How is leachate treated in a landfill?
Mar 29, 2019 · Feedback: Solid Waste. See “What a Scientist Sees” on page 399. D is labeled “Part of drainage grid: Perforated drains collect leachate for treatment.” Question 7 of 25 4.0/ 4.0 Points An example of source reduction is A. removal of dioxin chemical compounds from medical wastes. B. separating wastes prior to recycling.
What are the most toxic contaminants in landfill leachate?
Sep 24, 2017 · Question 5 of 25 40 40 Points Where in the sanitary landfill illustrated below from SCIN 140 at American Public University. Study Resources. Main Menu; ... Question 5 of 25 4.0/ 4.0 Points Where in the sanitary landfill illustrated below is leachate collected for treatment? ... Perforated drains collect leachate for treatment. ...
What are the drainage and barrier layers of a landfill?
The characteristics of landfill leachate may differ depending on the degradation procedure, climate, hydrology conditions and age of a landfill. Ecological pollution and health issues are commonly connected to the insufficient treatment of landfill leachate (Mojiri et al. 2016a).
Is leachate a potential problem for groundwater pollution?
Mar 13, 2016 · C.in sanitary landfills. D.in open dumps. E.by composting. Answer Key: C Feedback: Solid Waste . See Figure 16.3 on page 397 showing that 54.0% of municipal solid waste in the U.S. is discarded in sanitary landfills. Question 18 of 25 4.0/ 4.0 Points Where in the sanitary landfill illustrated below is leachate collected for treatment?
What is considered hazardous waste?
Household hazardous wastes may include small amounts of cleaning solvents, paints and paint thinners, oils, pesticides, and drugs if not restricted or their sale prohibited. The EPA and others have reported that hazardous wastes probably represent less than 0.5 percent of the total waste generated by households.
Can landfills be avoided?
Landfill leachate generation cannot in practice be entirely avoided, particularly during operation, except possibly in some arid climates. A tight soil cap and/or liner on completion can greatly minimize the possibility; however, a leachate-free landfill may not be entirely desirable. Leachate control measures for groundwa-ter ...
What is landfill leachate?
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.
What are the components of landfill leachate?
Inorganic macro components, such as sulphates, chloride, iron, ammonia, aluminium and zinc, comprise anions and cations ( Agbozu et al. 2015 ). Tałałaj (2015) argued that landfill leachate generally consists of large amounts of compounds, 80–95% of which are inorganic and approximately 52% are organic.
Why are bioreactors used in wastewater treatment?
Bioreactors have been applied for treating wastewaters during several years because these methods are simple and reliable, and highly cost-effective ( Gotvajn & Pavko 2015 ). But, the main drawbacks of bioreactor treatments involve temperature issues and leachate toxicity for microbial communities ( Lippi et al. 2018 ).
How is ammonia converted into nitrate?
Ammonia is transformed into nitrate under an aerobic condition, which in turn is reduced to N 2 by an anoxic condition during a conventional nitrification–denitrification process ( Thakur & Medhi 2019 ). In the process, firstly, ammonia is oxidised by ammonia-oxidising bacteria into nitrite ( ).
What causes water to turn yellow?
Colour is a common pollutant in landfill leachate. The decomposition of certain organic compounds, such as humic acid (HA), may cause water to turn yellow to dark brown ( Naveen et al. 2016 ). Gotvajn & Pavko (2015) emphasised that substances and particles produce colour and turbidity. TDS display the integrative influence of certain cations and anions, such as calcium, chlorides, magnesium, sodium, potassium and bicarbonates, on water/wastewater. Furthermore, TDS can be produced from small amounts of dissolved organic matter ( Sakizadeh 2019) and may inhibit or diminish the biological degradation of dissolved organic carbon ( Hanson et al. 2019 ). Hussein et al. (2019) expressed that high electrical conductivity and TDS may specify dissolved organic and inorganic substances in samples.
How does adsorption work?
Adsorption can be employed to diminish contaminants and leachate toxicity to provide favourable growth conditions for microbial growth ( Er et al. 2018 ). Munz et al. (2007) listed the advantages of combination of adsorption, such as activated carbon, and biological methods as: protecting microorganisms from load pick of inhibiting organic and inorganic compounds, improving refractory organics, improving sludge settleability and dewaterability capacity. Besides, the application of the adsorption technique together with the biological method leads to a reduction of the quantity of adsorbent employed for the wastewater treatment process ( Yi et al. 2018 ). Sawdust added to an SBR can remove 99% of COD and 95% of ammonia ( Mohajeri et al. 2018 ). More than 60% of ampicillin was eliminated by integrating adsorption and biodegradation ( Shen et al. 2010 ). Ammonia was removed at more than 70% from landfill leachate by integrated adsorption and biological treatment ( Yi et al. 2018 ).
Does membrane filtration help with membrane-fouling?
The integration of membrane filtration with AOPs may efficiently mitigate membrane-fouling problems, thereby enhancing overall separation performance ( Pan et al. 2019 ). Santos et al. (2019) removed 94–96% of COD and 96–99% of colour from landfill leachate by combining the Fenton, NF and MF processes. Santos et al. (2019) indicated that the concentration of dissolved solids may be high after an AOP–Fenton process owing to the presence of organic matter that has not been completely oxidised and the addition of salts and acid/basic agents. Thus, the use of membranes can resolve this issue.