CN104909422A - Application of phosphate slag in restoration of environmental heavy metal lead pollution - Google Patents

Abstract

The invention discloses an application of phosphate slag in restoration of environmental heavy metal lead pollution. The phosphate slag is waste slag generated after phosphoric acid is employed to clean steel surface scale. The restoration environments comprise water and soil. Waste slag-phosphate slag of steel plants is employed as a raw material, and is applied in waste water and soil with heavy metal lead pollution after simple pretreatment. The application has advantages of low cost, simple technology, no secondary pollution and good restoration effects, achieves treatment of a waste with another waste and change of a waste into things of value indeed and has an important meaning for solving environmental pollution and promoting refuse reclamation.

Description

The application of phosphoric acid slag heavy metal lead pollution in repairing environment

Technical field

The present invention relates to the field of the treatment of wastes with processes of wastes against one another, particularly the application of phosphoric acid slag heavy metal lead pollution in repairing environment.

Background technology

In the process of manufacture of steel industry, the courses of processing such as inevitably annealed, normalizing, quenching, welding, surface can produce the oxide skin of black often.Oxide skin not only affects the visual appearance of steel, also can have a negative impact to the following process of product, therefore the surface treatment such as pickling, polishing must be adopted before following process to be provided away.Acid cleaning process mainly cleans product with hydrochloric acid or sulfuric acid, hydrofluoric acid and phosphoric acid etc.A large amount of phosphoric acid slags can be produced in the process utilizing phosphoric acid to clean.The accumulation of phosphoric acid slag can cause environmental pollution, and then harm humans and vegeto-animal health.

At present for the process of phosphoric acid slag, the mode of most of enterprise is passive landfill, and therefore the process of phosphoric acid slag is disposed is current problem demanding prompt solution.

Along with the fast development of economy, the pollution that the discharge of heavy metal lead causes is more and more serious, and its refractory organics, enriching cause serious harm to the mankind, animals and plants.Anaemia is caused, infringement psychiatric system etc. as known from experience people.

Tradition heavy metal treatment process has three classes: chemical method, Physical, biological process, and these technique ubiquity costs are high, reaction causes the shortcomings such as secondary pollution slowly, easily.In recent years, adopt sorbent material removal heavy metal plumbous because the advantages such as technique is simple, easy to operate become the focus of people's research, therefore the selection of sorbent material is even more important.In numerous sorbent materials, the sorbent material of chemosynthesis also exists the shortcoming that cost is high, synthesis technique is complicated usually, as patent " publication number is CN102179233, CN 102389776 etc. ", natural adsorbent has advantage with low cost, but most natural adsorbent needs through chemical modification, this adds cost undoubtedly, its cheap property is had a greatly reduced quality, as used orange peel " Lugo-Lugo V, Hernandez-Lopez S, Barrera-Diaz C, et, al.A comparative study of natural, formaldehyde-treated and copolymer-grafted orange peel for Pb (II) adsorption under batch and continuous mode.Journal of Hazardous Materials.2009, 161, 1255-1264 ", patent " publication number CN 102513067 " etc.

Summary of the invention

In order to solve Utilizing question and the heavy metal lead pollution problem of Steel Plant's phosphoric acid slag, the present invention proposes with phosphoric acid slag be heavy metal lead pollution in raw material repairing environment waste water and soil.

The technical solution realizing the object of the invention is:

An application for phosphoric acid slag heavy metal lead pollution in repairing environment, described phosphoric acid slag is the waste residue produced after adopting phosphoric acid cleaning iron and steel; Described environment comprises water body and soil.

Wherein, when environment is water body, described application comprises the steps:

(1) phosphoric acid pulp water washed, naturally dry, broken cross 80 ~ 150 mesh sieves after for subsequent use;

(2) phosphoric acid slag is joined in lead waste water in the ratio of solid-to-liquid ratio 0.1g/50mL, pH be 2 ~ 6 (pH preferably 4 ~ 6), fully mix at 20 ~ 50 DEG C, the reaction times is not less than 60min.

When environment is soil, described application comprises the steps:

(1) phosphoric acid pulp water washed, naturally dry, broken cross 80 ~ 150 mesh sieves after for subsequent use;

(2) phosphoric acid slag is fully mixed with the mass ratio of lead pollution of soil by 10 ~ 20:100, place more than one month under natural condition.

