Landfill is a common solution for the final disposal of municipal solid waste in Turkey. In recent years, studies of landfill leachate treatment by Fenton process have indicated that these methods can effectively reduce concentrations of organic contaminants and colour. The aim of this study is to investigate the removal efficiencies of colour and organic matter as COD from young municipal landfill leachate and the effect of operating conditions such as initial pH and Fenton's reagent dosage. Leachate was collected from municipal sanitary landfill located in city of Konya, Turkey. The main characteristics of the leachate were: pH = 7.25, colour = 3510 ptCo, COD = 38200 mgL(-1), BOD5 = 22000 mgL(-1), ratio of BOD5/COD was 0.58 and alkalinity as CaCO3 = 10250 mgL(-1). It is observed that presenting a high value of COD and BOD5 and the rate of BOD5/COD values indicate that the leachate can be defined as young. The treatment of the leachate by Fenton process was carried out in a batch reactor. Under the optimal operation conditions (initial pH = 3, 2000 mgL(-1) Fe2+ and 5000 mgL(-1) H2O2), 55.9% of the initial COD and 89.4% colour were removed.

This study investigates the performance of an anaerobic baffled reactor (ABR) during the start-up period of raw young landfill leachate treatment at two chemical oxygen demand (COD) to SO4(2-) ratios of 20 and 4. The reactor was operated at ambient temperature and low organic loading rates (0.52, 0.76 and 1.05 kg COD/m3 per day). During the study, sulfate-reducing bacteria (SRB) activity increased at the lower ratio of COD/SO4(2-) producing higher levels of sulfide and alkalinity. The dissolved sulfide concentration reached an inhibitory level above 250 mg/L, which caused a sharp reduction in the total COD removal efficiency from 77-80% to 32%. Total volatile fatty acid (TVFA) production proceeded at a constant level despite increased organic loading. As the effluent total and organic COD concentrations increased, the inhibitory effect of the inborn sulfide was correlated to the limitation experienced in the hydrolysis/acidogenesis stages, and thus VFA production and organic matter removal.

Abstract:Leachate from sanitary landfills is a strong wastewater in terms of organic matter and ammonia. Both biological and chemical processes can be used for organic matter but ammonia reduction by nitrification-denitrification often poses problems due to inhibition. In this study, leachate from solid waste landfill in Konya Municipal area was used and organic matter and color removal were examined by using different chemical matters (Alum, FeCl 3 , FeSO 4 ) in the pH adjustment with lime, NaOH and H 2 SO 4 . For ammonium removal, air stripping and its removal efficiency were investigated. For organic matter removal, the highest efficiencies were achieved as 44% by using 9 g/L alum at pH 11 adjusted with lime and as 45% by using 15 g/L FeCl 3 concentration at pH 3. Color removal studies in coagulation experiments indicated that the highest color removal efficiencies could be obtained when pH was adjusted with lime. The lowest coagulant concentration 1 g/L yielded the similar removal efficiencies as the concentration increased. In ammonium removal with air stripping, the optimum flow rate was 1 L/min and the optimum aeration time was 8 hours.

Water treatment works using coagulation/flocculation in the process stream will generate a waste sludge. The works in Adana, Turkey uses ferric chloride. The potential for using this sludge for the treatment of reactive, direct, disperse, acidic, and basic dyestuffs by coagulation and sorption has been investigated. The sludge acted as a coagulant and removed colour with excellent removal efficiencies being obtained for basic, disperse and direct dyes. The optimum conditions were a pH value of 5 and a sludge dose of 2000 mg l(-1). Mediocre results were obtained for acidic and reactive dyes. The efficiency of the sludge was also compared with alum and ferric chloride for the same group of dyes. The sludge was also used as a coagulant to treat the wastewater from a textile factory. At doses of 2000-4000 mg l(-1), the sludge was as effective as ferric chloride and alum at removing COD. Sorption tests showed that the disperse and reactive dyes did not bind to the sludge. Langmuir and Freundlich constants were determined for the other three types of dye. Rate constants for the adsorption were determined using the Lagergren equation.

Treatment of young landfill leachate, collected from municipal solid waste site of city of Konya, was investigated by using the Fenton process. ). Overall kinetics can be described by a second-order rate equation followed by zero-order one. The kinetic studies were undertaken at the different temperatures and reaction rates increcesed by increasing temperature. The apparent kinetic constants at 303 K are k = 3.16 x10 , respectively. Fenton reagents effectively degraded the leachate organics and most of the degradation was completed within 30 minutes for all temperatures. The performance of Fenton process was not only presented as a COD removal but also expressed as the amount of generated sludge and its properties. Sludge properties were revealed with Capillary Suction Time (CST) and Sludge Volume Index (SVI). The minimum CST value was obtained at the optimum molar ratio of 4.12 mol/mol and increasing temperature resulted in a positive effect on CST values. All SVI values were significantly low which indicates that sludge itself had good settling properties.