Difference between revisions of "Team:Westminster/Practices"

INTERVIEW WITH LES BIRCHMORE FROM FULLER’S BREWERY (07/09/15)

We contacted Fuller’s brewery. This was our first encounter with the Chief of Engineering, Les Birchmore. He demonstrated a keen interest and enthusiasm towards our project. As a result he agreed to speak further with us, hence the interview. He was very forthcoming with the methods and potential ways to reduce the overall effluent of the brewery. As a result of this collaboration we have been fortunate to successfully secure a supply of waste water when needed for further and ongoing research. The wastewater that was collected from Fuller’s brewery was used to explore how Shewanella oneidensis grew. In our microbial fuel cell Clostridium bejierinrikii and S. oneidensis were grown together. The reason for this is because S. oneidensis metabolises secondary substrates such as pyruvate whereas C. bejierinrikii metabolises primary substrates. However, this proved unsuccessful, as the S. oneidensis did not grow and thus not produce any electricity. In the future it would be interesting to investigate the potential of our engineered Escherichia coli growing in wastewater.

1) How much waste water is produced?

On average approximately 600m³ of waste water is produced daily. There are 4 outlets around the brewery at various points. The effluent is collected in there and from these outlets Thames Water takes a sample in order to calculate the amount of waste water estimated to be released and discharged into the sewage for Thames Water to clean.
Fuller’s uses 250000 hectare liters annually in their treatment of the reactors used in beer production. Used to use water from wells. However this is no longer the case as they have ben comprised and subject to contamination. The process used, in order to clean their bioreactors, is:

• pre-rinse – clears solid material from the reactor
• detergent - washes away scum, debris build up
• Final rinse – measure pH

Thames Water make regular (not sure how frequently in terms of time scale) spot samples in order to assess the cost of cleaning the waste water produced by Fuller’s. The way this is measured is through the Mogden formula, which is used in order to calculate trade effluent. The greatest cost is COD (chemical oxygen demand).
Charges for trade effluent are based on the Mogden formula, which is

Charge per unit of effluent = R + [(V + Bv) or M] + B(Ot/Os) + S(St/Ss)⁷
Where
R = reception and conveyance charge [p/m³]
V = primary treatment (volumetric) charge [p/m³]
Bv = additional volume charge if there is biological treatment [p/m³]
M = treatment and disposal charge where effluent goes to sea outfall [p/m³]
B = biological oxidation of settled sewage charge [p/kg]
Ot = Chemical oxygen demand (COD) of effluent after one hour quiescent settlement at ph 7
Os = Chemical oxygen demand (COD) of crude sewage one hour quiescent settlement
S = treatment and disposal of primary sewage sludge charge [p/kg]
St = total suspended solids of effluent at ph 7 [mg/litre]
Ss = total suspe nded solids of crude sewage [mg/litre]


OFWAT (Office of Water Services). (2015). Modgen formula. [online]. Available at:
https://www.ofwat.gov.uk/nonhousehold/yourwaterbill/hownonhousehold/trade/mogden
[Accessed on 7^th September, 2015]

COD (chemical oxygen demand) is used as a measure in order to detect levels of organic compounds in water, such as effluent from Brewery waste water. COD and SS (settle able solids) is dictated to Fuller’s brewery regarding the cost. Whereas the other costs of the factors of Modgen formula are so small that they are almost insignificant.

2) Where is the waste water discharged?

The wastewater goes directly down to the public sewer. The effluent is then treated downstream at Thames Water. Fuller’s incurs the cost for this clean up.

3) What measures does Fuller’s have in place for reducing its carbon footprint?

New collection tank which will have the capacity to collect and store 50000 litres of effluent (waste water). This will be collected and removed 3 times a week.
When the new collection tank arrives it may require partial treatment using a DAF (Dissolved Air Flotation) unit. This can be used to reduce COD levels. It works by placing an agent in the unit in order to folliculate. Agents used unknown, its aim is to reduce bulk by scraping the scum off the surface of the wastewater in the unit, thus reducing the COD levels.
Offered effluent treatment plant that deals with high volume. Has reduced foot print.

4) How much electricity is required to power Fuller’s Brewery?

The amount of electricity used at Fuller’s- under megawatt per day. Last week= 1000 kilo watt per day (megawatt).The fridges are the highest demand of electrical output. Fridges are on all the time. The temperature of the fridges -3.30C.
The cost of water is £1 in and £2 out due to the effluent.
Used to use the well, capped now. As a result effluent prices were lower when using the wells, as the excess water provided from the wells washed away effluent. Therefore, the effluent comprised mostly of water. The wells are now capped as they were compromised due to cracked pipe which lead to contamination (as mentioned previously). The water from the wells also used to act as fridges, cooling the beer. Therefore, not only has the cost of effluent increased, so too has electrical demand which is now used in order to cool the beer.

