WO2018220462A1

WO2018220462A1 - Composition for adsorbing phosphorus and/or nitrogen from effluents or liquid waste, processes, products and uses

Info

Publication number: WO2018220462A1
Application number: PCT/IB2018/053426
Authority: WO
Inventors: Arthur Gabriel DA SILVA; Natália Gabriela SILVA PINHEIRO; Hamilton P. DA ROCHA JÚNIOR; Raphael CAPRUNI ANDRADE VAZ; Rochel MONTERO LAGO; Fernando Augusto MOREIRA
Original assignee: Universidade Federal De Minas Gerais - Ufmg
Priority date: 2017-06-01
Filing date: 2018-05-16
Publication date: 2018-12-06
Also published as: BR102017011655B1; BR102017011655A2

Abstract

The present invention relates to a composition for adsorbing phosphorus and/or nitrogen from effluents or liquid waste, comprising at least one supporting material, preferably serpentinite, vermiculite, plant charcoals (optionally modified by oxidative treatment) and/or sludge from phosphate-rich effluent treatment plants, said supporting material being impregnated with calcium, zinc, copper, manganese, molybdenum, boron, cobalt and/or nickel, and calcinated. The present invention also relates to use of the composition, the process for preparing the composition, the process for producing additives for conditioning soil and releasing nutrients, devices for recovering phosphorus and/or nitrogen and the additives produced.

Description

COMPOSITION FOR Phosphorus and / or Nitrogen Adsorption of Effluents or Liquid Waste, Processes, Products

AND USES_

[001] The present invention is a composition for phosphorus and / or nitrogen adsorption of effluent or liquid waste comprising at least one support material, preferably serpentinite, vermiculite, charcoals (modified by oxidative or non-oxidative treatments) and / or phosphate-rich effluent treatment plant sludge; such support material being impregnated with calcium, zinc, copper, manganese, molybdenum, boron, cobalt and / or nickel; and calcined. It also addresses the use of the composition, the process for preparing the composition, the process for producing soil conditioning and nutrient release additives, phosphorus and / or nitrogen recovery devices and the additives produced.

Phosphorus (usually in the form of phosphate) and nitrogen (present in various forms, such as ammonium, nitrate and urea), present in industrial and domestic effluents and waste, are an environmental problem as they cause eutrophication of rivers and lakes when discarded. A phosphorus concentration from 0.03 mg / L is already sufficient to cause cyanobacterial blooms (WANG, R. et al. Flickering gives early warning signals of a critical transition to a eutrophic lake state. Nature, v. 492, No. 7429, pp. 419-422, 12/20/2014 print. ISSN 0028-0836). Nitrogen also contributes to eutrophication, but to a lesser extent, since phosphorus is a limiting element for flowering (ROWE, EC et al. Vegetation Type Affects the Relationship Between Soil Carbon and Nitrogen Leaching. Water, Air, and Soil Pollution, v. 177, no. 1, pp. 335-347, 2006 // 2006. ISSN 1573-2932.). On the other hand, phosphorus and nitrogen are extremely important nutrients for agriculture. [003] Agriculture, the food and detergent industry are the main consumers of phosphorus (COOPER, J. et al., The Future Distribution and Production of Global Phosphate Rock Reserves. Resources, Conservation and Recycling, v. 57, p. 78-86,12,201. ISSN 0921-3449.). Agriculture accounts for approximately 85% of world phosphorus consumption (AHMAD, M .; CHAUDHRY, MG; CHAUDHRY, GM. Some non-price explanatory variables in fertilizer demand: The case of irrigated Pakistan. Pakistan Development Review, v. 39, 477+, 2000 Winter // 2000. ISSN 00309729.).

[004] In Brazil, agribusiness is one of the most important sectors for the economy, representing 1/3 of the country's wealth. Even being one of the world's largest food producers, most Brazilian soils are poor in macronutrients, which requires a large use of phosphate fertilizers. However, fertilizer production does not keep up with agricultural food production. Thus, the country is the 4th largest importer of fertilizers and the 2nd of phosphate fertilizers (ANDEF - National Plant Protection Association. Phytosanitary Application Technology Manual, 2004).

Phosphorus and / or nitrogen can be removed from effluents in two ways: biological or physicochemical. In biological treatment organisms capable of absorbing nutrients in the form of phosphate / nitrates are used. After absorption, the generated sludge is removed and digested anaerobically, which causes the absorbed compounds to return to the aqueous phase. This nutrient-rich liquid returns to the beginning of treatment. The physicochemical treatment uses iron, aluminum, magnesium or calcium ions to precipitate phosphorus in the form of phosphate, which is removed together with the sludge.

