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Abstract Urbanization and industrialization in this modern time actually cause less availability of daily based water. In searching of a preferable solution to overcome this critical problem, waste water treatment seems to be considered as a much valuable option for reusing water. For this, sewage water treatment plants (STPs) are widely used. But this solution is actually ironical, as STP treatment causes hazardous damage to the environment in treating waste water. This system needs lots of harmful chemicals, high energy, and high build-up to operate the process. But a newly considered technology has come to counteract all these problems of STPs and the method is ‘Vermifiltration’. In this technique, earthworms are used to treat waste water. Earthworm’s body acts as biofilter and it can reduce higher percentage of BOD, COD, TSS from the waste water compared to the STPs. Earthworms eat up the sewage, making them treated, neutralized, and non-harmful and finally excrete them with several useful microorganisms. The symbiotic activity between earthworms and microorganisms works to filter the waste water. This method is completely odour less and harmless. No sludge is formed. With having all these characteristics, vermifiltration becomes much better option for the environment. In this review, the method of vermifiltration, its limiting factors, utilization and future developments are properly discussed.

Urbanization and industrialization in this modern time actually cause less availability of daily based water. In searching of a preferable solution to overcome this critical problem, waste water treatment seems to be considered as a much valuable option for reusing water. For this, sewage water treatment plants (STPs) are widely used. But this solution is actually ironical, as STP treatment causes hazardous damage to the environment in treating waste water. This system needs lots of harmful chemicals, high energy, and high build-up to operate the process. But a newly considered technology has come to counteract all these problems of STPs and the method is 'Vermifiltration'. In this technique, earthworms are used to treat waste water. Earthworm's body acts as biofilter and it can reduce higher percentage of BOD, COD, TSS from the waste water compared to the STPs. Earthworms eat up the sewage, making them treated, neutralized, and non-harmful and finally excrete them with several useful microorganisms. The symbiotic activity between earthworms and microorganisms works to filter the waste water. This method is completely odour less and harmless. No sludge is formed. With having all these characteristics, vermifiltration becomes much better option for the environment. In this review, the method of vermifiltration, its limiting factors, utilization and future developments are properly discussed. Highlights: The present review reports the mechanistic pathway of vermifiltration method. An eco-friendly and reusable vermifiltration method is applicable for the treatment of wastewater. Various parameters such as hydraulic loading rate, salinity rate, clogging, and sunlight have a positive impact on the efficacy of sustainable vermifiltration system. Active zone of this system can remediate organics (COD, BOD), nitrate from nitrogen, total phosphorus, total nitrogen, dissolved phosphorus from several kinds of wasteeffluents. The integrated vermifilter technique reduces the consumption of land and promotes reutilization of wastewater for cultivation purpose. [ABSTRACT FROM AUTHOR]

Hog farm wastewater may require novel biological treatment techniques to improve efficiency and reduce costs. Previous studies combining vermifiltration with downstream hydroponics showed the need for a balanced wastewater nutrient content, particularly the nitrogen-to-phosphorus ratio. Here, a deep-water culture hydroponic system, growing lettuce as model culture, was used to remediate hog farm wastewater after an initial vermifiltration stage, aiming to produce an effluent suitable for irrigation. Supplemented vermifiltered wastewater (SVW) with added nutrients was tested against unsupplemented vermifiltered wastewater (VW) over 35 days, using a synthetic nutrient solution (NS) as a control. Supplementation was shown to improve lettuce growth, light use efficiency, and water use efficiency. Nutrient analysis over time showed a better-balanced phosphorus and nitrogen removal in SVW than in VW; in all treatments nitrogen and phosphorus content was reduced to legally acceptable levels for treated wastewater reuse in irrigation: nitrate 5 mgN L−1 in VW and undetectable in SVW and NS; ammonia undetectable in all treatments; and total phosphorus 2.4 mg L−1 in SVW, 0.9 mg L−1 in NS and undetectable in VW. Coliforms increased in VW and SVW during hydroponic treatment, which should be solved by disinfection. Overall, combining vermifiltration with downstream hydroponic culture proved to be a promising treatment to remediate nutrients in hog farm effluent to make it suitable to be reused for irrigation. [ABSTRACT FROM AUTHOR]

Vermifiltration is a promising technique that can help recover nutrients from wastewater for further use in agriculture. We conducted a field experiment to assess the effectiveness of vermicompost produced from the vermifiltration of liquid waste (manure and food production waste) and how it can affect the soil health and yield of a squash crop. We tested the effect of three rates of vermicompost (low, medium, and high) applied over two consecutive years and measured physical, chemical, and biological soil health indicators, squash yield, and nutritional status. The results showed that the use of vermicompost, especially at a high rate, increased total soil carbon, total nitrogen, potentially mineralizable nitrogen, and particulate organic matter, as well as the activity of C-N-P cycling enzymes, as compared to a control with only inorganic fertilization. The yield of the squash crop remained stable, while the crop nutritional value improved as the levels of boron and copper in the treated squash increased. These findings indicate an improvement in soil health after the use of vermicompost. Overall, results strongly support using this type of vermicompost as a sustainable management approach to recycle nutrients and enhance soil health. [ABSTRACT FROM AUTHOR]

Vermifiltration (VF) and a conventional biofilter (BF, no earthworm) were investigated by metagenomics to evaluate the removal rates of antibiotic-resistant bacteria (ARB), antibiotic resistance genes (ARGs), and class 1 integron-integrase (intI1), as well as the impact mechanism in combination with the microbial community. According to the findings of qPCR and metagenomics, the VF facilitated greater removal rates of ARGs (78.83% ± 17.37%) and ARB (48.23% ± 2.69%) than the BF (56.33% ± 14.93%, 20.21% ± 6.27%). Compared to the control, the higher biological activity of the VF induced an increase of over 60% in the inhibitory effect of earthworm coelomic fluid on ARB. The removal rates of ARGs by earthworm guts also reached over 22%. In addition, earthworms enhanced the decomposition of refractory organics, toxic, and harmful organics, which led to a lower selective pressure on ARGs and ARB. It provides a strategy for reducing resistant pollution in sewage treatment plants and recognizing the harmless stability of sludge. [ABSTRACT FROM AUTHOR]

