Composting of sugar-cane waste by-products through treatment with microorganisms and subsequent vermicomposting

Sustainable organic waste management using vermicomposting: a critical review on the prevailing research gaps and opportunities

Logistic growth of human population, exponential rate in agronomic industries and feeble waste management practices have resulted in the massive generation of organic wastes. Vermicomposting is one of the eco-biotechnological practices to efficiently transform them into stable and nutrient-rich organic manure with the synergetic actions of earthworms and soil microbiota. Vermicompost, a derivative product has the desirable physicochemical traits such as excellent porosity, buffering actions, aeration and water holding capacity. Also the presences of enzymic and microbial secretions contribute to growth and disease resistance of the crops. Owing to the benefits of soil nutrients restoration and effective organic waste management, vermicomposting has gained much attention among the scientific researchers and organic farmers. The present review is intended to provide comprehensive information on the site selection, screening of earthworms, different modes of operation and their desirable micro-environmental conditions. Also, the review has critically identified the prevailing research gaps viz. limited studies on the substrate formulation or optimization designs, poor control on the operational variables, lack of field-level investigations, technological feasibility of scale-up process, economic viability and cost-benefit analysis. Prospective researches can be made on these hotspots to identify the vermicomposting as a successful and profitable business model in the circular economy.

Compositional Analysis of Street Market Food Waste in Brazil

Current understanding of food waste quantities in the Brazilian retail sector is limited. In order to develop efficient measures for food waste prevention and valorisation, reliable data on waste generation and composition are necessary. In this study, a compositional analysis of street market waste was conducted in São Paulo, Brazil. In total, 4.1 tonnes of waste were sorted into 27 waste fractions, categorised using a three-level approach. The average waste generation in the studied street markets was 23.7 kg per stall, of which 12.8 kg was classified as unavoidable food waste, 3.6 kg as packaging waste, and 7.4 kg as avoidable waste. The results show large amounts of unavoidable food waste, comprised of coconut, sugarcane bagasse, and peels. A large share of the avoidable food waste is comprised of single leaves, tomatoes, oranges, and bananas. Large variations were observed among the street markets analysed, both in terms of the food waste generation rate, and composition. The results from scaling up the data at the city level indicated a total wastage of 59,300 tonnes per year, of which 18,400 tonnes are classified as avoidable food waste.

Processing Agroindustry By-Products for Obtaining Value-Added Products and Reducing Environmental Impact

Over four billion tons of foods are produced annually on the planet, and about a third is wasted. A minimal part of this waste is incinerated or sent to landfills for treatment, avoiding contamination and diseases; the rest is disposed of elsewhere. The current review was aimed at broadening the panorama on the potential of agroindustrial by-products in applications such as biofuels, biomaterials, biocompounds, pharmaceuticals, and food ingredients. It also exposes the main chemical, physical, and biochemical treatments for converting by-products into raw materials with added value through low environmental impact processes. The value of agroindustrial waste is limited due to the scarce information available. There is a need for further research in unexplored areas to find ways of adding value to these by-products and minimizing their contamination. Instead of throwing away or burning by-products, they can be transformed into useful materials such as polymers, fuels, antioxidants, phenols, and lipids, which will effectively reduce food waste and environmental impact.

Aerobic Composting of Sugar Pressmud with Stabilized Spentwash and selected Microbial Consortium

India is the world’s largest producer of sugar, with an annual production capacity of 29 million tonnes. Each crushing season, this intern produces over 10 million tonnes of pressmud, which is difficult to dispose of due to its inherent properties. The present study is part of larger investigation for treatment and disposal of pressmud and spentwash. Further, scope of this research article is confined to utilization of pressmud for aerobic composting of pressmud along with selected microbial consortium and stabilized spentwash. Composting was carried out in an open area with 50 kg of pressmud and 1% (w/w) dosage of microbial consortium. Stabilized spentwash was used at concentrations of 25, 50, 100, 150 and 200% (v/w) and applied at predetermined time intervals. The entire study lasted for 50 days and the results were compared to those recommended by the Fertilizer Control Order (FCO), Ministry of Agriculture, Government of India (1). In an organic compost, the FCO recommends a minimum concentration of 12%, 0.80%, 0.40%, and 0.40% in TOC, TKN, phosphorous and potassium, with a maximum C/N ratio of 20. During composting, the addition of 150% (CH5) stabilized spentwash resulted in a maximum nutrient concentration in the majority of the parameters analysed. CH5 showed that the concentration of TOC, TKN, C/N, phosphorous and potassium were 25.92±2.19%, 2.16±0.29%, 12.28±0.66, 6.55±0.11% and 15.90±1.37% respectively. Hence, it can be concluded that selected microbial consortium is capable of decomposing the organic matter found in pressmud. Additionally, the application of stabilized spentwash enhanced the nutritional content of end product.

