CN101164926B - A domestic waste landfill treatment technology and bioreactor with in-situ denitrification function - Google Patents

Abstract

The invention discloses a domestic garbage landfill treatment technology with in-situ denitrification function. In the nitrification reactor, the upper layer is aerated to form an environment with aerobic upper layer, anoxic middle layer and anaerobic lower layer. In the aerobic area, Ammonia is oxidized to NO ₃ ^- under the action of autotrophic nitrifying bacteria. In the anoxic zone, the denitrifying bacteria use organic matters as electron donors to reduce NO ₃ ^- to N ₂ and release it from the liquid phase. The conversion and removal of NH ₄ ⁺ -N, in the anaerobic zone, realizes the degradation of organic matter to produce methane. The present invention also provides a bioreactor using the above treatment technology. The present invention considers the landfill body, landfill gas and leachate as an organic whole, and sets an aeration layer on the upper layer of the nitrification reactor to form an aerobic upper layer, anoxic middle layer, and anaerobic lower layer environment in the nitrification reactor , Realize the biological in-situ denitrification function in the bioreactor landfill, without the need for separate off-site treatment of leachate, low investment and operation costs, and high treatment efficiency.

Description

A domestic waste landfill treatment technology and bioreactor with in-situ denitrification function

technical field

The invention relates to a domestic garbage landfill treatment technology, in particular to a domestic garbage landfill treatment technology with in-situ denitrification function and a bioreactor.

Background technique

The concentration of ammonia nitrogen in the leachate is much higher than that of the traditional sanitary landfill due to the anaerobic environment and cyclic accumulation of the bioreactor landfill with direct recirculation of leachate, which leads to the deterioration of the ecological environment in the landfill and delays the stabilization of the landfill process. However, physical and chemical treatment and off-site biological treatment are generally used for the removal of ammonia nitrogen in leachate. The investment and construction costs are high, and there are environmental risks, so it is not suitable for popularization. This design not only solves the biological in-situ denitrification function, realizes the rapid stabilization of domestic waste, but also avoids the secondary pollution of the landfill to the greatest extent.

Invention patent application 200410088806.7 discloses an integrated bioreactor for treating landfill leachate, which consists of two biological reaction areas and a regulating area, each biological reaction area is filled with biological fillers to form an aerobic area and an anaerobic area . In the aerobic zone, the organic matter is degraded into inorganic carbon by aerobic heterotrophic bacteria, and the nitrification process of ammonia nitrogen is controlled. In the nitrification stage, 50% of the ammonia nitrogen is oxidized to nitrite, and the effluent from the aerobic zone is mixed with After the pH regulator is mixed evenly, it enters the anaerobic zone. In the anaerobic zone, anammox bacteria use ammonia nitrogen as the electron donor to reduce nitrite, use nitrite as the electron acceptor to oxidize ammonia nitrogen, and convert ammonia nitrogen and nitrite nitrogen into nitrogen gas, and some organic matter becomes anaerobic microbial uptake or degradation. The technical solution is to separately treat the landfill leachate, and consider the main body of the landfill and the leachate separately, so the investment and operation costs are high.

Contents of the invention

The invention provides a domestic waste landfill treatment technology for solving the outstanding problem of excessively high ammonia nitrogen concentration in landfill leachate and realizing the organic combination of biological decarburization and biological in-situ denitrification.

A domestic waste landfill treatment technology with in-situ denitrification function, comprising the following steps: aerating the upper layer in the nitrification reactor to form an aerobic environment in the upper layer, anoxic in the middle layer, and anaerobic environment in the lower layer; in the aerobic area, Ammonia is oxidized to NO ₃ ^- under the action of autotrophic nitrifying bacteria. In the anoxic zone, the denitrifying bacteria use organic matters as electron donors to reduce NO ₃ ^- to N ₂ and release it from the liquid phase. The conversion and removal of NH ₄ ⁺ -N, in the anaerobic zone, realizes the degradation of organic matter to produce methane.

The present invention also provides a bioreactor based on the above treatment technology.

A domestic waste landfill bioreactor with the function of in-situ denitrification is composed of three-stage reactors in order of fresh landfill, methane production reactor and nitrification reactor through the bottom leachate of the previous one-stage reactor. The water outlet and the leachate water inlet on the top of the last stage reactor are connected to form a circulation system. There are garbage chambers and gas chambers in the reactors at all levels. The upper layer of the garbage chamber in the nitrification reactor is equipped with an aeration layer. From top to bottom are the aerobic zone, anoxic zone and anaerobic zone.

The leachate water outlet at the bottom of the methanogenic reactor communicates with the leachate water inlet at the top of the nitrification reactor through a three-phase separator, and the gas-phase channel of the three-phase separator is connected to the gas collection bag.

A plurality of gas collecting pipes are arranged in the methanogenic reactor, and the gas collecting pipes are connected to the gas collecting bags.

Water collection bottles and water inlet pumps are provided on the leachate circulation pipelines between the reactors of each stage and the reactors of the next stage.

The bottoms of the garbage chambers of the reactors at all levels are covered with gravel layers to facilitate the outflow of leachate.

The tops of the garbage chambers of the reactors at all levels are provided with a sand layer.