Vermifiltration is a promising technique that can help recover nutrients from wastewater for further use in agriculture. We conducted a field experiment to assess the effectiveness of vermicompost produced from the vermifiltration of liquid waste (manure and food production waste) and how it can affect the soil health and yield of a squash crop. We tested the effect of three rates of vermicompost (low, medium, and high) applied over two consecutive years and measured physical, chemical, and biological soil health indicators, squash yield, and nutritional status. The results showed that the use of vermicompost, especially at a high rate, increased total soil carbon, total nitrogen, potentially mineralizable nitrogen, and particulate organic matter, as well as the activity of C-N-P cycling enzymes, as compared to a control with only inorganic fertilization. The yield of the squash crop remained stable, while the crop nutritional value improved as the levels of boron and copper in the treated squash increased. These findings indicate an improvement in soil health after the use of vermicompost. Overall, results strongly support using this type of vermicompost as a sustainable management approach to recycle nutrients and enhance soil health.

This study was conducted in two natural meadows: first, soils were irrigated with raw wastewater (SIRWW) and in the second, soils were irrigated with treated wastewater (SITWW). Earthworms were sampled in eight soil blocks spaced 10 m apart at each site. Earthworm community was characterized and compared using density, biomass, composition, structure, species richness, and diversity parameters. At both meadows, 459 earthworm individuals from two families and seven species were collected. The highest earthworm density and species richness were recorded at SIRWW. Nicodrilus caligenus was the most abundant species. Most of earthworm community parameters decreased significantly at SITWW. Only two species (N. caligenus and Octodrilus complanatus) were common between the two grasslands. Among the seven species identified at both meadows, four (Allolobophora longa, Eisenia foetida, Allolobophora rosea, Allolobophora chlorotica) were exclusively present in SIRWW, whereas a single species (Amynthas sp.) was characterized in SITWW. Three ecological earthworm groups (epigeic, endogeic, and anectic) were represented in SIRWW, with the dominance of endogeics. Further studies are needed to quantify pollution in this soils and the accumulation of pollutant load in earthworms. It is also important to highlight the relationship between the abundance and diversity of earthworms in these two ecosystems with soil biological activity. HIGHLIGHTS Diversity and composition of earthworm community were studied in meadows receiving wastewater.; Species richness and abundance varied between sites irrigated with raw and treated wastewaters.; Grassland meadows irrigated with raw wastewater created a favorable environment for earthworms.; Endogeic species tolerate large variations of environmental conditions in wastewater-irrigated lands.;

This paper discusses the implementation of Tiger Worm Toilets (TWTs) as a sustainable alternative to pit latrines in areas with challenging environmental conditions. The study was carried out in Koinadugu, Sierra Leone, where TWTs were installed in 200 households, providing safe sanitation for approximately 1,200 individuals within a 17-month period. The study reveals that TWTs offer several benefits over traditional pit latrines, including higher cost efficiency. Despite some setbacks, TWTs have been well-received by the local communities, resulting in a significant reduction in open defaecation in areas where latrines are not viable. The study presents areas of further research and concludes with recommendations for future TWT designs based on the lessons learned. HIGHLIGHTS Community engagement facilitated the adoption of TWTs and ensured ongoing cooperation and financial viability.; A sustainable design is presented to prevent fly nuisance and rainwater infiltration in TWT biodigesters.;

The review discusses the advancements in vermifiltration research over the last decade, focusing on pollution removal mechanisms, system performance, the fate of filter components, and by-products. Vermifiltration has demonstrated remarkable capabilities, particularly in treating highly contaminated wastewater with Chemical Oxygen Demand (COD) levels exceeding 92,000 mg/L and Biochemical Oxygen Demand (BOD5) levels over 25,000 mg/L, achieving removal rates of approximately 89% and 91%, respectively. Importantly, vermifiltration maintains its effectiveness even with fluctuating organic loads at the inlet, thanks to optimization of parameters like Hydraulic Loading Rate, biodegradable organic strength, earthworm density and active layer depth. Clogging issues can be minimized through parameters optimization. The review also highlights vermifiltrations’ potential in co-treating the organic fraction of municipal solid waste while significantly reducing heavy metal concentrations, including Cd, Ni, Pb, Cu, Cr, and Zn, during the treatment process. Earthworms play a pivotal role in the removal of various components, with impressive removal percentages, such as 75% for Total Organic Carbon (TOC), 86% for Total COD, 87% for BOD5, 59% for ammonia nitrogen, and 99.9% for coliforms. Furthermore, vermifiltration-treated effluents can be readily utilized in agriculture, with the added benefit of producing vermicompost, a nutrient-rich biofertilizer. The technology contributes to environmental sustainability, as it helps reduce greenhouse gas emissions (GHG), thanks to earthworm activity creating an aerobic environment, minimizing GHG production compared to other wastewater treatment methods. In terms of pollutant degradation modeling, the Stover-Kincannon model outperforms the first-order and Grau second-order models, with higher regression coefficients (R2 = 0.9961 for COD and R2 = 0.9353 for TN). Overall, vermifiltration emerges as an effective and sustainable wastewater treatment solution, capable of handling challenging wastewater sources, while also producing valuable by-products and minimizing environmental impacts.

