4.4 Liquid Phase Design and Build Technology

An example of an effluent treatment plant

CPL Carbon Link undertake a systematic approach to the design and specification of liquid phase treatment systems. A range of technologies are available for the treatment of liquid streams containing unacceptable levels of organic contamination. These include carbon adsorption, chemical addition, chemical precipitation and stripping by air or vacuum, followed by treatment of the resultant off-gas.

Flue gases from the high temperature incinerator plant are treated in a sophisticated cleaning plant, involving quench towers for cooling, packed bed absorption units for acid gas control and electrostatic precipitators for the removal of particulate matter. The aqueous effluent containing a rich cocktail of dissolved organic compounds is chemically treated to remove the bulk of these materials.

As a progressive and responsible environmental company, a need was identified to improve further the efficiency of the aqueous treatment plant. In close consultation with the client, CPL Carbon Link designed, built and installed and activated carbon adsorption system. THe plant treats a 40m3 h-1 flow rate, efficiently removing particulate matter of <10µm and reduces the concentration of dissolved organic compounds to <0.1µg l-1.

The same approach was adopted in consultation with an operator of a chlor-alkali process where brominated compounds were present in an acid stream rendering it unusable. CPL Carbon Link provided a service to the client to design, build and install a filter system to remove this contamination using activated carbon.

The aggressive nature of the liquid to be processed required the use of a specially selected rubber coating to the interior of the adsorption vessels, and the treatment of the activated carbon to remove acid soluble matter. This permitted immediate use of the adsorbent without the use of otherwise expensive process chemical to commission the filter units.

The purified acid stream, once passed through the adsorption system was able to be used for further product manufacture, representing a cost saving to client. CPL Carbon Link provide a full maintenance service to this system, including emptying and filling of the adsorbers through the Site Services Division of the company. Fully certified vessels can be supplied to meet all requirements, fabricated from a range of materials, both steel and plastic. A complete turnkey service is available incorporating pipe work and ground works as well as all forms of treatment facilities from chemical dosing equipment to dewatering screens.

An acid purification plant