In the present invention, the landfill body, landfill gas and leachate are considered as an organic whole, and an aeration layer is set on the upper layer of the nitrification reactor, so that an aerobic upper layer, anoxic middle layer, and anaerobic lower layer are formed in the nitrification reactor. Environment, realize the biological in-situ denitrification function in the bioreactor landfill, without the need for separate off-site treatment of leachate, low investment and operation costs, and high treatment efficiency.

Description of drawings

Fig. 1 is a structural schematic diagram of the device of the present invention.

Detailed ways

As shown in Figure 1, a domestic waste landfill bioreactor with in-situ denitrification function consists of a three-stage reactor in which fresh waste landfill 12, methanogenic reactor 13 and nitrification reactor 14 pass through the front The leachate outlet at the bottom of the first-stage reactor is connected to the top leachate water inlet of the second-stage reactor through a water collecting bottle 9 and a water inlet pump 10 to form a circulation system. Garbage chambers and air chambers are provided in all reactors at all levels. 3. The air chamber 3 is provided with an air guide pipe 6 to facilitate the collection and utilization of landfill gas.

The bottom of the garbage chamber of the reactors at all levels is covered with a gravel layer 1 to facilitate the smooth discharge of leachate, and the top is provided with a sand layer 2 .

The leachate water outlet at the bottom of the methanogenic reactor 13 is communicated with the top leachate water inlet of the nitrification reactor 14 through a three-phase separator 8, water collection bottle 9 and water inlet pump 10, and the gas phase channel of the three-phase separator 8 is connected to the collection The gas bag 7 and the methanogenic reactor 13 are provided with several gas collecting pipes 4, and the gas collecting pipes 4 are connected to the gas collecting bag 7.

The upper layer of the garbage chamber of the nitrification reactor 14 is provided with an aeration layer 11, and the garbage chamber of the nitrification reactor 14 is successively composed of an aerobic zone, an anoxic zone and an anaerobic zone from top to bottom.

Household garbage is respectively loaded into the fresh landfill 12, the methanation reactor 13 and the nitrification reactor 14, and the device is operated, and the leachate from the fresh landfill 12 flows into the methanation reactor 13, and passes through the methanation reactor 13 After the three-phase separator 8 in the middle, it flows into the nitrification reactor 14, and the upper layer of the nitrification reactor 14 is aerated by limiting oxygen through the aeration pump 12, so as to realize an aerobic environment in the upper layer, anoxic in the middle, and an anaerobic environment in the lower layer, so that the upper layer of garbage The nitrifying bacteria in the medium are the dominant flora, and the number of denitrifying bacteria in the lower garbage medium is dominant, and it has the function of synchronous nitrification and denitrification biological in-situ denitrification. The leachate after simultaneous nitrification and denitrification biological denitrification by the nitrification reactor 14 is circulated to the fresh garbage landfill 12 through the water inlet pump. This cycle is carried out until the domestic waste is stabilized.

Claims (7)

1. consumer waste filling and embedding treatment process with in-situ denitrification function, it is characterized in that may further comprise the steps: be followed successively by the new refuse landfill yard by three reactor, methane-producing reactor and nitrator are communicated with the recycle system of forming by the bottom percolate water outlet of previous stage reactor and the top percolate water-in of back A reactor, be equipped with waste compartment and air chamber in each stage reactor, in nitrator, realize the upper strata aeration, the formation upper strata is aerobic, middle anoxic and lower floor's anaerobic environment, at aerobic zone, ammonia is oxidized to NO with it under the effect of autotrophic type nitrobacteria ₃ ^-, in the oxygen-starved area, by denitrifying bacterium with organism as electron donor, make NO ₃ ^-Be reduced to N ₂And from liquid phase, discharge, realize NH ₄ ⁺The conversion of-N and removal at anaerobic zone, realize organic degraded product methane.

2. consumer waste filling and embedding bio-reactor with in-situ denitrification function, be followed successively by new refuse landfill yard, methane-producing reactor and nitrator by three reactor and be communicated with the recycle system of forming by the bottom percolate water outlet of previous stage reactor and the top percolate water-in of back A reactor, it is characterized in that: be equipped with waste compartment and air chamber in each stage reactor, nitrator waste compartment upper strata is provided with the aeration layer, is followed successively by aerobic zone, oxygen-starved area and anaerobic zone in the nitrator waste compartment from top to bottom.

3. bio-reactor as claimed in claim 2 is characterized in that: the bottom percolate water outlet of described methane-producing reactor is communicated with through the top of a triphase separator and nitrator percolate water-in, the gas phase path access set airbag of triphase separator.

4. bio-reactor as claimed in claim 2 is characterized in that: be provided with some effusers in the described methane-producing reactor, effuser access set airbag.

5. bio-reactor as claimed in claim 2 is characterized in that: be equipped with collection bottle and intake pump on the percolate circulation duct between each stage reactor and the next stage reactor.

6. bio-reactor as claimed in claim 2 is characterized in that: each stage reactor waste compartment bottom is lined with metalling.

7. bio-reactor as claimed in claim 2 is characterized in that: each stage reactor waste compartment top is provided with sand bed.