WO2010122184A1

WO2010122184A1 - Method for preparing an environmentally friendly fertilizer based on seaweed, fish waste and lignocellulosic material

Info

Publication number: WO2010122184A1
Application number: PCT/ES2010/000147
Authority: WO
Inventors: Concepción BLANCO FANEGO
Original assignee: Pescados Rubén, S. L.
Priority date: 2009-04-22
Filing date: 2010-04-07
Publication date: 2010-10-28
Also published as: ES2347124A1; ES2347124B1

Abstract

Method for preparing an environmentally friendly fertilizer based on beach-wash seaweeds and fish waste, which comprises the steps of alternately superposing layers of seaweed, layers of fish waste and layers of lignocellulosic material, at ambient temperature and pressure, turning the stack for 2 months until an aerated, mixed and homogeneous compost is obtained, maturing and fortnightly turning for a further 2 months until a stable, mature compost is obtained, and screening said compost with a view to obtaining a homogeneous fertilizer that is easily incorporated into the land to be fertilized.

Description

Procedure for preparing organic fertilizer based on algae, fish remains and lignocellulosic material. Object of the invention

The present invention relates to a process for preparing an organic fertilizer comprising algae, fish remains and lignocellulosic material. Field of the Invention

The invention is included within the agricultural field, especially in the supply of natural fertilizers for organic farming, which respects the environment. Background of the invention

Within the strategy "Natural resources and waste management" of the VI European Environmental Program (2001-2010), the reintroduction of waste into the productive and economic cycle, through recycling or return to the environment in a useful way, is a priority action to achieve the sustainability of agricultural systems.

The sea provides a large amount of resources, one of which is the algae that, dragged by the tides and the action of the wind, arrive at the coasts. The set of algae deposited on the beaches are called

"up" or "up". Algae have been used for centuries as natural fertilizer in many coastal regions around the world (Zemke-White & Ohno, 1999; McHugh, 2003), due to their fertilizing capacity, the improvement they produce in the soil structure and the contribution of micronutrients and growth activators (Blunden, 1991;

Verkleij, 1992; López-Mosquera S- Pazos, 1997). An added advantage of this type of fertilization is the absence of weed seeds and pathogens, which can appear when other organic fertilizers are used.

In Galicia, with more than 1500 km of coastline, this ancestral practice is in disuse since the generalization of employment of chemical fertilizers and, above all, due to the increased cost of labor for their collection and transport, so that today it could be said that it is an underutilized resource for this purpose. On the other hand, in some cases, algae are considered a waste: in those areas where eutrophication problems cause excessive algae growth (Morand & Briand, 1996), - in tourist areas, in summer, the rotting processes associated with the contributions of algae on the beaches, make their collection necessary (Rosenberg, 1985; Piriou & Ménesguen, 1992), so they are removed and, normally, they are taken to landfill thus losing their potential as a resource, and also, in the areas shellfish where accumulation harms bivalve and aquaculture crops (Rodríguez et al., 1987; Niell et al., 1996).

However, it should not be forgotten that algae have an ecological mission and that a large number of organisms live in them. For this reason, its use must be raised through a respectful extraction with the environment.

Like algae, in coastal areas, fish remains have also been traditionally used as fertilizer, given their richness in nutritional elements (nitrogen and phosphorus, fundamentally) and their rapid decomposition. Today, there are different fertilizers on the market whose raw materials are fishmeal, products authorized on an exceptional basis for use in organic farming (EEC Regulation 2092/91). In the coastal areas there are several companies dedicated to the processing and processing of fresh fish, which generate a large amount of fish remains daily. Furthermore, the ports and auctions significant amounts of this type of waste _v also originate. In Galicia alone, during the year 2005, a total of 160,000 tons of fish were sold, which generated an approximate amount of 30,000 tons of waste.

These remains are normally collected by waste managers who primarily use them to manufacture fishmeal. Other uses that allow to value them is to extract from them the parts _' with commercial value. For example, they can. be used to make jellies and pates, artificial baits for automatic longlines _ or to take advantage of their proteins or oils. But, due to the increase in the cost of these processes, the companies that generate this waste seek alternatives for the recovery of their waste, and less expensive treatment techniques. There are companies located in Fazouro (Foz-Lugo, Galicia) dedicated to the processing of fresh fish from extractive fishing (fillets, slices, loins, etc.) of different species (sardine, mackerel, squid, horse mackerel, bonito, etc.) , such as the company Pescados Rubén, which annually generate large volumes of waste (remains considered category 3, suitable for use in agriculture once composted or ensiled, according to EEC Regulation 1774/2002). This ¹ company and others in the sector are looking for alternatives for the recovery of the waste they generate, which to date are left to waste managers.

