After almost three years after tsunami and earthquake in 2005 in Nias and Aceh, most rehabilitati... more After almost three years after tsunami and earthquake in 2005 in Nias and Aceh, most rehabilitation efforts from international organizations are now addressing longer term economic development and livelihood improvements. As a part of UNDP project reference: RFP/UNDP/ERTP/013/2006 "Organisations/Firms to manage Tsunami Recovery Waste Management Program" (TRWMP), environmental experts from Murdoch University conducted a technical assessment for local NGOs to advise on waste management livelihood goals for the rehabilitation process. Pre-training visits in affected areas of Banda Aceh occurred in June 2007 to identify the potential project opportunities. The outcome of this mission was matched with local NGOs and community identification. These were 3 potential activities: biogas, coconut processing, and plastic recycling processing. The two-day training workshops for each of three mentioned activities were conducted in February 2008 for NGOs and community representatives. These workshops have provided information to beneficiaries and NGOs staff on specific technical details for sustainable waste management livelihood opportunities. Wastewater application in horticulture using hydroponics technology should minimise the exposure and contamination risk to the workers. Since the edible parts of the plant, with the exception of root crops, may not be in direct contact with the wastewater, contamination to the edible parts may also be reduced. This chapter examined two hydroponics systems, nutrient film technique and water culture (without aeration), for their efficiency in causing pathogen die-off. Three treatments, secondary treated domestic wastewater, control medium (commercial hydroponics medium) and pathogen spiked control medium were tested in triplicate. S.typhimurium (ATCCI4028) and E.coli (WACC4) were used to spike one of the treatments (spiked control medium). The experiment was conducted over four months with the medium changed every fortnight. The results showed that there was a general decrease of pathogens over seven days (>40%) in the medium and complete die-off was observed after 14 days (99%), in both types of hydroponics systems. In both systems, there were no pathogens detected in the fruits. The hydroponics techniques for domestic effluent reuse, is a viable option for edible crop production as it reduces the risks of bacterial pathogen contamination.
In areas where population increase is rapid and the centralised wastewater treatment system is un... more In areas where population increase is rapid and the centralised wastewater treatment system is unavailable, decentralised wastewater treatment systems are ideal. Due to the increase in demand for quality water and water scarcity world wide, reusing treated domestic effluent is a viable option. Most domestic wastewaters are high in the macro-nutrients and some micro-nutrients required for food production. Pathogen contamination is the major fear for using treated effluent to grow edible food crops, although there has been little evidence of this. A method of reducing the risk of pathogen contamination is to use the hydroponics technique. This ensures that the edible parts of the plants are not in contact with the wastewater. This study assesses the viability of using secondary treated wastewater from a decentralised treatment system using hydroponics to grow edible food crops and flowers compared to a commercial hydroponics medium. Tomatoes and pansies were grown using secondary trea...
Municipal wastewater discharge causes severe environmental pollution and public health risk throu... more Municipal wastewater discharge causes severe environmental pollution and public health risk through improper practices. Centralised wastewater treatment plants are not a viable option to the current problems for wastewater disposal and water scarcity especially in developing countries, remote areas and arid regions. In arid regions all sources of good quality water are committed to domestic needs leaving very little for food production. Places such as Western Australia are faced with extreme conservation pressure on existing surface and groundwater supplies, creating the need for more efficient and sustainable use of freshwater. Properly planned use of domestic wastewater alleviates surface water pollution, conserves valuable water resources and makes use of the nutrients contained in sewage to grow crops. The high nitrogen and phosphorus content of secondary treated wastewater may reduce or eliminate the need for application of chemical fertilizers in agriculture. The major concern...
The ‘H2S test’ is being advanced for microbiological water quality testing where conventional col... more The ‘H2S test’ is being advanced for microbiological water quality testing where conventional coliform based methods are impractical or too expensive. It involves ambient temperature incubation of water samples with nutrient formulated to generate hydrogen sulphide when ‘faecal’ bacteria are present. Recently a WHO review identified several concerns including the limited number of comparative studies, formulation variability, and false positives and negatives. In response we have compared the H2S test's ability to detect and quantify faecal contamination in an aquifer impacted by septic tank leachfields with measurements obtained concurrently using conventional bacterial indicators, coliphages, faecal sterol biomarkers, Cryptosporidium and Giardia. Like these other analytes, H2S testing detected a contamination gradient ranging from high (septic liquid) to moderate (exfiltration zones), to background (e.g. domestic bores), corresponding to indicator removal + dilution by factors...