Using vermiwash to enhance performance of small-scale vermifiltration for swine farm wastewater

Pollution caused by swine wastewater is a growing concern in many countries. In the developing countries, swine wastewater is not properly collected and treated, the wastewater from swine farm pollutes the ecosystem. Especially for small swine farms, they could not afford to have wastewater treatment system. Therefore, farmers need cheap, sustainable technology for future mixed farming. Vermifiltration by earthworm has been introduced to be an answer for enhancing wastewater treatment. Vermiwash is the liquid gathered from vermicomposting that has high microbial activities and nutrients. This study was carried out on a small pilot scale to investigate swine wastewater treatment efficiency of vermifiltration system with and without vermiwash and compared with the geofiltration system. Vermiwash was incubated in vermifiltration and geofiltration systems for 1 week before the treatment. The result showed improved efficiency of vermifiltration incubated with vermiwash in swine wastewater treatment for biological oxygen demand (BOD), chemical oxygen demand (COD) and total suspended solids (TSS) removal, which was highest followed by vermifiltration without incubated vermiwash, geofilter incubated with vermiwash and geofilter, respectively. Good performance of vermifiltration incubated with vermiwash compared with the geofilter treatment was demonstrated for removal of BOD (91.29 ± 9.89%, n = 10), COD (91.42 ± 6.34%, n = 10) and TSS (86.02 ± 10.45%, n = 10). Furthermore, the burrowing activity of the test earthworm (Eisenia fetida) promoted the aeration condition in vermifilter which led to more dissolved oxygen (DO) in effluent (61.28 ± 20.05%, n = 10). Moreover, the amount of copper (Cu) in effluent was decreased compared with influent by up to 88% in all treatment. After 10 weeks of the experiment, the vermicompost that was incubated with vermiwash and produced from earthworm on the top layer was analyzed and showed that nutrients (nitrogen, phosphorus) and soil organic carbon were increased with vermifilter treatment (47.65, 81.61 and 31.79%, respectively) compared with geofilter treatment. In addition, bioavailability of Cu in soil in form of exchangeable Cu was decreased by increasing the bound to organic matter fraction. Transformation of Cu during vermifiltration happened and alleviated the mobility and availability of Cu. Copper in exchangeable form can change into non-toxic form. Therefore, vermifiltration process incubated with vermiwash could reduce the dispersion of copper in swine waste. In conclusion, vermiwash could enhance performance of vermifiltration for swine farm wastewater treatment. The available fraction of copper in vermicompost produced from vermifiltration decreased. Therefore, the farmer could produce vermicompost as the biofertilizer for agricultural production. Using vermifiltration for wastewater treatment in small swine farm could be the eco-solution for nutrient recovery, water resource recycles and minimize pollution.

Changes in Chemical Properties of Banana Pseudostem, Mushroom Media Waste, and Chicken Manure through the Co-Composting Process

Co-composting is an effective approach to biowaste management. The co-composting potential of banana pseudostem (BPS) and mushroom media waste (MMW) with chicken manure (CM) has not been explored, let alone their suitable ratios of co-composting being determined. Meanwhile, the imbalance ratios of the feedstocks used in the process severely restrict the physicochemical properties and quality of the finished product. For this reason, six different ratios of BPS, MMW, and CM, viz. 1:1:1, 1:2:1, 1:3:1, 2:1:1, 2:2:1, and 2:3:1, respectively (T1–T6), were composted together in aerobic conditions to identify the suitable ratio by evaluating the changes in the physicochemical properties in the composting process. According to the ratio of treatments, the feedstocks were mixed on fresh weight basis. The turning process of co-composting piles was repeated at seven-day intervals to maintain the uniform aeration throughout the composting period. The piles having BPS, MMW, and CM at ratios of 1:2:1, 1:3:1, and 2:3:1, respectively, demonstrated a longer thermophilic phase, indicating more complete decomposition and earlier maturity compared to piles with higher amount of BPS. Of the ratios, BPS:MMW:CM at 1:2:1 ratio (T2) resulted in the highest total nitrogen (1.53%), lowest C:N ratio (12.4), organic matter loss (54.5%), and increased CEC (41.3 cmol/kg). The highest germination index (129%) was also recorded in the T2 compost, indicating that it was toxic-free and safe for seed germination. The nutrient-rich compost with high alkaline pH (≥10) can effectively ameliorate soils of an acidic nature, for example, the acidity of Ultisols and Oxisols.

Vermicomposting: A Valorization Alternative for Corn Cob Waste

As vermicomposting has become a viable alternative for the valorization of organic waste; the objectives of this research were to (1) assess the feasibility of said process for corn cob waste (corn cobs and corn husks) and (2) evaluate the operation conditions for the biodegradation of different mixtures with load material (LM). LM did not include animal excreta as a nitrogen source, a practice widely used in a range of studies. The experiment consisted of an initial phase of pre-composting in order to obtain a partially stabilized substrate. Subsequently, four separate mixtures were made consisting of corn cob waste mixed with consistent load material (LM) containing vegetable waste and eggshells (CR, M1, M2, M3) to obtain a balance substrate able to facilitate degradation using Eisenia fetida earthworms. The following parameters were analyzed during the control process: temperature, pH, humidity, organic material (OM), total organic carbon (TOC), total nitrogen (TN) and carbon/nitrogen (C/N) ratio. The analysis of the final values of the stabilized mixtures showed that vermicomposting is indeed a feasible alternative for the degradation of corn cob waste for use as a soil improver.

