Water is the essence of life

System technology and componentsfor biological treatmentof industrial and municipal waste water

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GVA develops and supplies

perfectly co-ordinated processes

and technology for biological

treatment of industrial and munic-

ipal waste water. We have been

working closely with our custom-

ers on a global level for more than

20 years, our objective being to

ensure that clean water remains

a resource that future generations

can rely on.

We give the same careful con-sideration to the latest findings inenvironmental protection andresearch and international normsand standards during develop-ment, combining these with ourextensive experience and know-how gathered through the supplyof many systems.

GVA – system specialistsfor biological waste water treatment

“Water …you are life itself.”

Wind, sand and stars;Antoine de Saint-Exupéry (1900 –1944)

Comprehensive know-how in

process and system engineering

Customers all over the worldappreciate the competent consult-ing service we provide during thedesign and realisation of all typesof biological waste water treatmentsystems. In addition to patentedaeration and circulation compo-nents, GVA’s scope of services alsoencompasses process and systemengineering, particularly in relationto the further development andoptimising of treatment techniquesby our R&D department.

The GVA scope of services

Process, planning and service

New system conceptsModernisation and optimisingTRICYCLE process biologicaltreatment stagesService technology and pipelineconstruction

System engineering

and components

ELASTOX® energy-savingpressurised aeration systemsWEEDLESS energy-savingcirculation componentsGVA decanting equipment forclarified water discharge in SBRsystemsGVA monitoring systemsGVA environmental sampledatabase service system foraeration modules

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Innovative technologyinspired by nature

The sewage treatment plant in Brandenburg was also equipped by GVA. Turbocompressors, WEEDLESS-V vertical agitators and WEEDLESS-T submersionagitators, the GVA pressurised aeration system with approx. 3,200 m ELASTOX ®-Rtype 750 and the pipeline construction were supplied.

ELASTOX ®-T patented discair diffusers from GVA have set newstandards in aeration.

WEEDLESS-T submersion agitators canbe equipped with two or three-bladedpropellers.

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Further advantages are a particu-larly high oxygen utilisation, thanksto the fine-bubble aeration charac-teristics inherent in these systems,and a broad air flow range.

ELASTOX ® rubber membrane airdiffusers are available in threesystem versions:

ELASTOX ®-R tube air diffuser,ELASTOX ®-T disc air diffuserwith its patented central liftlimitation and spring-loadedcheck valve,ELASTOX ®-P plate air diffuser,the latest addition to theELASTOX ® product range.

ELASTOX ® aeration systems areused for a variety of applications,including fresh water aeration inbuffer tanks, oxygen input in aera-tion tanks and sludge stabilisation,or aeration of rivers, lakes andfishponds.

Efficient aeration of waste water

treatment tanks demands powerful

aeration systems that can be opti-

mally adapted to suit the respective

tank geometry and varied technical

requirements.

A further requirement is the dura-bility of materials and the reductionof operating costs. Continuousfurther development of membranequality means that system opera-tors receive state-of-the-art techno-logy. ELASTOX ® rubber membraneair diffusers from GVA were special-ly developed to provide systemoperators with tailored solutions forfine-bubble aeration applications,regardless of whether surface,oblique or spiral flow aeration isinvolved.

ELASTOX ® aeration systems aredistinguished by the excellent inter-mittent operating mode option theyprovide. This is a prerequisite forthe application of modern processengineering.

ELASTOX® aeration systems –the optimum solution for every application

ELASTOX ® aeration systems aredesigned specially to address differentoperating requirements.

Approx. 28,000 m of GVA ELASTOX ®-Rmembrane tube air diffusers are in usein the aeration tanks at the municipalwaste water treatment plant in Hanover.

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ELASTOX®-R tube air diffusers

– the revolution in pressurised

aeration technology

GVA developed the ELASTOX ®-Rrubber membrane aerator in 1983and ushered in the principle ofthe floodable support tube. Thelow-buoyancy hose aerator hassince established itself on an inter-national level and is subject to con-tinuous optimisation and furtherdevelopment. The ELASTOX ®-Rsupport tube thus now consists of asingle injection moulded compo-nent with an integrated air supply.All the materials used are highlyresistant to known chemical andbiochemical influences encoun-tered in the biological waste watertreatment process.

The aerator can be easily andspeedily fitted to the aeration gridsby a single person without the needfor special tools.

ELASTOX®-P plate air diffusers

– specialists for major challenges

GVA revealed the ELASTOX ®-Pplate air diffuser in 1996, launchinga low-buoyancy air diffuser on themarket that, although based on theconcept of the tube air diffuser, alsoincorporated the qualitative ad-vantages of the disc air diffuser. Itsdesign was selected to generallyenable its replacement with tubediffusers.

The ELASTOX ®-P plate air diffusercombines the advantages of boththese technologies in a mainte-nance and user-friendly aerationconcept distinguished by reducedinvestment and operating costs.An example of the advantages isthe possibility of realising remov-able aeration systems withoutdraining the tank, thanks to the lowbuoyancy of the unit.

