WO2015191011A2

WO2015191011A2 - Process for the sludge management using earthworms

Info

Publication number: WO2015191011A2
Application number: PCT/TH2015/000035
Authority: WO
Inventors: Paweena ARAMRATTANA; Vasimon RUANGLEK; Methee KHAMDUANG; Aroonsak SOPONTAMMAPAN; Arnat TANCHO
Original assignee: Scg Chemicals Company Limited; Ril 1996 Company Limited
Priority date: 2014-06-11
Filing date: 2015-06-10
Publication date: 2015-12-17
Also published as: WO2015191011A3

Abstract

The present invention relates to a process for the petrochemical wastewater sludge management comprising introducing earthworms to treat the petrochemical wastewater sludge at an appropriate condition for growth and reproduction of Perionyx sp. [1]. The process further comprising mixing the petrochemical wastewater sludge with the organic scrap obtained from household, municipality, gardening, livestock, agriculture and industry.

Description

Title of Invention

PROCESS FOR THE SLUDGE MANAGEMENT USING EARTHWORMS Technical Field

This invention relates to a process for the sludge management using earthworm. Background Art

The wastewater treatment system used in petrochemical process generally generates sludge which is the solid waste separated from wastewater or the excess solid. This sludge must be treated in the appropriate way. At present, the general processes for treating this sludge are incineration, land filling or composting.

Incineration is the way to treat sludge via combustion at high temperature. This method consumes large amount of energy resources and causes problems to atmospheric environment. Moreover, it might be a waste of energy both to transport this sludge to treat at incineration plant and to burn it as fuel for cement kiln because of its low heating value and high moisture of 80-90% in water content.

Land filling is another waste treatment process where sludge is piled up on landfill soil. Such action limits the exposure of oxygen to the waste pile where the decomposition rate is slowed down and consequently leads to an emission of methane gas, a known cause for the world greenhouse effect. In addition, this process will not only contaminate soil but also pollute both ground and surface water for the long run. Meanwhile, a large area requirement has limited the landfill treatment and made it less practical.

Composting is a sludge decomposition process by microorganisms in the presence of oxygen. This method requires large space and long decomposition time. It is not widely accepted due to uncertainty of its environmental impacts namely the contaminations of pathogens, heavy metals, and organic compounds in the surface and underground water sources including its toxic accumulation within cycle of food chain.

Regarding the above drawbacks, more efficient, environmentally friendly, and greener approaches have been studied for these past years.

Illustrated by various publications, earthworms have been considered and applied for different types of waste treatments and managements as follow.

US4108625A disclosed a system for producing fertilizers from fertilized vegetable matter using earthworm Eisenia foetida strain. EP0098753B1 disclosed a decomposition process of wastes consisting of animal waste solids and potato peelings waste solids using various strains of earthworms namely, Eisenia foetida or Eudrillus eugeniae or Perionyx excavates or Dendrobaena veneta.

WO2005/016833A1 disclosed a wastewater treatment process for liquid wastes derived from ariimal processing plants, food processing plant, or municipal sewage which biosolid byproducts are composted by various strains of earthworms namely, Eisenia foetida or Lumbricus rubellus or Perionyx excavates.

Bioresource Technology 97(2006) page 391-395 published a process of decomposing organic wastes from household, agriculture or textile industry using Eisenia foetida strain.

Journal of Hazardous Materials 168 (2009) page 262-268 published a process of decomposing sludge from food industry using Eisenia foetida strain.

Conference proceedings of the 2^nd National Soil and Fertilizer conference during 11 - 13 May 2011, "Using Earthworm Managed Agro-industrial Waste and Cadmium Contaminated soil", disclosed a vermicompost process to manage waste from agricultural industry using Eudrillus eugeniae strain.

Handbook for waste disposal using earthworms by The Cleanliness Division of Rangsit Municipality disclosed using Perionyx sp.[l] strain for decomposing solid waste from household or municipality.

Journal of Environmental Biology 26(1) (2005) page 43-47, disclosed a vermicomposting of a mixture of petrochemical sludge and foliage using Eudrillus eugeniae strain.

As above publications, there still be ho studies on the petrochemical wastewater sludge management using Perionyx sp. [l] strain according to this invention which is an efficient and appropriate management.