Another way of removing phosphorus from effluents is precipitation of struvite (ammonium phosphate and magnesium hexahydrate), which can be used in the manufacture of fertilizers. Struvite has a slow nutrient release rate, allowing lower frequency of fertilizer application (LUZ, E .; BASHAN, Y. Recent advances in removing phosphorus from wastewater and its future use as fertilizer (1997 ^" 2003). V. 38 , p. 4222 ^"4246, 2004).

Coals, vermiculite and serpentinites are commonly applied as additives for agriculture. Coals are very interesting both for their porous structures and high surface area, as well as their ability to increase soil organic matter content and cation exchange capacity, improving the efficiency of fertilizer use, promoting the development of beneficial microorganisms. plant growth, among other agronomically desirable characteristics (SANTALLA, M. et al. Effectiveness of wood ash containing charcoal as a fertilizer for a forest plantation in a temperate region. Plant and Soil, v. 346, no. 1, p. 63 -78,201 / 201 / 2011. ISSN 1573-5036). The possibility of using coal as a soil conditioner arose from observing certain chemical characteristics of the Amazonian Indian Black Earths (low fertility soils such as Amazonian Oxisols) can be transformed into fertile soils, not only by the addition of mineral sources. nutrients, but by the addition of stable organic compounds in the form of coal). The removal of ammonia in effluents using charcoals has been studied by several research groups (GLASER, B.; BIRK, JJ. Geochimica et al. Cosmochimica Acta, v. 82, pp. 39-51, 4/1 / 2012. ISSN 0016-7037; ASADA, T. et al., Ammonia Adsorption on Bamboo Charcoal with Acid Treatment, Journal of Health Science, v. 52, no. 5, pp 585-589, 2006).

Vermiculite is a mica-like mineral formed by hydration of certain basaltic minerals, with formula (MgFe, AI) ₃ (AI, Si) 4O ₁₀ (OH) ₂ .4H ₂ O. It has expansion capacity, when subjected to temperatures close to 900 ° C its volume may increase from 10 to 30 times. After this process gets the name of expanded vermiculite, where each flake trap air cells, giving the material insulating capacity. This expanded material, in addition to its insulating capabilities, is non-irritating to skin or lung, has low electrical conductivity, does not decompose and does not attract insects. Expanded vermiculite can absorb up to five times its mass in water, is a good lubricant and filter material. The application of vermiculite in agriculture is wide due to its characteristics such as high cation exchange capacity, good water retention, low mass and chemical reactivity, absence of toxicity, thermal insulation and good particle size. Thus, it can be used in the production of agricultural substrates, in the cover of seeds and seedlings, as soil conditioner, nutrient and herbicide / insecticide / fungicide container, sandy soil water retainer, grassy field antifreeze agent, manufacturing load. of pesticides and hydroponic agriculture (WU, N. et al. Organic intercalation of structure modified vermiculite. Journal of Colloid and Interface Science, v. 457, p. 264-271, 11/1/2015. ISSN 0021 -9797) .

Serpentinites comprise a class of ultrabasic magnesian metamorphic rocks composed mainly of calcium, magnesium and silicon oxides. Part of the serpentine mineralogical group are magnesium silicate materials derived from changes in the hydration of olivines, which may be in nature in the form of lizardite, antagonist or chrysotile. Serpentinite composition and arrangement vary from region to region due to metamorphism, which can shift silicate to carbonate phases (PEREIRA, D .; PEINADO, M. Serpentinite. Geology Today, v. 28, no. 4, p. 152- 156, 2012. ISSN 1365-2451). In Brazil, the serpentinite reserves are distributed in the following states: Bahia, Ceará, Goiás, Minas Gerais, Mato Grosso do Sul, Para, Paraiba, Paraná, Rio Grande do Sul, Sergipe and Sao Paulo. The use of rocks in agriculture is called rocking or remineralization. In this technique, rock dust is used to correct acidity and replenish soil nutrients. The water acts by slowly leaching nutrients from the rock, thus obtaining a natural soil conditioner with gradual release of nutrients. One of the advantages of this technique is the decrease in the consumption of industrial fertilizers (ANDEF - National Association of Plant Protection. Phytosanitary application technology manual. 2004). A problem with this technique is uncontrolled application, which can lead to nutritional imbalance and / or accumulation of heavy metals in the soil.

[010] The sludge produced by the phosphating industry has a very high phosphorus and urea adsorption capacity. Among the metal surface preparation processes used in the metallurgical industry, immersion phosphating stands out. During this procedure a residue called phosphate sludge or phosphate sludge is formed, formed from the reaction of Fe ³⁺ ions (originated by the oxidation of Fe ²⁺ ions present in solution) with phosphate ion (P0 ₄ ³ ), forming , iron phosphate (FeP0 ₄ ). Characterization studies by Giffoni & Lange (2005) show that the main constituents of sludge are iron, zinc, nickel and sodium due to the attack on the metal surface and the acid mixture formation of the phosphating tank.

