International Journal Of Recycling of Organic Waste in Agriculture - Latest Articles

Superabsorbent derived from cassava waste pulp

Zainal Mas¿ud — 2013-05-09T00:00:00Z

Background: Cassava waste pulp from the tapioca industry is abundant in Indonesia. However, there have been few Indonesian or international papers describing research on the possible use of cassava waste pulp as a superabsorbent after modification. The goal of this work was to increase the added value of cassava waste pulp by converting it into a superabsorbent. This conversion was carried out by a graft copolymerization of cassava waste pulp using acrylamide, ammonium persulfate, and N,N′-methylene-bisacrylamide as a monomer, an initiator, and a crosslinker, respectively. The copolymerization was conducted at 70°C for 3 h and saponified with 1 M NaOH for 2 h. Results: The superabsorbent had a maximum water absorption capacity of 1,014 g/g at pH 7.3; the absorbency was affected by the salinity of the medium. The rate parameter for absorption in distilled water was 5.4 min. The formation of a superabsorbent was confirmed by FTIR spectroscopy, as the spectra exhibited all characteristic bands of both cassava waste pulp and acrylamide. Conclusion: Cassava waste pulp has a great potential to be used as a superabsorbent, which could give added value to cassava.

Biochemical, morphological, and yield responses of lady's finger plants to varying ratios of palm oil mill waste (decanter cake) application as a bio-fertilizer

Asha Embrandiri — 2013-05-04T00:00:00Z

Background: Decanter cake is produced in large amounts, and its disposal is a major concern in palm-producing countries. Growth morphology and biochemical responses of lady's finger (Abelmoschus esculentus) plants grown on soil amended with different ratios of decanter cake (0%, 10%, 20%, and 30%) were investigated. Results: The soil pH decreased (unamended soil), whereas the electrical conductivity increased as compared with the control. There was a significant difference in ascorbic acid content with the increase in treatment ratio. Phenol content was however highest in 20% of the amendment (13.197 ± 0.36mg g−1). Conclusions: The results indicate that decanter cake amendments of up to 10% may be a probable substitute for inorganic fertilizers with respect to lady's finger (A. esculentus) plants due to high nutrient content, yield and biomass, as well as morphological characteristics. However, there were observable negative effects after 10% decanter cake amendment ratios.

Application of rural slaughterhouse waste as an organic fertilizer for pot cultivation of solanaceous vegetables in India

Malancha Roy — 2013-04-26T00:00:00Z

Background: The lack of electricity and water supply in rural abattoirs in developing nations prevents the adoption of waste-processing technologies practiced in economically advanced countries. This research attempts to recycle waste blood and rumen digesta generated in rural slaughterhouses as organic fertilizer, thus promoting sustainable agriculture. Results: The values of 5-day biochemical oxygen demand, chemical oxygen demand, total Kjeldahl nitrogen, concentrations of oil, grease, total suspended solids, total solids, and total phosphorus characterized blood and rumen digesta as highly polluting wastes. Waste blood and rumen digesta were mixed in 1:1, 2:1, and 3:1 ratios and dried to obtain ‘bovine-blood-rumen-digesta-mixture’ (BBRDM). The efficacy of the organic fertilizer was compared with diammonium phosphate (DAP) in a pot cultivation of tomato, chili, and brinjal. Five grams of BBRDM (N/P/K = 30.36:1:5.75)/kilogram of soil applied at the second and sixth weeks produced earlier fruiting by 2 weeks and yielded (in terms of total fruit weight) higher by 130% for tomato, by 259% for chili, and by 273% for brinjal in BBRDM (3:1)-cultivated plants compared to DAP. BBRDM-applied soils showed higher C, N, and P concentrations than DAP. High-nitrogen-containing BBRDM mineralized rapidly, and nitrogen and phosphorus were available within 6 days of drying. Although high nitrogen concentration caused toxicity when applied at the time of planting to young plants, BBRDM enhanced the yield and productivity when applied to mature plants after 15 days of plantation. Higher numbers of Azotobacter, phosphate-solubilizing bacteria, fungi, and amount of chlorophyll were isolated from soils treated with BBRDM than with DAP. Carbohydrate, protein, and fat contents of the vegetables were comparable to DAP-grown vegetables. Conclusions: Highly polluting abattoir wastes could be gainfully utilized, promoting a healthy environment around rural slaughterhouses. The application of BBRDM to crops of marginal returns is an attractive proposal.

