Electrochemical Oxidation Of Landfill Leachate In A Flow Reactor: Optimization Using Response Surface Methodology.

Response surface methodology based on Box-Behnken (BBD) design was successfully applied to the optimization in the operating conditions of the electrochemical oxidation of sanitary landfill leachate aimed for making this method feasible for scale up. Landfill leachate was treated in continuous batch-recirculation system, where a dimensional stable anode (DSA(©)) coated with Ti/TiO2 and RuO2 film oxide were used. The effects of three variables, current density (milliampere per square centimeter), time of treatment (minutes), and supporting electrolyte dosage (moles per liter) upon the total organic carbon removal were evaluated. Optimized conditions were obtained for the highest desirability at 244.11 mA/cm(2), 41.78 min, and 0.07 mol/L of NaCl and 242.84 mA/cm(2), 37.07 min, and 0.07 mol/L of Na2SO4. Under the optimal conditions, 54.99 % of chemical oxygen demand (COD) and 71.07 ammonia nitrogen (NH3-N) removal was achieved with NaCl and 45.50 of COD and 62.13 NH3-N with Na2SO4. A new kinetic model predicted obtained from the relation between BBD and the kinetic model was suggested.

STATISTICAL EVALUATION OF MATURE LANDFILL LEACHATE TREATMENT BY HOMOGENEOUS CATALYTIC OZONATION

This study presents the results of a mature landfill leachate treated by a homogeneous catalytic ozonation process with ions Fe(2+) and Fe(3+) at acidic pH. Quality assessments were performed using Taguchi`s method (L(8) design). Strong synergism was observed statistically between molecular ozone and ferric ions, pointing to their catalytic effect on (center dot)OH generation. The achievement of better organic matter depollution rates requires an ozone flow of 5 L h(-1) (590 mg h(-1) O(3)) and a ferric ion concentration of 5 mg L(-1).

LEACHATE TREATMENT PROCESS AT A MUNICIPAL STABILIZED LANDFILL BY CATALYTIC OZONATION: AN EXPLORATORY STUDY FROM TAGUCHI ORTHOGONAL ARRAY

Catalytic ozonation has been recognized in the scientific community as an efficient technique, reaching elevated rates of recalcitrant organic material mineralization, even at the presence of scavenger species of hydroxyl free radicals. This study presents the most significant factors involving the leachate treatment stabilized by the municipal landfill of the city of Guaratingueta, State of Sao Paulo, Brazil, by using a catalytic ozonation activated by metallic ions Fe(3+), Zn(2+), Mn(2+), Ni(2+) and Cr(3+). The Taguchi L(16) orthogonal array and its associated statistical methods were also used in this study. Among the researched ions, the most notable catalysis was obtained with ferric ion, statistically significant in the reduction of COD with a confidence level of 99.5%.

Kinetic studies of urban solid residues and leachate from sanitary landfill

Urban solid residues are constituted of food remaining, grass leaves, fruit peelings, paper, cardboard, rubber, plastic, etc. The organic fraction formed represents about 50% during the decomposition yields biogas and leachate, which are sources of pollution. Residue samples were collected from the landfill in different and cells from several ages and the corresponding leachate, both after treatments, were submitted to thermal analysis. Kinetic parameters were determined using Flynn-Wall-Ozawa method. The linear relation between the two kinetic parameters (ln A and E) was verified for organic residue urban`s samples, but not for leachate`s sample. The occurred difference can be attributed to the constituents present in leachate.

APPLICABILITY OF THE NITRITATION/DENITRITATION PROCESS IN THE TREATMENT OF A LANDFILL LEACHATE

The biological nitritation/denitritation process in the removal of organic matter and nitrogen in a landfill leachate was studied using an activated sludge sequencing batch reactor Treatment cycles were formed by an anoxic and an aerobic phases in which the conditions for oxidation of the influent N load and the prevalence of nitrite concentration at the end of aerobic treatment cycles were determined as well as the use of organic matter present in the leachate as a carbon source for denim-firing organisms in the anoxic stage The removal efficiencies of N-NO(2) at the end of the anoxic process (48h) ranged between 14 and 30% indicating low availability of biodegradable organic matter in the leachate As for the accumulation of N-NO(2) at the end of the aerobic phase (48h) of treatment cycles imbalances were not observed while 100% removal efficiencies of N and specific nth-dation rates from 0 095 to 0 158kgN-NH(3)/kgSSV per day were recorded demonstrating the applicability of simplified nitrification in the treatment of effluents with low C/N ratios

Exceptionally high-rate nitrification in sequencing batch reactors treating high ammonia landfill leachate

The nitrogen removal capacity of a suspended culture system treating mature landfill leachate was investigated. Leachate containing high ammonium levels of 300-900 mg N/L was nitrified in a bench scale sequencing batch reactor. Leachate from four different landfills was treated over a two year period for the removal of nitrogen. In this time, a highly specific nitrifying culture was attained that delivered exceptionally high rates of ammonia removal. No sludge was wasted from the system to increase the throughput and up to 13 g/L of MLSS was obtained. Settleability of the purely nitrifying biomass was excellent with SVI less than 40 mL/g, even at the high sludge concentrations. Nitrification rates up to 246 mg NI(L h) (5.91 g N/(L d)) and specific nitrification rates of 36 mg N/(gVSS h) (880 mg N/(gVSS d)) were obtained. The loading to the system at this time allowed complete nitrification of the leachate with a hydraulic retention time of only 5 hours. Following these successful treatability studies, a full-scale plant was designed and built at one of the landfills investigated.

Immature mosquitoes (Diptera: Culicidae) in a eutrophic landfill tank from State of Rio de Janeiro, Brazil

Introduction To determine the faunal composition of immature culicids inhabiting a percolation tank in the landfill of Sapucaia, State of Rio de Janeiro, Brazil, immature mosquitoes were collected over a two-day period during the third weeks of April, August and October 2011. Results The species found were Culex usquatus, Lutzia bigoti, Anopheles argyritarsis and Limatus durhamii. This study is the first to report the colonization of eutrophic breeding sites by these species. Conclusions The oviposition behavior observed in this study suggests a secondary adaptation or change in habit to select eutrophic environments during the developmental stages of the observed species.

Page County Landfill Association, June 30, 2001 & June 30, 2002

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Fremont County Landfill Commission, June 30, 2002

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Adair County Sanitary Landfill Commission, June 30, 2002

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Page County Landfill Association, June 30, 2003

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Fremont County Landfill Commission, June 30, 2003

Other Audit Reports - 28E Organization

Adair County Sanitary Landfill and Recycling Center, Independent Auditor's Reports, Financial Statements and Required Supplementary Information Schedule of Findings, June 30, 2004

Other Audit Reports - Adair County Sanitary Landfill and Recycling Center