Technologies We Use

Some of the technologies we use for the treatment of hazardous and non-hazardous waste are shown below. Sampling and laboratory analysis are used in conjunction with knowledge of the source of the waste stream to determine the most appropriate and cost effective solution for the treatment of the waste stream. Please contact us should you wish to discuss the specific requirements of your waste stream.



Thermal Desorption Technology

The approved technology Thermal Desorption allows onsite treatment of contaminated soils by heating it to temperatures that vaporise organic contaminants into their gaseous phase. 

The gas stream is then heated to an even higher temperature to destroy the gaseous phase organic contaminants. The gaseous stream is then cooled, drawn through a baghouse to remove any fine particulates and metals and then treated in a scrubber to remove acid gases before discharge to the atmosphere as air, carbon dioxide, and steam. The emissions are not harmful to human health and are controlled by licence conditions set by the Environment Agency. The plant has automatic soil feed shutoffs built in if a process parameter is recorded outside of an allowable operating range. These shutoffs ensure the integrity of the process, avoid excessive emissions, and prevent damage to the plant.

The treated soil from the thermal process is re-hydrated and chemically tested to ensure compliance.

Thermal Desorption is a proven sustainable technology and has a firmly defined outcome across a wide range of contaminants. Recycled fuel oil (used motor oil) can be used as the primary fuel as part of the plant’s sustainability goal. Thermal desorption is an appropriate solution for complex sites where contaminants are not readily treatable by other technologies.

Suitable waste streams for thermal desorption technology are those with organic contamination. This can range widely from halogenated organic wastes (such as wastes from pesticides/ herbicides manufacturing plants or contaminated areas) to wastes from former gas works sites and petroleum plants.
 


Stabilisation

Stabilisation/Solidification has a wide range of benefits and attractions in today's waste treatment and construction industry. It is the treatment of contaminated materials by the reduction of moisture content and contaminant mobility, facilitated by the addition of chemical additives to waste materials, in order to reduce the leachability of contaminants. 
 
Stabilisation is operated as an ex-situ mixing process, in which material is placed on the above ground treatment area and mixed with a cement-based additive via ‘rotavation’ in order to ‘bind’ contaminants to the material matrix.  Material is stored in stockpiles during the treatment period, allowing ease of processing in order to prevent physical properties of the material matrix being adversely affected by the additives.    
 
The stabilisation/solidification process comprises screening, stockpiling, spreading and primary treatment, secondary treatment (curing process), physical aeration and validation.
 



Bioremediation Technology

Bioremediation is the treatment of a hydrocarbon contaminated soil by microbial degradation of the ‘parent compounds’.   The objective of treatment is degradation that results in detoxification to a product that poses an acceptably reduced risk to human health and/or the environment.


An example of a typical metabolic pathway for hydrocarbons is summarised below:
Hydrocarbon                               CH3(CH2)nCH2CH2CH3
Alcohol                                        CH3(CH2)nCH2CH2CH3OH
Aldehyde                                    CH3(CH2)nCH2CH2.CHO
Fatty Acid                                   CH3(CH2)nCH2CH2.CHOOH
Fatty acid & acetic acid              CH3(CH2)nCOOH + CH3COOH
Carbon dioxide and water          CO2 + H2O
 
The bioremediation process is operated whereby material is placed in an above ground treatment area and stimulated to enhance the biodegradation of contaminants present.   The  treatment process  will  comprise elements of  material  processing (screening/ crushing~ usually required to allow conditioning of the material), stockpiling, bed preparation, construction of biopile, nutrient  addition, pH adjustment  and   physical   aeration   to   optimise  degradation  by   indigenous  microbial populations (and additional microbial introduction as required), covering material to control temperature and moisture content, monitoring and validation.   
 
Additives  such as straw, chicken manure, green waste, urea and enzymes may be  used  during  bioremediation.    
 
The contaminant groups treated comprise hydrocarbons (aliphatic and some aromatic).