Industrial ETP & ZLD Design Guide: Water Balance, MBR, RO, MEE and ATFD Explained
Designing an industrial Effluent Treatment Plant is not simply a matter of selecting an ETP capacity and arranging a series of tanks.
The real engineering problem is much broader:
Where does the water come from? Where does every cubic metre go? What contaminants enter each treatment stage? How much water can realistically be recovered? What happens to the reject? And what ultimately leaves the site?
These questions become even more important when the project requires Zero Liquid Discharge (ZLD).
A ZLD system does not end at biological treatment or even at reverse osmosis. It may require coordinated engineering across:
pre-treatment → biological treatment → membrane separation → RO → reject concentration → evaporation → solids handling → condensate recovery → reuse
Drawing on recent engineering work on an approximately 800 KLD industrial ETP/ZLD system, this guide explains how industrial wastewater treatment should be approached from the design basis through water balance, MBR, RO, MEE and ATFD.
For readers looking at municipal or faecal-sludge applications rather than industrial effluent, our earlier guides explain how 100, 200 and 500 KLD FSTPs are engineered and the difference between FSTP and STP systems.
What Is an Industrial ETP?
An ETP, or Effluent Treatment Plant, treats wastewater generated by industrial processes.
Unlike domestic sewage, industrial wastewater can vary enormously depending on:
industry,
raw materials,
manufacturing process,
chemicals,
washing practices,
production schedule,
cooling systems,
utility operations,
and product mix.
Two factories producing similar products may therefore generate very different wastewater.
Industrial effluent can contain:
high BOD,
high COD,
suspended solids,
dissolved solids,
oil and grease,
heavy metals,
colour,
salts,
silica,
hardness,
solvents,
nutrients,
acids,
alkalis,
and other process-specific contaminants.
This is why industrial ETP design must begin with actual wastewater characterisation rather than an equipment catalogue.
A useful starting point is our guide on the data required before designing an ETP.
What Is a ZLD Plant?
Zero Liquid Discharge describes a treatment philosophy in which liquid wastewater is not routinely discharged outside the facility.
Instead, the system attempts to:
recover reusable water,
concentrate the dissolved contaminants,
recover additional condensate where possible,
and convert the final residual stream into a manageable solid or concentrated waste.
A typical ZLD train may involve:
ETP
↓
Biological treatment
↓
Filtration / membrane treatment
↓
Reverse osmosis
↓
RO permeate reuse
↓
RO reject concentration
↓
MEE
↓
ATFD
↓
Salt / solid residue
while MEE condensate is typically recovered for appropriate reuse or recycling after quality verification.
For a broader regulatory and feasibility discussion, see our article on when an industry may need ZLD instead of normal ETP discharge.
ETP and ZLD Are Not the Same Thing
This distinction is important.
An ETP is primarily concerned with treating industrial wastewater to a required quality.
ZLD adds another objective:
eliminating routine liquid effluent discharge from the facility.
An industrial site may therefore have:
an ETP without ZLD,
ETP + tertiary treatment + reuse,
ETP + RO,
or a complete ETP + RO + MEE + ATFD ZLD system.
The correct configuration depends upon:
wastewater quality,
water availability,
regulatory requirements,
reuse demand,
recovery targets,
reject chemistry,
energy availability,
sludge and salt disposal,
and economic feasibility.
Adding more equipment does not automatically create a better wastewater solution.
Why the Water Balance Should Come Before the Equipment List
In our view, the single most important document in an industrial wastewater project is often the water balance.
Before deciding:
tank capacity,
RO size,
MEE capacity,
cooling-tower make-up,
condensate recovery,
or freshwater requirement,
the engineer should understand where every major water stream originates and where it goes.
A water balance may include:
Freshwater input
recovered water
condensate
internal recycle
=
process consumption
evaporation
product moisture
sludge moisture
reject streams
final disposal
The mathematics must close.