Despite the increasing number of small scale digesters operating, there remains a lack of informa... more Despite the increasing number of small scale digesters operating, there remains a lack of information with regards to performance optimization from an everyday user's standpoint. The objective of this study was to determine the effects of volumetric dilution and food waste composition on digester performance. Batch experiments utilizing food waste majoring in carbohydrate, protein, lipid, and cellulose, subjected to five concentrations of volumetric dilution (3.7%–17.1% total solids (TS)), were conducted. Irregardless of volumetric dilution, all assays achieved substrate degradation higher than 82.5% and did not suffer methanogenic inhibition, when provided with retention times comparable to those used in small scale digesters. Protein rich and cellulose rich waste achieved the highest methane potential varying between 0.410–0.539 m3/kg volatile solids (VS) and 0.450–0.535 m3/kg VS, respectively. Protein rich assays were also observed to be the first to achieve 50% of its Bo irr...
Many communities and villages around the world face serious problems with lack of sanitation espe... more Many communities and villages around the world face serious problems with lack of sanitation especially in disposing of the wastewater—black water and grey water from the houses, or wash outs from animal rearing sheds. Across the world diverting wastewater to the surroundings or to the public spaces are not uncommon. This is responsible for contaminating drinking water sources causing health risks and environmental degradation as they become the breeding grounds of mosquitoes and pathogens. Lack of collection and treatment facilities or broken down sewage systems noticed throughout the developing world are associated with this situation. Diverting the wastewater to trees and vegetable gardens was historically a common practice. However the modern world has an array of problems associated with such disposal such as generation of large quantity of wastewater, unavailability of space for onsite disposal or treatment and increase in population. This paper considers the wastewater garden...
International Journal of Environment and Waste Management, 2013
Vermifi ltration is an innovative wastewater treatment process that implies the use of composting... more Vermifi ltration is an innovative wastewater treatment process that implies the use of composting worms to treat water loaded with organic contaminants. It is considered to be an innovative technology that provides a sustainable solution for the treatment of wastewater with synchronous sludge reduction and treatment. In this paper, an overview of vermifi ltration systems in liquid waste management is presented. The paper starts by giving an overview of the vermifi ltration process and then provides details of current studies and technologies used to treat wastewater using the vermifi ltration process. The anti-clogging nature of vermifi ltration systems is compared with other biological treatment systems and the key factors infl uencing the process and the treatment effi ciency of the process are critically reviewed. The scope and improvements to the process are fi nally suggested.
Abstract Internationally, it has been reported to have over 30 million small scale anaerobic dige... more Abstract Internationally, it has been reported to have over 30 million small scale anaerobic digesters. Despite the large number of existing small scale anaerobic digesters and a growing interest in food waste digestion, there has been a paucity of research regarding ...
The effect of heavy metals Cu and Zn on dehydrogenase and protease activity of the substrate duri... more The effect of heavy metals Cu and Zn on dehydrogenase and protease activity of the substrate during vermicomposting was investigated. Three dosages of Cu and Zn were tested in mesocosm experiments to investigate their bioaccumulation and impact on the reproduction of Eisenia fetida. Cu accumulated within the worm tissues in dosage concentrations up to a maximum level of 213 mg Cu kg À1 . The number of juveniles decreased from the lowest to highest dosages of Cu and Zn after 10 weeks of the experiment. Dehydrogenase showed a strong negative correlation (P < 0.01) with increased dosage of Cu, while protease remained unaffected. An overall reduction on dehydrogenase activity with increasing dosages of Cu and Zn indicated that these metals would impact detrimentally on the soil microbiology and consequently the stabilisation of the dosed media.
The aim of this work was to test combination of the thermocomposting and vermicomposting to impro... more The aim of this work was to test combination of the thermocomposting and vermicomposting to improve the treatment eYciency and assess the optimum period required in each method to produce good quality compost. The results showed that pre-thermocomposting improved vermicomposting of kitchen waste. A 9-day thermocomposting prior to vermicomposting helped in mass reduction, moisture management and pathogen reduction.