Objects of the invention

The present invention relates to a process for the petrochemical wastewater sludge management using earthworm comprising preparing petrochemical wastewater sludge or a mixture comprising the petrochemical wastewater sludge and organic scrap wherein an amount of the organic scrap is in the range of 1% to 50% of an amount of the petrochemical wastewater sludge, introducing earthworm Perionyx sp.[l] strain to treat the petrochemical wastewater sludge or the mixture comprising the petrochemical wastewater sludge and the organic scrap at an appropriate condition for growth and reproduction of Perionyx sp. [1] strain including temperature in the range of 15 °C to 30 °C, moisture content in the range of 60% to 90% and pH in the range of 5 to 8, and harvesting a product.

The object of this invention is to provide a process for petrochemical sludge management using Perionyx sp.[l] which is considered sustainable, environmentally friendly, and low energy-consuming. In addition, the present invention also points to a conversion of the sludge which is a useless waste into a number of useful and value-added products such as vermicompost, vermicompost tea, etc.

Disclosure of Invention

The present invention relates to a process for petrochemical wastewater sludge management comprising introducing an earthworm to treat petrochemical wastewater sludge at an appropriate condition for growth and reproduction of earthworm Perionyx sp.[l] strain.

Morphology and Taxonomy of earthworm Perionyx sp. [l] strain are shown in table 1 and 2 as below:

Table 1 : Morphology of the earthworm, Perionyx sp. [l] strain.

Table 2: Nucleotide structure of 16S rDNA and Cytochrome c oxidase sequences (COI) in earthworm, Perionyx sp. [l] strain.

Strain 16S rDNA COI

GC% AT% GC/AT GC% AT% GC/AT Earthworm, Perionyx sp. [l] 39.18 60.82 0.64 42.60 57.40 0.74

In one embodiment of this invention, the petrochemical wastewater sludge is selected from a sludge obtained by a biological wastewater treatment system such as activated sludge system, trickling filters system, RBC system; a sludge obtained by a chemical wastewater treatment system such as coagulation; a sludge obtained by a sludge thickening process, etc. The preferable petrochemical wastewater sludge is obtained by an excess sludge from the activated sludge system which is subsequently treated by the sludge thickening process and having pH in the range of 6 to 8 and moisture content in the range of 80% to 90%.

In one embodiment of this invention, the appropriate condition for growth and reproduction of Perionyx sp. [l] further comprising mixing of petrochemical wastewater sludge with organic scrap wherein the organic scrap is obtained from household, municipality, gardening, livestock, agriculture or industry such as food scrap, vegetable scrap, sewage, gardening scrap, animal excretion, coconut dust, waste and/or sludge from sugar industry, food industry, beverage industry, dairy industry, textile industry, tanning industry, distillery industry, power plants or a mixture thereof, preferably food scrap, fresh vegetable scrap, gardening scrap, coconut dust or a mixture thereof. An amount of the organic scrap is in the range of 1% to 50% of the amount of the petrochemical wastewater sludge.

The petrochemical wastewater sludge or the mixture comprising the petrochemical wastewater sludge and the organic scrap acts or represents as nutritional substrates of earthworm or earthworm's food. After the earthworm consume or absorb into the earthworm's body, the petrochemical wastewater sludge or the mixture comprising the petrochemical wastewater sludge and the organic scrap is converted into the valuable and useful products such as vermicompost and vermicompost tea which can be used as fertilizers, supplementary nutrients for plant, soil conditioning agents, soil nutrients, and odor controlling agent, etc.

In one embodiment of this invention, an amount of the food scrap, the fresh vegetable scrap or the mixture thereof is in the range of 10% to 50% of the amount of the petrochemical wastewater sludge, preferably in the range of 20% to 35% of the amount of the petrochemical wastewater sludge.

In one embodiment of this invention, an amount of the gardening scrap, the coconut dust or the mixture thereof is in the range of 1% to 15% of the amount of the petrochemical wastewater sludge, preferably in the range of 5% to 10% of the amount of the petrochemical wastewater sludge.

In one embodiment of this invention, the appropriate condition for growth and reproduction of Per ionyx sp. [l] comprising a livestock density of Perionyx sp. [\] is in the range of 0.3 to 3.0 kg/m 2 , preferably in the range of 0.5 to 1.0 kg/m 2. These livestock density are suitable for earthworms to live, grow and reproduce. The higher population density leads to increasing mortality rate whereas decreasing the growth rate.

