Life cycle inventory of the commercial production of compost from oil palm biomass: a case study

This paper compared the life cycle inventory (LCI) obtained from three commercial oil palm biomass composting projects in Malaysia which use the open windrow composting system. The LCI was obtained and calculated based on the functional unit of 1 t of compost produced. The input of the inventory are the feed materials such as empty fruit bunches (EFB) and palm oil mill effluent (POME); and utilities which include electricity generated at palm oil mill and diesel used. Composting 2.0–2.5 t of EFB and 5.0–7.5 t of POME required diesel from 218.7 to 270.2 MJ and electricity from 0 to 6.8 MJ. It is estimated that the composting emitted from 0.01 to 0.02 t CO_2eq/t_compost mainly from diesel used to operate machineries. Composting saved 65 % of time required for a complete degradation of POME when compared to ponding system, and 89 % of time required for a complete degradation of EFB compared to mulching. In terms of land required, it required 36 % less land as compared to ponding for POME and 99 % less land as compared to mulching for EFB. Based on the case study, diesel was found to be the main contributor to the environmental impact. There is a potential of upgrading the process to be more economical and environmental friendly. Using electricity as the source of energy has a lower footprint for the composting process. Instead of using raw POME, studies had reported that using treated POME either from anaerobic ponding or digested tank can accelerate the composting process.     

Economic analysis of biogas and compost projects in a palm oil mill with clean development mechanism in Malaysia

This article is a case study to compare the economic viabilities of biogas generation and compost projects in a palm oil mill in Malaysia with and without clean development mechanism (CDM). Biogas is captured from anaerobic ponds or digester tanks treating palm oil mill effluent (POME) and converted to green renewable electricity for grid connection, while compost is produced from the shredded empty fruit bunch and raw untreated POME. The both technologies were compared by considering the changes of the materials flow and energy balances. A palm oil mill with a capacity of 54?t fresh fruit bunch per hour has the potential to produce either 6.9?GWh of electricity from biogas or fertilizer equivalent to 488?t of nitrogen, 76?t of phosphorus and 1,065?t of potassium per year. The economic analysis for 10?years project term analysis indicated that CDM gave a significant impact and ensured economic viability for both projects with 25?% of internal rate of return (IRR), RM 12.39 million of net present value (NPV) and 3.5?years of payback period (PBP) for biogas project, whereas 31?% of IRR, RM 10.87 million of NPV and 2.9?years of PBP for compost project, respectively. In addition, sensitivity analysis indicated that the profitability of both projects will vary depending on the economic situation, such as electricity price which is based on the government policy, whereas compost price that depend on fertilizer market price with 43?% NPV change in 20?% range of fertilizer value.     

Methane and algal production from poultry waste and its public health aspects

The results of this study indicate that the optimum solids concentrations for anaerobic digestion of poultry waste was 8% at incubation temperatures of 22 and 37 °C. Changes in the temperature of the digestion affected the total volume of biogas produced, its rate of production, and the time required for the digestion. Algal production on the digested effluent was a successful process, producing high biomass content. The bacteriological quality of raw and digested waste, as well waste during algal culture, reflects the possible health risks which may occur with the use of anaerobically digested sludge with or without treatment.     

Ultrasonically enhanced anaerobic digestion of waste activated sludge

Anaerobic digestion is increasingly applied to stabilise sludge and to reduce operating costs of the wastewater treatment plant by generating biogas, considered as a sustainable energy source. The process suffers from many drawbacks such as slow and incomplete degradation rates, the result of the slow and rate‐limiting sludge hydrolysis step, due to the low biodegradability of the cell walls and the presence of extra‐cellular biopolymers.

Methods to enhance the biogas formation should hence make the substrate more accessible to the anaerobic micro‐organisms. Research on increasing the biogas production is extensive, with low‐frequency ultrasound treatment emerging as the technical and economic most appropriate technology. Although ultrasound is now widely applied in practice, underlying phenomena and optimum operating conditions are still open to debate. Laboratory ultrasound treatment was coupled with digestion experiments (at 37°C) using 12 parallel digesters, two of them being used as control digesters with untreated sludge.

The present paper demonstrates that ultrasound treatment can – within specific ranges of energy‐input – achieve (i) an increased disintegration of the sludge, as witnessed by an increasing soluble COD‐fraction accompanied by an increasing presence of BOD; (ii) an increased release of volatile fatty acids as a result of the oxidising radicals being formed through cavitation; and (iii) a slightly reduced dewaterability of the residual sludge, needing an increased dosage of poly‐electrolyte to obtain a high degree of cake dryness.