Management of swine mortalities through the use of a mixed composting-accelerating bio-inoculant

A composting-accelerating bio-inoculant (Bacillus subtilis, Talaromyces sayulitensis (HC1), Steinernema sp., and Heterorhabditis sp.) was evaluated in a composting process made up of a different mix of wood chips, pig manure, urine, and swine mortality (raw material RM). Three different treatments (T1, T2, and T3) were assessed, and physicochemical, microbiological, and entomological evaluations were carried out at 0 and 45 days of the composting process. The highest organic nitrogen (1.34 %) concentration was detected in swine mortality, whereas the highest total oxidizable organic carbon (39.1 %) concentration was observed in wood chips. Salmonella spp., was not identified in any of the raw materials. Clostridium spp., count was 5.5, 2.0, and 1.0 Log10 unit, for pig manure, wood chips, and swine mortality, respectively. Pig manure, swine mortality, and wood chip total coliform count was 6.21, 5.32, and 1 Log10 unit, respectively. Helminth eggs were not detected in any of the RM and Cryptosporidium spp., oocysts were occasionally found in pig manure and wood chips. Several types of flies were identified, Musca domestica, Muscina stabulans, Stomoxys calcitrans, Fannia canicularis, Sarcophaga sp., and Calliphora sp. Treatment 3 (45.11 % swine mortality, 33.33 % wood chips, and 21.55 %, urine and bio-inoculant) had the greatest total oxidizable organic carbon availability, the highest carbon/nitrogen (C/N) ratio (20.67, p < 0.05), and the lowest dipterous larvae count. Moreover, Salmonella sp., was not observed and had only low Clostridium spp., and fecal coliform count. The bio-inoculant's effect on C/N ratio, cation exchange capacity, and electrical conductivity were beneficial, and resulted in production of a fertilizer complying with EPA 600/1-87-014, EPA 40 CFR Part 258, and NTC5167/11 norms. According to the characterization protocols used in this study the compost was apparently free from bacterial and parasitic pathogens and minimal dipteran counts. Last, maturation time was 15 days shorter compared with control (C4).

Management of lignocellulosic green waste Saccharum spontaenum through vermicomposting with cow dung

Saccharum spontaenum is considered as an invasive terrestrial weed spread across the world and its management possess big challenge to the research community. The current study illustrates the potential of vermicomposting for the management of lignocellulosic terrestrial weed Saccharum spontaenum under green waste management. The vermicompost experiments were done in five different mixing ratio of Saccharum spontaenum amended with cow dung 3:7, 4:6, 5:5, 6:4, 7:3 in vermireactors referred as R_ef1, R_ef2, R_ef3, R_ef4, R_ef5 respectively. The vermicomposting was carried out for total 45 days with one time feeding of the earthworms. The study indicates a mature vermicompost can be obtained with enhanced nutrients from proper mixing ratio. The different physicochemical parameters were observed to be varied among the reactors and between vermicomposting time significantly. The final C/N ratio was within 10-16 with highest decrease in R_ef1. Earthworm growth was observed to be highest in R_ef2 with percentage change of net biomass of earthworms with 34.25%. The highest TOC loss was observed to be 31.4% change in R_ef2 and maximum TKN was 2.95% in the final vermicompost of Ref3. Even though the mixing ratio of R_ef1 and R_ef2 was found to be ideal for the degradation of Saccharum spontaenum, the other reactors also produced acceptable quality end product. The study further reveals that the earthworm species Eisenia fetida was highly suitable for the biodegradation of this lignocellulosic weed material.

Enriched pressmud vermicompost production with green manure plants using Eudrilus eugeniae

Vermicomposting of pressmud with cow dung and nitrogenous green manures (Gliricidia sepium and Leucaena leucocephala) was carried out using Eudrilus eugeniae (50 days). The reduction in pH, total organic carbon, C/N ratio, water-soluble organic carbon (C_ws)/N_org and C/P ratios, and a pronounced increase in NPK contents and microbial population in vermicompost were observed. An enhanced TKN of 3.80% and 3.45% was recorded in vermicomposts of pressmud + cow dung + L. leucocephala (2:1:1) and pressmud + cow dung + G. sepium (2:1:1) respectively. The C/N and C_ws/N_org ratios in vermicompost ranged from 11.86 to 16.66 and 0.53 to 1.33, respectively. The activity of dehydrogenase, urease, acid and alkaline phosphatase declined towards the end, indicating the progression of vermicompost maturity. The pressmud and green manure substrates promoted more biomass of E. eugeniae, while cow dung with green manure combination favored reproduction. The amendment of cow dung and green manure plants to pressmud (2:1:1 ratio) results in nutrient-enriched vermicompost production.

