ENVIRONMENTAL PROTECTION Anita SZABÓ András OSZTOICS Dóra LAKY

Drinking Water

Other aspect: 1. Domestic - water for drinking, cooking, personal hygiene, lawn sprinkling, etc. 2. Public - water for fire protection and street cleaning and water used in schools or other public buildings 3. Commercial and Industrial – water used by restaurants, laundries, manufacturing operations, etc. 4. Loss - due to leaks in mains and house plumbing fixtures

WATER SOURCES Subsurface waters:  ground water  water of deep confined aquifers  karstic water  bank filtered water Surface waters:  river  lake  reservoir

waste disposal water table well back-housemanure fertilizer This water source is the most sensitive to pollution from point or non-point source. Pollutants occur here are most often due to human activity.

WATER OF DEEP CONFINED AQUIFERS 2nd aquifer 3rd aquifer well 1st aquifer water table no pollutants of human activity origin

KARSTIC WATER limestone CO 2 containing precipitation (rain water, melted snow) dissolves limestone no protecting layers (clay, or any others) during the water transportation from the surface into the deep  vulnerable to pollution

Karstic water The carbon-dioxide containing precipitation (rain, water, melted snow) have produced for itself corridors, tunnels and caves in limestone hills. H 2 CO 3 + Ca CO 3  Ca HCO 3 - Taking into consideration the geological structure of the limestone hills, in a lot of cases do not exist any protecting layers (clay or any others) during the water transportation from the surface into the deep.

BANK FILTERED WATER Most of the water of such wells originates from the rivers, but groundwater from the background (back side feeding) may also play a role. For abstraction of bank filtered water the wells can be set up on river banks, were hydrogeological conditions are favourable for the flow of high quantity river water towards to the water containing zone.

During the low water level period in the river, the quantity and quality of groundwater originated from the background can be significant.

1. Surface waters a.) River water: turbidity (suspended solids, phytoplankton) pathogen and other microorganisms organic matter humic, fulvic and lignine substances organic and inorganic micropollutants oil ammonium ions (especially in cold water) : Possible pollutans of drinking water sources:

b.) Lake water: turbidity ( phytoplankton, suspended matter ) pathogen and other microorganisms humic, lignine and fulvic substances organic matter oil ammonium ions (especially in cold water)

c.) Reservoir water: turbidity ( phytoplankton ) pathogen and other microorganisms humic, fulvic and lignine substances organic matter ammonium ions (especially in cold water or lack of dissolved oxygen)

2. Subsurface waters a.) Ground water: pathogen and other microorganisms ammonium, nitrite, nitrate iron and manganese compounds organic matter organic and inorganic micropollutants lack of dissolved oxygen

b.) Water of deep confined aquifers: humic fulvic and lignine substances volatile hydrocarbons (methane) ammonium, H 2 S iron and manganese high salt content high temperature arsenic ( geochemical origin) high CO 2 content

c.) Karstic water: turbidity ammonium and nitrate pathogenic and other microorganisms organic and inorganic micropollutants organic matters

d.) Bank filtered water: iron and manganese organic substances ammonium microorganisms organic and inorganic micropollutants hydrocarbons

Criteria colourless odourless does not contain: turbidity poisonous matters pathogenic microorganisms high salt content high organic content

What to do if criteria are not met? - abandone that source – bring water from other source - regional systems - TREATMENT

What to remove? 1. pathogen microorganisms 2. toxic components 4. N forms (ammonium, nitrite, nitrate) 5.substances causing aesthetic problems (e.g. suspended solids, humic substances, iron content, odour) 3. precursors

To what limit we should keep? STANDARDS: commendations – WHO regional regulation – EU national standards

Factors effecting treatment: - what parameters are problematic - how much water is needed (huge quantities, demand changes in time) - extent of the net - delivery time to the outermost consumer

Factors effecting treatment: - what parameters are problematic - how much water is needed (huge quantities, demand changes in time) - extent of the net - delivery time to the outermost consumer

What processes can we use? 1. oxidation-reduction 2. pH and buffering capacity adjustment (pH optimum of processes) 3. chemical precipitation (dissolved  particulate) 4. adsorption (bind to surface) 5. phase separation (removal of different phases: solid/liquid and gas/liquid phase separation) 6. other (e.g. reverse osmosis)