The said amount of the food scrap, the fresh vegetable scrap, the gardening scrap, the coconut dust or the mixture thereof and the said livestock density are the appropriate condition for Perionyx sp.[l] and thus could convert the petrochemical wastewater sludge to product in a range of from 80% to 100% conversion.

In one embodiment of this invention, the appropriate condition for growth and reproduction of Perionyx sp. [l] further comprising a bedding layer or a base layer which comprise loam, dried cow dung or a mixture thereof. The ratio of the mixture of the loam and the dried cow dung is in the range of 4 : 0.25 to 4 : 2, preferably 4:1. These ratios are suitable for earthworms to live, grow and reproduce.

In one embodiment of this invention, the appropriate condition for growth and reproduction of Perionyx sp. [l] further comprising an appropriate temperature is in the range of 15°C to 30°C, preferably in the range of 20°C to 27°C. If the temperature is too high or too low, the earthworm will not be able to reproduce and their conversion potential for the petrochemical wastewater sludge also get reduced.

In one embodiment of this invention, the appropriate condition for growth and reproduction of Perionyx sp.[l] further comprising the appropriate moisture content is in the range of 60% to 90%, preferably in the range of 70% to 80%. As the earthworms breathe through their skin, the moisture content should be controlled for providing the appropriate condition for the vermiculture treatment process. The inappropriate moisture content causes the low clitellum development, unhealthy earthworm, low growth rate, low consumption rate and short lifetime of earthworm.

In one embodiment of this invention, the appropriate condition for growth and reproduction of Perionyx sp.[l] further comprising the appropriate pH is in the range of 5 to 8, preferably in the range of 6 to 7. The pH value becomes lower as forced by carbon dioxide formed during the process. As the low pH adversely affects the earthworm growth and reproduction, the pH value is necessarily to be controlled. There are various methods for adjusting the pH value, preferably providing powder of eggshell crushed at an amount of 30 g/m²/week onto the surface of earthworms' food as thin film layer.

In one embodiment of this invention, the product comprising vermicompost, vermicompost tea, living earthworms, and/or dead earthworms which have various applications as fertilizers, supplementary nutrients for plant, soil conditioning agents, soil nutrients, odor controlling agent, protein sources for feeding animals, earthworm breeders, or using in waste management, etc.

The objective of this invention is to provide a process for petrochemical sludge management using Perionyx sp. [l] which is a sustainable, environmentally friendly, and low energy-consuming process. In addition, the present invention also converts the sludge which is a useless waste to useful and value-added products such as vermicompost, vermicompost tea, etc.

In one embodiment of this invention, the process for petrochemical wastewater sludge management using Perionyx sp.[l] comprising:

1) Preparing a building which can prevent the earthworm from rain, sunlight, and hunter. The building also should be dark, good ventilation, cool and shady. In addition, the water and electricity system should be installed for controlling the moisture content, light, and temperature suitable for earthworm's growth and reproduction, preferably the building's temperature is in the range of 34 °C to 36°C and the moisture content in the building is in the range of 84% to 88%.

2) Preparing a pit of 1-2 m wide, 5-9 m long and 0.8-1.0 m in depth in the building prepared in step 1). A base of the pit has a slope of 1-2% for releasing, discharging and preventing confinement of vermicomposting tea generated during the process. If the pit made from cement, the pH adjustment or pit pretreatment is required by com^bining the pit with water immerged with scrap of banana trunk for around 1 week.

3) Preparing a clarifier for vermicompost tea which having connecting pipe to the pit prepared in step 2) for storage vermicompost tea. The clarifier should have 1 - 2 m³ in volume per 100 m² of pit area.

) Preparing a bedding layer or a base layer comprising a mixture of loam 4 parts and dried cow dung 1 part in the pit prepared in step 2). The bedding layer is spread evenly and having 3 inch in depth.

) Adjusting the moisture content of the bedding layer prepared in step 4) to be in the range of 70%-80% by spraying water or vermicomposting tea. 6) Composting of the bedding layer or the base layer prepared in step 5) to provide the appropriate condition for growth and reproduction of earthworm. If the bedding layer or the base layer is sprayed with water, the bedding layer should be left pre-composted around 1 week. If the bedding layer or the base layer is sprayed with the vermicomposting tea, the pre-composted period is reduced to be around 0.5-1 day.

7) Adjusting the temperature of the bedding layer or the base layer prepared in step 6) to be in the range of26⁰C - 27°C.

8) Adjusting the pH of the bedding layer or the base layer prepared in step 7) to be in the range of 6-7 by scattering with the eggshell powder.