Our detailed article on how a water balance improves ETP design and ZLD feasibility explains this principle in more detail.
Why Gross ETP Flow Can Be Higher Than Factory Wastewater Generation
This often surprises project owners.
Suppose a factory generates:
800 KLD of process wastewater.
The ETP itself may generate or receive additional streams such as:
filter backwash,
membrane cleaning,
RO reject recycle,
equipment wash water,
condensate recycle,
sludge-dewatering filtrate,
chemical preparation water,
and other internal returns.
If these streams return upstream, the hydraulic flow through parts of the ETP can become higher than the original factory wastewater generation.
This means:
Fresh wastewater generation ≠ total internal treatment flow
Ignoring recycle streams can lead to undersized:
equalisation tanks,
pumps,
membranes,
pipelines,
and downstream equipment.
Water Recovery Is Different From Treatment Capacity
An 800 KLD ETP does not necessarily produce 800 KLD of reusable water.
The incoming flow is divided into multiple outputs:
Recovered water
evaporation
sludge moisture
concentrate
process losses
The designer therefore needs to distinguish between:
Treatment capacity
How much wastewater the plant can hydraulically process.
Water recovery
How much of that wastewater becomes reusable water.
ZLD recovery
How much liquid can ultimately be recovered after RO reject concentration and evaporation.
These are different design parameters.
Why Industrial ETP Design Starts With Waste Segregation
Not every wastewater stream should necessarily be mixed immediately.
A factory may generate:
high-COD wastewater,
low-COD wash water,
high-TDS streams,
metal-bearing wastewater,
cooling-tower blowdown,
boiler blowdown,
RO reject,
floor wash,
domestic sewage,
and relatively clean utility wastewater.
Combining all streams can sometimes make treatment more difficult and expensive.
For example, a small high-TDS stream can increase the TDS of the entire plant if unnecessarily mixed with low-TDS wastewater.
That may increase:
RO loading,
reject quantity,
MEE duty,
energy consumption,
and final salt generation.
Waste segregation should therefore be considered before the treatment flow sheet is finalised.
Equalisation Is Still Critical in Industrial ETPs
Industrial processes rarely discharge wastewater at a perfectly constant rate.
Production can vary by:
shift,
batch,
cleaning cycle,
product grade,
shutdown,
maintenance,
and production schedule.
Wastewater quality may also vary dramatically.
An equalisation system can help stabilise:
flow,
pH,
COD,
BOD,
suspended solids,
temperature,
and contaminant concentration.
This reduces shock loading on downstream treatment.
The required equalisation volume should be calculated from realistic operating patterns rather than simply selected as a percentage of daily ETP capacity.
Physical and Chemical Treatment
Depending on wastewater characteristics, preliminary or primary treatment can include:
screening,
oil separation,
pH correction,
coagulation,
flocculation,
precipitation,
clarification,
dissolved air flotation,
and metal removal.
The purpose is to remove contaminants that would interfere with downstream biological or membrane systems.
For example, excessive:
oil,
suspended solids,
metals,
or precipitated hardness
can create serious problems in membranes.
Why Jar Testing Still Matters
Chemical treatment should not be designed purely from theoretical chemical doses.
Jar testing can help establish:
coagulant selection,
coagulant dose,
polymer requirement,
pH window,
settling behaviour,
sludge production,
and achievable contaminant removal.
This is especially useful for wastewater containing:
metals,
colloids,
colour,
oils,
and difficult suspended solids.
An ETP can consume large quantities of chemicals if dosing is never properly optimised.
Biological Treatment: Why BOD/COD Relationship Matters
Biological treatment works primarily on biodegradable contaminants.
Two common wastewater parameters are:
BOD
Biochemical Oxygen Demand indicates biologically degradable organic load.
COD
Chemical Oxygen Demand represents a broader measure of oxidisable contamination.
The relationship between BOD and COD can provide useful information about biodegradability.
A wastewater with:
high COD but relatively low BOD
may contain a substantial fraction that microorganisms cannot readily degrade.