Water pollution, particularly from domestic wastewater contaminated with microplastics and heavy metals, poses significant threats to human health and ecosystems. The aim of this study was to assess the potential of vermifiltration combined with biochar to treat domestic wastewater using earthworm, Eisenia foetida. The objectives of this research were to monitor the change in water quality parameter (BOD, COD, TDS, TSS, Phosphate and Nitrate). Experiments were conducted using a Completely Randomized Design (CRD) with four treatments: Geofilter (Gf), Vermifilter (Vf), Geofilter + Biochar (Gf + Bi), and Vermifilter + Biochar (Vf + Bi). The result showed that using vermifiltration combined with biochar could reduce the biological oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS) in domestic wastewater treatment highest followed by vermifiltrater, geofilter with biochar and geofilter, respectively. The results demonstrated the percentage removal of BOD (94.28 %), COD (89.82 %), TDS (88.35 %) and TSS (95.30 %). The Vf + Bi system showed high efficiency in heavy metal reduction: Mn (99.37 %), Zn (100 %), Cu (100 %), Pb (44.00 %), and As (100 %). Microplastic contamination was reduced most effectively by Vf + Bi (88.64 %), followed by Gf + Bi (86.36 %), Vf (77.27 %), and Gf (75.00 %). Post-treatment vermibed analysis revealed increases in Nitrogen, Phosphorus, Potassium, and organic carbon content in bedding. This study concludes that the integration of vermifiltration and biochar could be the eco-solution for nutrient recovery, water resource recycles and minimize pollution and efficient wastewater treatment and generating valuable by-products such as biofertilizer.

Tiger Worm Toilets (TWTs) are a relatively recent innovation in sanitation technology, with the potential to offer affordable and safely managed on-site sanitation for underserved communities in line with Sustainable Development Goal 6. This article, authored by members of the International Worm-Based Sanitation Association (IWBSA), presents the state-of-the-art in TWT construction and operation based on frontier global experiences to-date, stemming from both knowledge from literature and the practical knowledge imparted by the authors, who were involved in the birth of this technology and are still active in the research and deployment of it today. The focus of this paper is on the implementation of TWTs to solve sanitation challenges in least-developed and lower-middle income countries specifically. The design of TWTs can be adapted to a wide range of environmental conditions including high water tables and rocky ground conditions, and in both rural and urban contexts. The challenge for TWTs therefore lies primarily in creating opportunities for scaling the uptake of this promising technology. Our article discusses the key barriers to this, identified to be broadly categorised as user preference, capacity and capability building, and governmental support–and proposes how to overcome these.

In the last few decades, vermifiltration has become a well-known alternative to conventional wastewater remediation methods owing to its economic viability and environmental sustainability. In the present study, we examined the effect of the organic strength [i.e., chemical oxygen demand (COD)] of an influent (i.e., synthetic dairy wastewater) and the depth of the vermibed on the performance of a macrophyte-assisted vermifilter (MAVF), in terms of organic-carbon and nitrogen removal. The to-date inadequately explored possible N-removal pathways in the designed MAVF system were also investigated. The designed MAVF, with its vertical subsurface flow, achieved maximum COD removal up to 96.5 ± 1.5% when the influent COD and vermibed depth were at 1,400 ± 89 mg/L and 20 cm, respectively. Similarly, the MAVF produced a significant reduction in the ammonium–nitrogen (NH4+ –N) and total nitrogen (TN) concentrations, whereas the effluent nitrate (NO3−)–N concentration was markedly enhanced compared to the influent concentration. The experimental run, using an influent COD of 1,400 ± 89 mg/L and a vermibed depth of 50 cm, yielded the maximum NH4+ –N conversion efficiency, at 96.4 ± 1.2%. In the same experimental run, the greatest increase in the NO3− –N concentration (21.5 ± 3 times its influent concentration) was recorded. The TN removal reached a maximum of 71.4 ± 0.7% in the experimental run, with an influent COD of 2,900 ± 94 mg/L and a vermibed depth of 50 cm. [ABSTRACT FROM AUTHOR]

BACKGROUND: Reclaimed wastewater is a potential source for irrigation, although its effect on seed germination and plant growth has not been widely investigated. The present study focused on treating wastewater by vermifiltration and investigating the effect on seed germination and seedling development of Zea mays, Triticum aestivum and Sorghum bicolor and their morphological, physiological and biochemical developments. A filter bed was constructed using indigenous and improved materials. The constituents used to develop the filter bed consist of matrix of garden soil, lateritic hardpan gravels and coconut coir inoculated with Eisenia fetida. RESULTS: The wastewater was obtained from a public septic tank toilet facility and contained 35–40% dry matter with high concentrations of total dissolve solids (TDS), total suspended solids (TSS), chemical oxygen demand (COD), biochemical oxygen demand (BOD), total nitrogen (Ntot) and phosphorus (Pavail). Portable water was used as the control. Vermifiltration of the wastewater was shown to be effective for the removal of 52–65% TDS, 56–62% TSS, 34–40% COD, 48–52% BOD, 56–62% Ntot and 53–58% Pavail. The results showed that the morphological, physiological and biochemical processes in Z. mays, T. aestivum and S. bicolor improved when seeds were subjected to treated wastewater. CONCLUSION: The present study demonstrated that a potential reuse of vermifiltered wastewater as a source of irrigation water with continuous monitoring of the water quality is productive and sustainable. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

There is a growing need to reclaim wastewater for agricultural use due to freshwater limitation. Integrating macrophytes in vermifiltration improves the treatment efficiency. However, the effect of treated wastewater on seed germination and seedling development is not widely investigated. The study investigated the use of Pistia stratiotes in a macrophyte-assisted vermifiltration of domestic wastewater and assessed the effect on seed and seedling development of Zea mays, Triticum aestivum and Sorghum bicolor. Three irrigation treatments of water were applied: macrophyte-assisted vermifiltration (VP), no macrophyte vermifiltration (VM) and potable water (PW) as the control. Results showed that VP had a removal of 41–44% EC, 65–67% turbidity, 52–65% TDS, 67–70% TSS, 29–34% COD, 42–46% BOD, 67–70% N total, and 74–78% P available compared to VM. VP treatment reduced inhibition in the morphological, physiological and biochemical developments of seed and seedling growth. The use of macrophyte-vermifiltered wastewater significantly (p < 0.05) increased the percentage of germination and the radical length of all seed species increased as well. In terms of the seedling development, seedling mortalities were significantly (p < 0.05) reduced and more than 75% chlorophyll pigments estimations (Cɑ, Cɓ, Cɑ+ɓ and Cx+c) were identified in all seedling species when macrophyte-vermifiltered wastewater was used to irrigate. HIGHLIGHTS Vermifiltration of domestic wastewater integrated with macrophytes proved effective.; Pistia stratiote was suitable as a macrophyte in the water treatment process.; Treated wastewater indicated a potential water source for irrigation.; Water treatment reduced inhibition in seed growth and development.; Macrophyte-assisted vermifiltration of domestic wastewater revealed a sustainable domestic wastewater treatment technology.;

