Vermicomposting and Vermifiltration are two low cost, options for human waste treatment in which earthworms are used as biofilters. The end-product is worm cast or vermicompost which contains reduced levels of contaminants and depending on the processes chosen can reduce volume of faecal sludge by over 90 %. Vermicompost contains water-soluble nutrients and is an excellent, nutrient-rich organic fertiliser and soil conditioner.Decomposed organic matter that results from a controlled aerobic degradation process. In this biological process, microorganisms (mainly bacteria and fungi) decompose the biodegradable waste components and produce an earth-like, odourless, brown/black material. Compost has excellent soil-conditioning properties and a variable nutrient content. Because of leaching and volatilisation, some of the nutrients may be lost, but the material remains rich in nutrients and organic matter. Generally, excreta or sludge should be composted long enough (2 to 4 months) under thermophilic conditions (55 to 60 °C) in order to be sanitised sufficiently for safe agricultural use.Consists of urine and faeces that are not mixed with any flushwater. Excreta is relatively small in volume, but concentrated in both nutrients and pathogens. Depending on the characteristics of the faeces and the urine content, it can have a soft or runny consistency.Refers to (semi-solid) excrement that is not mixed with urine or water. Depending on diet, each person produces approximately 50–150 L per year of faecal matter of which about 80 % is water and the remaining solid fraction is mostly composed of organic material. Of the total essential plant nutrients excreted by the human body, faeces contain around 39 % of the phosphorus (P), 26 % of the potassium (K) and 12 % of the nitrogen (N). Faeces also contain the vast majority of the pathogens excreted by the body, as well as energy and carbon rich, fibrous material.Mixture of solids and liquids, containing mostly excreta and water, in combination with sand, grit, metals, trash and/or various chemical compounds. A distinction can be made between faecal sludge and wastewater sludge. Faecal sludge comes from on-site sanitation technologies, i.e. it has not been transported through a sewer. It can be raw or partially digested, a slurry or semisolid, and results from the collection and storage/treatment of excreta or blackwater, with or without greywater. Wastewater sludge (also referred to as sewage sludge) originates from sewer-based wastewater collection and (semi-)centralised treatment processes. The sludge composition will determine the type of treatment that is required and the end-use possibilities.The liquid produced by the body to rid itself of nitrogen in the form of urea and other waste products. In this context, the urine product refers to pure urine that is not mixed with faeces or water. Depending on diet, human urine collected from one person during one year (approx. 300 to 550 L) contains 2 to 4 kg of nitrogen. The urine of healthy individuals is sterile when it leaves the body but is often immediately contaminated by coming into contact with faeces.Describes technologies for on-site collection, storage, and sometimes (pre-) treatment of the products generated at the user interface. The treatment provided by these technologies is often a function of storage and is usually passive (i.e. requires no energy input), except a few emerging technologies where additives are needed. Thus, products that are ‘treated’ by these technologies often require subsequent treatment before use and/or disposal. In the technology overview graphic, this functional group is subdivided into the two subgroups: “Collection/Storage” and “(Pre-)Treatment”. This allows a further classification for each of the listed technologies with regard to their function: collection and storage, (pre-) treatment only or both.Refers to the methods through which products are returned to the environment, either as useful resources or reduced-risk materials. Some products can also be cycled back into a system (e.g. by using treated greywater for flushing).A functional group is a grouping of technologies that have similar functions. The compendium proposes five different functional groups from which technologies can be chosen to build a sanitation system:
User interface (U), Collection and Storage/Treatment (S), Conveyance (C), (Semi-) Centralised Treatment (T), Use and/or Disposal (U).
A sanitation system is a multi-step process in which sanitation products such as human excreta and wastewater are managed from the point of generation to the point of use or ultimate disposal. It is a context-specific series of technologies and services for the management of these sanitation products, i.e. for their collection, containment, transport, treatment, transformation, use or disposal. A sanitation system comprises functional groups of technologies that can be selected according to context. By selecting technologies from each applicable functional group, considering the incoming and outgoing products, and the suitability of the technologies in a particular context, a logical, modular sanitation system can be designed. A sanitation system also includes the management and operation and maintenance (O & M) required to ensure that the system functions safely and sustainably. Simple, single cell organisms that are found everywhere on earth. They are essential for maintaining life and performing essential “services”, such as composting, aerobic degradation
of waste, and digesting food in our intestines. Some types, however, can be pathogenic and cause mild to severe illnesses. Bacteria obtain nutrients from their environment by excreting enzymes that dissolve complex molecules into more simple ones which can then pass through the cell membrane.

The process by which biodegradable components are biologically decomposed by microorganisms (mainly bacteria and fungi) under controlled aerobic conditions.
The utilisation of products derived from a sanitation system.
A mechanical separation process using a porous medium (e.g., cloth, paper, sand bed, or mixed media bed) that captures particulate material and permits the liquid or gaseous fraction to pass through. The size of the pores of the medium determines what is captured and what passes through.Any cellular or non-cellular microbiological entity capable of replication or of transferring genetic material (e.g. bacteria, viruses, protozoa, algae or fungi).
Any substance that is used for growth. Nitrogen (N), phosphorus (P) and potassium (K) are the main nutrients contained in agricultural fertilisers. N and P are also primarily responsible for the eutrophication of water bodies.
A sanitation system in which excreta and wastewater are collected and stored or treated on the plot where they are generated.
An organism or other agent that causes disease.A diverse group of unicellular eukaryotic organisms, including amoeba, ciliates, and flagellates. Some can be pathogenic and cause mild to severe illnesses.
The means of safely collecting and hygienically disposing of excreta and liquid
wastes for the protection of public health and the preservation of the quality of public water bodies and, more generally, of the environment.