As pre‐treatment to digestion, ultrasound enhances the biogas production by more than 40% at low specific energy‐inputs (SE), and approximately 15% at higher SE‐values.     

Studies on process optimization of biodiesel production from waste cooking and palm oil

This work investigated the optimisation of biodiesel production from waste cooking oil (WCO) and palm oil using a two-step transesterification process for WCO and base catalysed transesterification for palm oil. Transesterification reactions were carried out to investigate the effects of prepared catalyst CaO, methanol/WCO and methanol/palm oil ratio and temperature on the yield of biodiesel. A series of experiments were conducted to determine the best conditions for biodiesel production, using methanol/oil ratio between 4:1 and 11:1 and contact time varying between 2 and 4 h. Biodiesel yield of around 90 and 70% was obtained for palm and waste cooking oil at the methanol/oil ratios of 6:1 and 8:1 at temperature of 60 °C for reaction time of 4 h using prepared CaO as catalyst. The physicochemical properties of palm and WCO biodiesel were carried out using standard methods, while the fatty acid profile was determined using gas chromatography. The investigation concludes that biodiesel obtained from palm and waste cooking oil was within the specified limit.     

Environmental change,development and vectorborne disease: Malaysia’s experience with filariasis,scrub typhus and dengue

During Malaysia’s rapid economic development into becoming a middle income country in the past several decades, environmental changes resulted in altered land use patterns because of agricultural practices such as large scale rice, rubber and oil palm cultivation. The impact of environmental changes brought about by rice and rubber cultivation affected the breeding habitats of mosquito vectors which in turn affected the prevalence of two strains of lymphatic filariasis in different ways. With scrub typhus, the development of oil palm plantations affected the ecology of mite and rodent populations which resulted in very high incidence of the disease in affected populations. Malaysia’s relentless urbanization has resulted in increased incidence of dengue, as peridomestic mosquito vectors increasingly colonize urban habitats. This article discusses how ecological factors determine the way lymphatic filariasis, scrub typhus and dengue were spread in Malaysia. The nation’s experience with environmental changes due to rapid development provides lessons for other developing countries in control programs and public health policy.     

Recalculating GHG emissions saving of palm oil biodiesel

In 2010, the Renewable Energy Directive (RED) came into force in the EU and establishes a framework for achieving legally binding greenhouse gas (GHG) emission reductions. Only sustainable biofuels can be counted towards Member State targets. The aim of this paper is to calculate realistic and transparent scenario-based CO₂-emission values for the GHG emissions savings of palm oil fuel compared with fossil fuel. Using the calculation scheme proposed by the RED, we derive a more realistic overall GHG emissions saving value for palm oil diesel by using current input and output data of biofuel production (e.g. in South-East Asia). We calculate different scenarios in which reliable data on the production conditions (and the regarding emission values during the production chain) of palm oil diesel are used. Our results indicate values for the GHG emissions savings potential of palm oil biodiesel not only above the 19 % default and 36 % typical value published in RED but also above the 35 % sustainable threshold. Our findings conclude the more accurate GHG emissions saving value for palm oil feedstock for electricity generation to be 52 %, and for transportation biodiesel between 38.5 and 41 %, depending on the fossil fuel comparator. Our results confirm the findings by other studies and challenge the official typical and default values published in RED. As a result, the reliability of the Directive to support the EU’s low-carbon ambitions is being undermined, exposing the EU and commission to charges of trade discrimination and limiting the ability of Member States to achieve their legally binding GHG emission reductions.     

Concentrations, transport, fate, and releases of polybrominated diphenyl ethers in sewage treatment plants in the Pearl River Delta, South China

Wastewater has proved to be a significant source of polybrominated diphenyl ethers (PBDEs) in the environment. Seventeen congeners from tri- to deca-BDEs were determined to characterize the occurrence, fate, and transport of PBDEs in two sewage treatment plants in the Pearl River Delta, South China. The PBDE concentrations varied substantially from 13.3 to 2496.4 ng L(-1) in the raw wastewater, depending on the wastewater types and contents of the suspended particulate matter (SPM). The concentrations declined to 0.9 to 4.4 ng L(-1) in the treated effluent and were closely associated with SPM contents. BDE-209 was the predominant congener in the wastewater and sewage sludge. Most of PBDEs might have ended up in the sewage sludge, with <4.7% being discharged with the treated effluent. The results revealed that PBDEs were not significantly degraded by biological treatment and chlorination in the STPs. An annual release of PBDEs was estimated at 2280 kg/year through wastewater from the Pearl River Delta.     