This study aimed to develop a mathematical index for quantifying filter bed clogging in horizontal subsurface flow macrophyte‐assisted vermifilter (HSSF‐MAVF). The developed clogging index (CI) simulates the porosity reduction in the HSSF‐MAVF bed due to the combined actions of deposition of suspended solids, biofilm generation, and plant growth. A series of experiments based on HSSF‐MAVF were conducted to examine the key parameters related to clogging of the vermifilter such as hydraulic loading rates (HLR), organic strength (COD), and total suspended solid (TSS) at different operating conditions for the treatment of synthetic dairy wastewaters. The index was then validated using the data collected from the experiments. The predicted CI was observed to be highly capable of replicating the clogging phenomenon, as observed in this experimental study within the error range of 2–8%. Based on the visual observation and value of CI, filter beds can be grouped as unclogged (CI < 25), partially clogged (25 < CI < 40), and clogged (40 < CI). Clogged filter beds with higher CI resulted in a 5–15% reduction in the COD removal performance of HSSF‐MAVFs. Moreover, the CI also envisages one to understand the individual contributions of biofilm growth, suspended solid deposition, and plant roots growth on the filter bed clogging during the operation of vermifilter and thus helps in deciding the proper setting of operational conditions to prolong the time of HSSF‐MAVF operations within the acceptable range of bed materials clogging. Practitioner Points: A mathematical index was developed to quantify clogging of the HSSF‐MAVF.Flow is the most sensitive parameter based upon the sensitivity analysis.Dairy wastewater was used for the validation of CI. [ABSTRACT FROM AUTHOR]

The macrophyte-assisted vermifiltration (MAVF) technology was applied for treatment of food analysis laboratory wastewater at Industrial Technology Institute (ITI), Sri Lanka for the first time. Three laboratory-scale sub-surface vertical flow units were established:1) without earthworms and plants (Control unit), 2) with earthworms (Eisenia fetida) (vermi-filtration unit (VF unit), 3) with both earthworms and macrophytes (Canna indica) (MAVF unit). Wastewater was fed batch-wise with a feeding rate of 10 mL/min and seven days hydraulic retention time (HRT) for eight consecutive batches. Physiochemical parameters, Chemical Oxygen Demand (COD), Total Phosphorus (TP), Total Nitrogen (TN), pH, of the influent and effluent of all three units were analyzed to investigate the treatment efficiencies. One-Way ANOVA was performed to evaluate the significant differences in treatment efficiencies. The mean COD removal efficiencies of the control unit, VF unit, and MAVF unit were 60.2 % ± 10.7, 71.6± 8.07 %, and 72.0 % ± 8.86, respectively. Average TN removal efficiencies of the control unit, VF unit, and MAVF unit were 8.05 % ± 5.75, 10.9±6.4 %, and 24.9 % ±12.84, respectively. Average TP removal efficiencies were 35.84 % ± 17.5, 35.84 % ± 17.5 %, and 40.0 % ±16.76, respectively. The COD removal displayed promising results, whereas the means for enhancing TP and TN removal should be further studied. The findings of this study sensitizes the testing laboratories to go green by adopting in-house cost effective laboratory wastewater treatment systems. [Display omitted] • The authentic laboratory wastewater was treated by vermifiltration technology for the first time. • The laboratory wastewater was characterized by FTIR. • The substrate morphology and maturity were observed through SEM. • VF showed high COD removal. [ABSTRACT FROM AUTHOR]

Vermifiltration is a biological treatment process during which earthworms (e.g., Eisenia fetida) and microorganisms reduce the organic load of wastewater. To infer microbial pathways responsible for nutrient conversion, past studies characterized the microbiota in vermifilters and suggested that nitrifying and denitrifying bacteria play a significant role during this wastewater treatment process. In contrast to previous studies, which were limited by low-resolution sequencing methods, the work presented here utilized next generation sequencing to survey in greater detail the microbiota of wastewater from a commercial dairy during various stages of vermifiltration. To complement sequence analysis, nitrogenous compounds in and gaseous emissions from the wastewater were measured. Analysis of 16S rRNA gene profiles from untreated wastewater, vermifilter influent, and vermifilter effluent suggested that members of Comamonadaceae, a family of the Betaproteobacteria involved in denitrification, increased in abundance during the vermifiltration process. Subsequent functional gene analysis indicated an increased abundance of nitrification genes in the effluent and suggested that the nitrogen removal during vermifiltration is due to the microbial conversion of ammonia, a finding that was also supported by the water chemistry and emission data. This study demonstrates that microbial communities are the main drivers behind reducing the nitrogen load of dairy wastewater during vermifiltration, providing a valuable knowledge framework for more sustainable and economical wastewater management strategies for commercial dairies.

This study benchmarks vermifiltration (VF) as secondary wastewater treatment in three nature-based decentralized treatment plants using life-cycle assessment. The comparison is justified by the comparatively easier and cheaper operation of VF when compared to more traditional technologies, including small rate infiltration (SRI), constructed wetlands (CW), and activated sludge (AS). Standard life cycle assessment was used and applied to three case studies located in southern Europe. Material intensity during construction was highest for VF, but impacts during operation were lower, compensating those of the other phases. Impacts during the construction phase far outweigh those of operation and dismantling for facilities using constructed wetlands and activated sludge, when the number of served inhabitants is small, and due to lack of economies of scale. VF used as secondary treatment was shown to contribute to reducing the environmental impacts, mainly in constructed wetlands and activated sludge. The replacement of CW by VF seems to bring important environmental benefits in most impact categories, in particular in the construction phase. The replacement by VF in facilities with SRI seems to result in the improvement of some of the impact categories, in particular in the operation phase. As for dismantling, no conclusive results were obtained. HIGHLIGHTS Vermifiltration is a promising technology.; An LCIA is needed to better understand vermifiltration.; The quantification of the environmental impacts will help researchers in future works.; Constrution, operation and dismantling phases are crucial to understand the life cycle in Wastewater Treatment Plants.; LCIA is an important tool to study the environmental impacts of wastewater treatment.;