This has major consequences for biological treatment design.
For more detail, see our technical guide on BOD, COD, TSS and TDS in wastewater treatment.
What Is MBR?
MBR stands for Membrane Bioreactor.
It combines:
biological wastewater treatment
with
membrane solid-liquid separation.
Instead of relying only on a conventional secondary clarifier, membranes physically retain suspended solids and biomass.
This can produce high-quality treated water suitable for further polishing.
Potential benefits include:
low suspended solids,
compact footprint,
high biomass concentration,
improved separation,
and good feed quality for downstream systems.
However, MBR systems also introduce:
membrane fouling,
aeration requirements,
cleaning requirements,
membrane replacement,
instrumentation,
and operating complexity.
The decision to use MBR should therefore come from project requirements rather than technology preference.
MBR Is Not a Substitute for Correct Pre-Treatment
Membranes do not eliminate the need to control incoming wastewater.
Poor pre-treatment can lead to:
membrane fouling,
reduced flux,
higher cleaning frequency,
increased chemical consumption,
shorter membrane life,
and increased operating cost.
Particular attention should be given to:
oil and grease,
fibres,
suspended solids,
precipitates,
and chemicals that may damage or foul membranes.
Why MBR Permeate Can Be Suitable for RO Feed
Reverse-osmosis systems perform better when feedwater has:
low suspended solids,
low turbidity,
controlled fouling potential,
and stable quality.
MBR can provide a useful barrier before RO.
However, MBR primarily addresses biological and suspended contaminants.
It does not automatically solve dissolved-salt problems.
That is where RO becomes important.
What Does Reverse Osmosis Do?
Reverse osmosis separates water from dissolved salts using semi-permeable membranes.
The RO produces two streams:
Permeate
Lower-salinity water, usually considered for reuse.
Reject or concentrate
A smaller stream containing most of the dissolved salts rejected by the membranes.
For example, if an RO receives 100 KLD and operates at 70% recovery:
70 KLD → permeate
30 KLD → reject
The precise recovery should be determined through water chemistry and membrane design.
It should not be chosen simply because a higher recovery percentage sounds more efficient.
Why Maximum RO Recovery Is Not Always the Best Recovery
Increasing RO recovery reduces reject volume.
That sounds attractive.
But it also concentrates salts more aggressively inside the membrane system.
As recovery rises, concentrations of problematic compounds can increase.
Potential scaling species can include:
calcium carbonate,
calcium sulphate,
barium sulphate,
silica,
and other sparingly soluble salts.
A recovery target that looks attractive in a spreadsheet may become operationally unstable.
The better engineering question is:
What recovery can be sustained reliably at the actual feedwater chemistry?
Hardness and Silica Can Control RO Design
In many industrial water-recovery systems, RO recovery is constrained by specific contaminants rather than total TDS alone.
Two particularly important parameters are:
hardness
and
silica.
If they become supersaturated in the RO concentrate, scaling may occur.
Possible mitigation measures include:
pH adjustment,
antiscalant,
softening,
precipitation,
selective treatment,
recovery reduction,
staged RO,
and controlled blending.
The correct approach depends on the chemistry.
Why RO Reject Is the Beginning of the ZLD Problem
In a normal water-reuse system, the RO reject may have an approved disposal route.
In ZLD, it does not.
The reject must be treated further.
This is where the economics become much more challenging.
RO may recover a large proportion of water using relatively modest electrical energy compared with thermal evaporation.
But once dissolved salts become highly concentrated, membrane recovery becomes increasingly difficult.
The remaining reject may then require evaporation.
What Is an MEE?
MEE stands for Multiple Effect Evaporator.
Its purpose is to evaporate water from concentrated wastewater while making better use of thermal energy through multiple evaporation stages or “effects.”
The general objective is:
concentrated wastewater → evaporated water → condensate + concentrated liquor
The condensate may be recovered for appropriate reuse or returned to the treatment system depending on quality.