[01 1] Patent document CN102229506, entitled Ivlethod for recovering phosphorus and potassium from effluent and producing slow-release composite fertilizer of phosphorus and potassium, describes a method of recovering urine phosphorus by adding magnesium to precipitate struvite producing a slow release fertilizer. Formation of the desired composite is done by first analyzing the urine composition and then adding magnesium and phosphate salts to maintain some specific proportions of magnesium, potassium and phosphate in solution, following a pH adjustment of the solution. Under such established conditions and constant agitation, the desired salt precipitates as granules.

[012] The patent document CN 102167434, titled Ivlethod for recovering nitrogen and phosphorous from urine _^ discloses a method of separating sources of sewage and chemical method for treatment of urine recovery of nutrients, particularly nitrogen and phosphorus. Fresh urine is used to further measure the pH. The phosphorus and nitrogen concentration of the solution is adjusted by adding Na ₂ HPO ₄ and MgCl ₂ at the required concentrations. In this process struvite is obtained, with phosphorus and nitrogen recovery of about 95%. This document differs from the present invention in that it does not use the proposed composition.

[013] Patent document JP201417739, entitled Hecovery phosphorus _^ describes a process of phosphorus recovery in effluents using a material made of a metal oxide capable of adsorbing the phosphorus contained in the solution. The desorption process is done by placing the material in an alkaline solution. A precipitation process is then made by adding calcium to the solution.

[014] US20030196965, entitled Rocess for Recovery of Nutrients from Wastewater _^ describes a waste phosphorus recovery process involving conversion of phosphorus to salt using magnesium chloride at pH 8.4 to 10.7 which takes precipitation of struvite. It also describes the use of this salt as fertilizer.

[015] Patent Document PI 0204877-9, Titled ^{^} Sanitary Granulate used in the treatment and handling of pet waste, and the process of preparing it, utilizes the functioning vermiculite. as a sponge for the retention of animal waste that will later be used directly in agriculture.

[016] In the prior art no composition has been described that allows phosphorus and nitrogen adsorption directly from the effluent and which can subsequently be used as an agricultural input without the need for any treatment other than decontamination.

Already the present invention proposes a composition for phosphorus and / or nitrogen adsorption of effluents or liquid waste, comprising at least one support material, preferably serpentinite, vermiculite, charcoals (modified by oxidative or non-oxidative treatments) and / or phosphate-rich effluent treatment plant sludge; such support material being impregnated with calcium, zinc, copper, manganese, molybdenum, boron, cobalt and / or nickel; and calcined. This technology also addresses the use of the composition, the process for preparing the composition, the process for producing additives for soil conditioning and nutrient release, phosphorus and / or nitrogen recovery devices, the additives produced and their uses.

[018] The proposed composition allows phosphorus and nitrogen adsorption directly from the effluent and can subsequently be used as an agricultural input without the need for any treatment other than decontamination.

[019] The results obtained in the tests classify the waste as Class II ^" A (non-hazardous and non-inert). The leaching test did not yield any result above the established limits, thus discarding the classification of the waste as hazardous (Class I ) (GIFFIONI & LANGE, 2005). BRIEF DESCRIPTION OF THE FIGURES

Figure 1 depicts the phosphate adsorption isotherm using TEE sludge as adsorbent.

DETAILED DESCRIPTION OF TECHNOLOGY

[021] The present invention is a phosphorus and / or nitrogen adsorption composition of effluent or liquid waste comprising at least one support material, preferably serpentinite, vermiculite, charcoals (modified by oxidative or non-oxidative treatments) and / or phosphate-rich effluent treatment plant sludge; such support material being impregnated with calcium, zinc, copper, manganese, molybdenum, boron, cobalt and / or nickel; and calcined. It also addresses the use of the composition, the process for preparing the composition, the process for producing soil conditioning and nutrient release additives, phosphorus and / or nitrogen recovery devices and the additives produced.

[022] The proposed process for preparing the phosphorus and / or nitrogen adsorption composition of effluent or liquid waste comprises the following steps:

The. Add the support material to an aqueous solution of 0.5 to 50% (w / w) Ca, Zn, Cu, Mn, Mo, B, Co and / or Ni salts / oxides;

B. Keep the system under heating at 90 to 110 ° C and stirring until completely dry;

ç. Calcine the impregnated material obtained in (b) at temperatures between 100 and 900 ° C for 2 to 5 hours.