Effects of soil pH and texture on soil carbon and nitrogen in soil profiles under different land uses in Mun River Basin, Northeast Thailand

Soil carbon and nitrogen are essential factors for agricultural production and climate changes. A total of 106 soil samples from three agricultural lands (including two rice fields and one sugarcane field) and four non-agricultural lands (including two forest lands, one wasteland and one built-up land) in the Mun River Basin were collected to determine soil carbon, nitrogen, soil pH, soil particle sizes and explore the influence of pH and soil texture on soil C and N. The results show that total organic carbon (TOC) and nitrogen (TON) contents in topsoil (TOC: 2.78 ~ 18.83 g kg⁻¹; TON: 0.48 ~ 2.05 g kg⁻¹) are much higher than those in deep soil (TOC: 0.35 ~ 6.08 g kg⁻¹; TON: <0.99 g kg⁻¹). In topsoil, their contents of forest lands and croplands (TOC: average 15.37 g kg⁻¹; TON: average 1.29 g kg⁻¹) are higher than those of other land uses (TOC: average 5.28 g kg⁻¹; TON: average 0.38 g kg⁻¹). The pH values range from 4.2 to 6.1 in topsoil, and with increase in soil depth, they tend to increase and then decrease. Soil carbon, nitrogen and the C/N (TC/TN ratio) are negatively correlated with soil pH, demonstrating that relatively low pH benefits the accumulation of organic matter. Most soil samples are considered as sandy loam and silt loam from the percentages of clay, silt and sand. For soil profiles below 50 cm, the TOC and TON average contents of soil samples which contain more clay and silt are higher than those of other soil samples.

Pre-Composting and Vermicomposting of Pineapple (Ananas Comosus) and Vegetable Waste

In the last few years, pineapple (Ananas comosus) has grown to be considered one of the most important fruits worldwide due to its high production and consumption. However, inadequate disposal of the waste it generates, which represents up to 67% of its total weight, can have environmental impacts. Therefore, this study focuses on the degradation of organic waste produced in the industrialized processing of pineapple waste (rinds, crowns and cores), which undergo a process of vermicomposting at a laboratory level. The methodology used included the pre-composting process and vermicomposting through Californian red worms using mixes tested in three different proportions of pineapple waste (PR) and load material (LM) made up of vegetable waste and eggshells. Testing revealed that the pre-composting process for this waste was feasible as a first stage of the degradation process; the characteristics of the pre-composted material allowed a favorable adaptation for both the worms and general degradation. It also showed efficiencies in the removal of organic carbon between 36.40% and 45.78%. Results also showed the total nitrogen content remained between 1.2% and 2.2% and the carbon/nitrogen relation (C/N) had values under 20 as required for high-quality vermicompost.

Amelioration and degradation of pressmud and bagasse wastes using vermitechnology

This study evaluated the amelioration of pressmud (PM) and bagasse (BG) wastes by the vermiremediation process. The wastes were spiked with cattle dung (CD) in different concentrations to find out the best proportion supporting maximum earthworm growth and nutrients availability. The highest growth rate was observed in PMBG₅₀ (282.2mg/d/worm) feed mixture. Response surface design of earthworm growth parameters enumerated best concentration of wastes in CD with maximum value of 21.81% for earthworm number, 30.86% for earthworm weight, 27.09% for cocoons, 29.71% for hatchlings and 34.0% for hatchlings weight. Vermicomposting enhanced nutrient parameters like pH (6-8%), total kjeldahl nitrogen (19-48%), total phosphorus (9-67%), total calcium (13-111%), while decrease in total organic carbon (14-32%), electrical conductivity (21-30%), C:N ratio (36-51%), total potassium (9-19%) and total sodium (3-21%). Heavy metals in the final products were found to be under safe limits. SEM micrographs were more fragmented which indicated maturity and stability.

New Insight into Sugarcane Industry Waste Utilization (Press Mud) for Cleaner Biobutanol Production by Using C. acetobutylicum NRRL B-527

In the present study, press mud, a sugar industry waste, was explored for biobutanol production to strengthen agricultural economy. The fermentative production of biobutanol was investigated via series of steps, viz. characterization, drying, acid hydrolysis, detoxification, and fermentation. Press mud contains an adequate amount of cellulose (22.3%) and hemicellulose (21.67%) on dry basis, and hence, it can be utilized for further acetone-butanol-ethanol (ABE) production. Drying experiments were conducted in the temperature range of 60-120 °C to circumvent microbial spoilage and enhance storability of press mud. Furthermore, acidic pretreatment variables, viz. sulfuric acid concentration, solid to liquid ratio, and time, were optimized using response surface methodology. The corresponding values were found to be 1.5% (v/v), 1:5 g/mL, and 15 min, respectively. In addition, detoxification studies were also conducted using activated charcoal, which removed almost 93-97% phenolics and around 98% furans, which are toxic to microorganisms during fermentation. Finally, the batch fermentation of detoxified press mud slurry (the sample dried at 100 °C and pretreated) using Clostridium acetobutylicum NRRL B-527 resulted in a higher butanol production of 4.43 g/L with a total ABE of 6.69 g/L.

Management of food and vegetable processing waste spiked with buffalo waste using earthworms (Eisenia fetida)

The present investigation was focused on the vermicomposting of food and vegetable processing waste (VW) mixed with buffalo dung (BW) under laboratory condition employing Eisenia fetida earthworm species. Four different proportions of VW and BW were prepared and subjected to vermicomposting after 3 weeks of pre-composting. After vermicomposting, nitrogen (7.82-20.73 g/kg), total available phosphate (4.80-11.74 g/kg) and total potassium (7.43-12.75 g/kg) content increased significantly as compared to initial feed stocks. Significant reduction was observed in pH (7.56 to 6.55), total organic carbon (48.25-23.54%) and organic matter (83.18-40.68%). Metal content (Fe, Cu, Zn and Ni) was higher in all the vermicomposts than feedstocks. Data on growth and reproduction of earthworm revealed that the highest biomass gain and fecundity of worms were attained in 100% BW followed by [BW75% + VW25%] > [BW50% + VW50%] > [BW25% + VW75%] feedstocks. Results evidenced the suitability of VW (up to 50%) spiked with BW for increasing earthworm population and in providing potent organic manure for agricultural applications.