ELASTOX®-T disc air diffusers

– proven performance in millions

of practical applications

The ELASTOX ®-T disc air diffuserwas presented at the IFAT in 1984and represented one of the first airdiffusers of its kind. Its patentedcentral lift limitation set a highstandard of quality and soon tookthe lead among rubber membraneaeration systems. Central liftlimitation ensures that aeration isuniform over the entire aerationsurface. It is ideal for intermittentoperation and also reduces thevolume of air that emergeswhen damage occurs, thanks tothe integrated spring-loaded checkvalve.

ELASTOX ®-T disc air diffusers aremainly used for so-called full flooraeration, where air diffusers areuniformly distributed across thetank floor. Surface aeration doesnot depend on the shape of thetank, meaning that existingsystems can also be simply retro-fitted and modernised.

The low-buoyancy ELASTOX ®-Rtube air diffuser design is based onthe floodable support tube principle.

ELASTOX®-T disc air diffuser membranesare manufactured from special rubber(EPDM) or special silicone that has provenits effectiveness in a multitude of systems.

ELASTOX ®-P plate air diffusersare generally fitted in pairs to theaeration mesh.

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WEEDLESS agitators weredeveloped specially for waste waterengineering and the resultingstress. Their large-formatted, slowlyoperating propellers are designedfor maximum flow characteristicsand are available in horizontal orvertical versions. The angle of thepropeller blades can be varied, thusensuring optimum adaptation toflow speed.

WEEDLESS agitators are used formixing applications in anaerobicand anoxic zones, biological phos-phate elimination and denitrifi-cation, mixing and compensatingreservoirs and aeration withseparate circulation.

WEEDLESS agitators –keep your cleansing process moving

Only the best possible combinationof aeration and circulation (achievedhere with WEEDLESS-V verticalagitators) ensures the optimum result.

They ensure constant circulation

and mixing and must be designed

with precision with regards to their

performance to meet the technical

requirements of the process.

Although in themselves a simple

component, agitators are of

elementary importance for the

continuity and success of the

process in waste water treatment

systems.

WEEDLESS-T submersible agitators – three-bladed version

WEEDLESS-T

– the submersible agitator with

the patented suspension

Submersible agitators are the idealcirculation technology for tanks,enabling hermetic horizontal flowmovement in circular and ring-shaped systems, troughs andcirculation tanks. The WEEDLESS-Tpropeller and submersible gearmotor are secured together on asliding carriage with a patentedsuspension. The entire constructionis lowered into the water with atwin guide, resting there on aspecial shock absorber system.

The submerged gear motor of theWEEDLESS-T submersible agitatoris constantly monitored for leaks.This ensures that the bearingsand gear wheels are not subject todamage.

WEEDLESS-V

– the vertical agitator for mixing

and circulation

WEEDLESS-V vertical agitators aremainly used in square or rectan-gular tanks. A flow direction fromthe floor to the surface of the wateris usually selected here, thusgenerating a rolling flow current.The water on the surface thus flowsto the edge of the tank where it isdirected towards the floor of thetank.

Drive is provided by a dry-mountedgear motor connected to theagitator shaft that points verticallydownwards. The gear motor is fittedon a bridge portal constructionabove the surface of the water.This means that there are nomaintenance areas below the watersurface. The entire construction isstable and minimises vibration andis designed for continuousoperation.

WEEDLESS-S

– the floating vertical agitator

Our new floating WEEDLESS-Sagitator enables the realisation ofa uniformly-stable predeterminedsubmersion depth of the propellerunit for the first time, even wherethe water level is subject to change.This advantage makes the newfloating agitator the ideal option forapplications in buffer tanks or SBRsystems. WEEDLESS-S agitatorsare based on the vertical agitatordesign. However, in contrast to theWEEDLESS-V, they are secured to afloat-like construction on which thegear motor is also mounted.

Both WEEDLESS agitatorversions are designed

for applications involvingdiffering flow currents or

tank shapes.

WEEDLESS-S agitators are idealfor use in buffer tanks.

WEEDLESS-V vertical agitators aresimply suspended from above in the tank.

SBR systems – with GVA system

technology and components

SBR aeration systems (employingsequencing batch reactor process-es) are recognised as the state-of-the-art today and utilised withincreasing frequency. All biologicaltreatment steps are realised in aconsecutive cycle in this process ina single reactor. Varying processversions are employed during thisthat vary with regard to the mannerof waste water charging and cyclicprocedures. We supply our GVAcomponents for all SBR versionsfor aeration, circulation anddecanting, along with suitable GVAsystem technology that has alreadyproven its effectiveness underpractical conditions in a multitudeof systems all around the world.

