Compost feedstock characteristics and ratio modelling for organic waste materials co-composting in Malaysia

In Malaysia, large amounts of organic materials, which lead to disposal problems, are generated from agricultural residues especially from palm oil industries. Increasing landfill costs and regulations, which limit many types of waste accepted at landfills, have increased the interest in composting as a component of waste management. The objectives of this study were to characterize compost feedstock properties of common organic waste materials available in Malaysia. Thus, a ratio modelling of matching ingredients for empty fruit bunches (EFBs) co-composting using different organic materials in Malaysia was done. Organic waste materials with a C/N ratio of<30 can be applied as a nitrogen source in EFB co-composting. The outcome of this study suggested that the percentage of EFB ranged between 50% and 60%, which is considered as the ideal mixing ratio in EFB co-composting. Conclusively, EFB can be utilized in composting if appropriate feedstock in term of physical and chemical characteristics is coordinated in the co-composting process

Pengaruh Ph Tanah Terhadap Proses Biodegradasi Polycyclic Aromatic Hydrocarbon (Pah) Pada Tanah Terkontaminasi Batubara

Batubara alami (unburnt coal) mengandung polycyclic aromatic hydrocarbon (PAH) dengan kadar yang tinggi dan tingkat penyebaran relatif cepat. PAH sulit didegradasi karena bersifat toksik sehingga berpotensi mengkontaminasi tanah, terutama di wilayah pertambangan batubara tetapi belum mendapatkan perhatian yang serius. Kontaminasi tersebut dapat ditangani menggunakan salah satu teknologi bioremediasi yaitu co-composting. Salah satu faktor yang mempengaruhi proses co-composting adalah pH. Penelitian ini bertujuan untuk mengetahui pengaruh pH tanah terhadap biodegradasi PAH dalam proses co-composting dengan penambahan sampah organik. Co-composting dilakukan secara aerobik selama 98 hari dalam skala laboratorium. Variasi penelitian meliputi rasio tanah terkontaminasi PAH dengan sampah organik (100/0, 75/25, 50/50, 25/75, dan 0/100) dan pH tanah (asam dan netral). Analisis kadar 16 EPA-PAH dilakukan menggunakan metode Gas Chromatographic Mass Spectrometric (GC-MS). Proses co-composting berlangsung dalam kondisi lingkungan yang optimal yaitu suhu mesofilik (30-31°C), pH netral (6,5-7), dan kadar air optimum (50-60%). Hasil penelitian menunjukkan bahwa biodegradasi PAH yang terjadi tidak dipengaruhi oleh kondisi pH tanah. Hal ini dibuktikan dengan persentase kadar PAH yang terdegradasi tidak berbeda jauh antara pH tanah awal asam dan netral di rasio T/s 25/75 yaitu 75,15% dan 76,21 %

Co-composting of palm oil mill wastes.

Co-composting is one of the important bio-waste treatments in the palm oil industry for achieving sustainable process and zero waste. However, improper conditions of composting may cause several problems such as gas emission, bad odour, low quality product, production delay and high handling cost. Enhancing the efficiency of waste composting becomes a vital issue to overcome these problems. This review provides information on the practices and developments related to co-composting of the palm oil mill waste. The description on a typical palm oil mill process and the wastes generated, i.e. empty fruit bunch and palm oil mill effluent, as composting substrates are given. The common windrow composting system is described. The recent venture of using microorganisms in composting processes are also covered under the pretext of several researchers’ interpretation that composting can be accelerated by the introduction of microorganism to the process through its influence on the physical, dynamic and biological behaviours of organic material. The criteria of choosing functional microbes for fast composting are discussed

Critical parameters in the life cycle inventory of palm oil mill residues composting

Palm oil mill's co-products (empty fruit bunch – EFB and palm oil mill effluent – POME) management is a matter of concern in Indonesia. Co-composting is a promising waste management practice that would allow a reduction of environmental impact and a restitution of organic matter to the soil. This study is a part of a Life Cycle Assessment (LCA) project and aims to pinpoint the most environmentally impacting compartments of the palm oil production chain. It deals more specifically with the Life Cycle Inventory of data on the composting process based on site specific data. Data on the recycled biomass, energy demand and yielded compost properties were recorded in an industrial palm oil mill over one year. Due to the local conditions, high nutrient leaching from the compost were recorded and the compost remained very wet and hot (thermophilic phase). The composting process only led to 40% of methane avoidance compared to anaerobic digestion of POME, and the global nutrient recovery efficiency was below 50%. We identified the following critical parameters to increase environmental benefits from composting: i) the POME/FFB ratio from the mill ii) the roofing of the composting platform, iii) the POME/EFB ratio, iv) the turning frequency, v) the recycling of leachates and vi) the process duration and drying period. The nutrient recovery and the doses of compost applied in the field depend on all of those inter-connected parameters. The data presented will be used within LCA models to assess net environmental benefits from various POME and EFB co-composting systems