A simplified method for the design and sizing of anaerobic digestion systems for smaller farms

Anaerobic digestion (AD) as a waste treatment practice has existed for nearly 200 years and has become an accepted option for many farming and small-scale residential operations. Many developing countries now encourage the use of AD in order to meet new environmental regulations and/or to provide small amounts of energy resulting from methane generated during the process. This development has been met with some difficulty due to the lack of resources and knowledge of the systems in many of the rural communities in which these digesters are placed. A properly designed AD system can help prevent soil and water pollution as well as help mitigate methane emissions by capturing them for use as a potential energy source. This paper focuses on providing guidance to the proper design and sizing of an AD system for typical small farms, which account for the majority of dairy farms worldwide. A focus was on the implementation of such systems as they might be applied in Central America, although the aspects studied here can be applied for AD systems handling animal waste streams practically anywhere. We provide a method for sizing of anaerobic digester systems based on design standards from the US National Resource Conservation Service and using field sampled data of holding pen wash water runoff. An overview of the decision process for alternative designs is given, and simple-to-use nomographs are presented for use in sizing of an anaerobic digester system for smaller (non-industrial)-scale farms.     

OPTIONS FOR ENVIRONMENTAL SUSTAINABILITY OF THE CRUDE PALM OIL INDUSTRY IN THAILAND THROUGH ENHANCEMENT OF INDUSTRIAL ECOSYSTEMS

The crude palm oil industry plays an important role in the economic development of Thailand and in enhancing the economic welfare of the population. Despite obvious benefits of this industrial development, it also significantly contributes to environmental degradation, both at the input and the output sides of its activities. On the input side, crude palm oil mills use large quantities of water and energy in the production process. On the output side, manufacturing processes generate large quantities of wastewater, solid waste/by-products and air pollution. Current industrial wastes and recoverable materials are empty fruit bunches, fibers, shells and ash. It is estimated that in 2003, a total of 2.1 million ton of solid wastes/by-products and 2.5 million m³ of wastewater were generated. The concept of the industrial ecosystem points at the potential of industrial waste recycling resembling food chains, food webs and nutrient cycles of nature. Following the notion of industrial ecology crude palm oil mills can develop a number of waste recycling and reuse systems. This paper analyzes the nature of these industrial ecosystems, divided in in-plant ecosystems (clean technology options) and external waste exchange between crude palm oil industries and other economic activities in Thailand.     

Energy intensities and the impact of high energy prices on producing and consuming sectors in Malaysia

The increase in oil prices has put pressure on the global economy. Even economies that have a high degree of self-sufficiency concerning oil products are experiencing rising production costs and price increases for households energy use. Therefore, changes in energy policies are under consideration for countries highly dependent on imported energy as well as countries with a high degree of self-sufficiency. Examination of dependence on cheap energy sources for economic growth in different economic sectors is becoming more important as countries are trying to promote activities that are less energy intense. Among the policy changes under consideration, the adjustment of domestic energy subsidies is of particular interest. The effect of high energy prices on a fast growing economy, such as in Malaysia, is considerable, as the country will shift from being a net exporter of energy to a net importer in less than 10 years. Malaysia until recently has experienced increasing overall energy intensity and the growth up to 2,000 was quite high, especially for electricity intensity. A continued rise in energy intensity will be quite problematic in this new high oil price regime. This paper investigates the impact of rising energy prices on production costs for the different sectors of the Malaysian economy. Input–output (I–O) calculations demonstrate that the impact on the exporting component of the manufacturing sectors is less than for the average production. Therefore the production cost increase caused by, for example, an adjustment in electricity prices of 25% will result in less than 1/2% increase. As the competing countries in world markets are experiencing the same rise in energy costs, including electricity based on fossil fuels, there is no vital argument for not allowing domestic energy prices to adjust to the international price changes.

Fate, behavior and effects of surfactants and their degradation products in the environment

Surfactants are widely used in household and industrial products. After use, surfactants as well as their products are mainly discharged into sewage treatment plants and then dispersed into the environment through effluent discharge into surface waters and sludge disposal on lands. Surfactants have different behavior and fate in the environment. Nonionic and cationic surfactants had much higher sorption on soil and sediment than anionic surfactants such as LAS. Most surfactants can be degraded by microbes in the environment although some surfactants such as LAS and DTDMAC as well as alkylphenols may be persistent under anaerobic conditions. LAS were found to degrade in sludge amended soils with a half-lives of 7 to 33 days. Most surfactants are not acutely toxic to organisms at environmental concentrations and aquatic chronic toxicity of surfactants occurred at concentrations usually greater than 0.1 mg/L. However, alkylphenols have shown to be capable of inducing the production of vitellogenin in male fish at a concentration as low as 5 microg/L. More toxicity data are needed to assess the effects on terrestrial organisms such as plants.     