The concentrated liquor proceeds to further concentration or drying.
Why MEE Capacity Should Be Minimized
MEE treatment is far more energy-intensive than recovering water through biological treatment and membranes.
Therefore, a fundamental ZLD design principle is:
Recover as much suitable water as technically and economically practical before the wastewater reaches the evaporator.
Every additional cubic metre sent to the MEE affects:
heating duty,
steam or thermic-fluid consumption,
equipment size,
CAPEX,
condenser duty,
operating cost,
and maintenance.
A poor upstream water balance can therefore make the ZLD section unnecessarily expensive.
Steam vs Thermic Fluid for Evaporation Systems
Evaporation systems can use different thermal-energy arrangements depending on technology and site utilities.
The engineering decision can involve:
available steam,
boiler capacity,
thermic-fluid system,
waste heat,
fuel,
operating pressure,
vendor design,
and overall energy integration.
Thermal systems should be evaluated as part of the plant's utility balance, not only wastewater treatment.
This is also where water and energy engineering begin to overlap.
What Is an ATFD?
ATFD stands for Agitated Thin Film Dryer.
It is commonly used downstream of evaporation systems to further concentrate or dry high-solids streams.
A typical ZLD arrangement may be:
RO reject
↓
MEE
↓
concentrated slurry
↓
ATFD
↓
solid / semi-solid residue
The objective is to reduce the remaining liquid fraction and create a residue that can be handled according to its characteristics and applicable disposal requirements.
MEE and ATFD Are Not Standalone Solutions
Adding an MEE and ATFD to a poorly designed ETP does not create a good ZLD plant.
The upstream system still determines:
organic load,
scaling potential,
suspended solids,
hardness,
silica,
oil,
metals,
and total dissolved solids
entering the thermal system.
Poor upstream treatment can therefore create severe downstream problems.
ZLD needs to be engineered as one integrated process, not a series of vendor packages.
Condensate Recovery Is Part of the Water Balance
MEE condensate represents a substantial recovered-water stream.
However, condensate should not automatically be assumed to be clean.
Depending upon the wastewater and evaporator operation, condensate can potentially contain:
volatile organics,
ammonia,
COD,
or other carryover.
Condensate quality should therefore be verified.
Possible destinations include:
direct reuse where suitable,
utility use,
cooling-tower make-up,
process reuse,
or controlled recycle back to the ETP where quality does not meet reuse requirements.
The water balance should account for both normal condensate reuse and off-specification condensate management.
Internal Recycle Can Quietly Overload an ETP
ZLD plants contain many recycle streams.
These may include:
MEE condensate,
RO streams,
membrane cleaning solutions,
filtrate,
backwash,
and utility drains.
If they are all returned upstream, the hydraulic and contaminant load may increase significantly.
Therefore, every recycle should answer three questions:
How much flow?
What quality?
Where should it return?
A recycle should never be added to a PFD simply because returning it to equalisation looks convenient.
Sludge Production Must Be Calculated
Industrial ETPs can generate sludge from:
suspended solids,
biological biomass,
metal precipitation,
lime treatment,
chemical coagulation,
softening,
and other reactions.
This sludge affects:
holding volume,
dewatering capacity,
polymer consumption,
disposal frequency,
and operating cost.
A sludge dewatering unit should therefore be sized from a mass balance, not selected merely as an accessory.
For more on this subject, see our article on ETP sludge handling and waste-management compliance.
Why Hydraulic Design Is as Important as Process Design
A treatment process can be chemically correct yet hydraulically unworkable.
Engineering needs to establish:
flow between stages,
pump capacities,
pipe diameters,
static head,
friction losses,
valve losses,
tank elevations,
minimum and maximum operating levels,
and overflow conditions.
Where possible, gravity should be evaluated before automatically installing another pump.
Removing an unnecessary pumping duty can reduce:
CAPEX,
electricity,
cabling,
starters,
maintenance,
and potential failure points.
