WHAT IS ZERO LQUID DISCHARGE

Zero Liquid discharge refers to installation of facilities and system which will enable industrial effluent for absolute recycling of permeate and converting solute (dissolved organic and in-organic compounds/salts) into residue in the solid form by adopting method of concentration and thermal evaporation.

ZLD will be recognized and certified based on two broad parameters that is, water consumption versus waste water re-used or recycled (permeate) and corresponding solids recovered (percent total dissolved /suspended solids in effluents).

METHODOLOGY OF ZLD

Segregation of effluent by way of contamination of organic load, utility waste , sewerage, colour effluent etc .

Pre treatment for TSS and colour removal

Use biological process for BOD/COD reduction

UF RO for TDS reduction and make product water for reuse.

Use evaporation techniques such as Solar evaporation & Thermal evaporation for reject handling to achieve ZLD.

COMPLIANCE

Standards for compliance have been notified under the Environment Protection Act, 1986.

The notified standards permit industries to discharge the effluents only after compliance.However, CPCB and SPCBs / PCCs now, are insisting industries to reduce water consumption and also take measures to not-to-discharge effluents. But, it has been observed that industries are not able to meet all time compliance standards and as a result, rivers like Ganga, Yamuna and its tributaries is carrying high pollution load and it is the dilution available in river water which helps in minimizing pollution load.

Besides compliance , there is need of Corporate Social Responsibility of corporate and Industries towards our society to give clean environment , water and protect natural resources .

MAJOR CONCERNS…

•Reduce Foot Print

•Quality of water recovered for recycle.

•High Operating Cost due to steam consumption.

•Frequent scaling and choking of metal tubes resulting hours lost in capacityutilisation of plant

EVAPORATION – NATURE’S PURIFICATION METHOD

PROCESS

PRETREATMENT EVAPORATIONRE –USE

ORDISPOSAL

CONCENTRATE

WASTE WATER CLEAN WATER

MAKE UP WATER

ZERO DISCHARGE SYSTEM BY EVAPORATION

SINGLE EFFECT EVAPORATION

Specific Steam Consumption = 1.4

Vapour

Steam

Primary Condensate

Feed

Concentrate

CoolingWater

Condensate

1.4

1.0

CONDENSER

4-EFFECT MULTI-EFFECT EVAPORATION

Concentrate

Condensate

Vapour

SteamVapour

Waste Heat

Feed

Cooling

WaterCONDENSER

Vapour Vapour

Vapour

Primary Condensate

Specific Steam Consumption = 0.6

ARVIND ENVISOL INTRODUCES NEW EVAPORATION

TECHNOLOGYUSING LOW COST POLYMERIC FILM AS HEAT TRANSFER MEDIA

KEY FEATURES OF PFET(MVRE) TECHNOLOGY Thermodynamically, the most efficient technique to evaporate water is to use mechanical vapor thermo compression. The main components of the PFET system are: vacuum vessel, evaporative heat transfer surface installed inside the vessel and vapor recompression fan. Water boil inside the MVRE vessel ( Under Vacuum) at 60.5 deg. Vapor is extracted from the evaporation chamber and compressed by a fan to a pressure of 23 kpa corresponding temp.63.0 deg. The vapor, at 63.0 C, is passed back through a heat exchanger inside the evaporation chamber where it gives up its latent heat, to the evaporation chamber recirculation brine on the other side and, in doing so, condenses back to a liquid at 63.0 deg.C. The Heat of condensate coming out is also used in pre –heating of feed water. Once the process is established the only heat which needs to be supplied to the system is that required to heat the feed water from 60.5º C to 63.0º C

SCHEMATIC DIAGRAM

Uniform distribution of Liquid on the Surface of

Polymeric Heat Exchanger as seen

through Effluent doped with Dye.