Influence of different co-substrates biochemical composition on raw sludge co-composting

The influence of biochemical composition of different co-substrates added to raw sludge during co-composting process was studied. The physical properties of the composting mass and their influence on the biological activity were also investigated. Three treatments composed of mixtures of raw sludge and co-substrate (commercial fats, protein, and cellulose) were carried out and compared to a control composed of raw sludge. Mixture conditioning was performed on the basis on air filled porosity (40%). The results obtained in the co-composting processes reflected a higher biological activity and higher degradation percentages of dry and organic matter when compared with control. Higher temperatures (60, 67 and 62°C for fats, protein and cellulose, respectively) were also achieved in all co-composting experiments as compared to the control test (55°C). Biological activity was measured using both Static and Dynamic Respiration Indices obtaining higher values in co-composting experiments compared to the control test. Fats content reduction was higher (66%) at higher fats content in the initial mixture (10.6%). The addition of fats seems also to promote the degradation of cellulose and lignin. Co-composting experiments with fats and cellulose presented higher initial C/N ratio and lower nitrogen losses, 27.5 and 34.2% compared to 40% for raw sludge. It has been demonstrated that the addition of an adequate co-substrate to raw sludge leads to a higher degradation percentages of the different biochemical fractions and higher nitrogen conservation

Development of organic fertilizers from food market waste and urban gardening by composting in Ecuador

Currently, the management of urban waste streams in developing countries is not optimized yet, and in many cases these wastes are disposed untreated in open dumps. This fact causes serious environmental and health problems due to the presence of contaminants and pathogens. Frequently, the use of specific low-cost strategies reduces the total amount of wastes. These strategies are mainly associated to the identification, separate collection and composting of specific organic waste streams, such as vegetable and fruit refuses from food markets and urban gardening activities. Concretely, in the Chimborazo Region (Ecuador), more than 80% of municipal solid waste is dumped into environment due to the lack of an efficient waste management strategy. Therefore, the aim of this study was to develop a demonstration project at field scale in this region to evaluate the feasibility of implanting the composting technology not only for the management of the organic waste fluxes from food market and gardening activities to be scaled-up in other developing regions, but also to obtain an end-product with a commercial value as organic fertilizer. Three co-composting mixtures were prepared using market wastes mixed with pruning of trees and ornamental palms as bulking agents. Two piles were created using different proportions of market waste and prunings of trees and ornamental palms: pile 1 (50:33:17) with a C/N ratio 25; pile 2: (60:30:10) with C/N ratio 24 and pile 3 (75:0:25) with C/N ratio 33), prepared with market waste and prunings of ornamental palm. Throughout the process, the temperature of the mixtures was monitored and organic matter evolution was determined using thermogravimetric and chemical techniques. Additionally, physico-chemical, chemical and agronomic parameters were determined to evaluate compost quality. The results obtained indicated that all the piles showed a suitable development of the composting process, with a significant organic matter decomposition, reached in a shorter period of time in pile 3. At the end of the process, all the composts showed absence of phytotoxicity and suitable agronomic properties for their use as organic fertilizers. This reflects the viability of the proposed alternative to be scaled-up in developing areas, not only to manage and recycle urban waste fluxes, but also to obtain organic fertilizers, including added value in economic terms related to nutrient contents.Peer ReviewedPostprint (published version

Effects of Palm Oil Mill Effluent (POME) Anaerobic Sludge From 500m3 of Closed Anaerobic Methane Digested Tank on Pressed-Shredded Empty Fruit Bunch (EFB) Composting Process

