Working Principle of Swedish Mobile Toilets
The working principles of Swedish mobile toilets mainly include five technical types: packaging-type, biodegradable-type, foam-sealing-type, circulating filtration and chemical treatment, and modular self-circulating system. The core of all these technologies revolves around the on-site treatment or efficient collection of excreta.
Packaging-type technology uses mechanical devices to seal excreta in biodegradable plastic bags, enabling centralized collection of solid-liquid mixtures. This technology does not require a water flushing system and relies on biodegradable materials to reduce environmental pollution, making it suitable for remote areas without water supply and drainage networks or temporary event scenarios. Its advantages include simple operation and low maintenance costs, but it requires regular replacement of plastic bags and unified disposal.
Biodegradable-type technology utilizes microbial communities (such as anaerobic bacteria) to decompose organic matter in excreta under specific temperature and humidity conditions, with the final products being water, carbon dioxide, and a small amount of biogas residue. The biogas residue can be periodically removed and used as a soil conditioner, achieving resource utilization. This technology requires control of microbial activity and environmental parameters, making it suitable for scenarios with high environmental protection requirements. However, the degradation cycle is relatively long, and microbial supplements are needed periodically.
Foam-sealing-type technology generates a large amount of fine foam through a foaming device to cover the surface of the toilet bowl. The lubricating effect of the foam allows excreta to smoothly slide into the biochemical tank while blocking odors and reducing the amount of flushing water. This technology achieves a water-saving rate of up to 98% and offers better visual and olfactory experiences than traditional toilets, making it suitable for scenic spots, exhibitions, and other places with strict sanitation requirements. The core lies in the proportioning of the foam solution and the stability of foaming.
Circulating filtration and chemical treatment technology combines physical (such as flocculation and sedimentation) and chemical (such as disinfectants) methods to purify sewage, enabling it to meet the standards for reclaimed water reuse for toilet flushing or green irrigation; the solid part is separated and stored. Some models integrate solar power supply systems to form an independent energy cycle, reducing dependence on external resources. This technology is suitable for scenarios with water scarcity or long-term use, but the equipment cost is relatively high and requires regular maintenance.
Modular self-circulating system uses high-density polyethylene or fiberglass-reinforced plastic as materials and integrates the toilet compartment, sewage storage tank, and flushing device through a one-step molding process. The sewage storage tank uses gravity to separate solids and liquids, and the flushing system controls the water volume (0.5-1.5 liters per flush) through foot pedals or sensor valves. The gray water from the handwashing sink is filtered and reused for toilet flushing. This technology emphasizes compact structure and resource circulation, making it suitable for scenarios with limited space or requiring rapid deployment. However, the modular design may limit the treatment capacity.