LIQUID DISTRIBUTION ON POLYMERIC HEAT EXCHANGER

14

0

500

1000

1500

2000

2500

3000

00,20,40,60,811,2

Wall thickness, mm

Heat

tran

sfer

coe

ffici

ent,

U W

/m2o

C

SS 316 PE

OVERALL HEAT TRANSFER COEFFICIENT AS FUNCTION OF WALL THICKNESS

POLYMERIC EVAPORATIVE HEAT EXCHANGER CASSETTE

50 elements

Surface Area 200 m2

Total weight 50 kg

THE HEART OF

THE SYSTEM

IMAGE OF CASSETTE

MEE BASED ZLD 100 KLD

CENTRIFUGE

SOLID POWDER

CONDENSATE WATER

OUTLET 100 KLDETP/RO-REJECT

MOTHER LIQOUR

CONVENTIONAL MEE BASED ZLD

CENTRIFUGE

SOLID POWDER

CONDENSATE WATER80-90% Recovery @ 1 – 2% TDS

10-20 KLD REJECT

MEE ETP/RO-REJECTPFET 100

KLD

MOTHER LIQOUR

PFET BASED ZLD

TYPICAL EVAPORATOR LAY OUT (14 CASSETTES)

LARGE DIAMETER UNIT (3.8 mtr.)

CONTAINER SIZE EVAPORATOR (10 CASSETTES)

SMALL DIAMETER UNIT (2.4 mtr.)

INTERNAL ARRANGEMENT OF CASSETTES

MVR-FAN (HEART OF SYSTEM)

THE HEART OF

THE SYSTEM

BENEFITS OF PFET( MVRE) TECHNOLOGY

Arvind Envisol Polymeric Film Evaporation Technology, benefits achieved includes :Low cost evaporative surface results into• large heat transfer surface• small temperature difference – 2.5 deg.C• simple, low speed fan as vapor compressor• low power consumption @ 15 KW per M3 effluent• Very low steam consumption @ 15 kg. per M3 effluent.Polymer surface • Not prone for scaling• Can be operated in low pH• corrosion resistantSmooth surface• easy cleaningThe major advantage of this technology is huge heat exchanger surface area can be incorporated into the system at a very low cost.

TYPICAL APPLICATION AREAS

Textile industry Steel and metal industry Mining industry Pulp & Paper Food and Beverage Industry Landfill leachate Groundwater remediation Seawater desalination Chemical industry Electronic industry Power plants Pharma industryFertilizer IndustryAuto Industry

PFET PLANT (500 KL/D)

OUR AIM……!!!!!

200 KLD Capacity MEE & PFET(MVRE) Operation Cost Comparison Steam cost taken as Rs. 1.25/-kg. and power cost taken Rs. 6.5/- unit.

Sr. No. Description MEE - 4 effect PFET ( MVRE)- cooncentrate up to 12% solid

MVRE+Crystallizer for ZLD

1 Steam Consumption 280 kg/KL 15 kg/KL

2 Power Consumption 22 KWH/KL 15 KWH/KL

3 Operating Cost/KL ( Rs. Based On Steam & Power Consumptions)

500 116 200

4 Operating Cost/Day (Rs.) 100000 23200 40000

5 Savings in Operating Cost /Day (Rs.) NA 76800 60000

6 Annual saving through opex. For 300 working days

Rs. 2.3 Cr. Rs. 1.8 Cr.

7 Cooling Water Requirement High Small Small

8 Cleaning Chemicals Required No chemical required Less (required only for MEE)

9 Avg. Down Time /Day (hrs) 4 0 (for MVRE) 0 (for MVRE)

10 Cleaning waste Generated Yes No Not for MVRE

11 Structure requirement High Medium Medium

12 Foot Print Area High Low Medium

13 Operations Complex Easy for MVRE Easy for MVRE

14 Capital Cost High Less As compared to alone MEE Almost same

Arvind Envisol Private Limited

info@envisol.co.in

Satish Kumar Bhatt

THANK YOU