scholarly journals Treatment of landfill leachate with different techniques: an overview

Author(s):  
Amin Mojiri ◽  
John L. Zhou ◽  
Harsha Ratnaweera ◽  
Akiyoshi Ohashi ◽  
Noriatsu Ozaki ◽  
...  

Abstract Landfill leachate is characterised by high chemical and biological oxygen demand and generally consists of undesirable substances such as organic and inorganic contaminants. Landfill leachate may differ depending on the content and age of landfill contents, the degradation procedure, climate and hydrological conditions. We aimed to explain the characteristics of landfill leachate and define the practicality of using different techniques for treating landfill leachate. Different treatments comprising biological methods (e.g. bioreactors, bioremediation and phytoremediation) and physicochemical approaches (e.g. advanced oxidation processes, adsorption, coagulation/flocculation and membrane filtration) were investigated in this study. Membrane bioreactors and integrated biological techniques, including integrated anaerobic ammonium oxidation and nitrification/denitrification processes, have demonstrated high performance in ammonia and nitrogen elimination, with a removal effectiveness of more than 90%. Moreover, improved elimination efficiency for suspended solids and turbidity has been achieved by coagulation/flocculation techniques. In addition, improved elimination of metals can be attained by combining different treatment techniques, with a removal effectiveness of 40–100%. Furthermore, combined treatment techniques for treating landfill leachate, owing to its high chemical oxygen demand and concentrations of ammonia and low biodegradability, have been reported with good performance. However, further study is necessary to enhance treatment methods to achieve maximum removal efficiency.

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 946
Author(s):  
Chunlian Wang ◽  
Xiaojie Sun ◽  
Huijun Shan ◽  
Hongxia Zhang ◽  
Beidou Xi

This study explored the performance of TiO2 nanoparticles in combination with aged waste reactors to treat landfill leachate. The optimum conditions for synthesis of TiO2 were determined by a series of characterizations and removal rates of methyl orange. The effect of the ultraviolet irradiation time, amount of the catalyst, and pH on the removal efficiency for the chemical oxygen demand (COD) and color in the leachate was explored to determine the optimal process conditions, which were 500 min, 4 g/L and 8.88, respectively. The removal rates for COD and chroma under three optimal conditions were obtained by the single factor control method: 89% and 70%; 95.56% and 70%; and 85% and 87.5%, respectively. Under optimal process conditions, the overall average removal rates for ammonium nitrogen (NH4+–N) and COD in the leachate for the combination of TiO2 nanoparticles and an aged waste reactor were 98.8% and 32.5%, respectively, and the nitrate (NO3−–N) and nitrite nitrogen (NO2–N) concentrations were maintained at 7–9 and 0.01–0.017 mg/L, respectively. TiO2 nanoparticles before and after the photocatalytic reaction were characterized by emission scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and Fourier transform infrared spectrometry. In addition, TiO2 nanoparticles have excellent recyclability, showing the potential of the photocatalytic/biological combined treatment of landfill leachate. This simulation of photocatalysis-landfilling could be a baseline study for the implementation of technology at the pilot scale.


2021 ◽  
Author(s):  
Sharjeel Waqas ◽  
Noorfidza Yub Harun ◽  
Muhammad Roil Bilad ◽  
Taufik Samsuri ◽  
Nik Abdul Hadi Nordin

Abstract A large amount of wastewater is directly discharged into water bodies without treatment causing surface water contamination. Conventional treatment techniques produce lower effluent quality and are energy extensive. Rotating biological contactor (RBC) is an attractive biological wastewater treatment that offers a low energy footprint. However, its unstable removal efficiency makes it less popular. This study optimizes operating parameters in RBC combined with external membrane filtration (RBC-ME) in which the latter acts as a post-treatment step to stabilize the biological performance. Response Surface Methodology (RSM) was employed to optimize the biological and filtration performance by exploiting three parameters of disk rotational speed, hydraulic retention time (HRT), and sludge retention time (SRT). Results show that RBC-ME exhibits excellent biological treatment capacity and higher effluent quality. It attained 87.9 ± 3.2% of chemical oxygen demand, 45.2 ± 0.7% total nitrogen, 97.9 ± 0.1% turbidity, and 98.9 ± 1.1% ammonium removals. The RSM data demonstrated that the experimental data and model predictions agreed well. Under the most optimum parameters, the permeability of 144.6 L/m2 h bar could be achieved at 36.1 rpm disk rotational speed, 18 h HRT, and 14.9 d SRT. This work demonstrates the effective use of statistical modeling to enhance RBC-ME system performance to obtain a sustainable and energy-efficient treatment process to prevent human health and the environment.


Author(s):  
Amin Mojiri ◽  
Lou Ziyang ◽  
Wang Hui ◽  
Ali Gholami

Municipal solid waste has continued to be a major problem in many nations of the world. The primary methods of treating landfill leachate include physical-chemical and biological treatment processes. Pressure-driven membrane processes, such as microfiltration, ultrafiltration, nanofiltration, and reverse osmosis (RO), are among the utmost promising and capable ways for treating landfill leachate. The concentrated leachate created from pressure-driven membrane processes typically represents 13%–30% of total incoming landfill leachate. Concentrated leachate is a dark brown solution with high levels of pollutants. Treating concentrated leachate is extremely difficult, and thus, a combined treatment system is suggested. In the present study, concentrated landfill leachate was treated using a combined treatment technique that included electro-ozonation. The removal efficacies of chemical oxygen demand (COD), color, and nickel were monitored at original pH (7.3) as well as current and voltage of 4 A and 9 V, respectively.