5) What are the regulations?

Regulations:
pH
COD
Solids- (SS) settle able solids allow to settle
Shake up the settle able solids and take a sample
-(TDS) totally dissolved solids
Phosphorus
Residence time for MFCs high. Upscale issues.

Effluent treatment plant- microorganisms used in order to treat effluent. After a year the microorganisms no longer active. Not known what occurred in order to stop the microorganisms to stop working. Microorganisms line the drain and grow forming a biofilm in order to act to breakdown the wastewater.

THAMES WATER INTERVIEW WITH DR PHILLIP THOMAS (07/09/15)

We contacted a number of water companies throughout the UK requesting then potential of collecting wastewater for our microbial fuel cells. Thames Water and Anglian Water returned our request. Philip Thomas from Thames Water was able to answer some of the questions posed regarding the plant, as seen on the Human Practices tab. Wayne Dearsley, the Customer Liaison Manager of Anglian Water, directed us to Andy Taylor, who in turn would have informed us as to the nearest Anglian water plant in order to collect a pre-treatment sample. Unfortunately, this line of enquiry did not continue as this occurred in the final week of the project. Had we the time, the Anglican waste water would also have been utilised in further experiments.
Below is the telephone interview conducted with Philip Thomas.
Below is the follow up to the interview conducted on 7th September. Unfortunately the details of the wastewater composition and the quantity and cost of electricity used by Thames Water was not included.
Thames water has 350 sewage treatment works, which treat an average of more than 4.4 billion litres a day.
There are two sludge powered generators, and 19 combined heat and power plants, which generate 153GWh of renewable electricity.

Wastewater treatment
1) What are the methods used in order to treat wastewater?

1st Stage is referred to as the PRELIMINARY TREATMENT
This stage is mostly a physical screening. Any material/object over 6mm is held back. Such items include sanitary towels, nappies, wet wipes, leaves and such debris. Flow that is less than 6mm is able to travel through to the next stage. This stage also includes a gravel trap. The flow of the effluent is reduced to allow heavy waste to drop. The fluid flows on to the second stage. The materials collected are discarded.

2nd Primary Sedimentation
The flow is also slow during this phase so that the heavier materials collect at the bottom. This is referred to as sludge. This sludge is then collected. The liquid, also known as the settled sewage, then goes on for secondary treatment of which there are two methods:

-Trickling, the waste water literally trickles out from the outlet and over a solid media, comprising primarily of rocks, which is covered in a biofilm. The wastewater is sprayed in such a way that it is distributed evenly over the surface of the beads through a rotating arm lined with nozzles. This is the first step in the initial degradation of compounds in the wastewater. As the effluent trickles over the beads it flows through to the lower level which is populated with nitrifying bacteria. The bacteria aid the removal of ammonia through oxidation of ammonia to nitrite to nitrate.

Wastewater System (2013). Trickling Filter in Wastewater Plant. [online]. Available at:
http://www.wastewatersystem.net/2009/05/trickling-filter-in-wastewater-plant.html
[Accessed on 7th September, 2015]
-Aeration lanes which are large tanks in which air is pumped and thus an aerobic process.
The next stage is the FINAL EFFLUENT in which the water is treated before being discharged into the river. This is also another settlement stage. The sludge that is collected from this process is secondary sludge and is treated with the rest of the sludge from earlier treatment steps.
The process of removing and digesting the SLUDGE is anaerobic. Some of the sludge is siphoned off to be recycled to be used as fertilizer for agriculture. The byproduct of the digestion of the sludge is biogas. The biogas consists of approximately 65% biomethane, the remaining gases are comprised of carbon dioxide, hydrogen gas and other gases. These biogases are collected as used in CHP (combined heat and power) such as electricity and heat. Another stage in this process is the thermal heating of the sludge to solidify it. When burned this releases heat that can be captured and recycled as electricity.

2) What toxic compounds are found and how are they treated?

Toxic compounds are measured and discharged from industry- trade effluent. There are regulations limiting the quantities and compounds that industry can release. However these regulations are more difficult to control for domestic use as they cannot be measured.
An example of an industrial waste toxic compound is FOG (fats/oils/grease) from Food manufactures. Therefore they are limited to how much they can release. Another example is ammonia concentration, and there are limited COD demands.
Phillip did not offer up any chemicals that are used in the treatment. Only the methods/techniques used and the stages (as mentioned prior).
Phillip Thomas could not answer all my questions and said that he would get back shortly. In terms of how much water is used:
At the Beckton plant (the largest plant) it is estimated that 3 million people (measurement in terms of population equivalent) use the plant.