Concentrations and environmental fate of Ra in cation-exchange regeneration brine waste disposed to septic tanks and accumulation in sludge, New Jersey Coastal Plain, USA

Concentrations of Ra in liquid and solid wastes generated from 15 softeners treating domestic well waters from New Jersey Coastal Plain aquifers (where combined Ra ((226)Ra plus (228)Ra) concentrations commonly exceed 0.185 Bq L(-1)) were determined. Softeners, when maintained, reduced combined Ra about 10-fold (<0.024 Bq L(-1)). Combined Ra exceeded 0.185 Bq L(-1) at 1 non-maintained system. Combined Ra was enriched in regeneration brine waste (maximum, 81.2 Bq L(-1)), but concentrations in septic-tank effluents receiving brine waste were less than in the untreated ground waters. The maximum combined Ra concentration in aquifer sands (40.7 Bq kg(-1) dry weight) was less than that in sludge from the septic tanks (range, 84-363 Bq kg(-1)), indicating Ra accumulation in sludge from effluent. The combined Ra concentration in sludge from the homeowners' septic systems falls within the range reported for sludge samples from publicly owned treatment works within the region.     

Benefits and costs of oil palm expansion in Central Kalimantan,Indonesia, under different policy scenarios

Deforestation and oil palm expansion in Central Kalimantan province are among the highest in Indonesia. This study examines the physical and monetary impacts of oil palm expansion in Central Kalimantan up to 2025 under three policy scenarios. Our modelling approach combines a spatial logistic regression model with a set of rules governing land use change as a function of the policy scenario. Our physical and monetary analyses include palm oil expansion and five other ecosystem services: timber, rattan, paddy rice, carbon sequestration, and orangutan habitat (the last service is analysed in physical units only). In monetary terms, our analysis comprises the contribution of land and ecosystems to economic production, as measured according to the valuation approach of the System of National Accounts. We focus our analysis on government-owned land which covers around 97 % of the province, where the main policy issues are. We show that, in the business-as-usual scenario, the societal costs of carbon emissions and the loss of other ecosystem services far exceed the benefits from increased oil palm production. This is, in particular, related to the conversion of peatlands. We also show that, for Central Kalimantan, the moratorium scenario, which is modelled based on the moratorium currently in place in Indonesia, generates important economic benefits compared to the business-as-usual scenario. In the moratorium scenario, however, there is still conversion of forest to plantation and associated loss of ecosystem services. We developed an alternative, sustainable production scenario based on an ecosystem services approach and show that this policy scenario leads to higher net social benefits including some more space for oil palm expansion.     

Radioactivity concentration in liquid and solid phases of scale and sludge generated in the petroleum industry

Scales and sludge generated during oil extraction and production can contain uranium, thorium, radium and other natural radionuclides, which can cause exposure of maintenance personnel. This work shows how the oil content can influence the results of measurements of radionuclide concentration in scale and sludge. Samples were taken from a PETROBRAS unit in Northeast Brazil. They were collected directly from the inner surface of water pipes or from barrels stored in the waste storage area of the E&P unit. The oil was separated from the solids with a Soxhlet extractor by using aguarras at 90+/-5 degrees C as solvent. Concentrations of 226Ra and 228Ra in the samples were determined before and after oil extraction by using an HPGe gamma spectrometric system. The results showed an increase in the radionuclide concentration in the solid (dry) phase, indicating that the above radionuclides concentrate mostly in the solid material.     

226Ra and 228Ra in scale and sludge samples and their correlation with the chemical composition

In order to contribute to a future waste management policy related to the presence of technologically enhanced natural occurring radioactive material (TENORM) in the Brazilian petroleum industry, the present work presents the chemical composition and the (226)Ra and (228)Ra content of sludge and scales generated during the offshore E and P petroleum activities in the Campos Basin, the primary offshore oil production region in Brazil. The (226)Ra and (228)Ra content on 36 sludge and scales samples were determined by gamma-spectrometry. Based on X-ray diffractometry results, a chemical analysis schema for these samples was developed. The results have shown that scales are 75% barium and strontium sulfates, with a mean (226)Ra and (228)Ra content of 106 kBq kg(-1) and 78 kBq kg(-1), respectively. On the other hand, sludge samples have a much more complex chemical composition than the scales. The (226)Ra and (228)Ra content in sludge also varies much more than the content observed in the scales samples and ranged from 0.36 to 367 kBq kg(-1) and 0.25 to 343 kBq kg(-1), respectively.     