9) Selecting Perionyx sp. [l] which are strong and indicated by the presence of clitellum in their adult phase, then releasing them to the bedding layer or the base layer prepared in step 8). The livestock density of Perionyx sp. [1] is 0.5 kg/1 m².

0) Mixing petrochemical wastewater sludge and organic scrap having the ratio as shown in table 3 and providing the said mixture on the surface of the bedding layer or the base layer prepared in step 9) in a row pattern where each row may have some distance apart.1) Providing Perionyx sp. [l] consume the mixture of petrochemical wastewater sludge and " organic scrap provided in step 10) for around 1 week.

2) Providing more mixture of petrochemical wastewater sludge and organic scrap when the phenomenon of the fully conversion of the mixture of petrochemical wastewater sludge and organic scrap provided in step 10) is observed. The temperature, moisture content, pH and livestock density should be adjusted suitable for the earthworm's growth and reproduction.

3) Harvesting vermicompost from the pit and vermicompost tea from the clarifier produced in step 12). Table 3: The process for petrochemical wastewater sludge management using Perionyx sp.[l] at various type and content of organic scrap

Example 1 Example 2 Example 3 Example 4 Example 5

Type of organic scrap Food scrap Fresh Gardening Coconut vegetable scrap dust scrap

Amount of organic scrap 25 - 33 25 - 33 6.5 - 8 6.5 - 8 (% of amount of

petrochemical

wastewater sludge) Conversion rate 1.5-2.0 1.5-2.0 2.0-2.5 2.0 -2.5 2.0-3.0

(kg/earthworm 1

kg/lm²/lday)

Best Mode for Carrying out the Invention

The best mode of practicing the invention is as described in the above detailed description.

Claims

Claims What is claimed is:

1. A process for petrochemical wastewater sludge management using earthworm comprising

(a) preparing petrochemical wastewater sludge or a mixture comprising the petrochemical wastewater sludge and organic scrap wherein an amount of the organic scrap is in the range of 1% to 50% of an amount of the petrochemical wastewater sludge,

(b) introducing earthworm Perionyx sp.[l] strain to treat the petrochemical wastewater sludge or the mixture comprising the petrochemical wastewater sludge and the organic scrap prepared in step (a) at an appropriate condition for growth and reproduction of Perionyx sp. [l] strain including temperature in the range of 15 °C to 30 °C, moisture content in the range of 60% to 90% and pH in the range of 5 to 8.

(c) harvesting a product which is produced in step (b).

2. The process as claimed in claim 1, wherein the organic scrap is selected from organic scrap from household, municipality, gardening, livestock, agriculture, industry, preferably food scrap, fresh vegetable scrap, gardening scrap, coconut dust or a mixture thereof.

3. The process as claimed in claim 2, wherein an amount of the food scrap, the fresh vegetable scrap or the mixture thereof is in the range of 10% to 50% of the amount of the petrochemical wastewater sludge, preferably from 20% to 35% of the amount of the petrochemical wastewater sludge.

4. The process as claimed in claim 2, wherein an amount of the gardening scrap, the coconut dust or the mixture thereof is in the range of 1% to 15% of the amount of the petrochemical wastewater sludge, preferably from 5% to 10% of the amount of the petrochemical wastewater sludge.

5. The process as claimed in claim 1, wherein the appropriate condition for growth and reproduction of Perionyx sp. [\] strain further comprising a livestock density of Perionyx sp. [1] is in the range of 0.3 kg/m2 to 3.0 kg/m2, preferably from 0.5 kg/m2 to 1.0 kg/m2.

6. The process as claimed in claim 1, wherein the process further comprising preparing a bedding layer for Perionyx sp.[\] wherein comprises loam, dried cow dung or the mixture thereof.

7. The process as claimed in claim 6, wherein the mixture of the loam and the dried cow dung having ratio in the range of 4 : 0.25 to 4 : 2, preferably 4:1.

8. The process as claimed in claim 1, wherein the appropriate temperature for growth and reproduction of Perionyx sp. [1] is in the range of 20 °C to 27 °C.

9. The process as claimed in claim 1, wherein the appropriate moisture content for growth and reproduction of Perionyx sp. [1] is in the range of 70% to 80%.

10. The process as claimed in claim 1, wherein the appropriate pH for growth and reproduction of Perionyx sp. [l] is in the range of 6 to 7.