Methods of heavy metal pollution control in Electroplating
With the rapid development of the global economy, pollutants containing heavy metals enter the soil in various ways, causing serious soil pollution. Heavy metal pollution in the soil can affect the decline of crop yield and quality, endanger human health through the food chain, and lead to further deterioration of air and water quality. Therefore, it has attracted extensive attention from all over the world. At present, soils around the world are polluted by heavy metals to varying degrees. The world's average annual emission of Hg is about 15,000 t, Cu is 3.4 million t, Pb is 5 million t, Mn is 15 million t, and Ni is 1 million t. The vegetable bases and some commercial grain bases in large cities in northern China also have heavy metal pollution to varying degrees, such as Beijing, Tianjin, Xi'an, Shenyang, Jinan, Changchun, Zhengzhou, and other places;
Research on soil heavy metal pollutants began abroad in the 1960s and 1970s, such as in Australia, the United States, Germany, and other countries, especially Australia. In 1983, my country made a preliminary study on the main types of soil environmental capacity, such as proposing to study the ecological effect of heavy metals in soil, the zonal differentiation law, and division of critical content, etc.
At present, countries around the world attach great importance to the study of heavy metal pollution control methods and carry out extensive research work. In general, there are roughly the following four governance measures. Engineering treatment refers to the use of physical or physical chemistry principles to control soil heavy metal pollution.
There are:
1. Chemical treatment method: chemically stabilized and solidified by adding heavy metal stabilizers; the formed solidified substances can also inhibit the re-dissolution and diffusion of pollutants when the environmental conditions change (such as pH). The ultimate goal is to reduce heavy metal pollution.
2. Engineering treatment methods: foreign soil is to add uncontaminated new soil to the polluted soil; the soil is to remove the contaminated soil and replace it with uncontaminated new soil; soil turning is to turn the polluted topsoil to the lower layer; To remove topsoil is to remove contaminated topsoil, etc.
3. Bioremediation methods: use some habits of organisms to adapt, inhibit and improve heavy metal pollution. Animal treatment is to use some lower animals earthworms, rodents, etc. in the soil to absorb heavy metals in the soil; microbial treatment is to use some microorganisms in the soil to absorb, precipitate, oxidize and reduce heavy metals.
4. Agricultural governance methods: Controlling soil moisture refers to adjusting its redox potential (Eh) by controlling soil moisture to achieve the purpose of reducing heavy metal pollution;
Ø Chemical treatment method: Kechuang Heavy Metal Doctor uses the high-tech product Kechuang Heavy Metal Stabilizer to effectively solidify and stabilize the soil to reduce the lead content in the environment. Kechuang Heavy Metal Stabilizer is prepared by mixing various natural rock intermediates and additives in nature and has natural activity and adsorption. The mechanism of action of this technology is to imitate the formation process of metal ores, so that heavy metal particles are fixed by stabilizers under the action of natural rock intermediates such as adsorption, reaction adsorption, ion exchange, etc. And the high crystallization of low-crystalline minerals makes heavy metals become trace components in minerals. The resulting crystalline substance can generate interlaced crystals through the recrystallization process and between the particles to form a solidified network with a strong structure, and the solidified heavy metals are further sealed in the solidified network. This process not only achieves the effect of solidification but also achieves the effect of stabilization through the irreversible reaction process of crystal staggering and recrystallization. The formed solidified substance can also inhibit the re-dissolution and diffusion of contaminants when the environmental conditions change (eg pH). The ultimate goal is to reduce heavy metal pollution. On the high side of the management costs.
Schematic diagram of heavy metal stabilizer:
QQ screenshot 20160712091008
Ø Engineering treatment method: remove the surface soil and then add 20 cm of soil (added as new contaminated soil). In addition, the leaching method is to use eluent to wash the contaminated soil; the heat treatment method is to heat the contaminated soil to make the soil in the soil. The volatile pollutants (Hg) of the soil are volatilized and collected for recycling or treatment; the electrolysis method is to remove the heavy metals in the soil at the anode or cathode under the action of electrolysis, electromigration, electroosmosis, and electrophoresis. The above measures have the advantages of thorough and stable effect, etc., but they have disadvantages such as complicated implementation, high treatment cost, and easy to reduce soil fertility.
Ø Biological treatment method: Biological treatment refers to the use of certain habits of organisms to adapt, inhibit and improve heavy metal pollution. There are mainly: animal treatment is to use of some lower animals in the soil, earthworms, rodents, etc. to absorb heavy metals in the soil; microbial treatment is to use of some microorganisms in the soil to absorb, precipitate, oxidize and reduce heavy metals, etc. Reduce the toxicity of heavy metals in soil. The advantages of biological control measures are that the implementation is simpler, less investment, and less damage to the environment, but the disadvantage is that the treatment effect is not significant.
Ø Agricultural governance methods
Agricultural governance is to change some farming management systems according to local conditions to reduce the harm of heavy metals and to grow plants that do not enter the food chain on polluted soil. Reasonable use of agricultural ecosystem engineering measures can also maintain soil fertility, improve and prevent heavy metal pollution in soil, improve soil quality, and coordinate with natural ecological cycles and systems. Plant trees, flowers, grass, or commercial crops (such as castor bean) on both sides of the road in the polluted area as much as possible, plant turf or ornamental trees, and transplant and reproduce, which can not only beautify the environment but also purify the soil.
At present, there are very few domestic heavy metal pollution control companies that remove heavy metal water pollution. There are very few real soil and industrial pollution control companies. In the face of my country's economic and social development, the acceleration of industrialization, the accumulation of past development, and the impact of historical problems leftover, Heavy metal pollution is becoming more and more serious, which is related to people's physical and mental health. Pollution control is a major issue that people attach great importance to.
To this end, Beijing Keyi Innovation Environmental Technology Co., Ltd. (referred to as Heavy Metal Doctor), and the Eco-Environmental Research Center of the Chinese Academy of Sciences, Peking University, Huazhong University of Science and Technology, Dalian University of Technology, Japan University of Tokyo, Waseda University, the Asia Pacific Jointly initiated by the University and the Hong Kong University of Science and Technology, it is committed to solving the global heavy metal pollution problem and realizing the solution of the recycling and regeneration of heavy metal resources. Heavy metal doctors are widely used in soil remediation, sludge reuse, industrial waste residue, tailings slag, dust & fly ash, etc., to reduce the content of heavy metals, make pollutants discharge up to standard, and help enterprises solve problems. Reduce the harm caused by heavy metal pollution.
As far as the current domestic soil quality is concerned, it is a strategic issue for sustainable economic development and comprehensive social progress. It directly affects soil quality, crop growth, agricultural yield, and agricultural product quality, and also causes harm to human health throughout the food chain. Pollution control methods and technologies are more necessary and urgent.
Summary: Combining the above four methods of heavy metal pollution control, it is recommended to use the stabilization and solidification method (heavy metal stabilizer) to control heavy metal pollution in soil. , there will be no problem with secondary pollution. For the specific treatment process, you can consult a heavy metal doctor to understand and customize a heavy metal pollution treatment plan.
