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Title: Review And Appraisal Of Water Pollution Control Equipment
Author: P Wood
Author: N Bailey
Author: K Dooley
Author: Environment Agency
Document Type: Monograph
Annotation: Environment Agency Project ID:EAPRJOUT_412, Representation ID: 116, Object ID: 1752
The Environment Agency deals with over. 35,000 reported pollution incidents each year and it. is therefore essential that the response to these incidents is effective and efficient in order to minimise the impact on the enviromnent:.The Agency. has thus commissioned a detailed study to review and appraise .the performance of the water pollution control equipment currently:. used. This is the Technical Report of this review and appraisal. Sorbed The Agency should consider identifying .a restricted range of sorbent types based on performance, value -for money. and, environmental implications. Whereas organic sorbents are generally reported to be derived from sustainable resources there may, be a perceived environmental implication in their use. In contrast, some synthetic sorbents are manufactured from otherwise waste materials that would be disposed of to landfill. As far as is possible, the Agency should also consider within their purchasing mechanism, the possibility of introducing some standardisation in the colour of sorbents used -for particular duties. Ideally; sorbents .for application to hydrocarbons should .a11be the same COlourj while those for application to chemicals should-all be another colour.~It is further recommended that a combination of colour coding and labelling isaused: all sorbents that are oil only should be white and, bear the word a OILa in blackwhile all sorbents that are universal, and capable of handling the more aggressive chemicals, shouldabe yellow and bear the word aUNIVERSAL? in black. Most synthetic oil only sorbents were found to be similar in,perfonnance during laboratory. tests although, of those tested; Drizit 0140 performed best in many aspects. Liquitrol OPH 4843 also performed well and.was rated highly by Agency staff during their evaluation. Sphag Sorb and Peat Sorb were .the best. organic sorbents tested with oil. However, these materials are probably best suited for use on solid surfaces. Additionally;: as their performance does not .. appear to be better than the,.best synthetic sorbents, and, as there are ,possible perceived negative environmental implications. from the harvesting of the moss used in their. manufacture, it is recommended that use be restricted to special applications where.oil needs to be recovered from hard surfaces. Frogrnat .has potential to protect vulnerable. riverbanks although deployment and recovery I might be difficult. The removal of oil. sheen by sorbents would. still appear to be.. problematical. Most synthetic. universal .sorbents are appropriate for many chemicals but- .most are incompatible with at least some of the more- stronger acids, caustics and oxidisers. Organic universal sorbents should be avoided for use on many chemicals. -It is therefore recommended that synthetic sorbents only be used for chemicals. It is recommended that sorbent re-use be confined to the clean-up of solid surfaces. R and D Technical Report P212 It is recommended that sorbent disposal by incineration should be the preferred route for both organic and synthetic sorbents although costs will probably be significantly higher than for landfill. Environment Protection OfficerTs Kit A list ,of kit which -should be accessible to an Enviromnent.:Protection Officer .has been developed. The adoption of this list will provide some uniformity across the Regions and thus facilitate any transfer of staff. Equipment-Required by.Fire Services A list of equipment- required by Fire Services respondin, m to a spillage has also been developed. The following recommendations for best practice are also made:l l l l l due,consideration should be given to the leave alone option ..a, clay.leak preferred compared to epoxy based leak sealants sheets (or tubs) of clay based material,a and inflatable drain-seals/pipe blockers should be preferred to water. filled plastic bags or polyurethane sheeting for blocking drains. Where appropriate the clay sealant should be used in conjunction. with metal sheeting to reduce quantities used sorbent booms or other :sorbent- types should abe used in conjunction with containment booms for containment and recovery of liquids on water surfaces. wherever possible drums and overdrums or similar vessels should be lined with plastic prior to use, thus enabling potential re-use. Booms An evaluation of sorbent boom. for use in narrow -waterways has resulted in the following-: recommendations: l l l l booms without skirts can be used in stillzwater. booms with skirts should be:used where there is any water movement sorbent boom should .be used in combination with containment boom if there is any appreciable flow, such *that the containment boom,is downstream of the sorbent boom.. Alternatively, the containment boom can be used in conjunction with other sorbent types consideration should be given to the use of double booms, more than one single boom or a single boom along with other sorbent types