AU2015101436A4 - A novel soil amendment for immobilization of contaminates in cropland and soil quality improvement of sandy, acidic, saline and alkaline land - Google Patents

Abstract

A NOVEL SOIL AMENDMENT FOR IMMOBILIZATION OF CONTAMINATES IN CROPLAND AND SOIL QUALITY IMPROVEMENT OF SANDY, ACIDIC, SALINE AND ALKALINE LAND The present invention relates to methods of making and using and compositions of a novel soil amendment formed by green production techniques with natural materials. For example, the present invention relates to soil amendment formed with polysis and fermented biomass, minerals, iron nanoparticles and acid-base regulator and use of this amendment in immobilization of heavy metals or organic contaminants in paddy field or soil quality improvement of sandy, acidic, saline and alkaline land. In some embodiments, the invention comprises methods of making and using composition of amendment.

Description

1 A NOVEL SOIL AMENDMENT FOR IMMOBILIZATION OF CONTAMINATES IN CROPLAND AND SOIL QUALITY IMPROVEMENT OF SANDY, ACIDIC, SALINE AND ALKALINE LAND FIELD [0001] The present invention relates generally to agricultural soil amendment produced with natural materials by green production techniques, which can be used for immobilization of heavy metals or organic contaminants in cropland or soil quality improvement of sandy, acidic, saline and alkaline land. BACKGROUND OF THE INVENTION [0002] Cropland contamination by toxic elements such as cadminum (Cd), arsenic (As), other heavy metals and some organic matters mainly originates from anthropogenic activities and cause a descrease in the quantity and quality of agricultural products and inscrease in human disease. Anthropogenic activities associated with agricultural and mining activities, industrial processes, manufacturing, and the disposal of domestic and industrial waste materials are the major sources of contaminants enrichment in soils. For example, an offical study in 2014 released by the Chinese government showed that 1 9

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4 % of China's arable land contaminated. Agricultural soils in Australia, being predominatntly sodic, accumulate salts under seasonal fluctuations and have mutiple subsoil constraints such as alkalinity, acidity, sodicity, and toxic ions. Rice is one of the most widely consumed staple cereal foods in the world, constituting up to 90% of the diet of people in Asian countries. In many East and South Asian countries, including Japan, Bangladesh, Indonesia, and Kerea, the accumulation of metal(loid)s particularly As and Cd - in rice ecosystems, and its subsequent transfer to the human food chain, is a major environmental issue. Widely used techniques to remediation heavy metal contaminated or infertile soil include soil washing, phytoremediation and immobilization, of which in situ immobilizaiton by using nontoxic amendments into soil is a cost-effective and convenient choice for contaminated farmlands. For example, limestone, zeolite, steel slag, compost and so on are applied as amendment. However, the immobilization or improvement effect with these minerals, compost or industrial waste is limited. Namely, mineral material may increase sandification; compost is degradable in soil quickly; steel slag may introduce contaminates into soil. Therefore, a highly efficient soil amendment with long term effect should 2 be developed. See, Mulligan, C.; Yong, R.; Gibbs, B.; Engineering Geology 2001, 60, 193-207; Dermont, G.; Bergeron, M.; Richer, G.; Mercier, G.; Science of Total Environement 2010, 408, 1199-1211; Zhao, X.; Masaihiko, S.; Water, air, and soil pollution 2007, 183(1-4), 309-315; Rautaray, S.; Ghosh, B.; Mittra, B.; Bioresource Technology 2003, 90(3), 275-283; Mench, M.; Vangronsveld, J.; Bleeker, P.; Springer Netherlands 2006, 109-190; Rijkenberg, M.; Depree, C.; Science of the total environment 2010, 408(5), 1212-1220. SUMMARY [0003] The present invention relates to methods of making and using a soil amendment produced with natural materials by green production techniques, as well as the compositions themselves. For example, the present invention relates to soil amendment produced with natural materials and use of the amendment in immobilization of heavy metals or organic contaminants in cropland or soil quality improvement of sandy, acidic, saline and alkaline land. [0004] Compared with physical, chemical and microorganism methods, the present invention does not employ toxic chemicals as reaction agents or organic solvents are not therefore potentially dangerous to the environment and biological systems. [0005] In one aspect, the invention provides methods for making soil amendment. In some embodiments, the methods comprise providing pyrolysis carbon; providing natural mineral materials; providing green synthesized iron-complex nanoparticles; provide fermented organic matters; providing pH adjusting materials; and mixing all these ingredients to produce soil amendment. The amendment composition contains 50% to 70% w/w of pyrolysis carbon. For example, pyrolysis carbon can be provided by pyrolysis of any kind of biomass in range of 200 C - 800 C. For example, the pyrolysis carbon provides organic carbon, which is needed by plant growing. For example, the pyrolysis carbon can adsorb organic and inorganic contaminants. The amendment composition contains 2% - 10% w/w of natural minerals. For example, the natural materials can be aluminosilicate. For example, the minerals can adsorb contaminates, increase soil cation exchange capacity, and improve soil structure. The amendment composition contains 0.5% - 5% w/w of green synthesized iron nanoparticles. For example, the iron nanoparticles can be synthesized with iron salt solution and plant leave extracts. For example, the iron nanoparticles can adsorb heavy metals strongly. The amendment composition contains 5% to 10% w/w of fermented organic matters. For example, the fermented organic matters can be compost, or vinasse. For example, the fermented organic matters provide big molecular chelates 3 to chelate heavy metal contaminates. The amendment composition contains pH adjusting materials. For example, the pH adjusting materials can be lime, gypsum, plant ash, vinasse, acetic acid, citric acid, ferrous sulphate and ferric sulphate. The pH adjusting materials should be added according to soil acid-base property. All these components need to be mixed in mixing machine under room temperature and/or at about room pressure. For example, room temperature and pressure can be a temperature and pressure that is in a range that can be tolerated by humans. The soil amendment can be present in adsorption, chelation and nutrition effective for use in an application including, for example, immobilization of heavy metals or organic contaminants in cropland or soil quality improvement of sandy, acidic, saline and alkaline land. Finally, the subject compositions can be used to improve soil quality and increase the root mass of plants grown in the treated soil. Generally, the subject composition result in an increase in root mass of at least about 10% - 50% more than control plants, i.e. plants grown in untreated but otherwise substantially identical soil. EXAMPLE A. Pot experiments [0006] The merits of the amendment were examined by experiments. For example, cadmium and lead contaminated soils have been treated with 5% w/w amendment. Then soil solutions in water were analysed in certain days. The following results were observed: 7 days 14 days 28 days 56 days Cadmium concentration in soil 930 750 980 970 solution before amendment addition (mg - 1 ) Cadmium concentration in soil 21 10 20 25 solution after amendment addition (mg - 1

