CN103706623A - Method for repairing heavy metal polluted tailing - Google Patents

Abstract

The invention discloses a method for repairing heavy metal polluted tailing. The method comprises the following concrete steps: (1) applying modifying agents to the heavy metal polluted tailing, wherein the tailing contains excessive heavy metals of arsenic (As), zinc (Zn), lead (Pb) and copper (Cu), the modifying agents comprise peat, pig manure and plant ash, and 0.2-0.6 T of pig manure, 0.02-0.07 T of plant ash and 0.1-0.5 T of peat are applied in the heavy metal polluted tailing per ton; (2) planting forage grass in the tailing after being processed in the step (1) to keep moist, wherein the forage grass is pnnisetumpurpureum Pglaucum; and (3) harvesting the forage grass after growing in the step (2), wherein the forage grass reaches national health and safety standards of feeds and is used for feed production and livestock breeding. The method has the advantages of low cost and convenience in operation; and purposes of polluted soil repair and production can be achieved, and the after-treatment problem of repaired plants can be solved.

Description

A kind of method of repairing heavy metal pollution tailings

Technical field

The present invention relates to heavy metal pollution phytoremediation field, particularly a kind of method of repairing heavy metal pollution tailings.

Background technology

In mining and smelting process, can produce the tailings that contains in a large number high concentration heavy metal, these tailings are deposited in for a long time in tailings storehouse and can not get processing, and not only take a large amount of soils, and the environment of serious harm periphery.Plurality of heavy metal due to Exposure to Sunlight, drench with rain, washing etc. is with radial, funnel-form soil, surface water body and underground water diffusion towards periphery.The discarded tailings storehouse area of China is vast, how these discarded tailings is used, and be an important and urgent job.

Summary of the invention

A kind of method that the object of this invention is to provide repairing heavy metal pollution tailings.

Concrete steps are:

(1) tailings to heavy metal pollution applies modifying agent; In tailings, contained excessive heavy metal refers to arsenic (As), zinc (Zn), plumbous (Pb) and copper (Cu); Modifying agent is peat+pig manure+plant ash, executes 0.2～0.6 ton of pig manure, 0.02～0.07 ton of plant ash and 0.1～0.5 ton of peat in the tailings that applied amount is heavy metal pollution per ton.

(2) planting forage grass in the tailings after step (1) is processed, keeps moistening; Described herbage is hybrid Chinese pennisetum.

(3) treat that in step (2), herbage grows up, gather in the crops, this herbage reaches national feed safety sanitary standard, can be used for production of fodder and livestock culture.

Advantage of the present invention is: utilize herbage as the rehabilitation plant of heavy metal pollution tailings, by applying modifying agent Promoting plant growth and guaranteeing that the content of beary metal in herbage body reaches forage health standard, the herbage of results is for production of fodder and livestock culture.The method cost is low, easy to operate, not only can reach the object that repairing polluted soil limit, limit produces, and can solve the post-processed problem of rehabilitation plant simultaneously.

The specific embodiment

embodiment 1:

(1) from Huan Jiang county, Hechi City, Guangxi Tailings Dam, gather tailings, air-dry, dress basin, every basin 2kg, arranges 2 groups, every group of 3 basins; 1. control group (CK): do not apply modifying agent, i.e. every basin dress 2kg tailings; 2. modifying agent group (T): apply modifying agent: peat+pig manure+plant ash, i.e. every basin dress 1.5kg tailings+0.4kg pig manure+0.1kg plant ash+0.2kg peat.

After (2) one weeks, by 3 basins of every group of step (1), plant respectively hybrid Chinese pennisetum, every basin is transplanted three strain plants, and every day, regular watering, made water content remain on 75% of field capacity; The position of weekly regulation experiment basin, guarantees that the illumination of every basin and temperature are basically identical.After herbage growth 3 months, measure plant survival rate, plant height, the number of sheets, then gather in the crops plant sample and rinse well by deionized water, dry at 70 ℃, weigh, then pulverize, preserve to be measured.After plant results, in basin, remaining soil is taken back laboratory natural air drying, grinds 100 orders to be measured.

Soil pH value adopts soil: water=1:2.5 lixiviate, and acidometer is measured; The mensuration of arsenic (As), zinc (Zn), plumbous (Pb), copper (Cu) content: plant sample and pedotheque are all used nitric acid (HNO ₃)-hydrogen peroxide (H ₂o ₂) heating board digestion, ((AAS, AA-700, Company of PerkinElmer, American) measures for AFS (AFS, AFS-933, Beijing, China) and flame atomic absorption spectrophotometer.Test process adds national standard pedotheque (GBW07407 (GSS-7) laterite) and national standard plant sample (GBW10015 (GSB-6) spinach) to carry out quality control, records As, Zn, Pb, the Cu rate of recovery between 95%～105%.

Table 1: pH value and the content of beary metal of original soil

?	Control treatment (CK)	Modifying agent is processed (T)	Standard of soil environment quality secondary (GB15618-2008)
				pH	7.02*	6.90	?
As total amount (mg/kg)	255.4	216.3	35
				Zn total amount (mg/kg)	9446	7628	150
Pb total amount (mg/kg)	1296	1062	80
				Cu total amount (mg/kg)	61.93	58.67	50
As available state (mg/kg)	6.53	4.96	?
				Zn available state (mg/kg)	658.7	353.6	?
Pb available state (mg/kg)	138.7	135.7	?
				Cu available state (mg/kg)	4.12	5.23	?

* numerical value is the mean value of three repetitions.

Table 2: the growing state of hybrid Chinese pennisetum

Process	Survival rate (%)	Plant height (cm)	The number of sheets	Root dry weight (g/ strain)	Overground part dry weight (g/ strain)
						Control treatment (CK)	0	0	0	0	0
Modifying agent is processed (T)	100	96.9	12.3	1.0	11.1

* numerical value is the mean value of three repetitions.

Table 3: the plant content of beary metal (mg/kg) of hybrid Chinese pennisetum in modifying agent is processed

* numerical value is the mean value of three repetitions.

Discuss: this tests the tailings (table 1) that tailings used is As, Zn, Pb and Cu severe contamination.Hybrid Chinese pennisetum is all death in 3～5 days after transplanting seedlings when not adding any modifying agent.After having added modifying agent, plant grew well, all survivals, do not show any poisoning symptom, three months plant heights of plant growth reach 1m(table 2), and As in plant, Zn, Pb and Cu content require > > (DB35/562-2008) to these 4 kinds far below < < forage health standard > > (GB13078-2001) and < < pig chicken and duck by feed product safe mass, the requirement of content of beary metal, can be for livestock culture (table 3).

Claims (1)

1. a method for repairing heavy metal pollution tailings, is characterized in that concrete steps are:

(1) tailings to heavy metal pollution applies modifying agent; Excessive heavy metal contained in tailings refers to arsenic, zinc, lead and copper; Modifying agent is peat+pig manure+plant ash, executes 0.2～0.6 ton of pig manure, 0.02～0.07 ton of plant ash and 0.1～0.5 ton of peat in the tailings that applied amount is heavy metal pollution per ton;

(2) planting forage grass in the tailings after step (1) is processed, keeps moistening; Described herbage is hybrid Chinese pennisetum;

(3) treat that in step (2), herbage grows up, gather in the crops, this herbage reaches national feed safety sanitary standard, can be used for production of fodder and livestock culture.