The study was conducted in a hydroponics set-up to determine the suitability of zinc (Zn) and cop... more The study was conducted in a hydroponics set-up to determine the suitability of zinc (Zn) and copper (Cu) contaminated wastewater as a growth medium for edible crops; to identify accumulation of Zn and Cu in different parts of the plants and to understand their effects on plant growth. Silver beet was found to produce adequate yields in the Zn (1.7 mg/L and 2.0mg/L) and Cu (0.35 mg/L and 1.1mg/L) spiked medium but not in the secondary treated domestic effluent. The plants grown in secondary treated effluent showed stunted growth and accumulated Zn and Cu to a high level in their shoots. In all other mediums Zn and Cu accumulated more in the roots. The stunted growth of silver beet in secondary treated wastewater and uptake of Zn in particular was considered to be due to the deficiency of nitrogen and other plant nutrients rather than the effect of heavy metals. The study also revealed that if there was adequate amount of macronutrients available for growth, silver beet could be grown in domestic effluent without the risk of Zn or Cu contamination to the undesired level through hydroponics.
Waste Management & Research: The Journal for a Sustainable Circular Economy, 2013
Published national and state reports have revealed that Australia deposits an average of 16 milli... more Published national and state reports have revealed that Australia deposits an average of 16 million Mg of solid waste into landfills yearly, of which approximately 12.6% is comprised of food. Being highly biodegradable and possessing high energy content, anaerobic digestion offers an attractive treatment option alternative to landfilling. The present study attempted to identify the theoretical maximum benefit of food waste digestion in Australia with regard to energy recovery and waste diversion from landfills. The study also assessed the scope for anaerobic process to utilize waste for energy projects through various case study scenarios. Results indicated anaerobic digestion of total food waste generated across multiple sites in Australia could generate 558 453 dam3 of methane which translated to 20.3 PJ of heating potential or 1915 GWe in electricity generation annually. This would contribute to 3.5% of total current energy supply from renewable sources. Energy contribution from ...
After almost three years after tsunami and earthquake in 2005 in Nias and Aceh, most rehabilitati... more After almost three years after tsunami and earthquake in 2005 in Nias and Aceh, most rehabilitation efforts from international organizations are now addressing longer term economic development and livelihood improvements. As a part of UNDP project reference: RFP/UNDP/ERTP/013/2006 "Organisations/Firms to manage Tsunami Recovery Waste Management Program" (TRWMP), environmental experts from Murdoch University conducted a technical assessment for local NGOs to advise on waste management livelihood goals for the rehabilitation process. Pre-training visits in affected areas of Banda Aceh occurred in June 2007 to identify the potential project opportunities. The outcome of this mission was matched with local NGOs and community identification. These were 3 potential activities: biogas, coconut processing, and plastic recycling processing. The two-day training workshops for each of three mentioned activities were conducted in February 2008 for NGOs and community representatives. These workshops have provided information to beneficiaries and NGOs staff on specific technical details for sustainable waste management livelihood opportunities. Wastewater application in horticulture using hydroponics technology should minimise the exposure and contamination risk to the workers. Since the edible parts of the plant, with the exception of root crops, may not be in direct contact with the wastewater, contamination to the edible parts may also be reduced. This chapter examined two hydroponics systems, nutrient film technique and water culture (without aeration), for their efficiency in causing pathogen die-off. Three treatments, secondary treated domestic wastewater, control medium (commercial hydroponics medium) and pathogen spiked control medium were tested in triplicate. S.typhimurium (ATCCI4028) and E.coli (WACC4) were used to spike one of the treatments (spiked control medium). The experiment was conducted over four months with the medium changed every fortnight. The results showed that there was a general decrease of pathogens over seven days (>40%) in the medium and complete die-off was observed after 14 days (99%), in both types of hydroponics systems. In both systems, there were no pathogens detected in the fruits. The hydroponics techniques for domestic effluent reuse, is a viable option for edible crop production as it reduces the risks of bacterial pathogen contamination.
