Membrane technology to prosper under new US water rules

Membrane technology to prosper under new US water rules By Frederick

Pontius,

Pontius Water Consultants

New rules due to be introduced

Inc, Lakewood,

Colorado,

USA

Strategies

over the next several years are expected to

stimulate

further application

of membrane

technology

for drinking

water

treatment

in the USA. This article briefly outlines the rules and some of the

One or more actions

changes that they may bring about.

requirements The

The

US

Environmental

(USEPA)

is actively

Protection

preparing

formal

Agency

Membrane technologies Water

compliance

credit

options.

Under a Long Term 2 Enhanced Treatment

Rule (LT2ESWTR),

1) will apply

treatment

These “bins” have been structured

USEPA

for recovery,

Method

considering

as measured

1623 and

10

associated

the

using the

1 samples. Water

systems will have three years following classification

plants.

Cryptosporidium oocyst count,

total source water uncorrected

Surface Water

“action bins” (Table

to conventional

to meet the treatment

initial bin

requirements

with that bin. State agencies may grant

systems an additional

two-year extension to comply

when capital investments

MembraneTechnology

are necessary.

May 2002

properly

systems

addition

currently

using

to conventional for

this

membranes

treatment

technology

in bin

for each action bin. employs

a

“toolbox”

and the tools listed in Table 2, when designed

and implemented,

indicated

log credit

USEPA

will

determining

may receive towards

identified

LT2ESWTR

approach,

proposed

rules, and in some cases final rules have been set, technologies as that include membrane

from the array of strategies

in Table 2 must be used to meet the log treatment

designed

(or range

be

providing

if toolbox

receive the

of credit).

The

guidance

options

for

are properly

and implemented.

requirements. The additional bin requirement part,

on

the

treatment

plants

Enhanced

treatment table

assumption Water

achieve an average

of Cryptosporidium, The removal log,

requirements

2 log

correspond

and

2.5

to total

total

in the

1) are based,

that

in compliance

Surface

(IESWTR)

requirements

(Table

Treatment

and

Rule

log additional

reverse

LT2ESWTR

Cryptosporidium 1

substantial

of

configurations

all

ultrafiltration, osmosis toolbox,

removal

-

are

-

nanofiltration, included

in

the

and can be used to achieve credit

(2.5 logs or more)

for

C~ptosporidium. Water systems

treatment

C~ptosporidium removals

of

microfiltration,

of 3 logs removal bins with

Membrane configurations Membranes

conventional

with the Interim

for the action

4, 5 and 5.5 log, respectively.

in

treatment inactivation)

providing

(equivalent

a total of 2.5 logs of to

Bin

4

including

for C~ptosporidium in addition

to

V

v

Membrane Technology May 2002

conventional

treatment

reassessment

and A

LT2ESWTR. LT2ESWTR late 2002,

will

future

be exempt

during

under

proposal

formal

is scheduled

dominated

from

monitoring

for

to be released

with a final rule expected

wastewater

during

the

Revision

US

a nationwide

osmosis

source

is

viewed

pharmaceuticals meeting many

of the

surface

systems emerging

the systems,

as

inorganic

threats

in agricultural February

2006,

with a

arsenic

(MCL)

10 pg/L

200

reverse osmosis

microfiltration,

many

recent

Colorado

has

in

removing

contaminant,

the western

the

cost

membrane

many decreasing

organic

systems

organic

to

installed

USA.

Membranes

be

as US

develop

strategies

not

drinking

pharmaceuticals.

for

seems to

in

comply

requirements,

products,

chemicals,

trend

will

matter,

microbial

disrupting

Quality drinking Interestingly,

but

the

water

that

with

possible

best

within

resources.

Meetings

to meet

contaminants

mostly

sources,

several forms:

During

especially

dominated

in

US

to install

arsenic MCL.

Emerging

for

For

membranes

of organic organic

matter, over

very active present

and

could

as

degree

Research

the

matter,

microfiltration

be seriously

several years

on which

in

osmosis, is

membrane

effluent January

as well

is to

process

the University

certain

rules

a newly

for

provided.

level

by USEPA media

systems that

of

systems must

drinking

contaminants.

suppliers

processes,

assessing

maximum

Coagulation-assisted

the

from

as and

is in

membrane research

treatment and

importance as other

and arsenic.

such

applications.

Of

are faced

potential

source

wastewater

and

as

water

effluent-dominated In addition

few

ether

existing

many

waters.

endocrine

for

next

being considered.

of and

pharmaceuticals

Inorganic contaminant

within butyl

endocrine-disrupting

2003.

attention

of perchlorate.

March

released results

late

at certain

because

discharges.

During

during

source

the

also

those

found

2002,

in

the

stakeholder

meetings

of

contaminants The

receiving

research

includes

For more information, contact: Frederick W.

will be discuss to

candidate

the

round

150361, Lakewood, CO 80215, USA. Tel: +I 303 986

regulated.

9923, Fax: +I 303 716 7301, Email: fredpQ

contaminant

several

likely

Pontius, PE, Pontius Water Consultants Inc. PO Box

pontiuswatescom.

to

Optimization sofiware reduces whole-life membrane project costs Original equipment manufacturers and end-users

By Anthony Bennett, Specialist Technical Solutions Ltd, Keighley, West Yorkshire, UK This brief feature outlines the way in which software called Avista Advisor can be used to reduce whole-life membrane project costs.

The

software

equipment Membrane package

technologists to

optimize

prediction

can use a new sofrware their

reverse

systems

osmosis

potential

by calculating

required

chemical

dose

water

recovery

rates.

program

can

levels at optimal

systems. The

software,

membrane called

of scaling

released

specialist

Avista

Advisor.

by

Avista It

Membrane Technology May 2002

Using

independent

Technologies, allows

accurate

is

the

substantially project

costs.

product

Avista reduce

Advisor whole-life

in membrane

membrane

are involved separation which

treatment,

aimed

in a diverse applications

include

generation,

is

at

manufacturers

municipal

and range within water

desalination, oil

production

both

original

end-users

that

of membrane market

sectors

and wastewater

brewing,

power

and

general

industry.

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