System know-how and process engineering –take advantage of our specialised knowledge

GVA has been facing the contin-

uously growing challenges of bio-

logical waste water treatment for

over 20 years. Our know-how and

practically experience has kept

apace with this. GVA competence in

process engineering concentrates

on aeration processes that draw

their inspiration from nature. Our

research and development special-

ists have carried out pioneering

work in this respect and continually

advanced this technology.

Our industrial and municipal autho-

rity customers benefit from the

extensive know-how and expertise

embodied in our consulting service,

a strategy that enables us to pro-

vide the optimum system design

and ideal components to suit each

respective requirement.

HUMANA-Milchunion industrial plant,Everswinkel: SBR aeration systemwith GVA WEEDLESS-T submersible agitator,ELASTOX®-T disc air diffusers and decantingcomponents

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tanks, with the through-flowsequence changing in the nextcycle and the entire processcommencing anew after the thirdcyclic change.

The advantage in comparisons

with other biological processes:

100 % substrate and nitrateavailability for nitrificationHigh process stabilityLow overall nitrogenconcentration in sequenceExcellent controllability of thedenitrification processPeriodic cyclic change reducesenergy costs

TRICYCLE – the patented GVA

process for nutrient disintegration

We developed the TRICYCLEprocess, a technology for biologicalwaste water treatment, at the endof the 1980’s. Our intention was toachieve the greatest possi-ble elimination of nutrients througha high degree of stability duringnitrification, denitrification andbio-P elimination. The solution wasa patented process that employs atriple tank system, with each of theidentical tanks being fitted withaeration and circulation units thatcan be deactivated.

The various denitrification andnitrification process stages arerealised consecutively in the three

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The patented TRICYCLE process utilises a triple tank systemand enables the optimum disintegration of nutrients.

GVA decanting equipment –

a decisive process step

The clarified water discharge phaseis of decisive importance for thequality of cleansed waste water,particularly where SBR systems areinvolved. Specially-developed GVAdecanting units ensure effectivephase separation here and preventscum from collecting in the drain.Decanting unit dimensions arealways realised to suit drainagerequirements in this respect.

The decanting unit lowering pro-cedure is subject to positivecontrol, and lowering speed can beadapted to suit prevailing require-ments. The decanting unit is imme-diately raised to its uppermostposition on completion of decant-ing to prevent penetration bysludge mixture during subsequentoperating phases.

Position of GVA decanting unit in the Wesenbergtreatment plant during different clarified water discharge phases

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GVA technologies are success-

fully employed in several

hundred plants and systems

Our customers profit from processengineering know-how and the inpart patented process technologywe supply during planning andconstruction of waste water treat-ment systems. Whether pipelineconstruction or the installation ofcomponents such as aeration andcirculation systems is involved, allsystem components are perfectlyco-ordinated and ensure a highefficiency during daily operation.

GVA provides logical and project-

related projection and plants con-

struction of complete waste water

treatment systems for public

institutions and industrial custom-

ers from a single source – with all

the advantages of the extensive

know-how embodied in our new

system design, modernising and

optimising, system technology and

components, plant monitoring,

services and research and develop-

ment.

Take full advantage of our competence:complete technology concepts from a single supplier

The GVA maintenance systemenables direct access to aeration modules.

Plant construction byexperienced GVA specialistsensures safe and rapidcommissioning.

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We are also a reliable and

competent partner when it comes

to service. Our after-sales service

package encompasses:

Consultation on plant optimi-sation for greater efficiencyPlant inspections involvingsupportive measurement andexaminationPlant monitoring systemsMaintenance and refurbishmentof plant and componentsProvision of original spare partsand components subject to wear

We provide monitoring systemsfor our high-performance rubbermembrane aeration systems (e.g.employing differential pressuremeasurement to monitor perfectoperation of aeration equipment).The measurement procedure func-tions independently of fluctuationsin water level and can be inter-changeably employed at severalcontrol points using a measuringhead.

State-of-the-art technology

at all times

Our R&D specialists also take thedemands set by falling operatingcosts and growing quality require-ments into consideration duringcontinuous further development ofour tried and trusted system tech-nology and components.

Some of our answers to thesechallenges include:

Further development of siliconeand microbe-resistant EPDMmembrane quality for serialproductionThe new floating WEEDLESS-Svertical agitator with uniformly-maintained submersion depth,even where water levelsfluctuateThe revised WEEDLESS-Tsubmersible agitator design

In addition to this, we also work onthe development of new processtechnology for waste watertreatment (e.g. membranetechnology and other innovativesolutions). This means that ourcustomers can continue to facefuture challenges posed by wastewater treatment and the demandsof legislation with confidence.

Gesellschaft für Verfahren der Abwassertechnik mbH & Co. KG

Dieselstraße 6 · 42489 Wülfrath · Germany · E-mail: info@gva-net.dePhone: +49 (0) 20 58 / 92 10 - 0 · Fax: +49 (0) 20 58 / 7 26 40 · www.gva-net.de 01

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