Producing Safe Drinking Water: Ultra-filtration Membrane for the Removal of Indicator Bacteria

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(1)

Producing Safe Drinking Water:

Ultra-filtration Membrane for the

Removal

(2)

South African Vision

To provide access to an adequate,

safe and affordable supply of potable water to all people living in South

Africa

All people should be

knowledgeable about healthy living

practices and use water wisely

Water supply should be

sustainable and be provided by efficient and effective

services providers who are accountable and responsive to the customers they serve

(3)

Provision of Water Services

An estimated 30 – 40 % of South African population (14-18 M) without adequate water supply services

Prior 1994

South Africa has excellent advancements in the Water Sector

Since 1994

Delivery of water services to an estimated 12 M of previously un-served households

(4)

Ongoing expansion and upgrading of an extensive network of water infrastructure

Development of world class policies and legislation

Compulsory national standards for the quality of the potable water provided are defined in SANS 241: Specification for Drinking Water

(5)

 In terms of Constitution and the 1997 Water

Service Act (Act 108 of 1997),

 Water Service Providers (WSPs): Responsible

for the provision of safe drinking water (Local The South African National Water Act provides the

foundation for water to be managed in an integrated manner based on the principles of equity, efficiency and sustainability.

(6)

Each Water Service Authority must:

o implement a programme for monitoring the

quality of drinking water provided to

consumers

o Ensure satisfaction of the Compulsory

National Standards for Water (Gazette in

June 2001)

o Communicate immediately any threat to

public health to the Department of Water

Affairs and Forestry (DWAF) and to the

Department of Health (DOH)

(7)

The regulations require that water

supplied (by water service providers)

which is intended for drinking or

domestic purposes must be of a quality

consistent with SANS 241

 If the regulations relating to the

compulsory national standards are

contravened, the WSA will be held

accountable

(8)

 DWAF is the National Regulatory Authority o DWAF has the responsibility of ensuring

that Water Services Institutions producing water for drinking and domestic purposes comply with the Compulsory National Standards

 Safe drinking water that complies with

SANS 241 does not pose a significant risk to public health over a lifetime of consumption

(9)

Safe drinking water that complies with

the SANS 241 is the norm in almost all

South African metropolitan Areas

Safe drinking water still a dream in

rural areas

 High incidence of poor drinking water

quality

(10)

An estimated 5 million people in

South Africa still have no access to

treated drinking water within

reasonable distances from their

dwellings

 Many thousands more take water

from water sources and use it

untreated because of problems

experienced with adequate and

reliable potable water supply.

(11)

End user point - semi rural

(12)
(13)

o Lack of understanding by WSAs regarding the

requirements for effective drinking water quality management

o Inadequate management including monitoring of

drinking water services

o Inadequate asset management

o Inadequate Water Service Authority institutional

capacity (staffing, funding, expertise, education)

o Lack of intervention to address poor drinking

water quality when needed

(14)
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FRAMEWORK FOR A DIAGNOSTIC TOOL FOR TECHNICAL COMPLIANCE

TREATMENT PLANT MEASUREMENTS Design Aspects (from

manual/measurements) Quality Control (final water) Process Control (unit processes) Plant Monitoring (sampling; analyses; record keeping; communication; statistics)

Maintenance practices Risk Management

COMPARISON WITH STANDARDS

(comparison of the plant measurements against standards and accepted

norms) NEXT COMPLIANCE MONITORING CYCLE REPORT COMPLIANCE IN ORDER TO DWAF (web etc) PROGRAM START No problems identified Resample to confirm

(16)

FLAG PROBLEM - AREAS

Describe problems

Mention implications / consequences Rank in priority order

PROVIDE CORRECTIVE MEASURES AND PREVENTATIVE MEASURES

Immediate and Longer Term

Technical Management Problems identified REPORT COMPLIANCE NOT IN ORDER TO DWAF Re-measure

(17)

FRAMEWORK FOR A DIAGNOSTIC TOOL FOR NON-TECHNICAL COMPLIANCE

AUDITS OF MANAGEMENT ISSUES AND HUMAN RESOURCES ISSUES

Consider:

Strategic Level

Tactical Level (medium term planning) Operational Level (day-to-day)

AUDIT OF MANAGEMENT PRACTICES

Local and international management practices (Emanti/DWAF/AWWA)

Draw up own criteria when none are available

AUDIT OF HUMAN RESOURCES Number of personnel at the plant?

Qualifications?

Plant classification by DWAF Job conditions? (*) Motivational levels? (*) Inter-relationships? (*) Performance indicators? NEXT COMPLIANCE MONITORING CYCLE PROGRAM START R e -m e a s u re

(18)

FLAG PROBLEM - AREAS and

PROVIDE CORRECTIVE MEASURES

Immediate and Longer Term

REPORTING FINANCIAL Which financial systems in place? Are there sufficient funds for: operation? maintenance? overtime? Information sharing meetings? Procurement is it adequate? Transparency COMMUNICATION Which systems are in place? Emergency systems? Risk systems? COMMUNITY INVOLVEMENT AND AWARENESS Refer to earlier studies undertakenh by NGO's, etc. Develop minimum requirements for assistance with compliance Customer care Trust of the public SHEQ

Safety, Health and Environmental Quality R e -m e a s ure

(19)

Strategies to Ensure Sustainable Production of Safe Drinking Water in Water

Supply Systems

ECMA - Establishment of Catchment Management Agencies

(20)
(21)

Membrane technology potentially offers

the water industry a simple one or

two-step treatment barrier to secure

compliance with drinking water

standards

 In South Africa, the Institute of Polymer

Science, University of Stellenbosch,

has developed low cost capillary

membrane: CPSUF

Capillary Polysulphonate Ultra-Filtration

(22)

Table 1.1: Summary of UCPSUF module characteristics

Parameter Value

Type of module Hollow fibre, in/out operation, one

permeate outlet, 8 bundled modules

Total length 1200 mm

Max. feed pressure -48 Pa Hollow-fiber inner

diameter

0.8mm

Type of membrane Polysulphonate pH-range 4-9 Temperature-range (˚C) 5-45 Design performance

Feed water turbidity <20 NTU, permeate turbidity <0.2 NTU

(23)

UCPSUF system at the process evaluation facility, Wiggins Waterworks, Durban

(24)

The UCPSUF system has potential to produce high quality water that meets the standards required by South African

guidelines in terms of bacterial indicator

Current challenges for the system to be used in rural areas

 The cost of the membrane versus the quality of water it produces Increase of the operating cost of the system as due to the

fouling of the membrane after use

 Membrane blockage in the worst situation where the

membrane is operating in very high turbidity of greater than 100 NTU for extended periods

 Daily monitoring of the operating conditions ( pressure, flow rate,

turbidity)

 Mechanical servicing (break down of the different parts of the membrane

such as pumps, tubing pipes…) that needs to be done by experts.

(25)

Conclusions

Cost implication is one of the most crucial and controversial matters that seems to delay the implementation of UF system in rural areas

 A sustainable system must be cost effective  Choices exist in terms of developing a low

capital cost unit which will have high operating costs, or a higher capital cost unit, which will have lower operating costs

 The Conversely, the system could be highly

automated (high capital) with low operator requirements (low operating costs)

(26)

Tshwane University of Technology, Faculty of Science Department of Environmental, Water and Earth Sciences

Arcadia Campus, 175 Nelson Mandela Drive Republic of South Africa

mombamnb@tut.ac.za Tel W: +27(0)12 382 6365/6232

Fax: +27(0)12 3826233

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