CN105935688A

CN105935688A - Landfill method capable of stabilizing Cd-containing soil

Info

Publication number: CN105935688A
Application number: CN201610370348.9A
Authority: CN
Inventors: 张大磊; 李公伟; 郝志鹏; 赵昱皓
Original assignee: Qingdao University of Technology
Current assignee: Qingdao University of Technology
Priority date: 2016-05-30
Filing date: 2016-05-30
Publication date: 2016-09-14

Abstract

The invention provides a method for restoring Cd-containing soil through a landfill technology and stabilizing domestic waste at the same time. According to the method, the Cd-containing soil, the domestic waste, mineralized refuse and certain materials are jointly subjected to landfill; the Cd-containing soil is restored in a certain landfill manner and through a simple operation means, and meanwhile organic matter in the domestic waste can be fast stabilized; and waste leachate is treated at low cost.

Description

A kind of burying method that can contain Cd soil with stabilisation

Technical field

The present invention relates to a kind of burying method that can contain Cd soil with stabilisation, Cd soil will be contained and fill with domestic garbage mixing, and control certain condition, it is achieved the stabilisation of the two, belong to field of environment engineering technology.

Background technology

Cadmium exists with compound form in nature, does not has independent mineral deposit, normal and zinc ore, Pb-Zn deposits, copper/lead/zinc ore symbiosis.Cadmium is widely used in the fields such as electroplating industry, chemical industry, electronics industry and nuclear industry.The bio-toxicity of cadmium and lead is big and has latency persistency and irreversibility, is easier to be adsorbed by crops than other heavy metal, and remains in plant in soil.China's Cadmium in Soil and lead contamination event are multiple in recent years, as " cadmium rice " event etc. shows that Cadmium Pollution in Soils has been enter into food chain.Therefore the reparation of cadmium pollution soil is faced with stern challenge.

Improvement to cadmium, lead-contaminated soil at present is broadly divided into both direction: one is by modes such as chemical leaching, bioleaching or plant extractions, in making cadmium, lead be transferred to leachate or plant from soil thus reduce Cadmium in Soil content, but owing to Cd is insoluble in water, so this method is difficult to promote；Two is to be acted on by fixing/stabilising etc., make cadmium in soil by with soil desorbing, character or morphologic change so that its toxicity reduces.In the second repair mode, chemistry is fixing also known as chemical passivation, can quickly effectively pollution remission, the migration of blocking-up cadmium, it has also become the study hotspot that currently cadmium pollution soil is repaired.But this method needs firming agent, relatively costly.The patent No. 201510056406.6 describes a kind of curing containing Cd soil, but the method using substantial amounts of material, relatively costly, on the other hand solidification effect is unstable, the most easily there is carbonation in the calcium oxide as added so that alkaline-curing effect reduces.

Summary of the invention

For the deficiencies in the prior art, the present invention provides a kind of and utilizes the Landfill reparation method containing Cd soil Simultaneous Stabilization house refuse.This method will fill jointly containing Cd soil, house refuse and mineralized waste and certain material, by certain land-fill method and shirtsleeve operation means, while Cd soil remediation will be contained, again can be by rapid stabilization organic in house refuse, and the process percolate of low cost.

As shown in drawings, concrete operation step is as follows for this landfill yard building mode:

1. lay impervious barrier bottom, it lays punched collection pipe, for leachate collection, lay gravel above, for water conservancy diversion percolate, above gravel, lay mineralized waste layer, highly 30-300cm, it lays the elementary layer of 1-10；Insert multiple leachate recirculation conduits on the elementary layer surface of the superiors, be on the one hand used for getting rid of landfill gas, on the other hand can recharge percolate；

2. the paving mode of elementary layer is as follows: the mixed layer that bottom is made up of organic waste, mud and Gypsum Fibrosum forms, and mixed proportion is Gypsum Fibrosum: mud: organic waste=(1-10): (1-10): (1-40), lays height 10-100cm；Lay the soil horizon Han Cd above mixed layer, lay height 10-200cm；Lay mineralized waste layer containing Cd soil horizon top, lay height 10-100cm；Another one layer is re-layed above elementary layer, the like, gradually lay；

3. After collected percolate imports leachate collection pond, directly get at leachate recirculation conduit mouth with pump, until each pollutant levels COD < 50mg/L, Cd < 0.05 mg/L in percolate.

Present method be advantageous in that:

1. this method utilizes two kinds of principles of solidification solidification Cd, and first with the fixing Cd of alkalescence effect of Gypsum Fibrosum, in Gypsum Fibrosum, sulfate anaerobism is converted into sulfide and precipitate C d subsequently；

2. comparing other and process technique, this technique achieves the stabilisation of organic waste while containing Cd soil-burial stabilisation.

