unit 3 lesson 6 Flashcards
1
Q
What is the purpose of water treatment in a brewery?
A
To turn potable water into product water with the required mineral composition
2
Q
What are some common issues with water before brewing?
A
Too hard, high alkalinity, incorrect ratio of minerals, presence of free chlorine
3
Q
What is the first step in removing solids from base product water?
A
Mechanical filtration
4
Q
What is a cartridge filter made of?
A
Polymer fibres wound in a spiral
5
Q
What happens when solids block the channels in a filter?
A
Pressure increases between the filter’s inlet and outlet points
6
Q
True or False: Iron and manganese can negatively affect beer quality.
A
True
7
Q
What can be used to remove iron from water?
A
Air, ozone, or phosphoric acid
8
Q
What is the role of manganese dioxide in water treatment?
A
Speciality filters using manganese dioxide remove both iron and manganese
9
Q
Describe a method to reduce water alkalinity.
A
Decarbonation by heating, treatment with lime, or acid addition
10
Q
What is the chemical reaction for decarbonation by heating?
A
Ca(HCO3)2 ↔ CaCO3 + CO2 + H2O
11
Q
What is formed when calcium hydroxide is added to bicarbonate-rich water?
A
Calcium carbonate precipitates out
12
Q
Fill in the blank: Ion exchange systems remove undesirable ions and replace them with _______.
A
[desirable ions]
13
Q
What are the basic types of ion exchange resins used in water treatment?
A
- Weakly acidic cation
- Strongly acidic cation
- Weakly basic anion
- Strongly basic anion
14
Q
What does a weakly acidic cation resin remove?
A
Cations associated with weak acids
15
Q
What is the Bronsted-Lowry theory of acids?
A
An acid is a proton donor, and a base is a proton acceptor
16
Q
What happens during the regeneration of ion exchange resins?
A
The resin is flushed with a strong solution of desirable ions
17
Q
What is the main disadvantage of using strongly basic anion resins?
A
Relatively short resin life of 2-5 years
18
Q
What is the result of the reaction when bicarbonate-rich water passes through a weakly acidic cation resin?
A
The hydrogen ion exchanges for a calcium ion, forming water and CO2
19
Q
What is a consequence of manganese oxide formation in water treatment?
A
Hard deposits that are difficult to remove and can cause pitting of steel
20
Q
What is the chemical reaction for decarbonation by acid addition?
A
Ca(HCO3)2 + 2H+ → Ca2+ + 2CO2 + 2H2O
21
Q
What is the purpose of ion exchange in water treatment?
A
To exchange undesirable ions with more desirable ones
22
Q
What does the term ‘de-alkalisation’ refer to?
A
The removal of calcium and magnesium associated with temporary hardness
23
Q
What is the main function of the WAC ion exchanger?
A
To exchange calcium ions for hydrogen ions in water
This process helps to reduce water hardness.
24
Q
What chemical reaction occurs during the regeneration of WAC using hydrochloric acid?
A
(resin)2-Ca + 2HCl → 2 resin-H + CaCl2
This regenerates the resin for further use.
25
What happens to the pH of water as it passes through the WAC?
The pH drops slightly due to the addition of H+ ions
## Footnote
This conversion creates carbonic acid from temporary hardness.
26
What is the outcome of degassing water after passing through WAC?
CO2 gas is removed, converting carbonic acid back into water
## Footnote
This process can use mechanical aeration or a degasser membrane system.
27
What ions can be exchanged when using sodium as the exchange ion in WAC?
Calcium and magnesium associated with temporary hardness
## Footnote
This process is less common due to increased resin volume.
28
What type of functional groups do Strongly Acidic Cation (SAC) resins have?
Sulphonic acid functional groups
## Footnote
These resins are effective at removing all metal cations.
29
In what order do SAC resins remove cations when using H+ as the exchange ion?
Fe > Ca > Mg > K > Na > H
## Footnote
This order reflects the affinity of the ions for the resin.
30
What is the typical pH range of water after passing through SAC with H+ exchange ions?
pH 2.5 - 3.5
## Footnote
This significant drop occurs due to the formation of acidic compounds.