In this study, co-composting of pressed-shredded empty fruit bunches (EFB) and palm oil mill effluent (POME) anaerobic sludge from 500 m3 closed anaerobic methane digested tank was carried out. High nitrogen and nutrients content were observed in the POME anaerobic sludge. The sludge was subjected to the pressed-shredded EFB to accelerate the co-composting treatment. In the present study, changes in the physicochemical characteristics of co-composting process were recorded and evaluated. The co-composting treatment was completed in a short time within 40 days with a final C/N ratio of 12.4. The co-composting process exhibited a higher temperature (60 - 67℃) in the thermophilic phase followed by curing phase after four weeks of treatment. Meanwhile, pH of the composting pile (8.1 - 8.6) was almost constant during the process and moisture content was reduced from 64.5% (initial treatment) to 52.0% (final matured compost). The use of pressed-shredded EFB as a main carbon source and bulking agent contributed to the optimum oxygen level in the composting piles (10 - 15%). The biodegradation of composting materials is shown by the reduction of cellulose (34.0%) and hemicellulose (27.0%) content towards the end of treatment. In addition, considerable amount of nutrients and low level of heavy metals were detected in the final matured compost. It can be concluded that the addition of POME anaerobic sludge into the pressed-shredded EFB composting process could produce acceptable and consistent quality of compost product in a short time

Effect of organic amendment derived from co-composting of chicken slurry and rice straw on reducing nitrogen loss from urea

Co-composting of chicken slurry and rice straw with clinoptilolite zeolite and urea as additives was conducted to determine the characteristics of a compost and their effects on controlling ammonium (NH4+) and nitrate (NO3−) losses from urea. Quality of the compost was assessed based on temperature, moisture content, ash, pH, electrical conductivity, carbon/nitrogen (C/N) ratio, NH4+, NO3−, macronutrients, heavy metals, humic acid, microbial population, germination index, and phytotoxicity test. Moisture content and C/N ratio of the compost were 43.83% and 15, respectively. Total N, humic acid, ash, NH4+, NO3−, phosphorus (P), calcium (Ca), magnesium (Mg), potassium (K), and sodium (Na) increased after co-composting rice straw and chicken slurry. Copper, iron (Fe), manganese (Mn), zinc (Zn), and microbial biomass of the compost were low. The germination rate of Zea mays on distilled water and Spinacia oleracea growth on peat-based growing medium (PBGM) and compost were not significantly different. Urea amended with compost reduced N loss by retaining NH4+ and NO3− in the soil

Characteristics and microbial succession in co-composting of oil palm empty fruit bunch and partially treated palm oil mill effluent

Microbial communities and cellulolytic enzymes activities were analyzed during the co-composting of empty fruit bunch (EFB) and partially treated palm oil mill effluent (POME) in pilot scale. The physicochemical parameters were also measured during the composting. The diversity of the bacterial community was investigated using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). The results indicated that the composting process of EFB with partially treated POME was dominated by uncultured bacteria species. The dominant bacterial group changed from the phylum proteobacteria in the thermophilic stage to the phylum chloroflex in the maturing stage. Scanning electron microscope (SEM) analysis exhibited the significant degradation of EFB structure during the composting process. The maximum cellulase activity for carboxymethylcellulase (CMCase), filter paperase (FPase) and glucosidase were 13.6, 4.1 and 20.3 U/g of dry substrate, respectively at day 30 of composting. The results of this study significantly contributed to a better understanding of mechanisms involved in co-composting process in pilot scale

Bioremediation and biovalorisation of olive-mill wastes

Olive-mill wastes are produced by the industry of olive oil production, which is a very important economic activity, particularly for Spain, Italy and Greece, leading to a large environmental problem of current concern in the Mediterranean basin. There is as yet no accepted treatment method for all the wastes generated during olive oil production, mainly due to technical and economical limitations but also the scattered nature of olive mills across the Mediterranean basin. The production of virgin olive oil is expanding worldwide, which will lead to even larger amounts of olive-mill waste, unless new treatment and valorisation technologies are devised. These are encouraged by the trend of current environmental policies, which favour protocols that include valorisation of the waste. This makes biological treatments of particular interest. Thus, research into different biodegradation options for olive-mill wastes and the development of new bioremediation technologies and/or strategies, as well as the valorisation of microbial biotechnology, are all currently needed. This review, whilst presenting a general overview, focus critically on the most significant recent advances in the various types of biological treatments, the bioremediation technology most commonly applied and the valorisation options, which together will form the pillar for future developments within this fiel