What processes can we use? 1. oxidation-reduction 2. pH and buffering capacity adjustment (pH optimum of processes) 3. chemical precipitation (dissolved  particulate) 4. adsorption (bind to surface) 5. phase separation (removal of different phases: solid/liquid and gas/liquid phase separation) 6. other (e.g. reverse osmosis)

Oxidation and reduction The processes are parallel with each other, they take place at the same time The oxidation agent will be reduced, while the reduction agent will be oxidized In drinking water treatment chemicals are oxidized in order to make them non-soluble, in order to make them less toxic or in order to kill bacteria (disinfection) Oxidizing agents are: oxygen, ozone, chlorine, potassium permanganate, chlorine dioxide, chloramines, …

What processes can we use? 1. oxidation-reduction 2. pH and buffering capacity adjustment (pH optimum of processes) 3. chemical precipitation (dissolved  particulate) 4. adsorption (bind to surface) 5. phase separation (removal of different phases: solid/liquid and gas/liquid phase separation) 6. other (e.g. reverse osmosis)

Control of pH and buffering capacity pH control is important during several water treatment steps ( high efficiency )

What processes can we use? 1. oxidation-reduction 2. pH and buffering capacity adjustment (pH optimum of processes) 3. chemical precipitation (dissolved  particulate) 4. adsorption (bind to surface) 5. phase separation (removal of different phases: solid/liquid and gas/liquid phase separation) 6. other (e.g. reverse osmosis)

Chemical precipitation What is chemical precipitation? Transformation of water soluble compounds into poorly water soluble solid compounds in consequences of significant pH change or chemicals addition into water. solid-liquid: optimal removal of soluble compounds from the water transform into solid matters

What processes can we use? 1. oxidation-reduction 2. pH and buffering capacity adjustment (pH optimum of processes) 3. chemical precipitation (dissolved  particulate) 4. adsorption (bind to surface) 5. phase separation (removal of different phases: solid/liquid and gas/liquid phase separation) 6. other (e.g. reverse osmosis)

Adsorption What is adsorption? The physical and/or chemical process in which a compound is accumulated at an interface between phases (solid-liquid interface) The most important adsorbent is activated carbon: – able to remove dissolved organic substances from water – rremoval of organic micropollutants

What processes can we use? 1. oxidation-reduction 2. pH and buffering capacity adjustment (pH optimum of processes) 3. chemical precipitation (dissolved  particulate) 4. adsorption (bind to surface) 5. phase separation (removal of different phases: solid/liquid and gas/liquid phase separation) 6. other (e.g. reverse osmosis)

Gas / Liquid Phase Separation Removal of volatile compounds, gases Removal of volatile compounds, gases The mostly applied gas-liquid separation: aeration The mostly applied gas-liquid separation: aeration The volatile matters leave the liquid phase by flowing a high volume of inert gases or air The volatile matters leave the liquid phase by flowing a high volume of inert gases or air What is aeration?

During areation the water is saturated by oxygen ( by air flowing) During areation the water is saturated by oxygen ( by air flowing) Two processes take place: Two processes take place: – oxidation of compounds situated in their reduced form – the stripping of volatile compounds

Solid matters removal: coarse and fine separation processes coarse and fine separation processes coarse processes: – screening – microstraining – sand removal (sand trip) – sedimentation – flotation Solid / Liquid Phase Separation

Fine processes: – slow sand filtration – rapid filtration The fine particles are able pass through the filters too! Transform colloid, quasi colloid particles for sedimentation and filtration ( coagulation, flocculation) Transform colloid, quasi colloid particles for sedimentation and filtration ( coagulation, flocculation)

What processes can we use? 1. oxidation-reduction 2. pH and buffering capacity adjustment (pH optimum of processes) 3. chemical precipitation (dissolved  particulate) 4. adsorption (bind to surface) 5. phase separation (removal of different phases: solid/liquid and gas/liquid phase separation) 6. other (e.g. reverse osmosis)

Reverse Osmosis Reverse osmosis consists of separating a solvent, such as water from a saline solution by the use of a semi permeable membrane and hydrostatic pressure