31
What is the primary use of Weakly Basic Anion (WBA) resins?
To remove anions of strong acids like nitrate and sulfate
## Footnote
WBA resins do not remove weak acid anions or silica.
32
What is the regeneration chemical used for WBA resins?
Sodium hydroxide (NaOH)
## Footnote
This facilitates the removal of strong acid anions.
33
What is a disadvantage of using WBA resins in brewing?
They do not remove carbonate, potentially causing pH adjustments
## Footnote
This can affect the quality of brewing water.
34
What is the main feature of Strongly Basic Anion (SBA) resins?
They have quaternary ammonium compounds as functional groups
## Footnote
SBA resins can remove a wide range of anions depending on the exchange ion used.
35
What are the three types of SBA resins?
Type I, Type II, and acrylic
## Footnote
Each type has different effectiveness based on the water's composition.
36
What is the effect of using hydroxyl ions as exchange ions in SBA?
The treated water pH remains unchanged
## Footnote
Hydroxyl ions neutralize any H+ produced.
37
What are the two configurations of ion-exchange systems?
Serial systems and mixed bed systems
## Footnote
Each configuration serves different demineralization purposes.
38
What is the impact of high levels of free chlorine on ion exchange systems?
It negatively affects ion exchange resins and their performance
## Footnote
Maintaining feed water quality is crucial for effective ion exchange.
39
What does microfiltration remove?
Particles down to about 0.1 micrometres (μm)
## Footnote
It effectively removes yeast cells, suspended solids, and large colloids.
40
What is the typical pressure range for ultrafiltration systems?
2-7 bar
## Footnote
Ultrafiltration is more effective than microfiltration.
41
What is the primary function of membrane filtration?
To allow certain ions and molecules to pass while retaining others
## Footnote
The size of the filter pore determines the filtration level.
42
What is ultrafiltration?
A membrane technology that performs 10 times better than microfiltration with a filter pore size down to 0.01μm
## Footnote
Ultrafiltration removes most viruses, colloids, and large organics but does not remove dissolved substances.
43
What is the typical pressure range for ultrafiltration systems?
2-7 bar
44
What is the pore size of nanofiltration?
0.001μm or 1 nanometre (nm)
45
What percentage of dissolved salts does nanofiltration remove?
20-80%
46
What is the pressure range required for nanofiltration?
6-10 bar
47
What is reverse osmosis (RO)?
A process where water is diffused across a semi-permeable membrane from high to low solute concentration by applying pressure
48
What is the smallest membrane pore size in reverse osmosis?
0.0001μm
49
What percentage of dissolved minerals can reverse osmosis typically remove?
More than 98%
50
What is the pressure range for reverse osmosis systems?
10 to 20 bar (up to 82 bar for sea water)
51
What happens to the water during reverse osmosis?
Water molecules pass through the membrane to create purified water, while minerals remain in the reject stream
52
What is the reject rate for most RO units?
Around 25% of feed water volume
53
What is the main advantage of reverse osmosis?
Converts feed water into virtually pure water
54
What is the most popular method for removing chlorine and organic contaminants from water?
Activated carbon
55
What process does activated carbon use to remove impurities?
Physical adsorption into its honeycomb structure
56
What is the reaction of sodium metabisulphite in water?
Forms sulphur dioxide, which reacts with chlorine to form chloride and sulphate
57
What does UV photolysis do to chlorine?
Breaks chlorine's molecular bonds, yielding chloride and water
58
What are two chemical sterilization methods mentioned?
* Chlorine dioxide
* Ozone
59
Why is chlorine dioxide preferred over chlorine in breweries?
It does not produce flavour taints and is non-corrosive
60
What is the typical concentration of chlorine dioxide used?
Up to 1.5 mg/L
61
What is the bactericidal activity of ozone attributed to?
Oxidation of bacteria cell membranes
62
What is the disadvantage of using ozone for sterilization?
High running cost compared to other methods
63
What is the wavelength range for UV light used in sterilization?
200-280 nm
64
What is sterile filtration?
Using a porous membrane to retain microbiological contaminants
65
What is the pore size needed for effective sterile filtration?