Accompanying drawing explanation

Fig. 1 is that landfill lays schematic diagram

It is embodied as example as follows:

Example 1:

1. lay impervious barrier bottom, it lays punched collection pipe, for leachate collection, lay gravel above, for water conservancy diversion percolate, above gravel, lay mineralized waste layer, highly 200cm, it lays the elementary layer of 4；Insert multiple leachate recirculation conduits on the elementary layer surface of the superiors, be on the one hand used for getting rid of landfill gas, on the other hand can recharge percolate；

2. the paving mode of elementary layer is as follows: the mixed layer that bottom is made up of organic waste, mud and Gypsum Fibrosum forms, and mixed proportion is Gypsum Fibrosum: mud: organic waste=2:5:15, lays height 100cm；Lay the soil horizon Han Cd above mixed layer, lay height 200cm；Lay mineralized waste layer containing Cd soil horizon top, lay height 100cm；Another one layer is re-layed above elementary layer, the like, gradually lay；

3. After collected percolate imports leachate collection pond, directly get at leachate recirculation conduit mouth with pump, until each pollutant levels COD < 50mg/L, Cd < 0.05 mg/L in percolate；

4. constantly being recharged to conduit by collected percolate, through about two weeks left and right time, Cd < 0.05 mg/L, in the stable percolate of about 1 year, < 50mg/L stops recharging each pollutant levels COD.

Example 2:

1. lay impervious barrier bottom, it lays punched collection pipe, for leachate collection, lay gravel above, for water conservancy diversion percolate, above gravel, lay mineralized waste layer, highly 150cm, it lays the elementary layer of 7；Insert multiple leachate recirculation conduits on the elementary layer surface of the superiors, be on the one hand used for getting rid of landfill gas, on the other hand can recharge percolate；

2. the paving mode of elementary layer is as follows: the mixed layer that bottom is made up of organic waste, mud and Gypsum Fibrosum forms, and mixed proportion is Gypsum Fibrosum: mud: organic waste=3:8:30, lays height 100cm；Lay the soil horizon Han Cd above mixed layer, lay height 200cm；Lay mineralized waste layer containing Cd soil horizon top, lay height 100cm；Another one layer is re-layed above elementary layer, the like, gradually lay；

4. collected percolate is constantly recharged to conduit, through about two weeks left and right time, Cd < 0.05 Mg/L, in the stable percolate of about 1 year, < 50mg/L stops recharging each pollutant levels COD.

Claims

1. one kind can stabilisation containing the burying method of Cd soil, its building mode is: impervious barrier is laid in bottom, punched collection pipe is laid on it, for leachate collection, lay gravel above, for water conservancy diversion percolate, above gravel, lay mineralized waste layer, highly 30-300cm, it lays several elementary layer；Insert multiple leachate recirculation conduits on the elementary layer surface of the superiors, be on the one hand used for getting rid of landfill gas, on the other hand can recharge percolate.

A kind of burying method that can contain Cd soil with stabilisation, the paving mode of elementary layer is as follows: the mixed layer that bottom is made up of organic waste, mud and Gypsum Fibrosum forms, mixed proportion is Gypsum Fibrosum: mud: organic waste=(1-10): (1-10): (1-40), lays height 10-100cm；Lay the soil horizon Han Cd above mixed layer, lay height 10-200cm；Lay mineralized waste layer containing Cd soil horizon top, lay height 10-100cm；Another one layer is re-layed above elementary layer, the like, gradually lay.

A kind of burying method that can contain Cd soil with stabilisation, gravel layer contains certain slope, lays punched collection pipe at the bottom of slope；Punched collection tube wall has aperture, aperture 1-3cm, each hole separation 20-50cm, and collecting pipe caliber 10-30cm, for leachate collection.

A kind of burying method that can contain Cd soil with stabilisation, leachate recirculation conduit caliber 10-30cm, manage deep 1-2m, every 5-10m and lay a conduit.

A kind of burying method that can contain Cd soil with stabilisation, after collected percolate imports leachate collection pond, direct pump is got at leachate recirculation conduit mouth, until each pollutant levels COD < 50mg/L, Cd < 0.05 mg/L in percolate.

6. elementary layer paving mode as claimed in claim 2, organic waste therein includes domestic waste and food garbage.

7. elementary layer paving mode as claimed in claim 2, mud therein can be the anaerobism in sewage treatment facility, hold concurrently oxygen or aerobic sludge.