[023] In step a, the support material should preferably be serpentinite, vermiculite, activated or non-activated charcoals (modified by oxidative treatments or not) and / or phosphate-rich effluent treatment plant sludge. Serpentinite (Mg ₃ Si ₂ 0 ₅ (OH) 4) should preferably be powder, with a particle size between 1 and 5 mm.

[025] The particle vermiculite is preferably present from 0.3 ^"0.6 cm and approximate composition of (Al _0. ₃₀ Fe ₀ .o4 Ti ₀ .63 Mg _2. ₀ o) (Si _3. Al ₂ i _0. ₇₉₎ (OK (OH) ₂ , Mg _0. ₀ i 3 In. ₀₂ K _0. i ₀ (H ₂ 0) n).

[026] Activated or non-activated charcoals may undergo oxidative processes for the insertion of acidic groups on their surface by reaction with hot concentrated HN0 ₃ (80 to 100 ° C) for 5 to 30 minutes.

[027] The process for producing soil conditioning additives and nutrient release from effluent and / or liquid waste comprises the following steps:

The. Leave the effluent and / or liquid residue in contact with the adsorbent material composition defined above, in the proportion of 1 to 60% of adsorbent in the effluent, for residence times of 10 seconds to 12 hours;

B. Collect adsorbent material;

ç. Decontaminate adsorbent material.

In step a the effluent may be selected from the group comprising industrial effluent and / or domestic effluent free of heavy metals or toxic organic molecules and shall contain phosphate concentrations greater than 10 mg / l or 0.03 ppm.

In step a1 the liquid residues are preferably human or animal urine, free of heavy metals or toxic organic molecules, with phosphate concentrations between 100-1000 mg / l and urea on the order of 1-20 g / l, wherein the adsorbent material may be contained in a wrapper, such as sachets or cases. In step c, the decontamination of the adsorbent material can be carried out by using NaCIO, 0 ₃ , H ₂ 0 ₂ , artificial (Hg lamp) or natural (sun) UV light, combined or not. The invention also relates to a device for phosphorus and / or nitrogen adsorption of effluents or liquid waste and production of soil conditioning and nutrient release additives, comprising the phosphorus and / or nitrogen adsorption composition defined in The present invention is contained in a casing, such as sachets or cases, which allows effluent or liquid waste to pass through and retains the composition for reuse. Shells shall have sufficient mechanical and chemical resistance not to degrade and / or rupture when in contact with effluent / liquid waste. Provided that the permeability and resistance characteristics (both chemical and mechanical) are observed, the malleability of the enclosures will depend on their use.

[031] In addition, the present technology addresses the additive for soil conditioning and nutrient release obtained by the proposed process.

[032] An important property of these soil conditioning additives is that they are capable of adsorbing nutrients only from aqueous media and at concentrations above 10 mg / L or 0.03 ppm. When allocated in soils, they allow the controlled release of these nutrients.

[033] The proposed composition may be used for phosphorus and / or nitrogen adsorption for treatment of phosphorus and / or nitrogen rich industrial and / or domestic effluents; or for the production of additives for soil conditioning and nutrient release.

[034] The material may also be used as a bed for poultry tailings storage bed. In this process, poultry manure comes into contact with the composition of the present invention and the nutrients from such manure are adsorbed / retained on the material, which may later be used as an additive for soil conditioning and nutrient release.

The present invention may be better understood by the following non-limiting examples.

EXAMPLE 1 ^" Preparing the Composition with Different Support Materials

The phosphorus and / or nitrogen adsorption composition of effluent and / or liquid waste comprises at least one support material selected from the serpentinite, vermiculite, charcoal and phosphate-rich effluent treatment plant sludge group; the support materials being impregnated with calcium, zinc, copper, manganese, molybdenum, boron, cobalt and / or nickel; and calcined.

[037] To prepare the materials, impregnations, whether or not combined, of calcium, zinc, copper, manganese, molybdenum, cobalt boron and nickel are performed. Subsequently, some of these materials are heat treated at temperatures ranging from 300 ° to 700 ° C for three hours.

[038] In order to obtain adsorbent materials based on serpentinite, vermiculite or ETE sludge, the base material was calcined, accompanied by surface calcium impregnation with CaO (lime) or CaCl ₂ in aqueous medium with heating. and constant stirring for water evaporation and calcium impregnation on the material surface evenly. Calcination temperatures range from 100 to 900 ^Q C with an increase of 10 ^Q C per minute with 180-minute levels in the final temperature.

[039] The calcination process, accompanied by calcium impregnation on the surface of the materials, becomes able to capture phosphate by adsorption via chemical bonds with the phosphate groups present in solution, according to the following equation: Equation (1): 3Ca ²⁺ _(aq) + Ρ0 ₄ ^{3 "} _{3ς) ¾ Ca ₃ (P0 ₄ ) _{2 (s)} .