How Are ETP Pumps Sized?
Pump selection should be based on:
Required flow
How much water must move during the available operating period?
Total Dynamic Head
The sum of:
static elevation,
friction loss,
valve loss,
fitting loss,
equipment pressure drop,
and required discharge pressure.
Simply knowing that a tank is “100 KL” does not tell us what pump is required.
The transfer time and hydraulic route matter.
Why Pipe Sizing Matters in an Industrial ETP
Incorrect pipe sizes can create long-term operating problems.
Undersized pipes
Can cause:
excessive velocity,
high pressure loss,
larger pumping energy,
and restricted plant capacity.
Oversized pipes
Can cause:
unnecessary CAPEX,
poor velocity,
settlement of solids,
and stagnant sections.
Different services may also require different materials depending on:
pH,
chloride,
chemicals,
pressure,
temperature,
abrasion,
and structural conditions.
Electrical Load: Installed Load vs Operating Load
Industrial wastewater plants can contain a large number of motors.
These may include:
transfer pumps,
recirculation pumps,
blowers,
mixers,
membrane pumps,
RO high-pressure pumps,
sludge equipment,
chemical dosing systems,
MEE auxiliaries,
cooling systems,
and ATFD auxiliaries.
But not every motor operates simultaneously.
Electrical design should therefore distinguish:
installed load
from
actual operating load
and
maximum demand.
This affects:
transformer coordination,
panel sizing,
cable sizing,
DG requirements,
and operating-energy estimates.
ZLD Is Also an Energy Project
Water recovery and energy consumption cannot be separated.
Consider:
pumps consume electricity,
MBR aeration consumes electricity,
RO requires pressure,
MEE requires thermal energy,
ATFD requires thermal and electrical energy,
cooling systems consume water and electricity.
A ZLD project can therefore reduce freshwater consumption while significantly increasing energy demand.
This is why water, wastewater and energy should increasingly be assessed together.
SARK's industrial water-audit services and industrial energy-cost reduction services address these utility systems from complementary perspectives.
Why Existing ETPs Often Need Redesign Rather Than Replacement
When an industrial ETP performs poorly, replacing everything is not automatically the correct solution.
The actual problem may be:
inadequate equalisation,
changing wastewater characteristics,
poor chemical dosing,
undersized aeration,
incorrect recirculation,
overloaded clarifiers,
membrane fouling,
poor sludge removal,
inappropriate RO recovery,
or operating practices.
An engineering assessment should first identify the bottleneck.
Our guide on ETP augmentation versus installing a new ETP discusses how this decision can be approached.
Why ETPs Fail After Installation
Many ETP failures are not caused by one defective machine.
Common reasons include:
incorrect design basis,
wastewater characteristics different from assumptions,
poor operator training,
insufficient sludge wasting,
shock loads,
wrong chemical dosing,
inadequate aeration,
hydraulic bottlenecks,
missing instrumentation,
and vendor designs that were never integrated properly.
Our article on why ETP plants fail after installation explores these causes in greater depth.
Vendor Proposal vs Engineering Design
A vendor proposal and an engineering design are not the same thing.
If three vendors are simply asked:
“Quote an 800 KLD ETP with ZLD”
they may produce three completely different systems.
One may assume:
70% RO recovery.
Another:
80%.
One may include:
MBR.
Another:
conventional clarification.
One may size MEE based on a high reject load.
Another may assume aggressive membrane recovery.
One may include standby equipment.
Another may not.
The quotations may therefore be impossible to compare meaningfully.
A Better Procurement Sequence
A technically stronger sequence is:
Wastewater characterisation
↓
Water balance
↓
Design basis
↓
Process selection
↓
Mass balance
↓
Hydraulic calculations
↓
Equipment duties
↓
PFD / P&ID
↓
Technical specifications
↓
RFQ
↓
Vendor comparison
Now vendors quote against a substantially common requirement.