Digestates from low-tech digesters need to be post-treated to ensure their safe agricultural reuse. This study evaluated, for the first time, vermifiltration as a post-treatment for the digestate from a low-tech digester implemented in a small-scale farm, treating cattle manure and cheese whey under psychrophilic conditions. Vermifiltration performance was monitored in terms of solids, organic matter, nutrients, and pathogens removal efficiency. In addition, the growth of earthworms (Eisenia foetida) and their role in the process was evaluated. Finally, the vermicompost and the effluent of the vermifilter were characterized in order to assess their potential reuse in agriculture. Vermifilters showed high removal efficiency of chemical oxygen demand (55–90%), total solids (60–80%), ammonium nitrogen (83–97%), and phosphate-P (28–49%). Earthworms effectively grew and reproduced on digestate (i.e. earthworms number increased by 183%), enhancing the vermifiltration performance, while reducing clogging and odour-related issues. Both the vermicompost and effluent produced complied with legislation limits established for soil improvers and wastewater for fertigation, respectively. Indeed, there was an absence of pathogens and non-detectable heavy metals concentrations. Vermifiltration may be thus considered a suitable post-treatment option for the digestate from low-tech digesters, allowing for its safe agricultural reuse and boosting the circular bioeconomy in small-scale farms. [Display omitted] • Vermifiltration to enhance the safe reuse of digestate from low-tech digesters. • Vermifilters showed high removal efficiency of COD, TS, ammonium-N and phosphate-P. • Earthworms grew and reproduced on digestate enhancing vermifiltration performance. • Vermicompost and effluent can be safely reused in agriculture. • Vermifiltration boosts the circular bioeconomy in small-scale farms. [ABSTRACT FROM AUTHOR]

Emerging contaminants (ECs), especially pharmaceuticals and personal care products (PPCPs), that are present in aquatic and soil matrixes, have become a major concern for the competent authorities, because they are persistent and pose potential threats to human health, aquatic life, and the soil ecosystem. As an environmentally sustainable and economical EC remediation technology, constructed wetlands (CWs) and vermifiltration (VF) have become popular for treating wastewater and vermicomposting (VC) has gained the attention of the researchers as a sewage sludge or solid waste treatment technology. Although extensive literature is available on the potential of CWs for the remediation of ECs, a review of earthworm-based EC removal technologies has not been performed, to the best of the authors' knowledge. Therefore, this paper aims to review the potential of all the aforementioned natural EC remediation technologies. CWs and VF could emerge as suitable alternatives to conventional wastewater remediation methods to eradicate ECs, and VC has the potential to substantially eliminate ECs from organic solid wastes. In addition, risk assessments suggest that these technologies are more efficient in expurgating the level of toxicity imposed by ECs on the ecosystems that receive them than the conventional treatment methods. [ABSTRACT FROM AUTHOR]

Tiger Toilets use a worm-based ecosystem to degrade human waste and have recently been demonstrated as a cost-effective innovation in on-site sanitation. The benefits over traditional pit latrines include slower fill rate, fewer odours, and safer emptying. However, a question remains around how to measure the rate of accumulation of vermi-compost and predict the fill rate into the future. In this study, fifteen Tiger Toilets of varying installation ages in the villages of Jejuri, Bhalgudi and Walhe/Adachiwadi, in Maharashtra province, India were investigated to determine the rate of filling. A laser measure was used to define cross-sections of the depth to vermi-compost layers within the Tiger Toilet digesters. Bench-scale column tests were used to estimate liquid infiltration rates from the digesters into the surrounding soils. Changes over time in the interior digester conditions were photographed and a video camera was installed in selected digesters to confirm and observe the worm activity in situ under red light. Calculated fill rates of the Tiger Toilets were significantly lower compared to estimated fill rates of traditional pit latrines of a similar size and usage rate. The infiltration of the liquid fraction of the waste into the surrounding soil was observed to be a key factor in filling. [ABSTRACT FROM AUTHOR]

Objective: A research was conducted to explore the reuse possibilities of the textile dye effluent propagated from the textile dye industry. The current study reports vermiculture based effluent treatment method through the chief intention of interconversion of contaminated effluent water into ecologically harmless water. Methods: Hence a new and typical technology, vermifiltration of effluent using wastewater eating earthworms has been evolved. Results: Outcome recommended that vermifilter revealed maximal chemical oxygen demand (126 mg L−1), Biological oxygen demand (56 mg L−1), Total suspended solids (181 mg L−1) and Total dissolved solids (298 mg L−1) decreased by 85–89%, 76–80%, 73–77% and 71–76% by the result of vermifiltration. Bioavailability of some heavy metallic compounds such as Ni, Cd, Cu, Zn, Pb, and Cr brought down considerably during vermifiltration. Vermifilter and control metal accumulations ranged from 0.2 ppm to 2.34 ppm and from 0.10 ppm to 2.98 ppm respectively. The SEM illustration reveal that the morphology of the vermicast of control and vermifiltration which is differing significantly. When the concentration of textile dye sludge increases it also increases the destruction of tissues constantly. Histological of the gut domain exposed moderate harm in 50% dilution. Conclusions: Therefore, these studies concluded that vermifiltration can be used as an eco-friendly technique which can be considered the same as a paradigm for textile industries effluents remedial development.