0.2-0.45 μm
66
What is required to convert raw water into brewing product water?
A series of treatment steps to adjust alkalinity, mineral levels, and remove contaminants
67
What is the final form of water that meets brewing specifications called?
Brewing product water
68
What should brewing product water be tested for?
* Alkalinity
* Microbiological contamination
* pH
* Target mineral specifications
69
What is the significance of achieving the correct water specification for brewing?
It allows for the successful creation of water deemed worthy of brewing
70
True or False: Chlorination is still widely used in municipal water supply.
True
71
Fill in the blank: The main disadvantage of reverse osmosis is the _______.
[high energy and maintenance costs]
72
What is Activated Carbon?
A form of carbon processed to have small, low-volume pores that increase the surface area available for adsorption or chemical reactions
## Footnote
Used to remove organic contaminants and chlorine from water.
73
Define Alkalinity.
The capacity of water to neutralize acids, primarily due to the presence of bicarbonates, carbonates, and hydroxides.
74
What is Backwashing?
The process of reversing the flow of water through a filter to clean and remove trapped particles.
75
What is Bicarbonate?
A form of carbonate in water that contributes to alkalinity and can be removed through decarbonation processes.
76
Explain the Bronsted-Lowry Theory.
A theory of acids and bases where an acid is a proton (H⁺ ion) donor and a base is a proton acceptor.
77
What is Calcium Carbonate (CaCO₃)?
A compound that forms scale in water systems and can be removed through heating or lime treatment.
78
What is a Cartridge Filter?
A type of filter that uses a replaceable cartridge to remove suspended solids from water.
79
Define Catalytic Media.
Materials like manganese dioxide or greensand used in filters to remove iron and manganese from water.
80
What is Chlorine Dioxide used for?
A powerful oxidizing agent used for water sterilization, produced by reacting hydrochloric acid with sodium chlorite.
81
What are Colloids?
Small particles that remain suspended in water and can be removed through filtration processes like ultrafiltration.
82
What does Conductivity measure?
A measure of water’s ability to conduct electricity, influenced by the concentration of ions in the water.
83
What is Decarbonation?
The process of removing bicarbonates from water, typically through heating, lime treatment, or acid addition.
84
Define Degassing.
The removal of dissolved gases, such as CO₂, from water, often using mechanical aeration or membrane systems.
85
What is Demineralization?
The removal of dissolved minerals from water, often achieved through ion exchange or reverse osmosis.
86
What are Dissolved Solids?
Minerals and organic matter dissolved in water, which can affect water quality and taste.
87
What is Filtration?
The process of removing particles from water by passing it through a porous medium.
88
What is Free Chlorine?
Chlorine present in water that is not bound to other compounds and is available for disinfection.
89
What is Greensand?
A type of sand containing glauconite, used in filters to remove iron, manganese, and hydrogen sulfide from water.
90
Define Hardness in water.
The concentration of calcium and magnesium ions in water, which can cause scale formation and affect brewing processes.
91
What are Hydroxyl Ions (OH⁻)?
Ions that can be used in ion exchange processes to remove anions from water.
92
What is Ion Exchange?
A water treatment process where undesirable ions are exchanged for more desirable ones using resin beads.
93
What is Mechanical Filtration?
The use of physical barriers, such as screens or filters, to remove suspended solids from water.
94
Define Membrane Filtration.
A filtration process using semi-permeable membranes to remove particles, colloids, and dissolved substances from water.
95
What is Metabisulphite used for?
A chemical used to remove chlorine from water by reacting with it to form chloride and sulphate.
96
What is Microfiltration?
A membrane filtration process that removes particles down to about 0.1 micrometres, including yeast cells and bacteria.
97
What is Nanofiltration?
A membrane filtration process that removes particles down to about 0.001 micrometres, including most organics and some dissolved salts.
98
What is Osmosis?
The diffusion of water across a semi-permeable membrane from a low solute concentration to a high solute concentration.
99
What is Ozonation?
A water sterilization process that uses ozone to oxidize and kill bacteria, viruses, and other contaminants.
100
What is Permeate?
The filtered water that passes through a membrane in processes like reverse osmosis.