Energy analysis for onsite and offsite suburban wastewater

The environmental consequence of meeting the planet’s energy requirements has shown that biological degradation of organic constituent from wastewater does not only produces biogas. It also produces flammable methane that has 21 times more global warming potential or greenhouse effect than carbon dioxide. This becomes a loss of potential renewable energy when it is flared. This study investigates recoverable energy from cassava wastewater and effect of unrecovered onsite (not from treatment plant) wastewater energy. Sludge from both onsite untreated and offsite treated wastewater from a cassava processing station in a sub urban community of Nigeria was analyzed. The result shows that the offsite treatment has a methane potential of 27.428 m³/day compared to the onsite methane emission potential with 17.807 m³/day. The onsite 17.807 m³/day of methane is equivalent to 0.126 kgCH₄/year of emitted methane base on industrial procedure standards by the IPCC (2006) guidelines for national greenhouse gas inventories. An additional 54.03% of methane will be recovered if the onsite emissions were to be captured . At an emission efficiency of 0.025 kgCH₄/kg COD, the untreated wastewater indicates a potential contribution to the greenhouse effect. A mathematical model analysis was presented for ease in determining the amount of methane emitted from the untreated wastewater. This study support suggested methodologies and previous work comparing anaerobic offsite methane potential and untreated wastewater methane emission potentials along with its greenhouse effects.     

The oil palm boom: socio-economic implications for Q’eqchi’ households in the Polochic valley,Guatemala

Oil palm (Elaeis guineensis) has become one of the most rapidly expanding crops in the world. Many countries have promoted its cultivation as part of a broader rural development strategy aimed at generating paid work and producing both export commodities and biofuels. However, oil palm expansion has often occurred at the expense of ecosystems and subsistence agriculture, and on lands riddled with tenure conflicts. In this article, we analyse the implications of the combined effect of labouring in oil palm plantations and land access on households, and we discuss how these implications affect human well-being in two indigenous communities of the Polochic valley, Guatemala. Combining participant observation, semi-structured interviews, and land-time budget analysis at household level, we reveal how oil palm cultivation increases incomes for plantation workers’ households, but decreases the productivity of maize cultivation, reduces the time that household members have available for other activities and, particularly, reduces women’s resting time. In contrast, households that focus more intensively on maize cultivation show higher degrees of food security and women can allocate more time to social activities. However, our results also show that maize consumption per capita has not decreased in households working in oil palm plantations since such crop is considered sacred by the Q’eqchi’ and plays a central role in their diet and culture. In conclusion, we argue that while working for an oil palm cultivation can increase specific elements of the basic material conditions for a good life, other aspects such as food security, health, freedom of choice, and social relationships can become deteriorated.     

Toxicity removal from hard board wastewater

The rapid growth of industry in Egypt in recent years has made industrial pollution an important issue. During the past decade fish production in some canals and lakes have virtually ceased due to the discharge of industrial and agricultural wastewater. The alternatives under study include effluent treatment before discharge to receiving water. Highly polluted wastewater from a hard board mill was treated using the activated sludge process. Factors affecting the efficiency of the treatment were detention time and organic loading rate. The results indicated that BOD and phenol reduction reached 82% and 94% respectively. when the organic loading rate was 0.1 (kg BOD/kg SS). The process proved to be successful in completely eliminating the toxicity effect of the waste on Nile fish (Tilapia nilotica).     

Selection of an effective sludge dewatering system for a small wastewater treatment plant

The Jahra Plant was commissioned in 1981 as a secondary treatment plant employing the extended aeration process. The plant has been upgraded since that time by constructing additional tertiary filtration units to improve effluent quality. The plant has a design capacity of 66 000 m³/d. At present, the daily inflow to the plant is about 47 000 m³/d of domestic sewage. The sludge produced at the Jahra Plant can be classified as excess activated sludge which combines the primary and secondary solids. At present, there are 30 drying beds receiving about 100 m³ of sludge dally. Sewage-sludge production represents about 0.5% of the total flow treated at the plant and is increasing yearly with increases in population and water consumption. Present dewatering systems are not adequate to cope with expansion in sewage treatment. Increasing the capacity of the existing plant would require more drying beds that could exacerbate existing odor problems. Some dewatering systems, such as the belt filter press and the centrifuge, have been tested to determine the most effective one under local conditions. Appropriate polymer doses for thickening have been determined. This paper describes present sludge dewatering units and operating techniques which have been developed during the operation of this facility.