[040] For preparation of the composition using vermiculite as a support material, previously expanded commercial vermiculite was used. The vermiculite used had particles between 0.3 ^" 0.6 cm and approximate composition of (Al _0. ₃ o Ti _0. ₀ 4 Fe _0. ₆ 3 Mg _2. ₀₀ ) (Si _3. ₂ i Al _0. ₇₉ ) (O ₁₀ ( OH) ₂ , Mg _0. at ₀ i _3. O.10 2 ₀ (H ₂ 0) n). impregnations were carried out, whether or not combined, in concentrations ranging from 0.5 to 50% (w / w) Ca, Zn, Cu, Mn, Mo, B, Co and Ni For the impregnation, the salts / oxides of the metals were solubilized in water, the vermiculite was added to the suspension and the system was kept under heating and stirring to dryness. After this step, the material was bake for 3 hours at 300 ° C, 500 ° C and 700 ° C. Another procedure used was impregnation without further calcination.

Serpentinite rock samples of the general formula Mg ₃ Si ₂ 0 ₅ (OH) ₄ were extracted in a mine and had Mg and Fe contents of 12-17% m / m and 2-3% m / m, respectively. . Serpentinite powder was used, with particle size ranging from 1 to 5 mm. Serpentinite samples were sprayed and retained on 200 mesh sieves. The composition containing the serpentinite as support was prepared in the same manner as with vermiculite. The metal ions were dispersed in water, the serpentinite was added and the system was left under heating and stirring until complete drying. After metal impregnation at concentrations ranging from 0.5 - 50% (w / w), the materials were calcined for 3 hours at temperatures of 300 ° C, 500 ° C and 700 ° C. These materials can be prepared without the impregnation step, with only calcination for three hours at 500 ° C, 700 ° C and 900 ° C for powdered material and calcination at 700 ° C for three hours for material with particle size ranging from 1 to 5 mm. [042] Activated or not activated charcoals are subjected or not to oxidative processes for insertion of acidic groups on their surface by reaction with hot concentrated HN0 ₃ (80 to 100 ° C) for 5 to 30 minutes. Subsequently, the metal impregnation step, Ca ²⁺ , Zn ²⁺ , Cu ²⁺ , Mn ^{x +} , Mo ⁶⁺ , B ⁺ , Co ²⁺ and ΝΓ, are carried out at concentrations between 0.5 ^" 50% ( The activated carbon used in this example was produced from coconut shell and activated using water vapor at 800 ° C, with a surface area between 600-800 m ² / g and ash content of the order of 5%.

[043] For the composition using automobile effluent treatment plant (ETE) sludge, the base material was calcined, accompanied by surface calcium impregnation with CaO (lime) or CaCl ₂ in aqueous medium. with constant heating and stirring for water evaporation and calcium impregnation on the material surface.

[044] The characterization of phosphate sludge samples and the sludge generated at the car company treatment station analyzed by X-ray fluorescence shows a high concentration of phosphorus. Analyzes indicate the absence of arsenic, cadmium, lead and mercury, potentially toxic metals in agriculture. Chromium, the only toxic metal present in the samples, is below the limits established by Normative Instruction 27 of June 5, 2006 of the Ministry of Agriculture and Livestock (MAP IN 27/2006), which shows their potential in agriculture. . Table 1 presents the results obtained by X-ray fluorescence.

Table 1 ^" Sample Characterization by X-Ray Fluorescence DOSED ELEMENTS (%) Phosphate Sludge WWTP

41, 83 38.10 Fe ₂ 0 ₃ 30.80 1 1, 33 ZnO 18.66 6.47

Si0 ₂ 2.90 3.06 CaO 0.80 31, 77

NiO 0.83 1.99

MnO 1, 70 1.81

K ₂ 0 2.16 0.65 SrO <0.01 0.086

Al ₂ 0 ₃ <0.10 2.66 Ti0 ₂ <0.01 1, 19 S0 ₃ <0.01 0.54 Cr ₂ 0 ₃ 0.09 0.08

ND = Not Detected

EXAMPLE 2 ^" Phosphorus and / or nitrogen adsorption efficiency tests

To ascertain the efficiency of the materials prepared according to example 1, tests were performed with standard phosphate and urea solutions at concentrations found in human urine, 300 mg / L and 7.1 g / L. In these tests, the standards were left in contact with the materials under slight agitation for periods of between 3 and 12 hours. After this time, the materials were collected and the solutions filtered and analyzed.