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. [ABSTRACT FROM AUTHOR]

Wastewater treatment and reuse is one of the most promising efforts to stem global water crisis. With the present shift towards sustainable development as a priority, the wastewater companies should respond to this requirement. To downturn, the negative impact of anthropogenic activities, advanced green technologies (AGTs) are being practiced. AGTs refer to a group of natural, green technologies that includes practical methodologies and materials based on non-toxic chemical processes, clean energies, and environmental monitoring to slow down the negative impact induced by human activities. The main motive of green technologies is to provide high end results without compromising on environmental sustainability. Among all the existing options, green technology such as vermifiltration is the natural & sustainable choice. Vermifiltration is an extension of the vermicomposting process. It is a biofilter with earthworms, where the earthworms digest the suspended particles screened on the filter bed, and degrade organic matter through enzymatic activity, and in the process of ingestion; they passively aerate the system by burrowing action and removes pathogens. In this context, the present graphical review envisages the current state of the technical knowledge of the vermifiltration process, factors affecting the process and performance of vermifilters under different scenarios related to the treatment mechanisms and effective applications and advantages of the technology. This technology is a stand-alone technology providing tremendous benefits such as decentralized solution and high value end products like vermicompost and can be considered as a new paradigm for wastewater treatment processes.

The objective of this study was to evaluate the vermifiltration of different cassava effluent concentrations using of earthworms by applying standard methods. Results for physiochemical parameters before treatment ranges from 3. 91 to 5.94, 28.6to 28.7(μS/cm), 12480 to 13999 (mg/l), 7900 to 9511(mg/l), 168 to 207(mg/l), 8068 to 9718(mg/l), 225 to 284(mg/l), 114 to 132(mg/l), 1040 to 1680(mg/l), 400 to 540(mg/l), 52 to 72(mg/l), 24 to 40(mg/l), 20 to 30(mg/l), 33 to 65(mg/l) for pH, Temperature, EC, TDS, TSS, TS, COD, BOD, Hardness, chlorine, calcium, magnesium, sodium and potassium, respectively, while after treatment ranges from 6.45 to 10.1, 28.6 to 29, 12021 to 12621(μS/cm), 8100 to 9846(mg/l), 199 to 211(mg/l), 8299 to 10057(mg/l), 260 to 291(mg/l), 140 to 120(mg/l), 760 to 1160(mg/l), 260 to 440(mg/l), 48 to 62(mg/l), 22 to 39(mg/l), 19 to 28(mg/l), 31 to 60(mg/l) for pH, Temperature, Electrical Conductivity (EC), TDS, TSS, TS, COD, BOD, Hardness, Chlorine, Calcium, Magnesium, Sodium and Potassium, respectively, across the different concentrations (100%, 75%, 50% and 25%) of cassava effluent. It was therefore, observed that the use of earthworm in the treatment of cassava effluent was effective, though, it could not treat the cassava effluent to the acceptable World Health Organization (WHO) Standards for irrigation use. Keywords: physiochemical characteristics, cassava, effluent concentrations, vermifiltration

For potential use in air treatment by biofiltration, a new material composed of vermicompost and earthworms (Eisenia fetida) was tested for the removal of a volatile organic compound (VOC), toluene. The removal rate of toluene was measured during batch experiments in presence of vermicompost only, earthworms only and a mixture of both. In the chosen experimental conditions, no mortality of earthworms was recorded and the results showed that the presence of earthworms allowed an increase in toluene removal rate (0.213 mg h−1) compared to vermicompost only (0.084 mg h−1) and earthworms only (0.136 mg h−1). From the experimental data, mechanisms of toluene transfer and adsorption/biodegradation by microorganisms from vermicompost and/or earthworms were proposed. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the vermifiltration of different cassava effluent concentrations using of earthworms by applying standard methods. Results for physiochemical parameters before treatment ranges from 3. 91 to 5.94, 28.6to 28.7(μS/cm), 12480 to 13999 (mg/l), 7900 to 9511(mg/l), 168 to 207(mg/l), 8068 to 9718(mg/l), 225 to 284(mg/l), 114 to 132(mg/l), 1040 to 1680(mg/l), 400 to 540(mg/l), 52 to 72(mg/l), 24 to 40(mg/l), 20 to 30(mg/l), 33 to 65(mg/l) for pH, Temperature, EC, TDS, TSS, TS, COD, BOD, Hardness, chlorine, calcium, magnesium, sodium and potassium, respectively, while after treatment ranges from 6.45 to 10.1, 28.6 to 29, 12021 to 12621(μS/cm), 8100 to 9846(mg/l), 199 to 211(mg/l), 8299 to 10057(mg/l), 260 to 291(mg/l), 140 to 120(mg/l), 760 to 1160(mg/l), 260 to 440(mg/l), 48 to 62(mg/l), 22 to 39(mg/l), 19 to 28(mg/l), 31 to 60(mg/l) for pH, Temperature, Electrical Conductivity (EC), TDS, TSS, TS, COD, BOD, Hardness, Chlorine, Calcium, Magnesium, Sodium and Potassium, respectively, across the different concentrations (100%, 75%, 50% and 25%) of cassava effluent. It was therefore, observed that the use of earthworm in the treatment of cassava effluent was effective, though, it could not treat the cassava effluent to the acceptable World Health Organization (WHO) Standards for irrigation use. [ABSTRACT FROM AUTHOR]