101
What is Phosphoric Acid used for?
An acid used to remove iron from water by forming insoluble iron phosphate.
102
Define Regeneration in ion exchange.
The process of restoring the capacity of ion exchange resins by flushing them with a solution of desirable ions.
103
What is Reverse Osmosis (RO)?
A membrane filtration process that removes dissolved ions and molecules from water by applying pressure to overcome osmotic pressure.
104
What is Sodium Hydroxide (NaOH)?
A strong base used in the regeneration of ion exchange resins and for pH adjustment.
105
What is Sterile Filtration?
A filtration process that removes microbiological contaminants from water using a membrane with pore sizes between 0.2-0.45 micrometres.
106
What is a Strong Acid Cation (SAC) Resin?
An ion exchange resin that removes all metal cations, including those bound to bicarbonates, at any pH.
107
What is a Strong Base Anion (SBA) Resin?
An ion exchange resin that removes both strong and weak acid anions, including silica and carbonic acid.
108
Define Temporary Hardness.
Hardness in water caused by bicarbonates of calcium and magnesium, which can be removed by boiling or ion exchange.
109
What are Trihalomethanes (THMs)?
Organic halogenated compounds formed by the reaction of chlorine with organic material, which can cause taste and odor issues in water.
110
What is Ultrafiltration?
A membrane filtration process that removes particles down to about 0.01 micrometres, including most viruses and large organics.
111
What is Ultraviolet (UV) Light used for?
A method of water sterilization that uses UV light to destroy the DNA of microbiological contaminants.
112
What is a Weak Acid Cation (WAC) Resin?
An ion exchange resin that removes cations associated with temporary hardness and alkalinity.
113
What is a Weak Base Anion (WBA) Resin?
An ion exchange resin that removes anions of strong acids but not weak acids like carbon dioxide or silica.
114
What is the primary focus of water treatment in brewing?
To make potable water suitable for brewing by adjusting its mineral composition and removing impurities.
115
What impurities might potable water contain despite municipal treatment?
High levels of hardness, alkalinity, incorrect mineral ratios, and free chlorine.
116
What is one of the first steps in water treatment?
Removal of solids.
117
What mechanical filtration steps are involved in pre-treatment of water?
* Screening through metal grids
* Sand filtration
118
What is the purpose of using a cartridge filter at the brewery?
To remove any remaining suspended solids.
119
What materials are cartridge filters typically made of?
Polymer fibers wound in a spiral.
120
What happens to filter mediums over time?
Solids block the available channels, increasing pressure and indicating the need for replacement or cleaning.
121
What types of particles require a final filtration step?
Solid particles that are too small to be trapped by the initial filter.
122
How can iron and manganese be removed from water?
* Using catalytic media like manganese dioxide or greensand
* Injecting air or ozone
* Using phosphoric acid
* Ion-exchange systems
123
What is the purpose of reducing alkalinity in water treatment?
High alkalinity levels are not suitable for brewing.
124
What is one method of decarbonation used in water treatment?
Dosing water with calcium hydroxide.
125
What do ion exchange systems use to remove undesirable ions?
Resin beads.
126
What types of ion exchange resins are used in water treatment?
* Weakly Acidic Cation (WAC)
* Strongly Acidic Cation (SAC)
* Weakly Basic Anion (WBA)
* Strongly Basic Anion (SBA)
127
What is the Bronsted-Lowry theory of acids and bases?
An acid is a proton donor and a base is a proton acceptor.
128
What do Weakly Acidic Cation (WAC) resins specifically remove?
Cations associated with weak acids.
129
What is the result of using Strongly Acidic Cation (SAC) resins?
They remove all metal cations, including calcium and magnesium.
130
What is the regeneration process for ion exchange resins?
Flushing with a strong solution of desirable ions.
131
What is the effect of using hydrogen ions in SAC resins?
The water pH drops significantly.
132
What do Weakly Basic Anion (WBA) resins exchange?
Hydroxyl ions for the anions of strong acids.
133
Why are WBA resins less commonly used in brewing?
They cannot remove carbonate and may slightly increase pH.
134
What functional groups do Strongly Basic Anion (SBA) resins have?