For the phosphorus analysis in the samples a molybdate based colorimetric method in acid medium was used. This anion, in the presence of ascorbic acid, reacts with the phosphorus present in the sample forming the molybdenum blue, thus allowing analysis by spectrophotometry in the UV-Vis region (reading performed at 840 nm), according to the equations below:

Equation (2): P0 ₄ ^{3 "} + 12Mo0 ₄ ^2" + 27H ⁺ "H ₃ P0 ₄ (Mo0 ₃ ) i 2 + 12H ₂ 0

Equation (3): H ₃ P0 ₄ (Mo0 ₃₎ + C ₁₂ H ₈ 0 ₆ ₆ "molybdenum blue

[047] In order to quantify the urea present in the samples after the adsorption experiments, total organic carbon (TOC) readings and the indophenol method were taken before and after each experiment.

[048] For the use of the composition, in this example, devices have been developed in the form of sachets for use in chemical toilets and in the form of urinal cases. The sachet and case should allow liquid waste to pass through and prevent solid material from entering. In addition, they must retain the composition and allow its recovery to prepare additives for soil conditioning and nutrient release.

EXAMPLE 2.1 ^" Phosphate Removal Efficiency Tests with Coil-Based Materials

Capture assays were performed using a standard mass of 80 mg of the material synthesized in 40 mL of the standard phosphate solution, where the material remains in contact with the solution for about 8 hours, with constant stirring at 100 to 180 rpm. All initial standard solutions had an initial concentration of 300 mg / L, with percentage removals calculated from this concentration.

Table 2 - Unpregnated serpentinite phosphate removals

Cone Temperature. Final Removal

Sample

calcination (° C) (ppm) (%)

Serpentinite

500 279 7 ground

Serpentinite 700 266 1 1 ground

Serpentinite

900 291 3 ground

Serpentinite 0 297 1

Serpentinite 700 280 7

[050] In the second test, it is observed that the 700 ^Q C calcined granular serpentinite is capable of removing more phosphate than serpentinite without heat treatment. This is due to exposure and consequently the disposition of magnesium to bind to phosphate. In ground serpentinite there is a small increase in removal due to the larger specific area when compared to granular serpentinite.

Table 3 - Removals of 2% CaCl ₂ impregnated serpentinite phosphate.

Cone calcination temperature. Final Removal

Sample

(° C) (ppm) (%)

Serpentinite

700 204 32 1

Serpentinite

700 191 36 2

Serpentinite

700 196 34 3

In CaO-impregnated serpentinite-based materials, a white precipitate was noted during the removal test. Part of the precipitated calcium phosphate is then believed to be leached from the material to the solution. Therefore, we started with the strategy of impregnating serpentinite with calcium chloride, because as a This is very soluble in water, it is believed that during the impregnation process, the dispersion in the serpentinite is greater.

[052] During the removal test, on calcium chloride impregnated materials, phosphate removals averaged 34%.

Table 4 - Serpentinite phosphate removals 5% CaCl ₂ Sample Calcination temperature (° C) Cone. Final (ppm) Removal (%) Serpentinite 7ÕÕ 179,90 40

[053] In the 5% calcium chloride impregnated serpentinite, there was an increase in removal when compared to the 2% CaCl ₂ impregnated serpentinite.

Table 5 - Effect of agitation on phosphate removals with

serpentinite impregnated with 2% and 5% CaCl ₂

Cone Temperature Content. Final Removal

Sample

CaCl 2 calcination (° C) (ppm) o (%)

Serpentinite in

2% 700 241 19

rest

Serpentinite under

5% 700 231 23

frenzy

Serpentinite in

2% 700 139 54

rest

Serpentinite under

5% 700 256 15

frenzy

Table 6 - Serpentinite phosphate 7% CaCl2 removals

Cone Temperature. Final I Removal

Sample

calcination (° C) (ppm) (%)

Serpentinite in

700 221 26

rest Serpentinite under

700

frenzy

[054] Calcium chloride impregnated materials were studied under the stirring parameter during the test. For this the materials impregnated with 2; 5; and 7% CaCl ₂ were tested under stirring and at rest. It is observed that in most cases agitation favors phosphate removal.

EXAMPLE 2.2 ^" Phosphate Removal Efficiency Tests with Vermiculite Based Materials

Similar tests to those made with serpentinite were made with vermiculite samples under the same conditions of phosphate impregnation and removal.

