(3) Characteristics of landfill leachate and its influencing factors
Landfill leachate has the characteristics of high concentration of organic matter,
complex composition and a large number of viruses and pathogenic bacteria,
among which up to dozens of organic pollutants can be detected, such as monocyclic aromatic hydrocarbons, polycyclic aromatic hydrocarbons, heterocycles,
alkanes, olefins, alcohols and phenols, ketones, carboxylic acids and esters, amines,
etc. There are many kinds of pollutants in leachate with high concentration and
wide variation range of concentration. With the change of water quantity, its
concentration can vary by dozens of times in different months, and its water
quantity may even vary by hundreds of times in the dry and the rainy seasons.
Therefore, general landfill leachate has the characteristics of rapid change of water
quality and quantity.
(4) Influence of landfill time on leachate quality
The quality of leachate changes greatly. Practice has proved that in general, the
quality of leachate varies greatly in different landfill stages. At the beginning of
landfill, BOD 5 /COD is about 0.5, and the biodegradability is good, but with the
extension of landfill time, mainly the extension of duration of refuse at the landfill,
BOD 5 /COD gradually decreases and the biodegradability is poor. In addition,
different stacking positions of refuse affect the output time of leachate, which will
also affect the leachate quality. To some extent, this affects the irregular change of
leachate quality. Besides, there is a certain correlation between leachate quality and
water quantity.
(5) Influence of refuse composition on the quality of filtrate
The refuse is mainly composed of kitchen waste, furnace dust, brick pottery, dirty
soil, paper, plastic, glass, metal, etc. The main pollutants in landfill leachate are
organic matter and ammonia nitrogen. COD and NH 3 –N in leachate are mainly
produced by organic matter in kitchen waste. When the furnace dust content in
refuse is similar, if the kitchen waste content is higher, the concentration of COD,
BOD 5 and NH 3 –N in leachate will also be higher. If the organic matter content and
calorific value are higher, the concentration of COD and BOD 5 and C/N ratio in
leachate will be lower, the concentration of NH 3 –N will be higher, and the phosphorus content will be lower.
(6) Influence of climate conditions on landfill leachate
In general, there is more rainfall in South China, and refuse is showered, washed
and soaked in the rain. Generally speaking, the concentration of organic matter in
leachate is low and the amount of water becomes larger, but the total amount of
pollutants in leachate increases within a certain period of time, so that the refuse
dump will enter a stable period more quickly. Rainfall has the greatest impact on
the quality and quantity of landfill leachate, and rainfall is generally proportional to
the total amount of leachate. In South China, the amount of leachate is particularly
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Landfill leachate has the characteristics of high concentration of organic matter,
complex composition and a large number of viruses and pathogenic bacteria,
among which up to dozens of organic pollutants can be detected, such as monocyclic aromatic hydrocarbons, polycyclic aromatic hydrocarbons, heterocycles,
alkanes, olefins, alcohols and phenols, ketones, carboxylic acids and esters, amines,
etc. There are many kinds of pollutants in leachate with high concentration and
wide variation range of concentration. With the change of water quantity, its
concentration can vary by dozens of times in different months, and its water
quantity may even vary by hundreds of times in the dry and the rainy seasons.
Therefore, general landfill leachate has the characteristics of rapid change of water
quality and quantity.
(4) Influence of landfill time on leachate quality
The quality of leachate changes greatly. Practice has proved that in general, the
quality of leachate varies greatly in different landfill stages. At the beginning of
landfill, BOD 5 /COD is about 0.5, and the biodegradability is good, but with the
extension of landfill time, mainly the extension of duration of refuse at the landfill,
BOD 5 /COD gradually decreases and the biodegradability is poor. In addition,
different stacking positions of refuse affect the output time of leachate, which will
also affect the leachate quality. To some extent, this affects the irregular change of
leachate quality. Besides, there is a certain correlation between leachate quality and
water quantity.
(5) Influence of refuse composition on the quality of filtrate
The refuse is mainly composed of kitchen waste, furnace dust, brick pottery, dirty
soil, paper, plastic, glass, metal, etc. The main pollutants in landfill leachate are
organic matter and ammonia nitrogen. COD and NH 3 –N in leachate are mainly
produced by organic matter in kitchen waste. When the furnace dust content in
refuse is similar, if the kitchen waste content is higher, the concentration of COD,
BOD 5 and NH 3 –N in leachate will also be higher. If the organic matter content and
calorific value are higher, the concentration of COD and BOD 5 and C/N ratio in
leachate will be lower, the concentration of NH 3 –N will be higher, and the phosphorus content will be lower.
(6) Influence of climate conditions on landfill leachate
In general, there is more rainfall in South China, and refuse is showered, washed
and soaked in the rain. Generally speaking, the concentration of organic matter in
leachate is low and the amount of water becomes larger, but the total amount of
pollutants in leachate increases within a certain period of time, so that the refuse
dump will enter a stable period more quickly. Rainfall has the greatest impact on
the quality and quantity of landfill leachate, and rainfall is generally proportional to
the total amount of leachate. In South China, the amount of leachate is particularly
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235