The influence of flue gas desulphurization gypsum additive on characteristics and evolution of humic substance during co-composting of dairy manure and sugarcane pressmud

For the purpose of evaluating the effect of flue gas desulphurization gypsum (FGDG) additive on characteristics and evolution of humic substance (HS) during composting, HS from composts with FGDG (CPG) and without FGDG (CP) were extracted and assessed with respect to their particle size, elemental analysis, FTIR and UV-vis spectroscopy, and the molecular composition of HS was characterized via pyrolysis-GC/MS as well. The particle size of HS ranged between 300 and 600nm, representing a bimodal distribution. As composting proceeded, the C/H of HS increased, and C/N decreased. The FTIR and UV-vis spectroscopy indicated that the aromatization of HS was promoted over the composting process. Adding FGDG increased the unsaturated degree and aromatization of HS. Pyrolysis-GC/MS showed the level of alkane decreased, and the level of benzene and nitrogen compounds increased upon the addition of FGDG. The nitrogen compounds of HS in CPG was significantly higher than that in CP.

Impacts of adding FGDG on the abundance of nitrification and denitrification functional genes during dairy manure and sugarcane pressmud co-composting

To investigate the impacts of flue gas desulphurization gypsum (FGDG) amendment on the nitrification and denitrification during composting, dairy manure and sugarcane pressmud co-composting with FGDG (CPG) and without FGDG (CP) were conducted in this work. The physico-chemical parameters and the copies of nitrification and denitrification functional genes with real-time quantitative polymerase chain reaction (qPCR) during composting were analyzed. FGDG amendment displayed an inhibitory effect on the copies of 16S rDNA and delayed the occurrence of the highest gene copies of amoA during composting. The nxrA gene copies was inhibited by FGDG amendment during the mature phase. The addition of FGDG increased the relative content of narG and nirS during composting, contributing to more NO3(-)-N being reduced to NO2(-)-N. The amoA showed significant negative correlation with OM and NH4(+)-N, and positive correlation with NO3(-)-N. The nxrA displayed a negative correlation with temperature. These results demonstrated FGDG amendment significantly affected the copies of nitrification and denitrification functional genes, which changed the nitrogen flux of composting. Taken together, these data shed an insight into FGDG amendment affecting the nitrogen transformation during composting on a molecular level.

Improving green waste composting by addition of sugarcane bagasse and exhausted grape marc

The composting of lignocellulosic waste into compost is a potential way of sustainably disposing of a waste while generating a useful product. The current study determined whether the addition of sugarcane bagasse (SCB) (at 0, 15, and 25%) and/or exhausted grape marc (EGM) (at 0, 10, and 20%) improved the two-stage composting of green waste (GW). The combined addition of SCB and EGM improved composting conditions and the quality of the compost product in terms of temperature, water-holding capacity, particle-size distribution, coarseness index, pH, electrical conductivity, water-extractable organic carbon and nitrogen, microbial numbers, enzymatic activities, polysaccharide and lignin content, nutrient content, respiration, and phytotoxicity. The optimal two-stage composting and the best quality compost were obtained with the combined addition of 15% SCB and 20% EGM. With the optimized two-stage composting method, the compost matured in only 21days rather than in the 90-270days required for traditional composting.

Management of Sugar Industrial Wastes through Vermitechnology

The present paper discusses the role of earthworms in recycling of sugar industrial wastes. The wastes generated from sugar industry are pressmud, bagasse, bagasse fly ash, sugar cane trash, sugar beet mud, sugar beet pulp, molasses etc. These wastes when mixed with other organic substrates become ideal mixtures for growth of earthworms. These wastes if stored in open field’s causes contamination in the environment and may cause several diseases in public health. But the governments have been unable to tackle the menace of solid waste pollution due to dearth of appropriate technologies, finance and space. Therefore, environment friendly and cost effective technologies for nutrient recycling or remediation of wastes are being advocated as an alternative means for conserving and replenishing natural resources of the ecosystems. Vermicomposting is one such technology that synergises microbial degradation with earthworm’s activity for reducing, reusing and recycling waste materials in a shorter span of time. Earthworm technology can convert sugar industrial wastes into valuable fertilizing material. The final product (vermicompost) produced during the process of vermicomposting is nutrient rich organic fertilizer with plant available nutrients such as nitrogen, potassium, calcium and phosphorus. In the present study an attempt has been made to document the role of earthworms in reuse of sugar industry waste.