Our ETP vendor proposal review checklist is useful when comparing technical offers.
What Should an Industrial ETP/ZLD Basic Engineering Package Include?
A serious project can require substantially more than a process flow diagram.
A Basic Engineering Package may include:
Design Basis Report
Defines:
wastewater flow,
wastewater quality,
treated-water requirement,
reuse requirement,
regulatory basis,
operating philosophy,
and design assumptions.
Water Balance
Tracks all major:
raw water,
wastewater,
recycle,
permeate,
reject,
evaporation,
condensate,
sludge,
and final-disposal streams.
Mass Balance
Tracks pollutants and solids through treatment stages.
Process Design Report
Explains why each treatment stage is required.
Design Calculations
Can include:
equalisation,
chemical treatment,
biological treatment,
oxygen requirement,
membrane sizing,
RO recovery,
sludge generation,
evaporation load,
pumps,
pipe sizing,
and utilities.
PFD
Shows major process streams.
Hydraulic Flow Diagram
Shows flows and operating elevations.
P&ID
Shows equipment, lines, valves, instrumentation and control interfaces.
General Arrangement
Confirms that the equipment fits the available plot.
Mechanical Equipment List
Defines quantity and design duty.
Motor and Electrical Load List
Defines installed and operating loads.
Technical Specifications
Provide a common basis for vendor procurement.
RFQ Package
Allows structured technical and commercial comparison.
SARK's engineering design services and project documentation services cover these stages from engineering development through procurement documentation.
Why P&IDs Matter in an ETP/ZLD Project
A PFD explains the process.
A P&ID explains much more about how the plant actually works.
It can show:
pumps,
tanks,
pipelines,
valves,
instruments,
bypasses,
drains,
sampling points,
recycle lines,
and control relationships.
Without this level of engineering, important interfaces can be left for contractors to decide during construction.
This is one reason why vendor-package integration becomes difficult in complex ETP/ZLD projects.
How Restricted Plot Area Changes ETP Design
Industrial sites frequently have very limited space available for treatment infrastructure.
This affects:
tank geometry,
building arrangement,
access,
membrane skids,
pipe racks,
chemical systems,
sludge equipment,
electrical panels,
MEE,
ATFD,
cooling systems,
and maintenance clearances.
A design can work perfectly on a process flow diagram and still fail to fit the actual site.
Plant layout should therefore develop alongside process engineering, not after equipment procurement.
Why Maintenance Access Must Be Designed
A compact layout is not successful if equipment cannot be maintained.
Engineers need to consider:
membrane removal,
pump dismantling,
blower access,
motor lifting,
filter media replacement,
sludge-equipment maintenance,
tube-bundle access,
chemical handling,
and vehicle movement.
A plant may operate for decades.
The engineering should therefore consider how equipment will be repaired five or ten years after commissioning.
What Does a Good ETP/ZLD Design Optimise?
A good design is not necessarily the one with:
maximum automation,
maximum RO recovery,
maximum number of treatment stages,
or the highest equipment count.
Instead, it should balance:
compliance
water recovery
energy consumption
CAPEX
OPEX
reliability
operability
maintenance
available space
There is no universal optimum.
The answer depends on the project.
Engineering Lessons From an 800 KLD Industrial ETP/ZLD Assignment
Recent engineering work on an approximately 800 KLD industrial wastewater and ZLD project reinforced several principles.
1. Close the water balance first
The process cannot be properly sized while major recycle and recovery streams remain unknown.
2. Separate treatment capacity from recovery
An ETP's hydraulic capacity does not tell us how much usable water will ultimately be recovered.
3. RO recovery should follow chemistry
Hardness, silica and scaling potential can control membrane recovery.
4. Minimise thermal load
Water recovered before the MEE generally avoids much more energy-intensive treatment later.
5. Condensate needs a destination
Recovered condensate must be characterised and deliberately routed.
6. Every recycle changes the plant
Internal recycle can increase hydraulic and contaminant loads.