The review discusses the advancements in vermifiltration research over the last decade, focusing on pollution removal mechanisms, system performance, the fate of filter components, and by-products. Vermifiltration has demonstrated remarkable capabilities, particularly in treating highly contaminated wastewater with Chemical Oxygen Demand (COD) levels exceeding 92,000 mg/L and Biochemical Oxygen Demand (BOD 5 ) levels over 25,000 mg/L, achieving removal rates of approximately 89% and 91%, respectively. Importantly, vermifiltration maintains its effectiveness even with fluctuating organic loads at the inlet, thanks to optimization of parameters like Hydraulic Loading Rate, biodegradable organic strength, earthworm density and active layer depth. Clogging issues can be minimized through parameters optimization. The review also highlights vermifiltrations' potential in co-treating the organic fraction of municipal solid waste while significantly reducing heavy metal concentrations, including Cd, Ni, Pb, Cu, Cr, and Zn, during the treatment process. Earthworms play a pivotal role in the removal of various components, with impressive removal percentages, such as 75% for Total Organic Carbon (TOC), 86% for Total COD, 87% for BOD 5 , 59% for ammonia nitrogen, and 99.9% for coliforms. Furthermore, vermifiltration-treated effluents can be readily utilized in agriculture, with the added benefit of producing vermicompost, a nutrient-rich biofertilizer. The technology contributes to environmental sustainability, as it helps reduce greenhouse gas emissions (GHG), thanks to earthworm activity creating an aerobic environment, minimizing GHG production compared to other wastewater treatment methods. In terms of pollutant degradation modeling, the Stover-Kincannon model outperforms the first-order and Grau second-order models, with higher regression coefficients (R 2  = 0.9961 for COD and R 2  = 0.9353 for TN). Overall, vermifiltration emerges as an effective and sustainable wastewater treatment solution, capable of handling challenging wastewater sources, while also producing valuable by-products and minimizing environmental impacts., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Vermifiltration of wastewater using waste eater earthworms is a newly conceived novel technology. The present study evaluated BOD, COD and TS showing significant variation in decrease by 95%, 90% and 80% respectively through vermifiltration of distillery effluents. The nutrient contents (TN, TP, TK, TCa and TMg) in the vermicasts had increase (1.82 % in TN, 0.24% in TP, 2.15% in TK, 2.07% in TCa and 2.86 % in TMg) in the range of fold than the control level. The morphology of the control and experimental vermicast samples were analyzed with SEM and the image showed significant variation. The FT-IR spectrum analysis showed reduction of aliphatic/aromatic (C=C and OH) compounds in the vermicompost. Thus, the present study significantly highlights the vermifiltration technology in treating distillery effluent. [ABSTRACT FROM AUTHOR]

Purpose: Vemifiltration units are sludge-free, noise-free and low- or no-electricity-requiring systems of operation. The aim of this study was to emphasize wastewater treatment by vermifiltration technology using waste-eater earthworms to highlight the benefits of clean and nutritive vermifiltered water (vermiaqua) uses in agriculture to the farmers. Methods: Wastewater sample was filtered through fabricated vermifiltration unit to study physio-chemical and biological properties of vermiaqua and uniform-sized Allium cepa (Onion) bulbs were kept for root germination at different concentrations (10−1, 10−3, 10−5, 10−7, 10−9) of wastewater and vermiaqua at room temperature for 5 days to study impacts of vermiaqua on morphological and cytological characteristics of onion. Results: Vermiaqua was odorless, pale yellow in appearance, lower in turbidity and highly nutritive as ammonia and nitrate contents were highly increased. In E. coli-free vermiaqua, BOD5 loads were also reduced by 91%. Almost all vermiaqua-treated root germinations were 'accelerated', whereas all wastewater-treated root germinations were 'retarded'. The highest number of germinated roots was counted at 10−5 concentration of vermiaqua, whereas at the same concentration of wastewater no germination was observed. Many types of chromosomal abnormalities were observed at metaphase and anaphase stages of wastewater-treated roots, whereas the single type of chromosomal abnormality was observed at anaphase stage of vermiaqua-treated roots. Conclusions: Earthworms upgraded the performance of fabricated systems having integrated methods (biological, chemical and physical) of wastewater purification. Morphological and cytological studies revealed vermiaqua highly promoted the root germination without any chromosomal abnormalities. [ABSTRACT FROM AUTHOR]

The fate of filter materials and microbial communities during the vermifiltration process were studied for 5 months while treating the concentrated greywater. Four filters were filled with 10 cm gravel of which a layer of medium size gravel (5 cm thickness, aggregate size 20–40 mm) at the bottom and a layer of coarse gravel (5 cm thickness, aggregate size 10–20 mm) at the top, then filled with 20 cm sand (d 60 = 0.2 mm, d 10 = 0.118 mm). Finally, Vermifilter 1 (VF1), control unit and Vermifilter 2 (VF2), were filled with 40 cm fine sawdust (0.05–5 mm) but Vermifilter 3 (VF3), was filled with 40 cm cow dung (0.05–5 mm). Three filters were inoculated with 200 individuals of Eudrilus eugeniae except for the control unit which was filled with sawdust. Five sampling ports were installed on the wall of the filters at 10 cm intervals with reference to the surface of the top layer. Three of the filters were supplied with concentrated greywater and VF1 was supplied with drinking water at the hydraulic loading rate of 16 L m−2.d−1 on batch basis, i.e., four times a day at 8:00 a.m., 11:00 a.m., 2:00 p.m. and 5:00 p.m. Weekly, samples from influent and effluent, and monthly, samples of filter materials collected via sampling ports, were collected and analyzed.The removal efficiencies of biological oxygen demand (BOD 5), total chemical oxygen demand (tCOD), and dissolved chemical oxygen demand (dCOD) of VF2 and VF3 were 5–7% higher than the control unit, but little differences were observed in terms of total suspended solids (TSS). However, the removal efficiencies of nutrients for the control unit was slightly better than VF2 and VF3. The pH and Moisture content (MC) of filter materials increased along the depth, but percentage of volatile solids to total solids (VS/TS) decreased through time due to the high number of microbial communities and earthworms dominating the top layer compared to the bottom. The performance of VF2-sawdust was slightly better than VF3-cow dung to treat concentrated greywater. • Fate of filter materials and microbial communities during vermifiltration process were studied. • Ratio of volatile solids to total solids decreased during vermifiltration process in filter materials. • The bacteria, actinomycetes and fungi intensified where earthworms dominated. • VF2-Sawdust performed slightly better than the VF3-Cow dung. [ABSTRACT FROM AUTHOR]

Vermifiltration is a biological treatment process during which earthworms (e.g., Eisenia fetida) and microorganisms reduce the organic load of wastewater. To infer microbial pathways responsible for nutrient conversion, past studies characterized the microbiota in vermifilters and suggested that nitrifying and denitrifying bacteria play a significant role during this wastewater treatment process. In contrast to previous studies, which were limited by low-resolution sequencing methods, the work presented here utilized next generation sequencing to survey in greater detail the microbiota of wastewater from a commercial dairy during various stages of vermifiltration. To complement sequence analysis, nitrogenous compounds in and gaseous emissions from the wastewater were measured. Analysis of 16S rRNA gene profiles from untreated wastewater, vermifilter influent, and vermifilter effluent suggested that members of Comamonadaceae, a family of the Betaproteobacteria involved in denitrification, increased in abundance during the vermifiltration process. Subsequent functional gene analysis indicated an increased abundance of nitrification genes in the effluent and suggested that the nitrogen removal during vermifiltration is due to the microbial conversion of ammonia, a finding that was also supported by the water chemistry and emission data. This study demonstrates that microbial communities are the main drivers behind reducing the nitrogen load of dairy wastewater during vermifiltration, providing a valuable knowledge framework for more sustainable and economical wastewater management strategies for commercial dairies.

