COD In Leachate Research Articles

Kadar BOD dan COD Air Lindi dengan Perlakuan Fitoremidiasi Tanaman Teratai (Nymphaea Sp.) dan Apu-Apu (Pistia stratiotes L.) (Studi Kasus TPA Jetis Purworejo)

Phytoremediation is one of alternative methods to remove pollutant in leachate. Leachate from Jetis Landfill was applied in this research. The purposes of the study were to analysis the change of BOD and COD concentration using Nymphaea sp. and Pistia stratiotes L. and to observe plants condition.The research was carried out by laboratory experiment. Tools and materials used in this research were reactors with 50 L capacity, 455 L of leachate, 12 pcs of Nymphaea sp., 120 pcs of Pistia stratiotes L., 12 kg of palm fiber, and 120 kg of gravel. There were 25 reactors consisted of 1 control reactor, 12 reactors with 3 day of resident time (H3) and 12 reactors with 7 days of resident time (H7). Each of reactors is filled with 15-20 L of leachate which consisted of only plant reactors (T or A) and palm fiber, gravel and plant reactors (TIK or AIK). Each reactor was tested the BOD and COD. Plant conditions were observed daily. Changes of BOD and COD levels for each treatment presented in graphs then analysed descriptively.The results showed that BOD and COD levels of each reactor were lower than control. The difference was relatively small. The AIK-H7 reactor was the most optimum in reducing BOD levels, although the percentage of reduction only 24.11%. In TIK-H7, the COD level was 576 mg/L, the reduction percentage reached 23,6%. The plant observation, found on the 3rd day of treatment, the leaves of the Nymphaea sp. have begun to decay, while the leaves of the Pistia stratiotes L. have started to dry and turn yellow. On the 7th day the whole plant was died. Phytoremediation with Nymphaea sp. and Pistia stratiotes L. in this research was not maximum to remove BOD and COD in leachate of Jetis Landfill.

Toxicological Characteristics of Leachate from Non-Sanitary Municipal Solid Waste Landfill

This research evaluated the toxicity and hepatotoxic effects of non-sanitary MSW landfill leachates on freshwater fish, Oreochromis niloticus. Toxicity test was conducted based on the OECD Guidelines for Testing of Chemicals. Fish was exposed to different leachate concentrations for 96 hours under static method. Acute mortality was closely monitored and analyzed using the Probit method. During the toxicity test, observations of fish test samples were performed on behaviour, mortality, and anatomical pathology. Results showed the content of ammonia, nitrate, sulphate, BOD, COD, and Zn in non-sanitary landfill leachate of Cot Padang Nila was found in high concentration. Against the leachate, freshwater fish, Oreochromis niloticus has acute mortality, LC50 for 96 hours at the value of 20.172%. High mortality rate of fish was strongly influenced by the concentration level given (P<0.05). During the toxicity test, observations of fish behavioural changes showed symptoms of acute and sub-acute poison, including acceleration of operculum motion, hyperactivity, sudden jerks and loss of swimming power, and hyperpigmentation. Some fish organs undergo pathologic changes in the eyes, fins, scales, gills, and spleen. Histopathologically, gill tissue changes include epithelial release of lamella, hyperplasia, lamella fusion, and necrosis. The histopathologic features of liver show changes including fat degeneration, congestion, haemorrhage, inflammatory cell infiltration, and hepatocyte cell necrosis.

Zero-valent iron nanofibers (ZVINFs) immobilized on the surface of reduced ultra-large graphene oxide (rULGO) as a persulfate activator for treatment of landfill leachate

