Module 3: Environmental Objectives, Programme of Measures, Economic Analysis, Exemptions Remediation & Removal of River Pollutants Michael Jackman- Chemistry Expert Afyon, 2015 POLLUTION ABSORBENTS 1) Once the pollutant has entered the water course one needs to consider how to remove or deactivate the pollutant.
One means of treating a spillage is by the application of sorbent materials to absorb the chemical. These include synthetic and natural materials such as: polypropylene, polyethylene, peat fibre, wool, clay and activated carbon. These can be in the form of rolls, booms, fibres, or granules Selection Criteria When selecting the absorbent one has also to take into account: Availability & costs; Location and type of pollutant; Whether the absorbent can be regenerated after use. Overview
Case Study Examples Lessons Learnt Nine Key Components of an EWERS Application of the absorbent as a hydrocarbon filter 1) Overview Case Study Examples Lessons Learnt Nine Key Components of an EWERS WATER TREATMENT Sometimes it is possible to set up temporary treatment works and
an example of this is the Temporary Oil/Water Separator Tank . Overview Some separators are readily assembled but delays can be Case such Study large Examples incurred transporting units. Lessons Learnt Nine Key Components of an EWERS However, there are also collapsible ones which can be easily assembled on site, which are preferable in an emergency
Collapsible oil/water emergency oil spill containment and separation 1) Overview Case Study Examples Lessons Learnt Nine Key Components of an EWERS SKIMMERS When the pollutant has discharged into the river one has to consider ways of controlling it, limiting its effects and if possible, removing it from the river. One way of effecting this is by the application of Skimmers.
Skimmers are devices that used are for the application of the absorbents to be suspended into the polluted water to absorb the pollutant. There are two main types of skimmers. Passive Skimmers Passive skimmers do not use any external forces or mechanisms to present the sorbent. Overview Case Study Examples The polluted water can be passed through the contained Lessons Learnt absorbentNine or these can be pillows
the sorbent, such as Key Components of anofEWERS activated carbon, with buoyancy aids, which are floated on top of the water surface to absorb the supernatant pollutant. Passive Skimmers 1) Overview Case Study Examples Lessons Learnt Nine Key Components of an EWERS
Active Skimmers Active skimmers use a continuous belt of material, synthetic or otherwise, which can remove oil from the surface of water, by means of adsorption or absorption. This utilizes a polypropylene material to form a continuous loop of material, which floats on the surface of water, at the interface of the oil and water. This adsorbs the oil and then the material loop continues on to mechanical wringers and washers to desorb the oil into storage containers. These types of skimmer system are continually being developed so that there are a number of different designs such as the mop, disc, drum, brush, belt, and tube or weir skimmers Mop Skimmers
Overview Case Study Examples Lessons Learnt Nine Key Components of an EWERS Belt Skimmers Belt Skimmers are only available as vertical deployment systems . This seriously limits the effectiveness of the skimmer, since it is located down through the oil layer at one very localized location, which can be useful for boreholes, but not lakes lagoons or rivers where oil
may be spread over a wide area. OPERATIONAL EXAMPLES OF REMEDIATION Removing Surface Pollution from Streams Streams are usually small in width and relatively easy manage. By treating the streams surface but allowing the continuation of water flow at the base, one can treat surface pollution, particularly oil. A length of PVC tubing or pipe is laid on the bottom of the stream with a small section of containment boom and adsorbent boom above at the surface to capture floating contamination such as oil. If there are large amounts of pollution are involved a series of these installations may be required.
Removing Surface Pollution from Streams Application of Booms to remove surface pollution in Streams Trapped Localised Oil Pollution 1) Overview Absorbent Case Study Examples
Boom Lessons Learnt Stream Flow Nine Key Components of an EWERS Pipe Attenuating Boom Pipe Trapped Localised Oil Pollution Hydraulic Methods
Hydraulic Techniques can be used to manage the flow of the water by using dams to either attenuate the flow to localise the pollution plume for treatment, or by accelerating the flow so that the pollutant is diluted and/or flushes the pollutant rapidly past sensitive sites such as drinking water treatment works. If the pollutant is in a small stream then temporary dams can be used to localise the pollution plume for disposal Hydraulic Methods HYDRAULIC REMEDIATION FOR SMALL STREAMS To Tanker, or lagoon
1) Trap and Diversion Method Overview Case Study Examples Stream Flow Lessons Learnt Nine Key Components of an EWERS Temporary Dam Pump
Temporary Dam Pollution Plume Diversion Removing Surface Pollution from Rivers Owing to the high flow rate in rivers, it is not possible to deal with the problem of oil pollution as with streams. A boom deployed at right angles to a body of water flowing at a rate in excess of 1 knot is virtually useless. To boom a river effectively, angles must be used as much as possible to allow deflection of the floating oil to a convenient point at the riverbank
suitable for vehicle access. In these circumstances it is important to remove the collected pollutant with the skimmer as quickly as possible, otherwise the pollutant will be sucked under the boom. In choosing a suitable position for collection, it is advisable to pick a spot near, or on the inside bend of the river where the flow is considerably slower than the water flowing on the outside of the bend. Removing Surface Pollution from Rivers Removing Surface Pollution in River Using Boom & Skimmer 1)
River Flow Overview Case Study Examples Lessons Learnt Nine Key Components of an EWERS Surface pollution Mop Skimmer W rin g
e rS y s te m Temporary Boom Removing Suspended or Dissolved Pollution When the pollutant is dissolved or mixed with the water the above techniques cannot be applied. Other techniques must be applied such as:
chemical techniques using air or hydrogen peroxide to oxidise the pollutant to either change it chemically, or to also change it physically to an insoluble form, such that this settles on the river bed so that it can be removed at a later stage Removing Suspended or Dissolved Pollution In the UK two purpose built vessels have been built and each can inject up to 30 tonnes of oxygen per day directly into the River Thames. These are used during periods when the dissolved oxygen is low, following a pollution incident, or after a storm has stirred up the river bed. Thames VitalityOxygenating Ship
Removing Suspended or Dissolved Pollution 1) Overview Case Study Examples Lessons Learnt Nine Key Components of an EWERS Thames VitalityOxygenating Ship Advanced Combination Techniques The application of suspend static skimmers or
absorbent filter can be used in combination with connected anchored boats. These filters are suspended between the boats. This technique is best applied to slow flowing narrow rivers or canals Advanced Combination Techniques Remediation of a canal or slow flowing river 1) Suspended Static Skimmers or Absorbent Filters
River Flow E-1 Overview Case Study Examples Lessons Learnt Nine Key Components of an EWERS E-6 Anchored Boats E-7
E-5 Finally These are only examples for remediation there are many more ways. It all depends on the incident So whatever you do Dont Panic! ok teekkr ederim