Waste matter that is transported through the sewer.
An open channel or closed pipe used to convey sewage. See C.3 and C.4
A product that enhances the water and nutrient retaining properties of soil.
The organic molecule (NH2)2CO that is excreted in urine and that contains the nutrient nitrogen. Over time, urea breaks down into carbon dioxide and ammonium, which is readily used by organisms in soil. It can also be used for on-site faecal sludge treatment. See. S.18An infectious agent consisting of a nucleic acid (DNA or RNA) and a protein coat. Viruses can only replicate in the cells of a living host. Some pathogenic viruses are known to be waterborne (e.g., the rotavirus that can cause diarrheal disease).
Used water from any combination of domestic, industrial, commercial or agricultural activities, surface runoff/stormwater, and any sewer inflow/infiltration.

Both Vermicomposting and Vermifiltration are aerobic treatment systems. Two parameters are particularly important: moisture content and the carbon to nitrogen (C:N) ratio. Faecal sludge has a high moisture and nitrogen content, while organic solid waste is high in organic carbon and has good bulking properties which promotes aeration. By combining the two, the benefits of each can be used to optimise process and product. The most commonly used method of Vermicomposting is the invessel method. Vermifiltration happens in a water-tight containerand can receive more liquid inputs such as wastewater or watery sludge.

Design Considerations

The design of a Vermi composting facility is similar to Co-Composting T.11 using vessels and with the addition of earthworms. Vermifilters consist of enclosed reactors containing filter media and worms. These are used on a small scale in Worm-Based Toiletsm S.12 . In Vermifiltration systems the solids (faecal sludge and toilet paper) are trapped on top of the filter where they are processed into humus by the worms and bacteria  while the liquid passes through the filter. In separating solid and liquid fractions the quality of the effluent is increased. Ventilation must be sufficient to ensure an aerobic environment for the worms and microorganisms, while also inhibiting entry of unwanted flies. The temperature within the reactor needs to be maintained within a range suitable for the species of compost worms used. The specific design of a vermifilter will depend on the characteristics and volume of sludge. Vermi composting or vermifilters can be combined with other treatments - for example, the digestate from an aerobic digestion S.13 S.14 S.15 S.16 could be vermifiltered to achieve solids reduction and increase pathogen elimination. Effluent produced during the vermifiltration process can be directly infiltrated into the soil, or further treated through evapotranspiration in a planted system.

Materials

Vermi composting tanks can be made from local materials (bricks or concrete). Vermifilters require enclosed reactors made from durable materials that eliminate vermin entry, usually plastic or concrete. Filter material for the vermifilter can be sawdust, straw, coir, bark mulch or peat. Worms are required, and three species to date have been successfully used: Eisenia fetida, Eudrilus eugeniae and Eisenia andrei. It is possible to find worms in the local environment, buy them from vermi composting or vermifilter businesses or import them. Prefabricated composting vessels of different sizes are available on the market.

Applicability

Vermifiltration can be applied in all emergency phases provided there is access to worms. Vermi composting requires a high level of organisation and labour to sort organic waste, manage the facility and monitor treatment efficiency and is therefore unlikely to be practical in the acute response phase of emergency situations. However, it can be considered a viable option in the stabilisation and recovery phases where there is an available source of well-sorted organic solid waste and space. Experience has shown that vermi composting facilities operate best when they are established as a business venture with compost as a marketable product that can generate revenue to support cost recovery. However, compost sales cannot be expected to cover the full cost of the service.

Operation and Maintenance

A Vermicomposting facility requires well-trained maintenance staff to carefully monitor quality and quantity of the input material and worm health as well as manage moisture and oxygen content. Organic waste must first be sorted so it is free from plastics and other non-organic materials. Turning must be periodically done with either a front-end loader or by hand using a pitch fork or shovel. A Vermifilter has low mechanical and manual maintenance requirements, and where gravity-operated requires no energy inputs. Recirculation, if required for improved effluent quality, would require a pump.

Health and Safety

Unlike Co-Composting T.11 , pasteurizing temperatures cannot be achieved as worms and bacteria are sensitive to extreme temperatures, thus for wastes containing high levels of pathogens (such as raw sewage or septic tank waste), further treatment may be required to produce a pathogen-free compost. Health risks can be minimised if adequate control measures are consistently practiced, and workers adopt basic precautions, hygiene practices and wear personal protective equipment. If material is found to be dusty, workers should wear masks. Vermi compost should be stored for at least a year before use. If resources exist, helminth egg inactivation should be monitored as a proxy measure of sterilisation. If reuse is not intended the compost can Either be buried or brought to a final disposal site. The World Health Organization guidelines should be consulted for detailed information.

Costs

Costs of building a Vermicompost facility vary depending on the method chosen and the cost of local materials and if machinery such as aerators are included in the design. The main costs to consider are the overall operation requirements including transport and supply of faecal sludge and organic solid waste and disposal of compost. The cost of vermifilters depends on the scale and design of the system.

Social Considerations

Before considering a Vermi composting system, the concept needs to be discussed with the affected community beforehand. If the community has experience with separating organic waste and composting this can be a facilitating factor. Identifying that compost made from human waste is an acceptable product for potential users (market survey) and ensuring that the compost product conforms to local guidelines/ standards are necessary prerequisites. Without these, different treatment processes should be identified.