In this research, the performance of zero-valent iron nanofibers/reduced ultra-large graphene oxide (ZVINFs/rULGO) as a persulfate (PS) activator was investigated for the treatment of synthetic and real leachate. Ultra-large graphene oxide (ULGO) was prepared by chemical expansion of natural flake graphite using chromium trioxide and hydrogen peroxide and then oxidation using potassium permanganate. ZVINFs/rULGO was prepared by adding sodium borohydride as a reducing agent to a solution containing Fe(II) ions and ULGO. The material characterization was performed by XRD, SEM, EDS, and BET analysis. The effects of the pH, ZVINFs/rULGO dosage, PS/COD ratio, reaction time, and temperature on the removal of COD and NH3 were evaluated to find the optimum operational conditions (i.e., pH 3, ZVINFs/rULGO dosage: 1.6 g L−1, PS/COD: 3, and reaction time: 45 min). Under the optimum conditions, the removal efficiencies of COD and NH3 were 93.64 and 84.8%, respectively. The presence of ZVINFs/rULGO led to 3.8 and 4.2 times decrease in the activation energies of COD and NH3, respectively. Finally, the ZVINFs/rULGO-PS system was applied for removal of COD and NH3 in real leachate obtained from the Aradkouh’s landfill located in Tehran, Iran. The COD and NH3 removal efficiencies for the fresh leachate were 80.87 and 72.38%, respectively, and the biodegradability (BOD5/COD) of the real leachate enhanced from 0.25 to 0.52, respectively.

Construction of Fe2O3/Co3O4/exfoliated graphite composite and its high efficient treatment of landfill leachate by activation of potassium persulfate

Landfill leachate, as one of high-ammonia nitrogen organic pollutants, has been characterized to be potentially dangerous on ground water and soil. However, traditional technologies cannot deal with these substances swiftly. Thus, in this study, exfoliated graphite (EG) immobilized ferric oxide and cobaltosic oxide species has been successfully constructed by a facile heating-precipitation strategy. Subsequently, physicochemical properties of Fe2O3/Co3O4/EG were investigated by scanning electron microscope, X-ray diffraction, N2 adsorption/desorption, X-ray photoelectron spectroscopy measurements. Results indicated that Fe2O3 and Co3O4 nano-particles were successfully deposited onto the surface and interstice of EG substrate. In addition, activation performance of Fe2O3/Co3O4/EG composite was evaluated by activating potassium persulfate (PS) to degrade the landfill leachate. In addition, effect of some critical operating parameters on the removal of landfill leachate was studied systematically. The experimental results showed that 90.6% of NH4+-N and 67.1% of COD in landfill leachate could be removed at the optimized conditions of pH 5, PS concentration 0.05 M and Fe2O3/Co3O4/EG dosage 0.1 g. Furthermore, Fe2O3/Co3O4/EG sample also displayed good recycle and reusable capacities. Besides these, high-efficient removal mechanism of Fe2O3/Co3O4/EG was proposed. This study provides a feasible strategy to prepare catalyst which could be potentially applied in refractory contaminants elimination.

Economically and technically feasible treatment for residue-driven leachate of landfills

Sri Lankan government has a policy on land filling along with the implementation of 3R (Reduce, Reuse, Recycle) where landfills are to be used only to dispose residue waste instead of unsorted waste. Sri Lanka, in response to this policy, has planned to have several landfills in the country with a view to managing the residue waste generated following the process of composting. Residue-waste comprise of long term biodegradable waste or/and non-biodegradable waste where the long term biodegradables account for large amount of tannins, cellulose, hemicelluloses. These tannins can accumulate to a level that is toxic to bacterial degradation. Tannin is characterized with high COD, BOD, TOC and turbidity levels in leachate. There has been an issue of only using biological treatment for residue-driven leachate as it may create a situation where biological treatment alone would not be possible to yield the acceptable level of treatment. Hence, it is of utmost importance to eliminate tannin prior to biological treatment. This study was carried out to find the most economical and technically feasible method to treat residue-driven leachate. Chemical treatment encompassing coagulation and flocculation chemical process is used to treat tannin in residue-driven leachate with different combinations of coagulants and flocculants at pH 7. Optimum treatment results were observed with a combination of alum and a polyelectrolyte having removal efficiencies for COD, BOD, TOC, turbidity, and tannin to be in the range of 38-40%, 25-28%, 92%, 85% and 80% respectively. It was also noted that the black color changed to colorless indicating higher levels of tannin removal. Further, the sludge arising from chemical treatment that would be easily managed within the landfill is an added advantage. Thus removal of tannin from residue driven leachate with chemical treatment prior to the biological treatment is highly recommended. As chemically treated residue-driven leachate showed BOD and COD levels higher than the proposed leachate emission levels an aerobical treatment using activated sludge can be carried out with the bio reactor. Keywords: Chemical treatment, Coagulation, Leachate, Residue-waste