During the year 2006, we proceeded to characterize the upwellings arrived at six representative beaches and close to the company. Monthly, the volume of seaweed in order to know its availability with a view to being used in an industrial transformation process. The arrival of algae on the coast depends on climatic factors, beach exposure and tides, therefore it is usually an irregular presence resource that makes it difficult to schedule its collection. In spite of this, it was found that in the study area the availability of upset was important (more than 8000 t / year in fresh), appearing the largest quantities in the months of November and December. The species that dominated the upstairs throughout the year were Laminaria sp. and Cystoseira sp. In addition to quantifying the volumes of algae and their botanical composition, the chemical characterization of the upwellings and the different species was performed. The chemical study of the fish remains originated month by month in the company was also carried out. The results obtained allowed the establishment of composting strategies for the preparation of a fertilizer from both components and their. subsequent agronomic valorization in culture. , Composting initiatives, as the most appropriate biotechnology from an economic and environmental point of view (Potoky and Mazé, 1988; Mazé et al, 1993; Vallini et al., 1993 '; Cuomo, et al., 1995; Eyras and Sar, 2003; Aguilar and Guerrero, 2005), have been carried out especially in those areas where algae have been a waste by episodes of eutrophication (Venice, French Brittany, Peru, Argentina, etc). In this way, it is possible to reduce the volume of algae (fundamentally, Ulva sp.) Arriving at the beaches and a quality compost is obtained, given its richness in nutritional elements, especially potassium, calcium and magnesium, perfectly sanitized and free of contaminants, such as heavy metals or phytotoxic compounds. Due to the low C / N ratio (carbon / nitrogen) of the algae, it is always necessary that they be mixed with a proportion of a lignocellulosic material that provides aeration and carbon (Mazé et al., 1993). The final physical, chemical and biological characteristics of the compost obtained make it a good material to be used as a crop substrate or as an organic fertilizer (Cuomo et al ^L. , 1995).

In different parts of the world have experimented ^w compost fish remains viable alternative to transform them into useful products in agriculture (Frederick et al, 1989; Logsden, 1991; Gould, 2004) technique. In most of the cases, we worked mainly with remains from aquaculture. To make the compost piles, as in the case of algae, materials such as pine bark, pruning remains, etc. were provided to improve aeration conditions and the carbon / nitrogen C / N ^ ratio (Laos et al, 2001).

Currently, the area dedicated to organic farming in Spain is almost one million hectares, having grown exponentially from 1991 to date. The largest autonomous region is Andalusia, followed by Aragón and Extremadura. Although this area is mainly dedicated to extensive crops (pastures, fodder, cereals and legumes), horticultural crops, tubers, vineyards, olive and nuts occupy important areas (MAPYA, 2006). Within this context, in 2006 Galicia had a total registered area of 9,624 hectares. This type of agriculture is legally regulated in Spain through the community regulation R (EEC) N ° 2092/91, on organic agricultural production and its indication in agricultural and food products. In its Annex II, section A. Fertilizers and Soil Conditioners of these regulations, the products authorized for the fertilizer and soil improvement are specified. Among them, mention is made of the use of fishmeal (without specifying its origin) and of algae and products derived from them, always with the recognized need of the control body or authority. Actually, this regulation does not specify the criteria that indicate that it is considered an ecological fertilizer, this situation will change with the new European regulation of application from January 1, 2009 (Regulation (EC) N ° 834/2007). At the moment, organic fertilizers with official certification do not exist in the market, only with certifications made by private companies. This system of agricultural production seeks to achieve food of the highest quality respecting the environment and conserving soil fertility through the optimal use of resources. Organic farming defends the recycling of nutrients within the farm itself and if you need to purchase products to maintain soil fertility, they should not be synthetic, conferring a preponderant role to organic matter to maintain fertility in the system ground-floor

The demand for organic products, both in the most immediate markets and worldwide, is growing and the prospects for the future is that this type of agriculture is of increasing importance. However, today, despite the development of organic farming, there is a clear shortage of quality organic fertilizers to be used in this type of farms, so it seems very appropriate to ^' introduce a product made in the market to from natural components from the sea, which in the future could be credited as ecological.

No studies have been found in which the co-composting of algae and fish remains is carried out. The combination of both products with a lignocellulosic material (for example, pine bark generated by surrounding industries) is a viable solution to recycle the remains of fish produced in fisheries and fish markets, in addition to contributing to using a resource Very valuable fertilizer such as seaweed of upright. The resulting product will have quality to be used in the most demanding agricultural systems, such as organic farming.

DESCRIPTION OF THE INVENTION According to a first aspect, there is provided a method for preparing an ecological fertilizer that, from seaweed algae, that is, those seaweed washed by the sea and deposited in coastal areas, ¹ - fish remains and material lignocellulosic, comprises a series of stages that are set out below and thanks to which a stable, mature and suitable product for agriculture is obtained as an organic fertilizer and free of any chemical additive.

