Mobile, autonomous, automated and remotely monitored unit for wastewater treatment and reusable water generation by Vermifiltration and physicochemical post treatment

Abstract

Improper disposal of sewage has serious risks to public health and the environment. Studies point out that the lack of basic sanitation has negative impacts in areas such as education, health, work, income, tourism, learning of children and youth, among others (Instituto Trata Brazil, 2014). In the international sanitation ranking with 200 countries, Brazil occupies the 112th position (Instituto Trata Brazil, 2014), with approximately 34 million Brazilians without access to sewage disposal system (IBGE, 2010). Worldwide, 2.5 billion people (36%) live without adequate sanitation (UNICEF, 2014).In the meantime, businesses and industries also require solutions for wastewater and especially for the residues of their productive processes, a factor of environmental degradation. These compounds are some of the main pollutants of wastewater from chemical and pharmaceutical industries, hospital sewage, and others, and even in low concentrations alter water potability (Archela, 2003).In this context, compact systems have been adopted for wastewater treatment presenting satisfactory results in pollutants removal. However, these solutions are of difficult maintenance and operation due to the system complexity, the efficiency loss from the residual sludge generation, besides difficult implementation and costly. The biological treatment based on vermifiltration appears as a technology of equivalent performance for pollutants removal, having potential application in simpler systems to install and maintain, turning it a technically efficient and economically attractive alternative to solve problems related to sewage treatment. The Vermifilter consists of a biofilter with an intermittent flow that combines a vermicomposting process with microbiological degradation. It has a top layer of soil with organic material and earthworms and other layers generally formed by materials such as pebbles, gravel and crushed stone. The systems are relatively new, for which there are no default setting. In the literature, it is found that each researcher seeks a configuration and composition using different substrates for the worms and various materials for the subsequent layers, besides distinct thicknesses for each layer. The expected average efficiency for the new system is about 90% in removal of BOD, under TAS of 2,000 L / m2.day, making viable its application to supply both industrial demands and population basic sanitation. This project aims to research and develop a raw sewage treatment system, through vermifiltration reactors with physical-chemical after treatment, providing several innovations (technical-scientific and business model) that intend to deliver higher mobility and lower weight to the system, as well as easier and less frequently maintenance, with residual sludge production reduction to negligible values. The union of vermifiltration system to mobility, automation, remote monitoring and low costs should be the key to solve many current problems of sanitation access. The proposal runs through several fronts of new approaches to the problem, such as: use of lighter filling materials for the vermifilter with high surface area such as biomass fasteners formed of polyurethane foam or expanded clay; fabrication of complete and modular systems; use of electronics devices and energy-efficient equipments; and the possible development of a new business model. The remote monitoring and energy management will be essential to enable both research and future commercial application of the system, reducing installation and maintenance costs and allowing future analysis on the macro environmental sanitation. (AU)