Modeling and optimization of photocatalytic treatment of landfill leachate using tungsten-doped TiO2 nano-photocatalysts: Application of artificial neural network and genetic algorithm

Abstract One of the most important practices in each water and wastewater treatment process is the accurate modeling, optimization, and finding the best condition which leads to achieve maximum efficiency. Recently, artificial neural network and genetic algorithm have been accepted as efficient tools for empirical modeling and optimization, especially for non-linear phenomena. In the present study, Artificial Neural Network (ANN) was applied to model the temporal variations of landfill leachate COD in the photocatalytic treatment process using tungsten-doped TiO2 (W-doped TiO2) nano-photocatalysts. Four influential parameters on the process efficiency, pH, tungsten content (wt.%), calcination temperature (Temp), and exposure time (T) of leachate were considered to predict temporal variations of the leachate COD concentration. Different ANN structures were developed, trained, validated and tested using the data from 150 experiments. Optimal ANN structure was determined based on three performance measures, MAPE, NRMSE, and R. Prediction process inside the optimal ANN was extracted in the form of simple and user-friendly mathematical formulas. Genetic Algorithm (GA) was used to find the most efficient W-doped TiO2 nano-photocatalysts in the COD removal of landfill leachate. The process optimization was conducted at a fixed exposure time using a GA whose objective function was the mathematical formulas obtained from the optimal ANN model. Based on the modeling results, the ANN model, as a non-linear model, has a high predictive accuracy (4% mean error and 0.98 correlation coefficient) when it comes to prediction of temporal variations of the leachate COD in the photocatalytic treatment process using W-doped TiO2 nano-photocatalysts. Based on the optimization results, the most efficient W-doped TiO2 nano-photocatalysts were provided when tungsten content, calcination temperature, and leachate pH were 2.2 percent by weight, 529 °C, and 6.3, respectively.

Mechanism, adsorption kinetics and applications of carbonaceous adsorbents derived from black liquor sludge

Abstract Pretreatment processes in second generation bioethanol production produce a lignin-based black liquor. Polyaluminum chloride (PACl) was employed to treat black liquor using coagulation, in which the generated sludge was converted to a carbonaceous adsorbent. The bioethanol black liquor sludge-based carbonaceous adsorbent (BBLS-CA) was characterized physically, and its adsorption mechanism, kinetics, and ability to absorb methylene blue (MB) were evaluated. Additional studies revealed the performance of BBLS-CA to treat peat water and landfill leachate. The results demonstrate that BBLS-CA decolorized a 100 mg/l solution of MB by 98% within 30 min. MB components reclaimed from BBLS-CA reveal the presence of NH2, substituted and p-disubstituted benzene rings, and =CH2, suggesting that physical and chemical mechanisms are operative during adsorption. Isotherm analysis reveals that adsorption equilibrium followed the Langmuir model and exhibited pseudo second-order kinetic behavior. BBLS-CA adsorbed 100% iron and manganese; and remediated 72% color and 67% COD in peat water, as well as 57% COD in landfill leachate. This report highlights a by-product from black liquor sludge that can be applied to the removal of wastewater pollutants. Further, the development of method is required to obtain activated carbon which fulfills standard properties of activated carbon.

Estimating landfill leachate BOD and COD based on rainfall, ambient temperature, and waste composition: Exploration of a MARS statistical approach

Abstract Municipal solid waste generation is increasing rapidly globally. Increasing storage of waste in landfills means increased production of liquid landfill leachate. Leachate contains organic and inorganic pollutants which must be treated to reduce its potential impact on surrounding water supplies. To design landfill leachate treatment, its chemical composition must be known; however, the composition of leachate can vary widely depending on waste composition. Measuring leachate constituents can be expensive and time consuming, and is not possible for a landfill under construction. A global model able to forecast leachate quality parameters based on a landfill’s waste composition, ambient temperature, and rainfall rate is critically needed. This research represents a first step in development of such a model. Laboratory data on leachate biochemical and chemical oxygen demand (BOD, COD) was collected as functions of waste composition (food, paper, yard, textile), temperature (70, 85, 100 °F), and rainfall rates (2, 6, 12 mm/day), according to a statistical experimental design. Multivariate Adaptive Regression Splines (MARS) models were developed for BOD and COD, with adjusted- R 2 of 0.92 and 0.95, respectively. This exploratory research demonstrated the usefulness of MARS in capturing complex relationships among waste composition, temperature, and rainfall rate in order to forecast leachate quality parameters over time.

