Based on extensive experience with soil treatment technology, Stuyvesant Environmental Contracting's associated company Boskalis Dolman has developed highly efficient Mobile Separation & Dewatering Plants. These MSDPs have been designed and constructed using standardized shipping container modules to facilitate quick and easy transport. The incorporation of the latest technical developments minimizes the use of fuel and additives, and optimises plant uptime and efficiency. The capacity of the MSDPs is much higher than comparable mobile plants and even most modern permanent soil processing plants.

The different modules are built from standardized skid-mounted and containerized equipment including screening and separation units, a polymer dosing unit, plant automation and control equipment, and 'plug and play' belt filter presses. The plant can be set up in different configurations, depending on the site and project requirements.

The plant includes two-stage screening prior to sand separation. All material +3mm is screened. There is a log washer for additional cleaning of this material (to make it suitable for beneficial use where necessary).

The counter-current washer, used as a polishing step for the sand fraction separated using the hydrocyclones, is normally an integrated component of the sand separation module. However, the use of the counter-current washer is optional, depending on soil and contaminant characteristics.

Mechanical dewatering is normally performed using one or more belt filter presses. Depending on project specific demands, the belt filter presses may be exchanged for other types of dewatering equipment including plate and frame presses or decanting centrifuges.

A dosing and mixing unit for adding lime, cement, or other stabilizing reagents to the produced filter cake is optional. This may be necessary depending on specific requirements for the transport and disposal of the filter cake.

An MSDP is designed to handle more then 100 ('wet') metric tons of contaminated soil per hour. The wet feed includes the material 'as is', in other words a mixture of debris and coarse particles, sand, silt/clay and moisture. In a typical situation, the mobile plant throughput will be limited either by the capacity of the sand separation module or by the mechanical dewatering module.

Our plant covers an area of approximately 2,500 m2. The total footprint of an area with sufficient storage capacity, wheeled loader manoeuvring space, etc. is typically 10,000 m2.

Process water is normally recycled at the plant. However, water intake and discharge options must be available to cope with discharge and storm water management.