Quaternary ammonium compounds.
135
What is the difference between Type I and Type II SBA resins?
Type I is more effective in removing silica, while Type II is typically used for brewing.
136
What is the pore size range for microfiltration?
About 0.1 micrometres (μm).
137
What does ultrafiltration remove?
Most viruses, colloids, and large organics.
138
What is the significance of nanofiltration in water treatment?
It achieves filtration down to 0.001 micrometres (nm) and removes most organics.
139
What is the pore size of ultrafiltration?
0.01μm
## Footnote
Ultrafiltration performs 10 times better than microfiltration and removes most viruses, colloids, and large organics.
140
What substances does ultrafiltration not remove?
Dissolved substances
## Footnote
Ultrafiltration does not change the water’s chemical characteristics.
141
What is the pore size of nanofiltration?
0.001μm or 1 nanometre (nm)
## Footnote
Nanofiltration achieves 10 times more filtration than ultrafiltration.
142
What percentage of dissolved salts does nanofiltration typically remove?
20-80%
## Footnote
Nanofiltration also removes most organics, including precursors to trihalomethanes (THM).
143
What is the pore size of reverse osmosis (RO)?
0.0001μm
## Footnote
RO removes dissolved ions and molecules by applying pressure to overcome osmotic pressure.
144
What is the typical removal rate of dissolved minerals by RO?
More than 98%
## Footnote
Significant pressures are required to overcome osmotic pressure in RO systems.
145
What are some advantages of RO systems?
* Removal of alkalinity
* Removal of problem compounds like manganese, silicates, and iron
## Footnote
However, there are also disadvantages associated with RO systems.
146
What are some disadvantages of RO systems?
* Difficulty of disposing of concentrate
* High reject rate
* Expensive membrane replacement
## Footnote
If feed water is hard, an ion exchange unit is recommended before RO.
147
What is a recommended method to prevent fouling of RO membranes?
Anti-scalent dosing
## Footnote
This can prevent silica and hardness scale from blocking membranes.
148
What is the role of an activated carbon filter in RO systems?
Removes chlorine
## Footnote
Chlorine can damage the RO membranes.
149
What is the main advantage of RO in water treatment?
Converts feed water to virtually pure water
## Footnote
This allows for precise adjustment of water composition for brewing.
150
What is the most popular method for removing organic contaminants?
Activated carbon
## Footnote
Activated carbon adsorbs impurities through physical adsorption.
151
What happens to activated carbon based on contamination levels?
Requires replacement or regeneration
## Footnote
This depends on the contamination level and filter capacity.
152
How does metabisulphite remove chlorine?
Forms sulphur dioxide, which reacts with chlorine
## Footnote
This results in the formation of chloride and sulphate.
153
What does UV photolysis do to chlorine?
Breaks chlorine’s molecular bonds
## Footnote
UV light reduces chlorine to chloride and water.
154
What is the effectiveness of UV light in killing microorganisms?
Kills 99.99% of bacteria and viruses
## Footnote
UV light is effective in sterilization techniques.
155
What are chemical sterilization methods?
* Chlorination
* Chlorine dioxide
* Ozonation
## Footnote
These methods are essential to prevent microbiological contamination.
156
What is produced during ozonation?
Ozone
## Footnote
Ozone is injected into water to achieve bactericidal activity.
157
What is the typical pore size for sterile filtration?
0.2-0.45 μm
## Footnote
This method uses a porous membrane to retain microbiological contaminants.
158
What is a disadvantage of UV light sterilization?
Lacks residual killing potential
## Footnote
Sterilization occurs only at the point of irradiation.
159
What is the water treatment process prior to brewing?
Raw water undergoes multiple treatment steps
## Footnote
These steps ensure the water is potable and free from vegetative microbiological contaminants.
160
What is required for water to be suitable for brewing?
Further treatment steps to achieve correct alkalinity, mineral levels, and microbiological purity
## Footnote
Potable water may not meet brewing specifications.
161
What is tested in the treated water before brewing?
* Alkalinity
* Microbiological contamination
* pH
* Target mineral specifications
## Footnote
If specifications are met, water is directed into a hot water tank.