Compared with prior art, its remarkable advantage is in the present invention:

(1) material using phosphoric acid slag as remediating heavy metal lead, effectively alleviates the processing pressure of Steel Plant's phosphoric acid slag;

(2) phosphoric acid slag of the present invention is good to the removal effect of heavy metal in waste water lead, and clearance can reach 99.99%, embodies the removal ability that phosphoric acid slag is good to Pb In Exhausted Water; To the lead in soil, also there is good fixed effect, reduce the harm of lead pollution of soil;

(3) phosphoric acid slag of the present invention can directly apply to the reparation of heavy metal lead, does not need to pass through the further course of processing again, simple to operate;

(4) can direct filtering separation from water after phosphoric acid slag of the present invention application, can not secondary pollution be produced, significant for refuse reclamation.

Accompanying drawing explanation

Fig. 1 is that the difference of initial pH removes the plumbous influential effect graphic representation of heavy metal in waste water to phosphoric acid slag.

Fig. 2 is that temperature removes the plumbous influential effect graphic representation of heavy metal in waste water to phosphoric acid slag.

Fig. 3 removes the plumbous influential effect graphic representation of heavy metal in waste water to phosphoric acid slag the time.

Fig. 4 is that phosphoric acid slag dosage is different from each form content influence graphic representation plumbous in contaminated soil.

Fig. 5 is that after repairing, the toxicity of Lead In Soil leaches change curve.

Embodiment

Below in conjunction with specific embodiment, the invention will be further described, do not form any limitation of the invention.

The evaluation test of phosphoric acid slag Potential environmental risk:

(1) pre-treatment of phosphoric acid slag: phosphoric acid pulp water is washed, naturally dries, broken cross 80 ~ 150 mesh sieves after for subsequent use;

(2) phosphoric acid slag Potential environmental risk evaluation test: for leaching toxicity from solid waste test (TCLP).Take pretreated phosphoric acid slag 1g, add TCLP extracting solution 20mL according to pH value, filter after (18+2) h that vibrates under normal temperature, measure the content of common heavy metal.The heavy metal concentration threshold value that contrast toxicity leaching standard specifies the results are shown in Table 1.As shown in Table 1, leach the concentration threshold of common heavy metal concentration lower than regulation in phosphoric acid slag, therefore do not belong to the Hazardous wastes with Leaching, can be applicable to subsequent experimental.

Table 1 phosphoric acid slag toxicity leaches heavy metal

Embodiment 1

The difference that initial pH is discussed removes the impact of the plumbous effect of heavy metal in waste water on phosphoric acid slag:

Preparing 5 parts of 50mL lead concentrations is the simulated wastewater of 200mg/L, the impact of the different initial pH of research, regulates initial lead pH value of solution to be 2,3,4,5,6 by HCl, NaOH solution, adds phosphoric acid slag 0.1g respectively, be placed in 200r/min constant temperature oscillation case vibration 5 hours, temperature controls at 30 DEG C.Reaction terminates rear sampling filtering, measures the content of heavy metal lead, calculates removal effect.Learnt by calculation result, pH is 4,5, and when 6, clearance is the highest, reaches 99.99%.PH is too low is unfavorable for plumbous removal, as Fig. 1.

Embodiment 2

Temperature removes the plumbous effect of heavy metal in waste water impact on phosphoric acid slag is discussed:

Preparing 4 parts of 50mL lead concentrations is the simulated wastewater of 200mg/L, the impact of research differing temps, by the Optimal pH in each solution HCl, NaOH solution modulation embodiment 1, add phosphoric acid slag 0.1g respectively, every part of lead solution is placed in respectively 4 200r/min constant temperature oscillation case vibrations 5 hours, temperature controls at 20 DEG C, 30 DEG C, 40 DEG C, 50 DEG C.Reaction terminates rear sampling filtering, measures the content of heavy metal lead, calculates removal effect.From calculation result, plumbous clearance raises with temperature and increases, but when temperature is normal temperature, clearance can reach 99.90%, illustrates that phosphoric acid slag is removed heavy metal in waste water lead and can be carried out at normal temperatures, as Fig. 2.