In areas where population increase is rapid and the centralised wastewater treatment system is un... more In areas where population increase is rapid and the centralised wastewater treatment system is unavailable, decentralised wastewater treatment systems are ideal. Due to the increase in demand for quality water and water scarcity world wide, reusing treated domestic effluent is a viable option. Most domestic wastewaters are high in the macro-nutrients and some micro-nutrients required for food production. Pathogen contamination is the major fear for using treated effluent to grow edible food crops, although there has been little evidence of this. A method of reducing the risk of pathogen contamination is to use the hydroponics technique. This ensures that the edible parts of the plants are not in contact with the wastewater. This study assesses the viability of using secondary treated wastewater from a decentralised treatment system using hydroponics to grow edible food crops and flowers compared to a commercial hydroponics medium. Tomatoes and pansies were grown using secondary trea...
Municipal wastewater discharge causes severe environmental pollution and public health risk throu... more Municipal wastewater discharge causes severe environmental pollution and public health risk through improper practices. Centralised wastewater treatment plants are not a viable option to the current problems for wastewater disposal and water scarcity especially in developing countries, remote areas and arid regions. In arid regions all sources of good quality water are committed to domestic needs leaving very little for food production. Places such as Western Australia are faced with extreme conservation pressure on existing surface and groundwater supplies, creating the need for more efficient and sustainable use of freshwater. Properly planned use of domestic wastewater alleviates surface water pollution, conserves valuable water resources and makes use of the nutrients contained in sewage to grow crops. The high nitrogen and phosphorus content of secondary treated wastewater may reduce or eliminate the need for application of chemical fertilizers in agriculture. The major concern...
The ‘H2S test’ is being advanced for microbiological water quality testing where conventional col... more The ‘H2S test’ is being advanced for microbiological water quality testing where conventional coliform based methods are impractical or too expensive. It involves ambient temperature incubation of water samples with nutrient formulated to generate hydrogen sulphide when ‘faecal’ bacteria are present. Recently a WHO review identified several concerns including the limited number of comparative studies, formulation variability, and false positives and negatives. In response we have compared the H2S test's ability to detect and quantify faecal contamination in an aquifer impacted by septic tank leachfields with measurements obtained concurrently using conventional bacterial indicators, coliphages, faecal sterol biomarkers, Cryptosporidium and Giardia. Like these other analytes, H2S testing detected a contamination gradient ranging from high (septic liquid) to moderate (exfiltration zones), to background (e.g. domestic bores), corresponding to indicator removal + dilution by factors...
Despite the increasing number of small scale digesters operating, there remains a lack of informa... more Despite the increasing number of small scale digesters operating, there remains a lack of information with regards to performance optimization from an everyday user's standpoint. The objective of this study was to determine the effects of volumetric dilution and food waste composition on digester performance. Batch experiments utilizing food waste majoring in carbohydrate, protein, lipid, and cellulose, subjected to five concentrations of volumetric dilution (3.7%–17.1% total solids (TS)), were conducted. Irregardless of volumetric dilution, all assays achieved substrate degradation higher than 82.5% and did not suffer methanogenic inhibition, when provided with retention times comparable to those used in small scale digesters. Protein rich and cellulose rich waste achieved the highest methane potential varying between 0.410–0.539 m3/kg volatile solids (VS) and 0.450–0.535 m3/kg VS, respectively. Protein rich assays were also observed to be the first to achieve 50% of its Bo irr...
Many communities and villages around the world face serious problems with lack of sanitation espe... more Many communities and villages around the world face serious problems with lack of sanitation especially in disposing of the wastewater—black water and grey water from the houses, or wash outs from animal rearing sheds. Across the world diverting wastewater to the surroundings or to the public spaces are not uncommon. This is responsible for contaminating drinking water sources causing health risks and environmental degradation as they become the breeding grounds of mosquitoes and pathogens. Lack of collection and treatment facilities or broken down sewage systems noticed throughout the developing world are associated with this situation. Diverting the wastewater to trees and vegetable gardens was historically a common practice. However the modern world has an array of problems associated with such disposal such as generation of large quantity of wastewater, unavailability of space for onsite disposal or treatment and increase in population. This paper considers the wastewater garden...