Management of Sugar Industrial Wastes through Vermitechnology

The present paper discusses the role of earthworms in recycling of sugar industrial wastes. The wastes generated from sugar industry are pressmud, bagasse, bagasse fly ash, sugar cane trash, sugar beet mud, sugar beet pulp, molasses etc. These wastes when mixed with other organic substrates become ideal mixtures for growth of earthworms. These wastes if stored in open field’s causes contamination in the environment and may cause several diseases in public health. But the governments have been unable to tackle the menace of solid waste pollution due to dearth of appropriate technologies, finance and space. Therefore, environment friendly and cost effective technologies for nutrient recycling or remediation of wastes are being advocated as an alternative means for conserving and replenishing natural resources of the ecosystems. Vermicomposting is one such technology that synergises microbial degradation with earthworm’s activity for reducing, reusing and recycling waste materials in a shorter span of time. Earthworm technology can convert sugar industrial wastes into valuable fertilizing material. The final product (vermicompost) produced during the process of vermicomposting is nutrient rich organic fertilizer with plant available nutrients such as nitrogen, potassium, calcium and phosphorus. In the present study an attempt has been made to document the role of earthworms in reuse of sugar industry waste.

Heavy metal variation and characterization change of dissolved organic matter (DOM) obtained from composting or vermicomposting pig manure amended with maize straw

A mixture of pig manure and maize straw was vermicomposted with Eisenia fetida or naturally composted for 60 days; basic parameters, heavy metal variation, dissolved organic matter (DOM) content, and its characterization were determined, aiming to explore different dynamics of DOM characterization and heavy metal variation during composting or vermicomposting. The results showed that vermicomposting led to higher pH, TC, and available P but lower EC, TN, available N, and available K in the substrate residues compared with natural composting; the total or available Cu/Zn content in the substrate residues similarly increased after composting or vermicomposting, but Cu was easily enriched in earthworm bodies and its intestinal vermicompost while vermicomposting enhanced the formation of dissolved Zn in DOM; moreover, much more fulvic and humic acid-like materials and much greater aromaticity were exhibited in DOM obtained from vermicomposting residues compared with DOM from composting residues, which may contribute to the variations of Cu/Zn enrichment in earthworms and its migration to the vermicomposting residues or its DOM.

Exposure and Health Effects of Fungi on Humans

Fungi are ubiquitous microorganisms that are present in outdoor and indoor environments. Previous research has found relationships between environmental fungal exposures and human health effects. We reviewed recent articles focused on fungal exposure and dampness as risk factors for respiratory disease development, symptoms, and hypersensitivity. In particular, we reviewed the evidence suggesting that early exposure to dampness or fungi is associated with the development of asthma and increased asthma morbidity. Although outdoor exposure to high concentrations of spores can cause health effects such as asthma attacks in association with thunderstorms, most people appear to be relatively unaffected unless they are sensitized to specific genera. Indoor exposure and dampness, however, appears to be associated with an increased risk of developing asthma in young children and asthma morbidity in individuals who have asthma. These are important issues because they provide a rationale for interventions that might be considered for homes and buildings in which there is increased fungal exposure. In addition to rhinitis and asthma, fungus exposure is associated with a number of other illnesses including allergic bronchopulmonary mycoses, allergic fungal sinusitis, and hypersensitivity pneumonitis. Additional research is necessary to establish causality and evaluate interventions for fungal- and dampness-related health effects.

Potential of Effective micro-organisms and Eisenia fetida in enhancing vermi-degradation and nutrient release of fly ash incorporated into cow dung-paper waste mixture

The interactions between earthworms and microorganisms activity has prompted several researchers to evaluate the potential of artificially inoculating vermicomposts with additional specific microbes, with the intention of enhancing the vermicomposting process. This study evaluated the potential of inoculating fly ash (F)-cow dung-paper waste (CP) mixture (F-CP) with a specialized microbial cocktail called Effective micro-organisms (EM) during vermicomposting using Eisenia fetida earthworms. Inoculation with EM alone did not result in significantly (P>0.05) different changes in C/N ratio and dissolved organic matter (DOC) compared to the control with no EM and E. fetida. A significant interaction between EM and E. fetida presence resulted in greater changes in C/N ratio and DOC, which were not statistically different from the E. fetida alone treatment. It was also noteworthy that the activity of ß-Glucosidase was not influenced by the presence of EM, but was significantly influenced (P=0.0014) by the presence of E. fetida. However, the EM+E. fetida treatment resulted in a rate of weekly Olsen P release of 54.32mgkg(-1) which was 12.3%, 89.2% and 228.0% more that the E. fetida alone, EM alone and control treatments, respectively. Similarly, though higher in the E. fetida plus EM treatment, the phosphate solubilizing bacteria counts were not significantly different (P>0.05) from the E. fetida alone treatment. It is concluded that inoculation of F-CP composts with EM alone may not be beneficial, while combining EM with E. fetida results in faster compost maturity and significantly greater Olsen P release. It would be interesting to evaluate higher optimized rates of EM inoculation and fortifying EM cocktails with phosphate solubilizing bacteria (PSB) on F-CP vermicompost degradation and phosphorus mineralization.

