LAKE WIRE DREDGING (USA)
A source removal corrective action was performed on Lake Wire in the U.S. Storm water discharges have resulted in elevated concentrations of metals in sediments (predominately lead). These following remediation tasks have been undertaken
Mechanic dry-dredging via barge mounted excavators over 9,000 cubic yards of lead impacted sediments from a 12-acres spring fed lake down to a depth of 20-feet.
All dredged sediments were loaded into barge mounted intermodal steel containers. The wet sediments were removed with a 65-foot long reach excavator, placed into the steel containers, and transported to the edge of the lake.
Initially, the dredge sediments were dewatered using a plate and frame filter press. However, a number of complications associated with filter pressing the sediments resulted in delayed production. Accordingly, various alternatives were explored to solidify the sludge and thus increase the overall production rates.
After analyzing the various alternatives, it was determined that the addition of superabsorbent products was extremely effective in the rapid and economical solidification of the sediments.
After the transfer of approximately 200 tons of wet dredge sediments into the mix basin, approximately 2 cubic yards of superabsorbent polymer and phosphate-based lead fixating agent were added. The super absorbent polymer was used to solidify the sediments prior to stabilizing the contaminated metals. Approximately 1-ton of SAP was broadcast within a confined concrete cell to approximately 200 cubic yards of sediments where it was mixed using a long-reach excavator.
Once the solidified sediment transformed into a cohesive “soil”, the phosphate-based reagent was applied. Stabilized sediments were transferred to 250-tons stockpiles, loaded into dump trailers for transportation to a sub-title D landfill after analytical verification.
- Importing clean fill and replacing/backfilling the removed sediments in water depths of 4 foot or less
- Grading and sodding disturbed bank soils
- Wetland plantings
This removal action was intended to reduce or eliminate exposure risks of impacted sediments to reduce the rate of migration of lead to surface waters. This was accomplished by treating contaminated sediments to below TCLP metal standards to render the dredge sediments non-hazardous for landfill disposal
SLUDGE EXCAVATION (UK)
In England, a construction site is facing a large amount of sludge caused by directional drilling actions. It is impossible to collect the sludge and the situation requires an intervention in order to pursue any further work on site.
To find a solution to this issue, the superabsorbent product APROMUDTM P150XL was applied. The aim is to solidify the sludge in order to clear the site either by forming a solid heap aside or by transporting and evacuating the sludge off site.
APROMUDTM powder is sprayed on the sludge’ surface, then simply mixed thanks to construction machines such as excavators.
From only five 25KG bags, in other words 125KG, 60 tons of solid sludge initially liquid was created (see pictures below). This result was obtained within a few minutes only.
LAGOON CLEARING (USA)
Lagoon clearing was implemented to determine the source of previously dectected volatile organic compounds (VOCs) in a wastewater lagoon with previous collection of groundwater, surface water and sludge samples. VOCs above quality standards were detected in all samples.
The lagoon was dewatered (approximately 515,000 gallons), then the water was treated and disposed off-site. The remaining 280 tons of lagoon sludge was solidified using same superabsorbent products as those from APROMUDTM range. In total, 290 tons of solidified material was transported to a disposal facility.
Super absorbent polymer (SAP) was chosen for this project to reduce transportation and disposal costs. The use of traditional solidification agents, such as saw dust, lime kiln dust, or cement would have significantly increased the waste volume and overall transport and disposal costs. By using SAP products the client was able to save thousands of dollars.
BITUMINEOUS SLUDGE DEWATERING
Aida Farkish’s thesis (2013) from the University of Ottawa (Canada) explores the problematic issue of SAP based rapid dewatering process of oil sands mature fine tailings. This thesis demonstrates that the use of SAP products increases significantly the solidification process.
Products from APROSOILTM range are mainly dedicated to the optimization of agriculture. The implementation of superabsorbent products will increase the soil’s water-holding capacity, boost plants growth (via roots development) thanks to a higher amount of water and nutriments. It also offers a protection against hazardous climate.
PREVENTION FOR COMMUNICATION CABLES DAMAGE
Cables and optic fiber are mostly used underground, underwater or in air. Thus, water can penetrate into the cable when the external sheath is damaged, thereby causing problems.
In order to prevent water from penetrating into the cable, a layer of superabsorbent polymer is placed between the cable outer layer and the cable core. Therefore, if there is dame to the external sheath and water penetrates, the SAP polymer absorbs the water and swells, thus protecting the cable thanks to a gel blocking effect.
Schema hereunder illustrates the structure and mechanism for prevention of water penetration.
These superabsorbent polymers are quite different from those used for disposable diapers in that they are required to last for several tens of years. Indeed, they have a much higher capacity to resist to degradation by biological or other factors. The polymers based on polyacrylate chemistry have a high water absorptivity going up to 400 times it’s mass in water. An efficient formula against salt water has also been developed.
WATER RETAINERS FOR SOILS AND SUBSTRATES
To assure a strongest and fastest growth of young plants, shrubs or trees, APROSOILTM can be mixed to different substrates. Savings up to 50% can be made on watering process reducing costs (personnel and/or amount of water).
The behavior of plants fertilized within this mixture makes it possible to increase yield while at the same time protecting the environment from leaching. The polymer is added dry when the fertilizers are manufactured.
Fertilizers are active longer thanks to the delay in water dropping engender by the polymer. Savings up to 30% are observed in fertilizers dosage.
DUST CONTROL IN HORSE ARENA
A constant problematic issue regarding horse arena watering remains. Indeed, watering those arenas are required to assure a mechanic quality of soils and maintain horses’ health (because of dust inhaling). However, it is often put in question because of the amount of water used. Products from APROSOILTM are not harmful to the environment, humans and animals’ health. They guarantee a watering reduction of up to 50% and reduce dust while maintaining humidity in the soil.
Hereunder, a graph which represents the humidity percentage within the soil in time.
While reducing soil compaction, APROSOILTM will achieve absorbing and dropping cycles depending on the soil’s need of water. For instance, when soil dries the polymer drops back progressively the absorbed water in order to maintain certain humidity within the soil.
The polymer must be applied under 3 to 20 cm under the upper layer of the area depending on cases. The use of a rototiller or harrow to air the area is recommended.
- Reduces arena watering by up to 50%
- Control dust
- Adds bounce to the riding surface
- Lasts several seasons in the soil
- Cost effective
- Environmental friendly