Technology Evaluations for COD and TDS Reduction in Leachate

Technology Evaluations for COD and TDS Reduction in Leachate

Recirculation of reverse osmosis concentrate in lab-scale anaerobic and aerobic landfill simulation reactors

Leachate treatment is a major issue in the context of landfill management, particularly in view of the consistent changes manifested over time in the quality and quantity of leachate produced, linked to both waste and landfill characteristics, which renders the procedure technically difficult and expensive. Leachate recirculation may afford a series of potential advantages, including improvement of leachate quality, enhancement of gas production, acceleration of biochemical processes, control of moisture content, as well as nutrients and microbe migration within the landfill. Recirculation of the products of leachate treatment, such as reverse osmosis (RO) concentrate, is a less common practice, with widespread controversy relating to its suitability, potential impacts on landfill management and future gaseous and leachable emissions. Scientific literature provides the results of only a few full-scale applications of concentrate recirculation. In some cases, an increase of COD and ammonium nitrogen in leachate was observed, coupled with an increase of salinity; which, additionally, might negatively affect performance of the RO plant itself. In other cases, not only did leachate production not increase significantly but the characteristics of leachate extracted from the well closest to the re-injection point also remained unchanged. This paper presents the results of lab-scale tests conducted in landfill simulation reactors, in which the effects of injection of municipal solid waste (MSW) landfill leachate RO concentrate were evaluated. Six reactors were managed with different weekly concentrate inputs, under both anaerobic and aerobic conditions, with the aim of investigating the short and long-term effects of this practice on landfill emissions. Lab-scale tests resulted in a more reliable identification of compound accumulation and kinetic changes than full-scale applications, further enhancing the development of a mass balance in which gaseous emissions and waste characteristics were also taken into consideration. Results showed that RO concentrate recirculation did not produce consistent changes in COD emissions and methane production. Simultaneously, ammonium ion showed a consistent increase in leachate (more than 25%) in anaerobic reactors, free ammonia gaseous emissions doubled with concentrate injection, while chloride resulted accumulated inside the reactor.

Comparison of biogas recovery from MSW using different aerobic-anaerobic operation modes

Aeration pretreatment was demonstrated as an efficient technology to promote methane recovery from a bioreactor landfill with high food waste content. In this study, a short-term experiment was conducted to investigate the effects of aerobic-anaerobic operation modes on biogas recovery. Three landfill-simulated columns (anaerobic control (A1), a constant aeration (C1) and a gradually reduced aeration (C2)) were constructed and operated for 130days. The aeration frequency was adjusted by oxygen consumption in an aerated MSW landfill. After aerobic pretreatment was halted, the methanogenic phase was rapidly developed in both the C1 and C2 columns, reducing the volatile fatty acid (VFA) concentrations and increasing pH. The methane volumes per dry MSW produced from the C1 and C2 columns were approximately 62L/kg VS and 75L/kg VS, respectively, while methane produced from the A1 column was almost negligible. The result clearly showed that aerobic pretreatment with gradual reduction of aeration rates could not only improve methane recovery from waste decomposition, but also enhance leachate COD and VFA removal.

