2 and 4 kg COD/m3-day) were examined. An optimum pH of 2.5 and an optimum H2O2 dosage of 1,200 mg/L, for the OLR of 2 kg COD/m3-day, yield a COD removal of 85%. The results have clearly indicated that landfill leachate treatment by a combined AFBR and Fenton's Oxidation system is an appropriate treatment option to enhance the COD removal efficiency.

A Comparison of Leachate Treatment Between Rhode Island and Kuwait

The main objectives of this article were to present data on the characteristics of landfill leachate of Rhode Island Central landfill and those of Kuwait's Sulaibya landfill site, and to compare different experimental pilot plant studies for the treatment of sanitary landfill leachate, which was generally characterized by high concentration of heavy metals. The data obtained on the chemical analysis of leachate generated from two landfills in Rhode Island and Kuwait, identified variations in leachate quality due to landfill composition. Pilot Plant studies using physical/chemical and biological treatments (i.e., rotating biological contractor) were used to examine the treatment efficiency.

Enzymatic treatment of sanitary landfill leachate

The objective of this investigation was to study the effectiveness of applying enzymes (bioaugmentation) for enhancement of biological treatability of leachates generated in a typical municipal solid waste sanitary landfill. The basic purpose of enzyme use is to enforce the biodecomposition of organic constituents, as well as to reduce nitrogen content. A laboratory-scale sequencing batch (bio)reactor (SBR) was used for the examination of enzymatic application. The effect of different operation strategies on the efficiency of this biological treatment process was studied to optimize performance, especially for the removal of nitrogen compounds and of biodegradable organic matter. It was found that the enzymatic process was able to remove organic matter effectively (expressed as BOD 5 and COD) and nitrogen content, color and turbidity.

Comparison of two biological treatment processes using attached-growth biomass for sanitary landfill leachate treatment

The objective of this investigation was to compare two biological systems using attached-growth biomass, for treatment of leachates generated in a typical municipal solid waste sanitary landfill. A moving-bed biofilm process, which is a relatively new type of biological treatment system, has been examined. It is based on the use of small, free-floating polymeric (polyurethane) elements, while biomass is being grown and attached as biofilm on the surface of these porous carriers. A granular activated carbon (GAC) moving-bed biofilm process was also tested. This method combines both physico-chemical and biological removal mechanisms for the removal of pollutants. The presence of GAC offers a suitable porous media, which is able to adsorb both organic matter and ammonia, as well as to provide an appropriate surface onto which biomass can be attached and grown. A laboratory-scale sequencing batch reactor (SBR) was used for the examination of both carriers. The effects of different operation strategies on the efficiency of these biological treatment processes were studied in order to optimize their performance, especially for the removal of nitrogen compounds and of biodegradable organic matter. It has been found that these processes were able to remove nitrogen content almost completely and simultaneously, the removal of organic matter (expressed as BOD5 and COD), color and turbidity were sufficiently achieved.

Treatment of sanitary landfill leachate: Biological treatment

In most cases leachates from sanitary landfills are highly polluted (COD, BOD 5, ammonium) and must be treated before discharge. Treatment experiments with aerated lagoons, activated sludge plants and rotating biological contactors in laboratory and technical scale are described. Treatment with full degradation of organics and oxydation of ammonium (nitrification) are possible with attention to some special problems of leaching treatment such as high ammonium concentrations, the BOD 5 N-ratio , precipitation of inorganics, cooling, foaming etc. From aerated lagoons BOD 5-effluents ⩽ 50 mg l −1 could be obtained at volumetric loadings ⩽ 20 g BOD 5 m −3 day −1. Shorter retention times in activated sludge plants result in lower BOD levels (⩽ 25 mg l −1) at loading rates between 0.02 and 0.05 kg BOD 5 kg MLSS −1 day −1 provided that the BOD 5 N-ratio > 1 . In all other cases the dimension parameter for activated sludge plants is ammonium load ⩽ 0.03 kg N kg MLSS −1 day −1. Similar results are obtained with rotating biological contactors also with ammonium as the critical loading value, here as an area loading ⩽2 g N m −2 day −1. In all cases ammonium is the dominate parameter and careful operation is necessary because nitrification is a very sensitive process. Operation problems could result in serious water pollution problems with discharges of high concentrations of ammonium or nitrite.

Chemical‐Physical Leachate Treatment

The results of full-scale chemical physical treatment of sanitary landfill leachate are analyzed. The plant receives approximately 75,000 u cell (liters) per day from a lined 50 acre landfill. The treatment sequence consists of equalization, lime precipitation, sedimentation, and air stripping of ammonia. Overall percent removal efficiencies are BOD\d5, 69; kjeldahl-N, 53: cadmium, 59; copper, 38; iron, 98; lead, 66; mercury, 52; nickel, 54; zinc, 95, and, suspended solids, 95. Equalization markedly reduces operating costs. The effects of temperature and pH on heavy metals removal are also reviewed.