Modernizing a wastewater treatment process

The development of sludge-treatment technology in China has been slower than expected, meaning that processes create excessive volumes of sludge and water, while disposal is difficult, dewatering is not complete and processes are inefficient. Along with poor resource utilization, the generation of a large amount of polluted sludge has a significant environmental impact if not strictly controlled.

One sludge filter press manufacturer, keen to improve its practices and enhance public perception of its products and business, decided to carry out comprehensive system upgrades to increase processing efficiency, eliminate waste and reduce environmental pollution. For this, the company turned to water-treatment expert SEKO to deliver one of its innovative chemical-dosing solutions.

The SEKO technical team’s first task was to carry out a comprehensive assessment of the client’s production system, where they discovered that the existing process dosed flocculant into the sludge filter press via a screw pump.

​SEKO's Duotek AODD pumps are renowned for their flexibility in pumping difficult liquids at low pressure and flow

While this allowed efficiency to increase, it also reduced precision which inevitably caused excessive chemical dosing as well as costly wastage and accelerated the emission of sludge waste. In addition, the existing equipment had high power, large flow, and a considerable maintenance requirement.

Taking into account the client’s specific process requirements along with the nature of the flocculant to be dosed, SEKO recommended that the client replace the existing screw pumps with its Kosmo Series dosing pumps or Duotek series AODD pump for superior accuracy, reliability and cost-effective performance.

Solution I: Kosmo mechanical diaphragm pumps

Kosmo mechanical diaphragm pumps measure the volume ratio of flocculant to slurry through precision-controlled analogue dosing to achieve consistent mixing while minimizing chemical waste.

In addition, the Kosmo series, with its PTFE diaphragms and PVC/PVDF pump heads, provides excellent chemical compatibility that is ideal for flocculant dosing and ensuring reliability and long life.

Kosmo pumps are widely recognized for their outstanding performance in continuous dosing, courtesy of the dual advantages of zero leakage and stable dosing. This is achieved through the intelligent design of the pump’s ball valves, which can be disassembled for cleaning without the need for regular downtime – an attractive feature for a customer looking to reduce operating costs.

Kosmo pumps may also be equipped with variable-frequency motors or pulse dampers to further improve the stability of dosing, while a back pressure valve guarantees consistency even when water pressure fluctuates.

Solution II: Duotek AODD pump (Air-operated double diaphragm pump)

SEKO's Duotek AODD pumps are renowned for their flexibility in pumping difficult liquids at low pressure and flow and come in many sizes and materials.

These pumps allow almost every type of liquid, from highly corrosive acids through high-viscosity paints and adhesives to food and drink products, to be pumped. The range of applications is virtually limitless and the systems deliver flawless flocculant dosing.

Performance

• Variable flow and head pressures – easy to adjust without sophisticated controls.
• Portable and compact for multi-location use, optionally with trolley.
• Handles liquids with solids particles: ideal for abrasive and viscous media.
• Special air system: lube-free, non-stall, non-freeze.
• Wide range of sizes and materials suited to variety of conditions and chemical fluids.
• Efficient performance: high flow rates through optimal casing designs.
• Self-priming dry up to 6 m: works in suction lift applications.
• Efficient air distribution design for low air consumption.
• Can be customised to specific applications: multiple porting options available along with interface options.
• Safe “deadhead” function, against closed discharge, without pump damage.

Reliability

• 100% wet tested after final assembly: deadheading, priming, and sealing.
• All-plastic air system: strong and corrosion resistant in harsh environments.
• Can be dry run without damaging the pump or system: seal-less design.
• Serviceability: quickly and easily maintained without special tools.

Security

• ATEX certification in all versions: conductive plastic pumps available.
• Special air exhaust: designed to operate at low noise levels.
• Fully submersible: can be immersed completely according to fluid compatibility.
• All-bolted construction: provides maximum leak resistance and safety.

Features

• Materials: PP, PVDF, Aluminium, SS AISI 316 and POMC.
• Flow rate: 8 l/min to 1,000 l/min.
• Connection: ¼” to 3”.
• ATEX certification for Zone 2.
• EX II 3/3 GD c IIB T135°C.

Thanks to the comprehensive improvement of the sludge filter press dosing level, the operator saw treatment efficiency increase while sludge discharge dropped significantly. As well as ensuring that sludge treatment requirements in the on-site process were met, by making its products more environmentally responsible, the customer improved its brand perception among new and existing clients.

Another example of a SEKO solution helping customers achieve long-term, cost-effective improvements in their daily operations.