Impermeable materials for coating or sealing of garbage hygiene fills

Abstract

An impervious material used for covering or closing in landfill waste site consists of a main material and an additive of 5-25 % of the total weight, and the additive is characterized in that it is of strong self-hydroscopicity and good glutinosity and can swell when encountered water, in which: (1) the main material is sand, or earth, or crushed gravel-soil; (2) the additive is natural nanomaterial, the water absorption is 3-8 times of self-weight and the acid-swellable is 3-20 times of self-volume. The invention has advantages such as low cost and simple process, can effectively prevent the rain from infiltrating the waste to change to bleeder solution with no more than 1.0X10-7 cm per minute of seepage control coefficient, can evidently reduce the operation cost and strengthen integrated hermeticitycan, can reduce the odour intensity, orderly collect and use the marsh gas, extend the anaerobic process and time of disposing wastes, improve the methane output and bleeder solution biochemistry, then make the bleeder solution continuously and stably discharge according to an emission standard.

Description

(1) Technical field [0001] The present invention relates to a covering or sealing material, in particular to an anti-seepage material used for the middle covering of sanitary landfill waste bodies for landfill operations and the end field covering of waste landfills that have been filled to the designed storage capacity . (two), background technology [0002] 1. The "Technical Specifications for Domestic Garbage Sanitary Landfill" (CJJ17-2004) formulated by the Ministry of Construction stipulates the anti-seepage of garbage sanitary landfills as follows: [0003] (1) In the production of landfills, work should be carried out by division and unit. After the completion of each unit operation, the middle of the surface of the garbage body should be covered to prevent rainwater from seeping into the garbage body and turning into leachate. The thickness of the covering layer should be determined according to the covering material, and the thickness of the soil covering layer sho...

AI Technical Summary

Problems solved by technology

[0006] (1) For the anti-seepage layer of the final closure of the landfill, the price of the artificial anti-seepage layer is relatively high, and the price of a single layer of HDPE is generally 30-40 yuan / M 2 In addition, geotextiles need to be laid on the top and bottom as a protective layer to prevent the superstructure or sharp objects in the garbage from piercing the artificial anti-seepage layer, so the unit price of the composite anti-seepage layer is generally 45 yuan / M 2 If natural clay is used as the anti-seepage layer, the demand is too large, and it is easier to solve the source for small-scale sanitary landfills, but it is impossible to obtain a large amount of natural clay for large and medium-sized sanitary landfills, so natural clay is used. As an anti-seepage material, there is only theoretical feasibility

[0007] (2) During the production process of the garbage sanitary landfill, the general intermediate covering material is the gravel soil stored during the warehouse clearing, and the permeability coefficient of the gravel soil is about 1.0×10 -4 cm / s, so that about 80% of the rainwater seeps into the garbage body, resulting in a large increase in garbage leachate. A large amount of high-concentration leachate that is difficult to biochemically treat has become one of the two important constraints on the development of garbage sanitary landfill technology. , because the treatment cost of leachate is about 15-30 yuan / ton (depending on the discharge standards that meet the standards), it almost accounts for about 30-50% of the operating cost of the entire landfill site. Under certain conditions, the more rainwater becomes leachate, the greater the average daily production of leachate, the higher the total cost of leachate treatment, and the worse the overall operating efficiency of the landfill.

[0008] There are also some sanitary landfills that use HDPE film as the intermediate covering material, which cannot be used in large quantities due to price reasons, and the anti-seepage effect is not ideal.