HISTORICALLY, the development of sewerage services in Malaysia was mainly driven by local authorities to meet the basic sanitation needs of the public.
With the federalisation of sewerage services in 1994, Indah Water Konsortium (IWK) together with the governing agencies had overseen the realization of modern and efficient sewerage treatment system in Malaysia for the past 16 years.
With almost 100 per cent sanitation coverage nationwide to date, Malaysia is considered by our regional counterparts as a success model.
Modern mechanised treatment technologies predominates most of our urban landscape, which ensures that sewage is treated before the effluent is released back into our receiving water bodies.
These systems not only safeguard public health but also provide a green and healthy environment. The modern systems we enjoy today have evolved through scientific research and technological development.
The continual improvement and modernisation of municipal sanitation services have led to the present day sewerage network and mechanised as well as automated treatment systems.
IWK's R&D programme
Being cognizant of R&D's role in transforming the landscape of the sewerage industry, IWK's journey thus far encompasses a spectrum of research initiatives ranging from studies on collections systems, optimisation of sewage treatment performance, sewage sludge treatment, sewage by-products recovery and reuse of sewage such as bio-effluent and bio solids.
Its journey started with structured R&D collaborations with local research institutions and this formed IWK's core programme.
This was complemented with pilot trials of new technologies, in-house studies and research projects by university students.
Structured R&D with local research institutions are mainly funded by IWK, whilst leveraging on the local research institution's niche expertise to address key needs of improving sewage and sludge treatment along with reuse potentials over the long term.
Pilot trials were focused on the assessment of new or emerging technologies, which included testing of vendors' claims to investigations for technology adaptation or modification for local adoption.
IWK's in-house studies typically included desktop studies and lab experiments for exploratory and troubleshooting purposes. In addition, IWK facilitated university research students in terms of facilities, expertise and experience.
This is keeping in line with IWK's aspiration to promote local research and develop a Malaysian R&D Centre for sewerage services.
R&D focus areas
Traditionally, the focus of R&D was limited to developing technologies that ensured sewage treatment plants' final effluent met regulatory discharge limits as well as solutions to operational issues.
Presently, due to complex environmental challenges of climate, a water sensitive future and along with the need for sustainable sewerage business, research has now expanded to include green technology applications.
This includes resource recovery (by products reuse and nutrient recovery), renewable energy production as well as eco-friendly systems where biotechnology and nanotechnology will play a key role.
From the point of sewage collection to treatment and final disposal, the R&D focus for the sewerage sector over the years falls into four major key areas namely collection system, sewage treatment system performance, wastewater reuse and sludge management.
R&D in collection system
Sewage collection systems mainly comprise a network of pipelines, manholes, pumping stat ions or force mains to collect and transport sewage from residential, commercial and industrial buildings to sewage treatment facilities.
Collaborative research with Universiti Teknologi Malaysia (UTM) on fundamental subjects such as determination of per capita sewage load and inflow and infiltration in sewerage pipeline were conducted.
The former provided actual sewage load (quantity and strength) in a local catchment. Actual flow rate was measured at 202L/ PE.day (202 litres per population equivalent daily) as compared to the design standard of 225L/PE.day, whilst organic loading was found at BOD (biochemical oxygen demand) of 45g/PE.day (45 grammes per population equivalent daily) compared to design values of 55g/PE.day and SS (suspended solids) was detected at 20g/PE.day compared to 68g/ PE.day as recommended by the Malaysian Standard (MS1228).
These findings provided an insight on engineering design values and led to further data collection at other localities in Malaysia.
Similarly the study on inflow and infiltration in sewerage system provided scientific data to support engineering design.
Infiltration was found to be as low as 88L/day/km/mm diameter and as high as 4700L/day/km/ mm diameter, whilst leakage from the sewers can reach 8000L/day/ km/mm diameter and peak flow factor was measured at 2.3 much lower than the MS1228 value of 4.7 per cent.
Following these results, data from varying catchments and sewer systems will be continually col lected to determine the appropriate design value for Malaysian conditions.
Moving on from such fundamental studies, R&D into biotechnology solutions is being explored. Some studies being explored include those to investigate the potential of enzyme and microbe applications to resolve sewer blockages due to fat, oil and grease (a common problem in Malaysia), as well as in-pipe treatment innovations that use microbes to treat sewage in the sewer and thus lowering the pollutant loads that end up in the sewage treatment plant. Nanotechnology applications for sewer materials are being investigated on corrosion resistant and other areas of interest.
R&D in sewage treatment system
R&D studies on low cost innovations to improve and upgrade older treatment facilities include testing efficacy of chemical agents to enhance pollutant settling out and removal at communal septic tanks, bio- augmentation at oxidation ponds and using of bio-media to improve pollutant removal at Imhoff Tanks (IT).
It was found that chemical agents were able to improve coagulation and settling for the Communal Septic Tanks (CST) thus reducing SS and certain proportion of biochemical oxygen demand (BOD) and chemical oxygen demand (COD), whereby innovations into efficient dosing to realise economical chemical usage helped improve the systems.
Study on the use of biochemical and/or biological products at oxidation ponds, such as enzymes and microbes by UTM showed results that SS, COD, BOD, oil and grease as well as nutrients had been reduced by 15 per cent to 35 per cent.
Using media in a tank system to increase the surface area for microbial degradation was a concept proven to work in a collaborative study with UPM.
The study showed that media could improve removal by 20 to 30 per cent with less clogging problems compared to older IT media aggregates. Longer term monitoring studies on the system's desludging needs, efficacy over time and adaptation into nutrient recovery model is being pursued.
Beyond upgrading old systems to meet environmental standards, the current predominance of modern mechanised systems across the country has raised the need for energy saving innovations.