Use of agave bagasse for production of an organic fertilizer by pretreatment with Bjerkandera adusta and vermicomposting with Eisenia fetida

Agave tequilana Weber is used in tequila and fructans production, with agave bagasse generated as a solid waste. The main use of bagasse is to produce compost in tequila factories with a long traditional composting that lasts 6-8 months. The aim of this study was to evaluate the degradation of agave bagasse by combining a pretreatment with fungi and vermicomposting. Experiments were carried out with fractionated or whole bagasse, sterilized or not, subjecting it to a pretreatment with Bjerkandera adusta alone or combined with native fungi, or only with native bagasse fungi (non-sterilized), for 45 days. This was followed by a vermicomposting with Eisenia fetida and sewage sludge, for another 45 days. Physicochemical parameters, lignocellulose degradation, stability and maturity changes were measured. The results indicated that up to 90% of the residual sugars in bagasse were eliminated after 30 days in all treatments. The highest degradation rate in pretreatment was observed in non-sterilized, fractionated bagasse with native fungi plus B. adusta (BNFns) (71% hemicellulose, 43% cellulose and 71% lignin) at 45 days. The highest total degradation rates after vermicomposting were in fractionated bagasse pre-treated with native fungi (94% hemicellulose, 86% cellulose and 91% lignin). However, the treatment BNFns showed better maturity and stability parameters compared to that reported for traditional composts. Thus, it seems that a process involving vermicomposting and pretreatment with B. adusta could reduce the degradation time of bagasse to 3 months, compared to the traditional composting process, which requires from 6 to 8 months.

Generation of bioethanol and VFA through anaerobic acidogenic fermentation route with press mud obtained from sugar mill as a feedstock

Acidogenic anaerobic fermentation route was explored for the production of bioethanol and volatile fatty acids (VFA) from the press mud (PM) obtained from sugar mill. Slurry was prepared from PM having 10% of total solids and the same was hydrolyzed under acidic thermal conditions. Both press mud slurry (PMS) and pre-treated press mud slurry (PTPMS) was used as feedstock with mixed microbial consortia (MMC) and enriched mixed microbial consortia (EMMC). Mix of bioethanol and VFA were obtained in all the four cases (PMS-MMC, PMS-EMMC, PTPMS-EMC and PTPMS-EMMC), but, bioethanol and VFA yield of 0.04 g/g and 0.27 g/g, respectively obtained from PTPMS with EMMC was found to be comparatively higher. Control experiments carried out with glucose yielded bioethanol and VFA of 0.042 g/g and 0.28 g/g, respectively demonstrating that the organism was using reducible sugars in the feedstock for the generation of bioethanol by simultaneously producing the VFA from COD.

Filter Cake Oil-Wax as Raw Material for the Production of Biodiesel: Analysis of the Extraction Process and the Transesterification Reaction

The viability of using the waste obtained in the manufacture of sugar from sugarcane for the production of biodiesel has been analyzed. Two fundamental stages are necessary to obtain biodiesel; the first stage is the extraction process from the waste oil materials and the second is the transesterification reaction. Four techniques, Soxhlet, orbital shaker extraction, ultrasonic-assisted extraction, and supercritical fluid extraction, have been analyzed. For Soxhlet, orbital shaker extraction, and ultrasonic-assisted extraction, the organic solvent (hexane) was maintained for all experiment. In supercritical fluid extraction two solvents were evaluated: pure CO2and mixtures of CO2and 5% (v : v) methanol. The reaction kinetics of the transesterification reaction with an acidic catalyst and a basic catalyst were analysed. The results show that the supercritical extraction process produces a better product for the subsequent transesterification reaction. This finding is attributed to the high selectivity of carbon dioxide in the recovery of fatty acids and triglycerides in comparison with other solvents.

Changes of carbon, nitrogen, phosphorous, and potassium content during storage of vermicomposts prepared from different substrates

The study was conducted to determine the optimum storage time for vermicompost without significant loss of nutrients; nitrogen (N), phosphorous (P), and potassium (K). Cattle manure, paddy straw, municipal solid wastes, and fly ash were used for vermicompost preparations. The dynamics of N, P, and K in the vermicomposts were studied during 180 days of incubation at 28-32 °C. In general, N concentration increased in the first 90-105 days of incubation and then gradually decreased until the 180th day while P and K concentrations steadily decreased over the length of the study, with the rate of loss leveling off after 150 days. The rate of nutrient loss was directly related to the initial level, decreasing the fastest for the nutrients with the highest initial concentrations. Optimum storage times were substrate and N dependent.

Heavy metal and nutrient changes during vermicomposting animal manure spiked with mushroom residues

A pilot-scale trial of four months was conducted to investigate the responses of heavy metal and nutrient to composting animal manure spiked with mushroom residues with and without earthworms. Results showed that earthworm activities accelerated organic matter mineralization (e.g. reduction in C/N ratio, increase in total concentrations of N, P, K) and humification (e.g. increase in humic acid concentration, humification ratio and humification index). Despite composting increased total heavy metal (i.e. As, Pb, Cu, Zn) concentrations irrespective of earthworm, the availability of heavy metals extracted by DTPA significantly (P<0.05) decreased particularly in treatments with earthworms introduced. The shift from available to unavailable fractions of heavy metals was either due to earthworm bioaccumulation, as indicated by total heavy metal concentrations being higher in earthworm tissues, or due to the formation of stable metal-humus complexes as indicated by the promotion of humification. Our results suggest that vermicomposting process could magnify the nutrient quality but relieve the heavy metals risk of agricultural organic wastes.