[056] A test with 10% lime impregnated and calcined vermiculite at 500, 700 and 900 ^Q C was carried out in a 180 rpm agitation batch. The results are in the table below:

Table 7 - Phosphate removal with 10% lime impregnated vermiculite composition

Cone Temperature. Final Removal

Sample

calcination (T) (ppm) (%)

Vermiculite 500 156.40 48

Vermiculite 700 162.85 46

Vermiculite 900 147.10 51

[057] It is noted that the variation in calcination temperature of lime impregnated vermiculite slightly alters the removal of phosphorus in solution. Also a test was carried out with calcium uptake in vermiculite employing calcium chloride, all heat treated at 900 ^Q C with different CaCl ₂ concentrations. The data are in table 8.

Table 8 - Phosphate removal with different CaCl ₂ contents

Sample CaCl ₂ Cone content. Final (ppm) Removal (%)

Vermiculite 2% 265 12

Vermiculite 5% 249 17

Vermiculite 7% 198 34

Vermiculite 10% 203 33

Vermiculite 20% 1 100

[058] Increasing CaCl ₂ utilization also increased phosphorus uptake of the solution. However, with the content at 20%, despite the maximum removal, it was noticed in the solution high turbidity, indicating the precipitation of calcium phosphate outside the material. Therefore, the desired surface adsorption effects are best obtained at 5 and 7% CaCl ₂ .

EXAMPLE 2.3 ^" Phosphate Removal Efficiency Tests with ETE Sludge Based Materials

[059] WWTP sludge from metal surface treatment processes may have a high phosphorus content as well as its capture materials due to the metal surface process used in the metallurgical industry, called diphosphating. This consists in creating on the metallic surface, after the removal of impurities, phosphate crystals of the metal, converting it from metallic to non-metallic. As a result, phosphating improves paint adhesion and makes the metal surface up to 700 times stronger.

[060] Through x-ray fluorescence characterization, it was possible to determine the content of elements present in the ETE sludge of phosphating plants of an automobile company (Table 9). Table 9: Content of elements present in WWTP sludge

Dosed elements WWTP sludge

P ₂ 0 ₅ 5.00

Fe ₂ 0 ₃ 41.00

ZnO 1, 52

Si0 ₂ 9.30

CaO 41.00

NiO <0.10

MnO 0.35

K ₂ 0 0.23

SrO 0.13

[061] It is noticed through the characterization the high iron and calcium content in the WWTP sludge, enabling the same properties of the materials already tested.

[062] Simple phosphorus removal and capture tests were also conducted with the ETE sludge and the results obtained are described in table 10.

Table 10: Phosphorus removal from synthetic effluent using

ETE sludge-based adsorbents

Cone Temperature. Final Removal

Sample

calcination (° C) (ppm) (%)

WWTP sludge 0 16 44

ETE sludge 900 48 83

[063] It is noted that calcination was essential for improving material performance.

[064] Kinetic studies and adsorption isotherms were made to better understand the capabilities of the material. A simple kinetic test was conducted to understand the behavior of the calcined material and its minimum operating times. With sludge in contact with the standard phosphate solution, aliquots of the solution were analyzed at the times indicated in the table below:

Table 11: Kinetic Adsorption Test Using WWTP Sludge-Based Adsorbents

Sample Time (s) Cone. Final (ppm) Removal (%)

cin1 30 165 45

cin2 60 198 34

cin3 180 1 14 62

cin4 300 1 12 63

600 600 123 59

cin6 1800 7 98

[065] An expected decrease in the increase in phosphorus removals from the medium over time is noted. In about 30 seconds of contact with the material, 45% of the phosphorus in solution was captured, proving the fast performance of calcined sludge at 900 ° C.

The adsorption isotherm was made by repeating the material mass and volume, 200 mg and 20 mL, respectively, with the gradual increase of phosphorus concentration in the medium. The material was in contact with the solution for about 8 hours to ensure phosphorus adsorption and desorption equilibrium on its surface.

Table 12: Kinetic Adsorption Test Using WWTP Sludge-Based Adsorbents

Cone. initial cone. final m adsorbent / m adsorbent

Sample

(ppm) (ppm) (mg / g)

isol 25 2.50 2.25

iso2 50 0.00 5.00 iso3 100 0.00 10.00 iso4 150 0.50 14.95 iso5 300 48.40 25.15 iso6 500 40.10 45.99 iso7 800 390.85 40.92 iso8 1000 268.60 73.14

EXAMPLE 3 ^" Soil Fertilization Tests

[067] Tests carried out with phosphate treatment plant sludge have shown the absence of potentially toxic metals and the high concentration of phosphorus determined by fluorescence analysis. The solubility tests carried out aim to determine the availability of phosphorus in the soil in case of application of the materials in agriculture. For this, solubilization assays are performed in water and 2% citric acid solution. Table 13 presents these results obtained according to the methodology proposed in the Manual of Official Analytical Methods for Fertilizers and Correctives (MAPA, 2014).