First, a stage where layers of algae, fish debris and a lignocellulosic material overlap, such as pine bark. This stage takes place at ambient temperature and pressure, until a stack of approximately 1 m high is obtained.

Next, a step of turning the battery weekly for a period of 2 months until obtaining an aerated, mixed and homogeneous compost.

Subsequently, a stage of maturation and biweekly turning of the starting materials, for another 2 months, until a stable and mature compost _^. This stage includes controls for pH, humidity, electrical conductivity and carbon and nitrogen concentrations. At this stage it is simply sought that the battery matures and turns every 15 days.

Finally, a screening of the compost obtained in the previous stage is carried out through the use of a 20 mm mesh light sieve, in order to obtain a homogeneous fertilizer and easily incorporated into the> land to be fertilized. Both fish remains and algae have a C / N (carbon / nitrogen) ratio below the levels that are considered optimal for a quality compost (20-30). Therefore, in step a) of the process a layer of lignocellulosic material is interposed between the layers of algae and fish remains. Thus, to raise this C / N ratio, lignocellulosic material is used, such as pine bark with a particle size of 10-35 mm. The preferable and appropriate proportion of fish remains, algae and pine bark is 1: 1: 3. With this proportion an optimum C / N ratio is obtained for the good development of the composting process.

According to a second aspect, an ecological fertilizer is provided which is obtained by the procedure described above. Said fertilizer includes seaweed, fish remains from extractive fishing and lignocellulosic material in order to optimize the C / N ratio. Preferably, this material will be pine bark.

Description of a preferred embodiment

In the present example, to prepare the fertilizer as described above, 100 kg of algae, 100 kg of fish remains and 300 kg of pine bark are used as raw material. The above materials are deposited on the ground, alternately interposing layers of the previous materials to favor their interaction and mixing.

In this way, a battery is mounted that will be open and dynamic, with periodic flips.

For example, the stack will have a trapezoidal shape with a width at the base of 2 m and a height of 1 m, with. The length of the pile will adapt to the land on which it is built.

To avoid the leaching of nutritional elements towards the soil of the area where the battery will be located as a result of rainwater, the battery will be built on a waterproof floor and under cover.

The composting procedure lasts for a total of four months, from the moment the battery is implanted until the final product is obtained. During this time the different materials that make up the mixture are integrated until a completely mature product is ready for use.

With the systematic and continuous turns of the battery, the aeration, mixing and homogeneity of the compost is increased and temperature control in the thermophilic stage is favored. This turn is repeated weekly during the first two months, until the compost is stabilized and enters the ripening stage. After this time, the flips will be spaced every fifteen days in order to continue to favor the integration of the different fractions and their aeration.

In order to control the correct development of the compost, the battery is subjected to a continuous control of the physicochemical parameters indicative of the proper composting process. Of these parameters, O ₂ levels and temperature are measured daily during the first two months and then twice a week. While humidity, pH, electrical conductivity, C levels, carbon, and N, nitrogen, are measured once a week during the first two months, coinciding with the battery flips. Because these parameters are stabilized from the second month ^v, in the second stage, it is not considered necessary to continue recording them .

During months two, _v, three and four, a "degree of stability" analysis is performed to observe the degree of maturity of the compost. Parallel to these, and in order to prove the phytotoxic state of the same, the "Zucconi test" that characterizes its germination power is performed.

Once the compost is stable and mature, it is prepared for use as fertilizer in agriculture.

It is subjected to screening with a 20 mm mesh light sieve.

With this operation you get a homogeneous product and easily incorporated into the land.

Claims

1. Procedure for the preparation of an organic fertilizer from seaweed, fish remains and lignocellulosic material, characterized in that it comprises the stages

5 of: a) alternatively superimposing layers of algae, layers of fish remains and layers of lignocellulosic material, at ambient temperature and pressure, until a stack of approximately 1 m in height is obtained;

10 b) turn the battery weekly for a period of 2 months until obtaining an aerated, mixed and homogeneous compost; c) maturation and biweekly flipping for another 2 months, until obtaining a stable and mature compost, which includes control of pH, humidity, electrical conductivity and

15 concentrations of carbon and nitrogen, and d) screening the compost from step c) with a 20 mm mesh light sieve in order to obtain a homogeneous fertilizer.

2. Procedure for preparing an organic fertilizer according to claim 1, characterized in that in the stage

'20 a) the lignocellulosic material is pine bark.

3. Method of making an organic fertilizer according to claim 1 and 2, characterized in that the proportion of algae / fish remains / pine bark is 1: 1: 3.

4. Ecological fertilizer obtained according to the method defined in claim 1 characterized in that it comprises: seaweed, fish remains from extractive fishing and lignocellulosic material.

5. Ecological fertilizer according to claim 4, characterized in that the lignocellulosic material is bark ^'

30 pine.