2007 ◽  
Vol 56 (2) ◽  
pp. 9-16 ◽  
Author(s):  
X.L. Melamane ◽  
R. Tandlich ◽  
J.E. Burgess

Wine distillery wastewaters (WDW) are acidic and have a high content of potential organic pollutants. This causes high chemical oxygen demand (COD) values. Polyphenols constitute a significant portion of this COD, and limit the efficiency of biological treatment of WDWs. WDW starting parameters were as follows: pH 3.83, 4,185 mg/l soluble COD (CODs) and 674.6 mg/l of phenols. During operation, amendments of CaCO3 and K2HPO4, individually or in combination, were required for buffering the digester. Volatile fatty acid concentrations were <300 mg/l throughout the study, indicating degradation of organic acids present. Mean CODs removal efficiency for the 130 day study was 87%, while the mean polyphenol, removal efficiency was 63%. Addition of 50 mg/l Fe3 +  between days 86 and 92 increased the removal efficiencies of CODs to 97% and of polyphenols to 65%. Addition of Co3 +  improved removal efficiencies to 97% for CODs and 92% for polyphenols. Optimization of anaerobic treatment was achieved at 30% WDW feed strength. Removal efficiencies of 92% and 84% were recorded at increased feed strength from days 108 to 130. High removal efficiencies of CODs and polyphenols after day 82 were attributed to the addition of macronutrients and micronutrients that caused pH stability and thus stimulated microbial activity.


2014 ◽  
Vol 4 (3) ◽  
pp. 182-193 ◽  
Author(s):  
Sayed Mohammad Nazim Uddin ◽  
Zifu Li ◽  
Heinz-Peter Mang ◽  
André Schüßler ◽  
Tobias Ulbrich ◽  
...  

In Mongolia, as worldwide, communities are challenged by water scarcity, depletion and pollution. Greywater treatment and reuse could partially meet water demand and help protect the environment and health. In March 2010, greywater from six randomly sampled households in the Ger areas of Ulaanbaatar, Mongolia, was analyzed followed by the development of three innovative treatment systems: an underground (UG-), greenhouse (GH-) and ice-hole greywater treatment unit (IH-GWTU). The UG- and GH-GWTU were implemented to identify opportunities and challenges for future investments in greywater treatment and reuse. Users' and non-users' perceptions, and business opportunities, were assessed. Laboratory analysis showed a high chemical oxygen demand (6,072–12,144 mg/l), N-NH4+ (183.7–322.6 mg/l), PO4− (12.6–88.2 mg/l) and total suspended solids (880–3,200 mg/l) – values exceeding the WHO guidelines and much higher than in any other country: low water consumption combined with traditional diet might be major reasons. Odourless and colourless water after treatment in a UG-GWTU lead to more acceptance than a GH-GWTU. Business opportunities include the use of treated water for irrigation, considering WHO and national standards. Further research focuses on seasonality of installation, technical shortcomings, maintenance, biological quality control and user training.


Author(s):  
Edem K. Kolédzi ◽  
Nitale M’Balikine Krou ◽  
Kwamivi N. Ségbéaya ◽  
E. Aziablé

This study aims to determine the parameters measuring the reduction rate of the organic matter during fermentation and its bio-availability after maturation of the compost made using fermentable fractions of household waste. Thus, a physico-chemical characterization of the raw leachate and the leachate treated with lime and caustic soda was carried out. The results showed that, the contents of the other parameters measured are higher for the raw leachate compared to those obtained for the treated leachate. Organic and inorganic pollution is reflected by high Chemical Oxygen Demand (COD), absorbance at 254 nm, turbidity and suspended matter. The COD values ​​in the raw leachate vary between 13000 and 19150 mg/O2/L; those of the absorbance at 254 nm between 30.5 and 34.15 OD; those of turbidity between 156 and 255 NTU (Nephelometric Turbidity Unit) and those of suspended matter between 48 and 1600 mg/L. In the treated leachate, the COD values ​​oscillate between 4489 and 8743 mg/O2/L; those of the absorbance at 254 nm between 6.69 and 31.1 OD; those of turbidity between 57.8 and 122 NTU and those of suspended matter between 70 and 92 mg. These results reflect a good reduction after treatment with lime and soda.


Author(s):  
Dimas Eko Saputro ◽  
Siti Fatimah

Ethanol is produced from molasses by a fermentation process. In Bekonang, ethanol manufacturingby a home-scale industry so the waste just thrown away in free water then pollution occurs both in rivers and in paddy fields. Ethanol waste has very high chemical oxygen demand (COD) and contain high sulfide. Electrolysis that use for reduce leves COD dan Sulfide with electricity as main source for direct current flowing  electricity (dc) to the anode and cathode. Electrolysis time 10, 15, 20, 25 and 30 minutes and voltage variation 5, 10 and 15 volt. Based on data obtained in the test COD obtained optimum levels of  284.5 mg/L from the initial content of  586 mg/L , at a time variation of 30 minutes and voltage 15 volt. The sulfide test obtained optimum levels of 0.0661 mg/L from the initial content of 0.305 mg/L, at time variation of 25 minutes and a voltage of 15 volt.


Sign in / Sign up

Export Citation Format

Share Document