International Journal of Environment and Waste Management, 2013
Vermifi ltration is an innovative wastewater treatment process that implies the use of composting... more Vermifi ltration is an innovative wastewater treatment process that implies the use of composting worms to treat water loaded with organic contaminants. It is considered to be an innovative technology that provides a sustainable solution for the treatment of wastewater with synchronous sludge reduction and treatment. In this paper, an overview of vermifi ltration systems in liquid waste management is presented. The paper starts by giving an overview of the vermifi ltration process and then provides details of current studies and technologies used to treat wastewater using the vermifi ltration process. The anti-clogging nature of vermifi ltration systems is compared with other biological treatment systems and the key factors infl uencing the process and the treatment effi ciency of the process are critically reviewed. The scope and improvements to the process are fi nally suggested.
Abstract Internationally, it has been reported to have over 30 million small scale anaerobic dige... more Abstract Internationally, it has been reported to have over 30 million small scale anaerobic digesters. Despite the large number of existing small scale anaerobic digesters and a growing interest in food waste digestion, there has been a paucity of research regarding ...
The effect of heavy metals Cu and Zn on dehydrogenase and protease activity of the substrate duri... more The effect of heavy metals Cu and Zn on dehydrogenase and protease activity of the substrate during vermicomposting was investigated. Three dosages of Cu and Zn were tested in mesocosm experiments to investigate their bioaccumulation and impact on the reproduction of Eisenia fetida. Cu accumulated within the worm tissues in dosage concentrations up to a maximum level of 213 mg Cu kg À1 . The number of juveniles decreased from the lowest to highest dosages of Cu and Zn after 10 weeks of the experiment. Dehydrogenase showed a strong negative correlation (P < 0.01) with increased dosage of Cu, while protease remained unaffected. An overall reduction on dehydrogenase activity with increasing dosages of Cu and Zn indicated that these metals would impact detrimentally on the soil microbiology and consequently the stabilisation of the dosed media.
The aim of this work was to test combination of the thermocomposting and vermicomposting to impro... more The aim of this work was to test combination of the thermocomposting and vermicomposting to improve the treatment eYciency and assess the optimum period required in each method to produce good quality compost. The results showed that pre-thermocomposting improved vermicomposting of kitchen waste. A 9-day thermocomposting prior to vermicomposting helped in mass reduction, moisture management and pathogen reduction.
The study was conducted in a hydroponics set-up to determine the suitability of zinc (Zn) and cop... more The study was conducted in a hydroponics set-up to determine the suitability of zinc (Zn) and copper (Cu) contaminated wastewater as a growth medium for edible crops; to identify accumulation of Zn and Cu in different parts of the plants and to understand their effects on plant growth. Silver beet was found to produce adequate yields in the Zn (1.7 mg/L and 2.0mg/L) and Cu (0.35 mg/L and 1.1mg/L) spiked medium but not in the secondary treated domestic effluent. The plants grown in secondary treated effluent showed stunted growth and accumulated Zn and Cu to a high level in their shoots. In all other mediums Zn and Cu accumulated more in the roots. The stunted growth of silver beet in secondary treated wastewater and uptake of Zn in particular was considered to be due to the deficiency of nitrogen and other plant nutrients rather than the effect of heavy metals. The study also revealed that if there was adequate amount of macronutrients available for growth, silver beet could be grown in domestic effluent without the risk of Zn or Cu contamination to the undesired level through hydroponics.
Waste Management & Research: The Journal for a Sustainable Circular Economy, 2013
Published national and state reports have revealed that Australia deposits an average of 16 milli... more Published national and state reports have revealed that Australia deposits an average of 16 million Mg of solid waste into landfills yearly, of which approximately 12.6% is comprised of food. Being highly biodegradable and possessing high energy content, anaerobic digestion offers an attractive treatment option alternative to landfilling. The present study attempted to identify the theoretical maximum benefit of food waste digestion in Australia with regard to energy recovery and waste diversion from landfills. The study also assessed the scope for anaerobic process to utilize waste for energy projects through various case study scenarios. Results indicated anaerobic digestion of total food waste generated across multiple sites in Australia could generate 558 453 dam3 of methane which translated to 20.3 PJ of heating potential or 1915 GWe in electricity generation annually. This would contribute to 3.5% of total current energy supply from renewable sources. Energy contribution from ...
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