7. Layout must be checked early
Complex ZLD systems can rapidly consume available plot area.
8. Vendor packages require integration
MBR, RO, MEE and ATFD cannot be engineered as completely independent islands.
9. Sludge and salts are part of the design
ZLD does not make contamination disappear. It concentrates material into streams that still require management.
10. Water and energy optimisation must be considered together
High water recovery can carry a substantial energy penalty.
Frequently Asked Questions
What is ETP full form?
ETP stands for Effluent Treatment Plant. It treats wastewater generated from industrial or commercial processes.
What is ZLD full form?
ZLD stands for Zero Liquid Discharge, a treatment philosophy intended to eliminate routine liquid wastewater discharge by recovering water and converting remaining contaminants into concentrated or solid residual streams.
What is MBR in an ETP?
MBR stands for Membrane Bioreactor. It combines biological treatment with membrane separation to produce low-suspended-solids treated water.
What is RO recovery?
RO recovery is the percentage of feedwater converted into permeate. The remaining stream becomes RO reject or concentrate.
Can RO recovery be increased to reduce MEE capacity?
Potentially, but only within sustainable membrane and water-chemistry limits. Hardness, silica and other scaling species can restrict achievable recovery.
What is MEE?
MEE stands for Multiple Effect Evaporator. It removes water from concentrated wastewater using multiple evaporation stages to improve thermal efficiency.
What is ATFD?
ATFD stands for Agitated Thin Film Dryer. It can be used downstream of evaporation to further concentrate or dry high-solids streams.
Is MBR compulsory before RO?
No. The appropriate RO pre-treatment depends on wastewater characteristics and the selected process. MBR is one possible biological and solids-separation approach.
Is ZLD compulsory for every industry?
No universal answer applies to every industry and location. Regulatory requirements, discharge conditions, sector-specific norms, consent conditions and project circumstances must be checked individually.
Is a ZLD plant expensive to operate?
ZLD can be energy-intensive, particularly where substantial wastewater reaches thermal evaporation. Operating cost depends strongly on recovery, reject quantity, thermal integration, wastewater chemistry and equipment efficiency.
What should be designed first in a ZLD project?
A reliable design basis and closed water balance should be established before final equipment sizing.
Can an existing ETP be converted to ZLD?
Sometimes, but the existing plant must first be evaluated for treatment quality, hydraulic capacity, biological performance, membrane suitability, sludge handling and downstream reject-treatment requirements.
Industrial ETP & ZLD Engineering Support
SARK Engineers & Consultants provides independent engineering support for industrial wastewater, water reuse and Zero Liquid Discharge projects.
The scope can include:
wastewater characterisation,
site assessment,
water balance,
mass balance,
ETP feasibility,
existing ETP assessment,
process redesign,
biological treatment,
MBR engineering,
RO recovery evaluation,
ZLD feasibility,
MEE and ATFD integration,
sludge calculations,
pump sizing,
piping and hydraulic engineering,
PFDs,
P&IDs,
general arrangements,
mechanical equipment schedules,
electrical load schedules,
Basic Engineering Packages,
technical specifications,
vendor RFQs,
technical bid evaluation,
and implementation engineering support.
For industrial projects requiring a complete treatment-system review, see our Industrial Wastewater Treatment Consulting services.
Projects requiring independent engineering development can also explore our Engineering Design services.
The Most Important Principle in ZLD Engineering
The goal of ZLD is not to install an MEE.
It is not to install an RO.
And it is not to assemble the largest possible treatment train.
The real objective is to understand and control the complete movement of water, contaminants, solids and energy through the industrial facility.
A technically sound sequence is:
Measure
→ Balance
→ Segregate
→ Treat
→ Recover
→ Concentrate
→ Reuse
→ Manage the residuals
When that sequence is followed, the ETP becomes more than a pollution-control facility.
It becomes part of the factory's overall water and utility-management system.
Comments