Evaluation of composting performance of mixtures of chicken blood and maize stover in Harare, Zimbabwe

Charity Pisa — 2013-04-26T00:00:00Z

Background: Chicken processing results in the production of a lot of blood which if disposed on land poses environmental hazards in terms of land pollution. The aim of the study was to develop an aerobic composting process for chicken blood to produce a nitrogen-rich soil amendment for use in agriculture. The study involved composting of blood and maize stover of different proportions (10%, 30%, 70% and 100% maize stover) in compost bins over 72 days and determining which proportions would yield compost with greater potential to support plant growth. Results: The performance of the different compost mixtures was evaluated by monitoring internal temperature, mineral N (NH4 +-N and NO3 --N), C/N ratio, pH, electrical conductivity and total cations. The concentration of ammonium N decreased by 8.75%, 50.5%, 33.5% and 18.8% for the 10%, 30%, 70% and 100% stover treatments, respectively, with composting time. Nitrate N peaked to 1.93 and 1.06 mg/kg for the 30% and 70% treatments, respectively, on day 43, while it peaked to 1.54 and 0.54 mg/kg for the 10% and 100% treatments, respectively, on day 50. The C/N ratios decreased significantly (p < 0.001) for all treatments. Conclusion: The 10% and 30% treatments had better composting performance than the 70% and 100% treatments as they reached and maintained thermophilic temperatures for at least 8 days. The 10% and 30% treatments appeared to have the greater potential of supporting crop growth.

Domestic scale vermicomposting for solid waste management

Meghdad Pirsaheb — 2013-04-17T00:00:00Z

Background: Vermicomposting has recently been recognized as one of the most appropriate methods to stabilize organic waste. In terms of a system for waste management, vermicomposting is sustainable, economically viable, and without detrimental effects to human health or to the environment. The aim of this study was to evaluate the process of vermicomposting using an indigenous species of earthworms (Eisenia fetida) on a small domestic scale as a system for waste management. Results: This study was carried out as an experiment using the following procedure: a plastic container was prepared for vermicomposting; then, a bed was prepared in a ready container with a layer of initial bedding, sieved garden soil, and compostable waste. It was inoculated with Eisenia fetida earthworms. Samples were taken after 30 and 90 days of vermicomposting, and measurements were taken for the following parameters: percentage of organic matter, phosphorus, total carbon, total nitrogen, moisture content, ash, electrical conductivity, and pH. Results for percentage of organic matter, phosphorous, ash, total carbon, total nitrogen, carbon/nitrogen ratio, electrical conductivity, moisture content, and pH of mature compost after 90 days were 42 ± 2.8, 53 ± 0.17, 22 ± 0.170, 1.12 ± 0.003, 20 ± 0.25, 2.8 ± 0.6, 1, 200 ± 200 cSu, 56 ± 5.5%, 8.3 ± 0.2, respectively, and all these parameters except moisture content were compared with the standards. Conclusion: According to these results, vermicomposting of municipal biodegradable waste by homeowners can be recommended as the best and most suitable method for solid waste disposal. This determines small-scale domestic vermicomposting as a suitable method for solid waste management. Reducing domestic waste at the source is an effective way to implement the main priorities of a waste management system in terms of its economy and its impact on the environment.

Effects of bulking agents, load size or starter cultures in kitchen-waste composting

Norazlin Abdullah — 2013-04-17T00:00:00Z

Background: To prevent the interruption of the carbon cycle by the disposal of waste to landfills, organic kitchen waste requires proper treatment such as composting to reduce its uncontrolled degradation on disposal sites and subsequent greenhouse gases, odour emissions and nutrient losses. This study investigated the effects of bulking agent, newspaper and onion peels, composting waste load sizes of 2 and 6 kg, or the use of starter culture on kitchen-waste composting consisting of nitrogen-riched substrates, vegetable scraps and fish processing waste in an in-vessel system. The optimised formulation of kitchen waste mixture was used for a 30-day composting study, where the temperature profiles were recorded and the carbon-to-nitrogen ratios were measured as an indication of compost maturity. The kitchen-waste composting process was conducted in parallel in two fabricated kitchen waste composters. Results: It was found that the onion peels were more suitable in producing matured compost where the carbon-to-nitrogen ratio reduced to 10 within 16 days of composting. A smaller kitchen waste load size of 2 kg gave a shorter composting time by half when compared to the 6 kg. The use of a microbial cocktail consisting seven types of bacteria and eight types of fungi isolated from soils as a starter culture for this kitchen-waste composting did not show advantages in accelerating the composting process. Conclusions: The results suggest that the in-vessel kitchen-waste composting can be efficient with a minimal load of about 2 kg using onion peels without additional starter culture.

A feasibility study on beef tallow conversion to some esters for biodiesel production