Aims Textile industries are among the manufactures which produce the highly polluted waste water. The purpose of this research was to evaluate the effect of vermifiltration on COD and color removal from textile waste water. Materials & Methods This experimental research was performed March to August 2014 in one of the textile factories of Kashan region, Iran. The glass cubic kits with- without Eisenia fetida were used to filter the waste water samples. Data was analyzed using Kruskal–Wallis and two-way analysis of variance in SPSS 19 statistical software. Findings The mean of COD concentration in the raw waste water samples was 1324.24±757.01mg/l which was decreased to 598.22±349.33 and 831.32±445.19mg/l after the experimental and control kits usage, respectively (p

Nowadays, natural resources are under increasing stress which fosters wastewater reuse planning and emphasizes on the decentralized wastewater treatment. Vermifiltration has been described as a viable alternative to treat domestic and urban wastewater, but few studies have focused on the impact of different filter packings on vermifiltration performance. This study evaluates the effect of vermicompost and sawdust in a single-stage vermifilter (VF) for urban wastewater treatment. After an acclimation period of 45 days, urban wastewater from a combined sewage collection system was applied continuously for 24 h. Earthworm stock density was of 20 g L, HRT of 6 h, HLR of 0.89 m m day and OLR of 7.38 g BOD day. System performance was assessed by the removal efficiencies of BOD, COD, TSS, NH , TN and TP, and fecal coliforms and helminth eggs elimination. Vermicompost (VE) and sawdust (SE) were tested, using an earthworm abundance of 20 g L. Treatment efficiencies were 91.3% for BOD, 87.6% for COD, 98.4% for TSS and 76.5% for NH in VE, and 90.5% for BOD, 79.7% for COD, 98.4% for TSS and 63.4% for NH in SE. Earthworms contributed to reduce NH and TN removal and to increase NO concentration. No treatment was able to eliminate fecal coliforms down to guidelines values for wastewater irrigation as helminth eggs were completely eliminated. Single-stage vermifiltration system using both filter packings is inconsistent and cannot meet EU guideline values for discharge in sensitive water bodies and WHO guidelines for irrigation with treated wastewater. [ABSTRACT FROM AUTHOR]

With global population explosion, the available water resources are slowly being polluted due to the excessive human interference. To encounter this, it is the need of this hour to find out sustainable pollution remediating technologies to meet the stringent discharge standards for domestic as well as industrial wastewaters. In addition, those techniques should have the capabilities for effective implementation even in developing countries. Based on the available literatures, one such technique, named vermifilter, has been identified which takes care of almost all the sustainable and economical criteria for its effective implementation even in developing countries. The aim of this meta-analysis is to provide a comprehensive review on assessment mechanisms involved, factors affecting the process and performance of vermifiltration under different scenarios. The present review envisages the current state of the knowledge regarding physical, chemical and biological aspects related to the treatment mechanisms and effective functioning of earthworms. This review has also proposed several suggestive plans on its application at any proposed site. [ABSTRACT FROM AUTHOR]

Optimization of a vermifiltration process was made for hydraulic retention time (HRT), hydraulic loading rate (HLR) and recirculation ratio (R), organic loading rate (OLR), earthworm abundance and reactor type on organic matter removal from urban wastewater using a small-scale vermifiltration process comprising single stage, and four-stage vermifilter (VF) systems. All reactor modules were made of PVC with a total volume of 25 L using vermicompost as the filtering material and quartz sand and gravel as the inert filter. System performance was assessed by the removal efficiencies of BOD 5 , tCOD, sCOD, pCOD, TSS and NH 4 + . In the earthworm study, four abundances were evaluated: 10 g L −1 (W10), 20 g L −1 (W20), 30 g L −1 (W30) and 40 g L −1 (W40). In the four-stage VF the earthworm abundance evaluated was 20 g L −1 . W20 proved to be the optimal treatment condition with efficiencies for BOD 5 , tCOD, pCOD, TSS and NH 4 + of 97.5%, 74.3%, 91.1%, 98.2% and 88.1%, for a pCOD/tCOD ratio of 0.20. The four-stage sequential VF promoted a decrease of BOD 5 (98.5%), tCOD (74.3%), pCOD (86.7%), TSS (96.6%), and NH 4 + (99.1%). Results indicate that sequential VF systems can significantly improve treatment efficiencies when compared to single stage VF. [ABSTRACT FROM AUTHOR]

A vermifilter (with earthworms, VF), with a conventional biofilter (no earthworms, BF) as a control, was established to examine the survival state and adaptability of earthworms in protein perspective. The VF behaved with a significantly higher organic matter decomposition and lower sludge yield due to the presence of earthworms. However, during the steady stage (12 months), the earthworm biomass decreased slightly from 32.0 to 24.2 g/L, while the earthworm average weight increased, indicating that the earthworm suffered some adverse effects from the VF. Notably, from the perspective of the earthworm protein, the earthworms showed a higher Shannon-Weaver index (from H = 2.76 to 3.06) than the BF and up-regulated some proteins to cope with the negative effects from the VF. These up-regulated differential proteins played a variety of crucial roles in many cellular processes. The results suggested that a more specialized and stable protein expression of earthworms was developed in the VF, reflecting the adaptabilities of the earthworms in the VF. [ABSTRACT FROM AUTHOR]