Table 13 - Water Solubilization Assay with 2% Citric Acid

MUD

ETE PHOSPHATE BLANK ANALYSIS

P ₂ 0 ₅ Total (%) 33.10 22.75

P ₂ 0 ₅ (%) in water 0.80 0.04

P ₂ 0 ₅ (%) in 2% Citric Acid 12.99 17.79

PH 5.0 6.0

One age (%) 52.36 66.82 Average Generation (T / month) 6.0 60.0

[068] Data analysis indicates the low solubility of total phosphorus in water. Such a feature may be favorable for agricultural application because it reduces immediate nutrient availability and therefore minimizes leaching loss.

[069] Solubility in citric acid simulates nutrient availability when associated with roots with mycorrhizae, ie, in this condition the available phosphorus is absorbed by the plant, obtaining greater use of it, so this feature is extremely favorable for fertilizer production.

Claims

1 . Composition for phosphorus and / or nitrogen adsorption of effluent or liquid waste, characterized in that it comprises at least one support material selected from the group comprising serpentinite, vermiculite, charcoals (modified by oxidative or non-oxidative treatments) and / or treatment plant sludge. phosphate-rich effluents; such support material being impregnated with calcium, zinc, copper, manganese, molybdenum, boron, cobalt and / or nickel; and calcined.

Process for preparing the composition as defined in claim 1, characterized in that it comprises the following steps: a) Adding the support material to an aqueous solution 0.5 to 50% (w / w) Ca, Zn, Cu salts / oxides Mn, Mo, B, Co and / or Ni; (b) keep the system under warming at 90 to 110 ° C and stirring until completely dry;

c) Calcining the impregnated material obtained in (b) at temperatures between 100 and 900 ° C for 2 to 5 hours.

Process according to claim 2, step a, characterized in that the support material is selected from the group comprising serpentinite, vermiculite, charcoal (activated or not) and / or phosphate-rich effluent treatment plant sludge.

Process according to Claim 3, characterized in that the serpentinite (Mg ₃ Si ₂ 0 ₅ (OH) 4) is preferably powder, with a particle size between 1 and 5 mm.

5. Process according to claim 3, characterized in that the vermiculite particles preferably have between about 0.3 ^"0.6 cm and approximate composition of (Al _0. ₃₀ Ti _0. 4 ₀ Fe _0. 3 ₆ ₂ Mg. ₀₀₎ (Si _3. i ₂ Al _0. ₇₉₎ (O ₁₀ (OH) ₂ In Mgo.i ₃ ₀ ₀ .io .o2 K (H ₂ 0) n).

Process according to Claim 3, characterized in that the activated charcoals, whether activated or not, are optionally subjected to oxidative processes for insertion of acidic groups on its surface by reaction with hot concentrated HN0 ₃ (80 to 100 ° C) for 5 to 30 minutes.

7. PROCESS for the production of soil conditioning additives and nutrient release from effluents and / or liquid waste, characterized by the following steps:

(a) leaving the effluent and / or liquid residue in contact with the adsorbent material composition defined in claim 1 in a proportion of 1 to 60% adsorbent in the effluent for residence times of 10 seconds to 12 hours;

(b) collect adsorbent material;

c) Decontaminate the adsorbent material.

Process according to claim 7, step a, characterized in that the effluent is selected from the group comprising industrial effluents and / or domestic effluents, free of heavy metals or toxic organic molecules, containing phosphate concentrations greater than 10 mg / l or 0.03 ppm.

Process according to claim 7, step a, characterized in that the liquid waste is preferably human or animal urine, free of heavy metals or toxic organic molecules, with phosphate concentrations between 100-1000 mg / l and urea in the order 1-20 g / l.

A process according to claim 7, step a, characterized in that the adsorbent material is contained in a shell, such as sachets or cases.

1 1. A process according to claim 7, step c, characterized in that the decontamination of the adsorbent material is carried out by using NaCIO, 0 ₃ , H ₂ 0 ₂ , artificial (Hg lamp) or natural (sun) UV, combined or not. .

Apparatus for phosphorus and / or nitrogen adsorption of effluent or liquid waste, comprising the composition defined in claim 1, contained in a casing, such as sachets or cases, which allows the effluent or liquid waste to pass through; retain composition for reuse; and exhibits chemical and mechanical resistance.

Additives for soil conditioning and nutrient release, characterized in that they are obtained by the process defined by claims 7 to 11.

Use of the composition defined in claim 1, characterized in that it is in the adsorption of phosphorus and / or nitrogen for treatment of phosphorus and / or nitrogen rich industrial and / or domestic effluents, or as a basis for poultry tailings storage bed.

Use of the composition defined in claim 1, characterized in that it is in the production of additives for soil conditioning and nutrient release.