Leachate direct-discharge limits and incentives related to landfill aftercare costs

Society needs sustainable methods for landfilling from an environmental perspective, but they have to be cost effective and affordable. Aftercare represents considerable costs within waste management system and costs can be expected to accrue over a long period of time showing the need to compare different management options. Direct-discharge limits for leachate COD and nitrogen are different in various (European) countries. When leachate COD or nitrogen has decreased at the latter part of the aftercare period, effluent limits 50 or 200 mg/l for COD and 10 or 70 mg/l for nitrogen have a considerable impact on period length. The objective of this paper is to discuss the effects of leachate discharge limits on landfill aftercare and leachate management costs in various conditions. Landfill simulator results and modelling are used to estimate leachate concentrations in three different scenarios. It is suggested that stricter discharge limits (shown before) impact on the costs of activated carbon filtration (1.4-fold) and biological treatment (1.1–1.24-fold). Stricter limits also extend the aftercare period length considerably, but with substantial water circulation the differences are clearly smaller. These results support the recent suggestion of aftercare incentives, and some details of applying these incentives in different conditions are discussed.

Field‐scale monitoring test of aeration for enhancing biodegradation in an old landfill in China

The field‐scale test of aeration to accelerate biodegradation of the waste was conducted, which was selected in an old landfill in Hubei province in China. The long‐term monitoring was presented, lasted for 11 months, to estimate the degradation stability of the landfill. The monitoring parameters included the temperature, COD and BOD of leachate, gas concentration, water level, settlement, and cellulose/lignin. The results show that the waste degradation rate was increased under the aeration condition, while there was a trend of the stability in the whole waste body. The water level within the landfill was adjusted by discharge measurements, contributing to the buildup of the oxygen environment in landfill. The C/L could be used to assess the stability of the full‐scale waste during the degradation process. But, there was obviously discrete by means of drilled sampling. The field‐scale test was needed to provide the evidence for aeration engineering operation. © 2015 American Institute of Chemical Engineers Environ Prog, 35: 380–385, 2016

Analysis of Degradation by Aerobic Recharge for Concentrated Leachate

Concentrated leachate obtained from landfill leachate by membrane separation was treated using technique of aerobic recharge. Variation of effluent COD, NH3-N and pH in concentrated leachate during aerobic recharge was studied. The impact of hydraulic loading on the removal rate of COD and NH3-N was investigated. The results indicate that, after passing through the three stages of rapid declining, smooth declining and stabilization, the variation of effluent COD of the concentrated leachate versus time maintains in the range of 900~2000 mg/L, and the corresponding removal rate is 88%~92%. The variation of effluent NH3-N versus time indicates a trend that it climbs up initially and then declines. The effluent NH3-N starts from 700 mg/L. After 35 days, it declines down to 18 mg/L and maintains in the range of 93%~99% with a corresponding removal rate up to 98%. Aerobic recharge reduces the build up of organic acids in the early stage. After 10 days, the pH value of the leachate maintains in the range between 7.5 and 9.0. The COD removal rate decreases from 94.39% down to 75.75% when the hydraulic loading increases from 12.5 mL / (L·d) to 75mL / (L·d), indicating a strong trend. In the mean time, the NH3-N removal rate decreases from 98.14% down to 90.11%, indicating a weak tread.

Fouling potential and reclamation feasibility for a closed landfill leachate treated by various pretreatment processes on membrane system

A closed sanitary landfill leachate with high recalcitrant organics (COD = 4,000 mg/L) in a full-scale plant was intended for reuse. Various methods including coagulation, enhanced coagulation, microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO) were conducted, and modified fouling index (MFI) was used to evaluate the membrane fouling potential. The results showed that the current biological treatment process (activated sludge and sedimentation) in the full-scale plant only achieved 20% of COD removal with MFI still higher than 550,000 s/L2. After conventional coagulation (CC) process, the MFI reduced only to 22,497 s/L2, and additional MF/UF processes can only lower the MFI value to 28.5 s/L2, which is still higher than the recommended operational value of 10 s/L2 for NF or 2 s/L2 for RO. Consequently, enhanced coagulation was used to replace the current coagulation process before MF/UF processes, and the result shows the MFI value was capably lowered to 10.98 s/L2 with COD removal efficiency of 50.7%. The correlation of MFI, COD, and SS of leachate was derived by linear regression as follows: log MFI = 2.70 × log COD + 1.72 × log SS − 7.11. The minus sign in the coefficient of “ − 7.11” indicates fouling would occur only at COD and SS were higher enough to surpass the negative values in this equation. This regression equation not only can predict the fouling potential, but also can evaluate the optimum operation parameters for the pretreatment before NF/RO membrane processes. Moreover, the NF and RO processes followed by these pretreatment procedures can reach COD removal efficiencies of 97.6 and 98.3%, and TN removal of 98.66 and 99.86%, respectively, indicating these treated effluents can be reused for the irrigation.