Mohamad Ali Ghazavi — 2013-03-07T00:00:00Z

Background: Nowadays, management and recycling of industrial by-products are one of the most important issues in developing and developed countries. Beef tallow is one of these residues produced in slaughter houses and primarily is utilized in soap production industry. However, when this industry is overloaded, the extra fats are usually incinerated or disposed in a sanitary landfill. However, beef tallow may be consumed in biodiesel production. Therefore, in this work, the process of biodiesel production in a pilot plant has been studied using beef tallow as raw material with methanol and potassium hydroxide as catalyst. The quality of the produced biodiesel is evaluated using Fourier transform infrared spectroscopy (FTIR) method. Results: FTIR analysis showed that the final product contains ester compositions which can be used as biodiesel fuel in diesel engines. The viscosity of natural beef tallow was very high, and actually, it was solid; however, after transesterification the viscosity of the final product decreased, and it became liquid. The viscosity of the final product measured at 40°C was 5.3 mm2 s−1, and the comparison of this biodiesel with the data of ASTMD-445 standard resulted in the similarity of this product with petroleum diesel (3 to 12 mm2 s−1). Conclusions: Alkaline transesterification of beef tallow with methanol decreases the viscosity of the final synthesized product and produces a high quality biodiesel for diesel engines. Beef tallow is one of the low cost residual materials available in slaughter houses. Therefore, the slaughter houses can be considered as one of the available sources to produce biodiesel. In this research, the process of biodiesel production from beef tallow was validated, but the economical viability must be improved by recovering methanol and glycerol.

Nutrient transport characteristics of livestock manure in a farmland

Yunhee Lee — 2013-01-19T00:00:00Z

Background: Livestock excretions containing high concentration of nutrient, pig liquid fertilizer, and cattle manure were applied to agricultural land. The characteristics of nutrient transport were examined in surface runoff and groundwater by an artificial rainfall event at real scale field site. Also, the effects of the artificial rainfall event on the characteristics of residual soil after the rainfall and phosphorus adsorption capacity were evaluated in the lab. Results: As results from the field experiments, nitrogen concentration was decreased by the repeatable precipitation in surface runoff, but the nitrate concentration in groundwater was gradually increased by biological metabolism, especially with pig liquid fertilizer. Phosphorus was mostly adsorbed into the soil, and its reduction was affected by the soil drainage due to surface runoff in summer. The adsorption capacity of the phosphorus via a jar test was determined as 0.7 mg P/kg of soil. Conclusion: The soil adsorption capacity would be an important factor for the optimum level of nutrient application that is required for agricultural performance and minimal environmental impact.

Co-composting of coir pith and cow manure: initial C/N ratio vs physico-chemical changes

Sudarut Tripetchkul — 2012-12-28T00:00:00Z

Background: As objective of this study was focused on efficacy of composting of a recalcitrant organic waste material, co-composting of coir pith with cow manure and rice bran was endeavored to evaluate influence of initial C/N ratios, i.e., 30, 25, and 20, on physico-chemical changes, e.g., temperature, pH, organic matter (OM) degradation, and total nitrogen (TN) losses. Results: Results showed that OM and TN losses were significantly affected by C/N ratio (p < 0.05), whereas C/N ratio played insignificant role on temperature and pH evolution within the pile (p > 0.05) during composting process. OM and TN losses were highest within the first 2 weeks of thermophilic phase. Through the composting process, pile with 25 C/N ratio showed the highest biodegradation rate constant of organic matter (k = 0.309 day−1) and the highest TN losses (41.9%), while pile with C/N ratio of 30 showed the lowest N loss (−7.3%). However, for all three compost piles, maturity, as indicated by the pile temperature converging to the ambient temperature, was attained within 1 month post-composting. Conclusion: Results suggested that simple pile turning yielded effective co-composting of coir pith under comparatively low C/N ratio. Considering the composting performance and the amount of coir pith to be utilized, the initial C/N ratio of 30 was considered suitable for coir pith composting.

Residual influence of organic materials, crop residues, and biofertilizers on performance of succeeding mung bean in an organic rice-based cropping system

Mohammadreza Davari — 2012-12-07T00:00:00Z

Background: The present investigation was undertaken to assess the residual influence of organic materials and biofertilizers applied to rice and wheat on yield, nutrient status, and economics of succeeding mung bean in an organic cropping system. The field experiments were carried out on the research farm of IARI, New Delhi during crop cycles of 2006 to 2007 and 2007 to 2008 to study the effects of residual organic manures, crop residues, and biofertilizers applied to rice and wheat on the performance of succeeding mung bean. The experiment was laid out in a randomized block design with three replications. Treatments consisted of six combinations of different residual organic materials, and biofertilizers included residual farmyard manure (FYM) and vermicompost (VC) applied on nitrogen basis at 60 kg ha−1 to each rice and wheat crops, FYM + wheat and rice residues at 6 t ha−1 and mung bean residue at 3 t ha−1 in succeeding crops (CR), VC + CR, FYM + CR + biofertilizers (B), VC + CR + B, and control (no fertilizer applied). For biofertilizers, cellulolytic culture, phosphate-solubilizing bacteria and Rhizobium applied in mung bean. Results: Incorporation of crop residue significantly increased the grain yield of mung bean over residual of FYM and VC by 25.5% and 26.5%, respectively. The combinations of FYM + CR + B and VC + RR + B resulted in the highest increase growth and yield attributing characters of mung bean and increased grain yield of mung bean over the control by 47% and net return by 27%. Conclusions: The present study thus indicate that a combination of FYM + CR + B and VC + CR + B were economical for the nutrient need of mung bean in organic farming of rice-based cropping system.