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4 1 month 2 months 3 months Lead concentration in soil 82 85 66 solution before amendment addition (mg - 1 ) Lead concentration in soil 4 2 6 solution after amendment addition (mg - 1 ) B. Field test [0007] The effects of the amendment in paddy remediation were tested. Four blocks of rice paddy (each block is 100 square meters) had been mixed with the amendment in 5% w/w. Another four blocks rice paddy fields beside each amended field were planted as controls. After 100 days growing, the rice grains were collected and analysed. The following results were observed: Cadmium Cadmium Cadmium Reduction of concentration in soil concentration in rice concentration in rice cadmium (mg kg- 1 ) grain without grain with concentration in rice amendment addition amendment addition grain in percentage (mg kg- 1 ) (mg kg-) 4.83 0.78 0.18 77% 0.50 0.33 0.11 67% 1.16 0.50 0.08 20% 4.63 0.75 0.14 81%

Claims (10)

1. A soil amendment composition consists of: a) pyrolysis carbon; b) natural minerals; c) green synthesized iron-polyphenol complex nanoparticles; d) fermented organic matters and d) pH adjusting materials.

2. The composition of claim 1, wherein said pyrolysis carbon is carbon produced from any kind of biomass in a pyrolysis process under a temperature range of 200 C - 800 C.

3. The composition of claim 1, wherein said natural minerals is aluminosilicate.

4. The composition of claim 1, wherein said green synthesized iron-polyphenol complex nanoparticles are synthesized with iron salt solution and plant leaves extracts.

5. The composition of claim 1, wherein said fermented organic matters are compost or vinasse.

6. The composition of claim 1, wherein said pH adjusting materials are lime, gypsum, plant ash, vinasse, acetic acid, citric acid, ferrous sulphate and ferric sulphate.

7. The composition of claim 2, wherein said pyrolysis carbon component is from about 50 to 70% w/w of said composition.

8. The composition of claim 3, wherein said aluminosilicate is from about 2 to 10% w/w of said composition.

9. The composition of claim 4, wherein said green synthesized iron-polyphenol complex nanoparticles is from about 0.5 to 5% w/w of said composition.

10. The composition of claim 5, wherein said fermented organic matter is from about 5 to 10% w/w of said composition.