The quantum of electrical energy consumed by more than 4,500 of such facilities nationwide gives opportunity to innovate for energy saving solutions.
In this regard, bio-technology is being explored as a new alternative for treatment process improvements where microbial products could be developed to enhance the treatment systems capability.
As of late, eco-friendly treatment systems are being explored whereby sewage treatment will need less space, produce less sludge and require lower energy whilst purifying the sewage before the effluent is released back into clean water.
The latest being a variation of sequencing batch reactors (SBR), moving bed bioreactor (MBBR), membrane bioreactor (MBR), combination of up-flow anaerobic sludge blanket (UASB) and aerobic polishing.
Some examples of on-going studies on eco-friendly systems are pilot trials of hybrid treatment systems, which is a combination of bio-film (attached growth on media) and activated sludge as well as pilot MBR systems at sewage treatment facilities in the country.
"It is envisaged that R&D will not only realise the variation of pilot eco-friendly systems in Malaysia but in the long term, the zero-waste concept will be demonstrated on a pilot scale whereby sewage treatment will be transformed into a resource recovery process with zero waste stream", says Datuk Ir Abdul Kadir, Chief Executive Officer of Indah Water Konsortium.
R&D in wastewater reuse
Currently, nationwide sewage treatment plants on aggregate produce 4,000 MLD of treated effluent that can be tapped for industrial cleaning purposes, agriculture, recreation, industrialplant cooling and recharge of groundwater.
This will greatly relieve water stress areas and contribute towards sustainable water resources. Previous R&D collaborative study between IWK and UTM established the benefits of treated sewage effluent (bio-effluent) reuse in landscaping and for industrial applications.
For industrial applications, a study on using continuous submerged MF (CMF-S) followed by reverse osmosis (RO) membrane for wastewater reclamation was implemented.
The results showed that reclaimed water was suitable for industrial applications and disinfection would be required to prevent post bacterial growth in post RO piping. Although the results were encouraging, RO systems require high investment and operational costs.
Thus, the tariff for water reclamation needs to be looked into along with research for lower cost filtration systems.
Additionally, the potential of MBR systems are being explored to produce high quality effluent with bacteria removal in combination with RO or down steam disinfection as to the long term alternative to realise bio-effluent recycling.
Depending on the applications, pre-commercialisation scale demonstration recycling technologies units can now be investigated by local researchers.
Such projects are in tandem with the country's green technology agenda as it will lower the nation's water footprint.
R&D in sludge reuse and management
Apart from recycled water potential, R&D on sewage sludge provides the scientific data for reuse of bio-solids (semi- solid dewatered form of sewage sludge) as fertilisers or soils amendment material.
Presently, domestic sewage treatment facilities in Malaysia generate approximately 200 tonnes a day of sewage sludge that is disposed to landfill.
This remains a huge potential for resource recovery. Local research has shown that the typical proportion of nitrogen (N):phosphorus (P): potassium (K) in bio-solids is 3 per cent whilst organic matter constitutes more than 50 per cent of the bio-solids and the presence of micronutrients such as calcium, magnesium and sulphur are beneficial for plant growth.
Field trials in collaboration with UPM on timber species, such as meranti tembaga, jelutong, acasia, kayu manis and merawan showed significant growth in terms of height and basal diameter whilst improving the soil Cation Exchange Equivalent (CEC).
The CEC was found to increase to 22meq/100g soil compared to 7.4meq/100g soil at the control plot. Research on rubber trees with UPM & RRIM (The Rubber Research Institute of Malaysia) also showed that bio-solids were able to increase growth rate and potential to double the wood yield. Additionally, UPM found that the rubber wood quality to be suitable for furniture use.
Stabilisation methods to further enhance the value of bio-solids were also explored and ranges from traditional composting to vermi compos t ing us ing earthworms.
Composting studies by UPM produced compost from sewage sludge that was comparable to commercial chemical fertilisers in potted ornamental plants.
Whilst vermicomposting study with MARDI (Malaysian Agr icul tural Research and Development Institute) showed that sewage sludge can be transformed by earthworms into valued added fertilisers.
Essentially by realising biosolid reuse instead of disposal to landfills will reduce greenhouse gas generation from the landfills.
This will contribute positively to a lower carbon footprint overall. Based on the research data collected, it would auger well to establish reuse guidelines for Malaysia and precommercialisation demo scale plants can be carried out to support Malaysia's Green Agenda.
Sewage sludge being rich in organic material can also be converted into an energy source. It can either be converted into methane gas (also known as biogas) as renewable fuel source or transformed into other fuel material and then fired for energy.
Biogas generated at IWK's facilities showed methane composition averaging 65 per cent whilst analysis of typical biosolids from IWK plants in Malaysia showed the calorific value ranging from 2500 to 4300 kcal/kg dry solids.
R&D on social-environmental sewerage management development
In addition to the four key R&D areas featured, there are other scopes being studied, for instance R&D study between Universiti Kebangsaan Malaya (UKM) and IWK was carried out to gauge the public's perception towards the reuse of bio-solids and bioeffluent.
Most respondents agreed with the reuse of bio-effluent for landscaping and industrial uses, whilst most were amenable to biosolids for non-food crops. The acceptance rate could be improved with educational and awareness tools. It is envisaged that local research studies will also include matters relating to policies and developmental strategies (for example, centralised versus de-centralised systems) as well as other management aspects of sewerage development.
Future R&D opportunities in a nutshell
Research and development for improvements in sewerage sector is inextricably linked to improving our environment for a sustainable future and it is envisaged that the next phase of R&D studies will involve exploration of biotechnology and nano-technology applications in wastewater treatment.