if the boom is to be left unattended: 1. An evaluation of containment boom for. use in narrow waterways has resulted in the following recommendations: l l for low velocity applications - lightweight, high visibility; inflation or permanent buoyancy boom with own brand connectors. (Height, -200-300 mm; freeboard;-minimum of 30 % of height; draft, minimum of 50 % of height.) for high velocity applications - heavier high visibility fence boom with standard ASTM or Unicon connectors and -which can .be easily cleaned. (Height,- --300.. mm -upwards;, freeboard; minimum of 30 % of height; draft; minimum of 50 % of height.). R and D Technical Report P212 iV The review of containment boom for coastal and- river use has resulted ain the following recommendations:. high strength; durable inflation boom- with standard ASTM or Unicon connectors and .a. multiple anchoring points and- which is easily cleanable. (Height,,:up to 2m; freeboard, minimum of 30% of height; draft, minimum of 55% of height; minimum breaking strain in rivers, 50 kN; minimum breaking strain in coastal area, 100 kN.) : Skimmers Skimmers that are considered more versatile and of potential use to the Agency include the suction, weir and disc type along.with rope-mops. However, as usage by the Agency seems to be very low it is recommended that the Agency does not require any permanent pieces of equipment of this type. Aeration Technologies Aeration technologies are important to the Agency operations. It is considered-that the use of hydrogen peroxide to achieve rapid oxygenation has considerable .potentialand achieves a more rapid improvement of- oxygen levels than aeration. alone. Should ::the ongoing investigation being funded. by--the Agency,. confirm the, benefits of hydrogen peroxide treatment then the Agency should increase the amount of-equipment they hold..*This can be;: readily achieved by either of the following two approaches: l l conversion of existing River Rovers- this equipment would have potential for,use in larger and deeper water bodies additional pumps and venturi devices - this equipment would have potential for use in both large/deep and small/shallow water bodies. The Oxyjet, for example, would appear to be versatile for these applications and it is recommended that this equipment be trialed and compared to the River Rover. i Spill Detection at -Night An evaluation of low cost.methods and equipment for the detection of oil and chemical spills at night has been undertaken. It is concluded that there is no portable and cheap equipment available.for this purpose,-although oil test papers are available. Encapsvlation Two encapsulation products, Unisafe and Unibiber, are both-suitable for encapsulating a range of;chemicals although each had different strengths and weaknesses. With the existing price structure for these two products it .would appear that the cost of treatment is significantly less with Unisafe. It is thus recommended that, while this cost differential exists, Unisafe :be used rather than Unibiber. However, users need to be informed. that there are ,potential hazards when this -product is used with strong oxidisers.. When either product is used on unknown. chemicals only a small amount- should be applied initially. R and D Technical Report P212 Drain Seals Laboratory based investigations suggest that, on clean surfaces, all types of drain seals tested can be expected to perform well although sand bags will probably allow some leakage. With non-clean surfaces, or surfaces with some roughness, clay material and inflatable seals can be expected to perform well. The sand bag is likely to allow significant leakage. The tetrahedral water-filled plastic bag and the polyurethane sheet are likely to result in excessive leakage. Temporary Storage and Oil-Water Separation The most appropriate temporary storage containers for immediate emergency use are rigid rectangular collapsible storage units such as Fastank and TroilTank. The TroilTank is the most rapid to deploy. Additionally, a low walled flexible tank such as the Pop-Up Pool is recommended as this has potential for the collection of leaking liquids in restricted spaces. Oil-water separation procedures would have potential in reducing the quantity of liquids that need to be transported and disposed of Separation would occur within storage tanks with bottom drawn liquid being discharged to the environment. This should be discharged through a sorbent filter if necessary or with the use of an oil-in-water monitor to ensure water quality. Any discharged liquid should be returned upstream of the collection point. The use of skimmer heads while collecting fluids into vacuum tankers would also assist in reducing volumes to be disposed of. Proprietary oil-water separators are expected to provide a better performance than separation in ordinary storage units. (Key words: oil, chemical, spills, skimmers, booms, sorbents, aeration, hydrogen peroxide, drain seals, storage vessels.) R and D Technical R and mrf P212 vi
Publisher: Environment Agency
Subject Keywords: Oil; Chemical; Spills; Skimmers; Booms; Sorbents; Aeration; Hydrogen peroxide; Drain seals; Storage vessels
Extent: 94
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