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.

Aims of the Study: The aim of this study was to determine the amount of lignin degradation and biodegradation of organic matter and change of biomass under compost and vermicomposting of sewage sludge.Materials & Methods: Sawdust was added to sewage sludge at 1: 3 weight bases to Carbon to Nitrogen ratio of 25: 1 for composting or vermicomposting. Lignin and volatile solids were determined at different periods, of 0, 10, 30, 40 and 60 days of composting or vermicomposting period to determine the biodegradation of lignocellulose to lignin. Results were expressed as mean of two replicates and the comparisons among means were made using the least significant difference test calculated (p<0.05).Results: After 60 days of experiment period, the initial lignin increased from 3.46% to 4.48% for compost and 3.46% to 5.27% for vermicompost. Biodegradation of lignocellulose was very slow in compost and vermicompost processes. Vermicomposting is a much faster process than compost to convert lignocellulose to lignin (p<0.05). Conclusions: The organic matter losses in sewage sludge composting and vermicomposting are due to the degradation of the lignin fractions. By increasing compost age, the amount of volatile solids will decrease.

Recent trend of declining sustainability in agricultural production is appearing as a major threat to most of the Asian countries. To combat the situation, increasing importance is now being paid on incorporation of organic materials for rejuvenating the health condition and, hence, the productivity of these soils. Large scale availability of conventional organic manures being a big problem nowadays, major attention is being paid on recycling of different kinds of organic wastes for this purpose. Apart from abatement of environmental pollution, such reuse of organic wastes in agriculture helps in the improvement of various physical, chemical and biological properties of the soils and, thus, helps in sustaining the soil health. While recycling different organic wastes in agriculture, it is essential to process the materials through an adequate period of composting for improving their usability in the soils. However, due to some short comings of traditional composting systems, the technology of recycling of organic wastes has not been widely accepted so far. Under this situation, vermicomposting has recently emerged as a simple but efficient biotechnology for recycling wide ranges of organic wastes with the help of some specific groups of earthworms. In view of the growing popularity of this biotechnology, various aspects of waste recycling in agriculture through vermicomposting have been dealt in this communication.

Background & Aims of the Study: Hydrogen sulfide (H2S) is a colorless and highly toxic, easily dissolved in water, flammable and explosive gas. Hydrogen sulfide gas is the main cause of odor emissions from municipal sewage plants. One method for removal of hydrogen sulfide gas is the use of biological systems, biofilter. The aim of this study was to survey removal hydrogen sulfide provide in septic tank by vermicomposting biofilter.Materials and Methods: In this study pilot-scale biofilter has been made of bed vermicompost and wood trash. To survey biofilter performance under real condition, the pilot installed in one wastewater pumping station of Ahwaz city, Iran. The study was carried out over 80 days. Inlet and outlet H2S concentration were measured on regular basis. To provide an optimal condition for bacterial growth, moisture was adjusted between 40% and 60% throughout the experiment.Results: Results showed that H2S concentration emitted from the pumping station during the study varied greatly between 33 and 54ppm.The maximum adsorption capacity of the biological bedding was recorded at 22.4 g/m3.hr and the mean efficiency of H2S removal account the startup time was 89.31%.The mean performance efficiency during the biological activity after the startup was recorded at 96.88%.Conclusion: use up biofilter with vermicompost bed and woodchip is an economic method for H2S removal of septic tanks. Removal efficiency of more than 96% is expected with this method.

The present study was conducted to investigate the effect of vermicomposting on heavy metals accumulation in plants and soil irrigated with contaminated water at the Campus of Agriculture and Natural Resources of Razi University. The research was carried in two treatments, using vermicomposting and non-use of vermicomposting (control) in three replications on the accumulation of copper, iron, zinc, cadmium and manganese in roots, shoots and fruits of tomato and okra plants as well as in two soil layers (0-30 and 30-60 cm). The results indicated that vermicomposting application significantly increased the amount of metals in most parts of tomato (fruit: Cu 10.1, Fe -11.86, Mn 5.97; leaves: Fe 8.4, Zn 9.73, Mn 2.97; root: Mn -5.56) and okra (fruit: Cu 6.73, Fe 9.98, Zn -7.18, Mn 3.06; leaves: Fe 9.51, Zn 6.63, Mn 3.84; root: Cu -9.7, Fe -10.2, Zn -14, Mn -7.12). Although vermicomposting treatment increased the amount of metals in the soil but it was not significant (only in the first layer Zn 6.33 showed a significant increase). Also, vermicomposting prevented moving of metals into the soil. Therefore, the use of vermicomposting and irrigation with contaminated water due to increase in heavy metals content in different part of plant and soil is not recommended