Study on Catalyst for Catalytic Ozonation to Leachate and Catalytic Process

Five kinds of catalyst were prepared with Chromium, cadmium, cobalt, copper, nickel loading on the γ–Al2O3. Catalyst loading rate, effects to the ozone suction rates and water quality change situation of catalytic ozonation to leachate were studied. It can be found that when the mO3/mCOD equaled 0.11, 0.15 and 0.26 separately, and mCatalyst/mCOD fixed at 5, the cobalt has the highest loading rate, the cadmium catalyst could improve the ozone absorption rate, the chromium catalyst makes against the ozone absorption rate, the copper catalyst can increase the COD removal rate and the nickel catalyst has advantages for the NH3–N removal rate. Results indicate that: the leachate COD removal rate increased by 20.2 percent by the copper catalyst adding and the NH3–N removal rate rise 20.7 percent with the nickel catalyst; the best dosage of the ozone in catalytic ozonation is mO3/mCOD at 0.12 to 0.13; the degree of oxidation is exited.

Treatment of landfill leachate by immobilized Ganoderma australe and crude enzyme

Landfill leachate is a complex environmental problem. Here, we used immobilized Ganoderma australe and crude enzyme to treat landfill leachate. The treatment by immobilized G. australe achieved 50% and 32% removals for leachate BOD5 and COD, respectively. Totals of 58%, 57%, and 62% of BOD, COD, and NH3-N percentage removal were obtained when the leachate previously treated with immobilized G. australe was continuously treated with crude enzymes. Using a continuous treatment with crude enzymes achieves higher percentages of COD and NH3-N removal.

BOD:COD Ratio as an Indicator for Pollutants Leaching from Landfill

The relationship of BOD to COD of leachate from a mature landfill site are investigated over a period of six years to determine the indicator to be used for prediction of leachate characteristic generating from landfill site. Results of the investigation reveal that BOD:COD ratio is a good indicator of degradation of organic matter in landfill. It can be used as an indicator for degradation of organic matter that differentiate the acetogenic phase from methanogenic phase in this landfill Index Terms—BOD:COD ratio, landfill leachate, waste decomposition.

Treatment of landfill leachate by Fenton process: parametric and kinetic studies

Fenton treatment of leachate of municipal landfill was investigated in this study. Physical and chemical characteristics of the leachate indicated that the waste is alkaline and is characterized by extremely high concentration of organic compounds. Different reaction conditions of Fenton treatment were examined including H2O2/chemical oxygen demand (COD) and Fe2+/H2O2 ratios in the present work. COD of leachate after Fenton treatment was removed by about 77 and 83% for initial COD 6,250 and 13,300 mgO2/L, respectively. Such a maximum removal was achieved at pH 3 and using reagent dosages as high as H2O2/COD = 4.4 and H2O2/Fe2+value of 50. Complete oxidation was not achieved even at optimum conditions due to the presence of inhibitors (carbonate) in the leachate wastewater. After removal of high carbonate content, the same removal efficiency could be achieved with lower H2O2/COD ratio (i.e. H2O2/COD = 3.3). A simplified kinetic study for Fenton treatment of leachate wastewater has been performed.

Effect of Adding Fillers on Rubbish Degradation and Leachate Yield and Water Quality

In order to study the effect of fillers with adsorption and drying on rubbish degradation, leachate production and water quality of leachate, five cylinder reactors for landfill disposal were built to simulate the operation of landfill, one reactor was used as contrast reactor, no filler added in it. Saw powder, activated carbon, zleolite and newspaper were added into another four reactors. In the experiment, rubbish cell height, leachate production, COD and NH3-N concentration of leachate and heavy metals concentration of leachate were monitored. The experimental results indicate that fillers with adsorption and drying in rubbish have strong effect on reducing leachate production, accelerating degradation of rubbish and reducing pollutants in leachate. Overall, saw powder is more perfect in taking these actions than other three fillers.