Embodiment 3

The discussion time removes the impact of the plumbous effect of heavy metal in waste water to phosphoric acid slag:

Preparing 11 parts of 50mL lead concentrations is the simulated wastewater of 200mg/L, the impact of search time, by the Optimal pH in each solution HCl, NaOH solution modulation embodiment 1, add phosphoric acid slag 0.1g respectively, temperature controls at 30 DEG C, is placed in 200r/min constant temperature oscillation case, by reaction times 10,20,30,40,60,90,120,150,180,240,300min sampling filtering, measure the content of heavy metal lead, calculate removal effect.From calculation result, within a certain period of time along with the increase of time, heavy metal lead clearance increases gradually, when time >=60min clearance reaches the highest.Illustrate that phosphoric acid slag is removed heavy metal in waste water and can be reached better removal effect, as Fig. 3 plumbous within a short period of time.

Embodiment 4

The different impact on solidification effect plumbous in contaminated soil of phosphoric acid slag dosage is discussed:

Take 6 parts of 100g lead pollution of soil respectively, according to soil quality 0%, 2%, 5%, 10%, 15%, 20% adds phosphoric acid slag, and soil conservation ability is 50% ~ 70%.Within 30 days, post-drying grinds the content that soil Tessier five step extraction method measures each form of Lead In Soil, measures Lead In Soil toxicity leach by TCLP method.From measurement result, the form of Heavy Metals in Contaminated Soils lead gradates as residual form, as Fig. 4 along with the increase of phosphoric acid slag dosage.When phosphoric acid slag dosage >=10%, soil remediation effect is best, after repairing, the plumbous leaching yield of heavy metal-polluted soil can reach the related request (TCLP<5mg/L) of " Hazardous wastes judging standard leaching characteristic identification " (GB5085.3-2007), reach immobilization effect, as Fig. 5.

Above-described embodiment 1-3 merely provides the impact of several different parameters on Pb In Exhausted Water removal effect, and pH is in the scope of 1-2, and removal effect is the poorest; Temperature parameter, can reach better removal effect at normal temperatures; Time parameter, according to time temperature equivalence principle, the time is longer within a certain period of time, and removal effect is better; Provide a kind of parameter in case study on implementation 4---dosage on the impact of Pb in Soil solidification effect, along with the increase solidification effect of dosage is better.At this, all parameters combination are not all enumerated, because cannot be exhaustive.

In embodiment 1-3, phosphoric acid slag consumption is certain value, add the preferred parameter such as pH, temperature, removal effect is best, can reach more than 99.9% even 100%, but in actual removal process, as long as phosphoric acid slag does not reach loading capacity, just removal effect can be produced, therefore, phosphoric acid slag consumption in actual procedure, is not restricted to the phosphoric acid slag consumption mentioned in above-described embodiment 1-3.

Claims (4)

1. an application for phosphoric acid slag heavy metal lead pollution in repairing environment, is characterized in that, described phosphoric acid slag is the waste residue produced after adopting phosphoric acid cleaning iron and steel; Described repairing environment comprises water body and soil.

2. the application of phosphoric acid slag heavy metal lead pollution in repairing environment as claimed in claim 1, it is characterized in that, when environment is water body, described application comprises the steps:

(1) phosphoric acid pulp water washed, naturally dry, broken cross 80 ~ 150 mesh sieves after for subsequent use;

(2) join in lead waste water by phosphoric acid slag in the ratio of solid-to-liquid ratio 0.1g/50mL, fully mix at pH is 2 ~ 6,20 ~ 50 DEG C, the reaction times is not less than 60min.

3. the application of phosphoric acid slag in repairing environment heavy metal lead pollution as claimed in claim 2, is characterized in that, fully mix at pH is 4 ~ 6,20 ~ 50 DEG C.

4. the application of phosphoric acid slag in repairing environment heavy metal lead pollution as claimed in claim 1, it is characterized in that, when environment is soil, described application comprises the steps:

(1) phosphoric acid pulp water washed, naturally dry, broken cross 80 ~ 150 mesh sieves after for subsequent use;

(2) phosphoric acid slag is fully mixed with the mass ratio of lead pollution of soil by 10 ~ 20:100, place more than one month under natural condition.