Effect of vermicomposting on calcium, sulphur and some heavy metal content of different biodegradable organic wastes under liming and microbial inoculation

A study was conducted to evaluate the changes in total calcium and sulphur and some heavy metal (Zn, Cu, and Pb) concentration of different organic wastes affected by liming and microorganism inoculation. Vermicomposting was an effective technology for disposal of organic substrates like municipal solid wastes (MSW), possessing comparatively higher concentration of heavy metals. The addition of lime in initial organic substrates significantly (P ≤ 0.05) increased total calcium and total sulphur content of vermicomposts. Inoculation of microorganisms significantly (P ≤ 0.05) reduced the heavy metal content of final products as compared to control. Fungal strains were comparatively more effective in detoxification of heavy metals than B. polymyxa.

Ammonia emissions during vermicomposting of sheep manure

The effect of C:N ratio, temperature and water content on ammonia volatilization during two-phase composting of sheep manure was evaluated. The aerobic phase was conducted under field conditions. This was followed by Phase II, vermicomposting, conducted in the laboratory under controlled conditions of water content (70% and 80%) and temperature (15 and 22 °C). The addition of extra straw lead to a 10% reduction in NH3 volatilization compared to sheep manure composted without extra straw. Temperature and water content significantly effected ammonia volatilization at 0 day in Phase II, with a water content of 70% and temperature of 22 °C leading to greater losses of ammonia. Nitrogen loss by ammonia volatilization during vermicomposting ranged from 8% to 15% of the initial N content. The addition of extra straw did not result in significant differences in total carbon content following vermicomposting.

Valorization of solid waste in sugar factories with possible applications in India : a review

Sugar production is a major agro-based industry in India that generates various solid wastes viz. sugarcane trash, bagasse, press mud and bagasse fly ash. This work examines the state-of-the-art in innovative value added products that can be obtained from the transformation of these wastes. Challenges in implementing these waste valorization solutions are also highlighted. It is observed that the extent of research and adoption of these solutions vary considerably. Both industry involvement as well as government encouragement is required in translating the research findings into commercial products.

The potential reuse of soybean husk as feedstock of Eudrilus eugeniae in vermicomposting

BACKGROUND

Soybean (Glycine max L.) is one the most commonly consumed legumes worldwide, with 200 million metric tons produced per year. However, the inedible soy husk would usually be removed during the process and the continuous generation of soybean husk may represent a major disposal problem for soybean processing industries. Thus, the main aim of the present study was to investigate the possibility to convert soybean husk (S) amended with market-rejected papaya (P) into vermicompost using Eudrilus eugeniae.

RESULTS

Soybean husk was mixed with market-rejected papaya in different ratios to produce five different treatments (1P:1S, 2P:1S, 1P:2S, S only and P only) for laboratory screening of solid wastes. Generally, the application of E. eugeniae permitted a significant increase in Ca (42.3-91.6%), K (93.8-235%), Mg (25.4-84.6%) and P (37.1-129%) but a decrease in the C:N ratio (21.4-52.8%) after 9 weeks of vermicomposting. Among all the treatments investigated, soybean husk which was mixed with an equal amount of market-rejected papaya (1P:1S) showed superior quality vermicompost. Waste mixtures also encouraged the growth of E. eugeniae except the treatments with soybean husk alone as well as soybean husk which was mixed with market-rejected papaya in 1P:2S ratio.

CONCLUSION

Vermicomposting could be used as an efficient technology to convert soybean husk into nutrient-rich organic fertiliser if it was mixed with market-rejected papaya in appropriate ratio.

Recycling of organic wastes by employing Eisenia fetida

This paper reports the recycling of nutrients by vermicomposting of cow dung (CD), poultry droppings (PD) and food industry sludge (FIS) employing earthworms (Eisenia fetida). A total of six vermicomposting units were established and dynamics of chemical and biological parameters has been studied for 13 weeks. The waste mixture containing 50% CD+25% PD+25% FIS had better fertilizer value among studied waste combinations. At the end of experiment, vermicomposts showed decrease in pH and organic C, but increase in EC, total Kjeldhal N, total available P and total K contents. The C:N ratio of final vermicomposts also reduced to 10.7-12.7 from 22.8 to 56 in different waste combinations. The earthworms have good biomass gain and cocoon production in all vermicomposting units but CD alone and 50% CD+25% PD+25% FIS were better than other studied combinations.

Enhancement of wood waste decomposition by microbial inoculation prior to vermicomposting

To investigate the feasibility of microbial pre-decomposition of timber wastes to quality production of vermicompost with higher agronomic value, timber wastes were inoculated with different combinations of the fungi Phanerochete chrysosporium, Trichoderma reesei, Aspergillus niger and the bacteria Azotobacter chroococcum (MTCC 3853) and Bacillus cereus (MTCC 4079) and incubated at 28-30 °C in a mechanical composter. The inoculation enhanced the degradation of timber wastes, increased total nitrogen and improved the quality and enhanced production of vermicompost generated with the native earthworm Drawida willsi Michelsen. Total nitrogen increased from 0.16% to 1.52% and total organic carbon (TOC) decreased from 42% to 13%. Out of 10 microbial combinations tested for pre-decomposition, the combination of P. chrysosporium+T. reesei was found best in terms of ligno-cellulosic decomposition, and P. chrysosporium+A. niger+B. cereus with respect of cast output. The study shows that microbial pre-decomposition of timber wastes to produce quality vermicompost is a feasible technology.