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Industrial Home Laundry Closed Loop Cleaning Process
Author(s) -
Scamehorn John F.,
Tucker Edwin E.,
Gecol Hatice,
Komesvarakul Napaporn,
Serventi Lorena K.,
Raney Kirk H.,
Capps Stephen F.
Publication year - 2007
Publication title -
journal of surfactants and detergents
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.349
H-Index - 48
eISSN - 1558-9293
pISSN - 1097-3958
DOI - 10.1007/s11743-007-1044-4
Subject(s) - laundry , chemistry , pulp and paper industry , filtration (mathematics) , emulsion , reuse , cleaning agent , chlorine , waste management , effluent , chromatography , environmental science , environmental engineering , engineering , biochemistry , statistics , mathematics , organic chemistry
This study presents a method to develop an efficient and economical system for cleaning home laundry on a commercial scale with both water and chemical (detergent) reuse. The experiments were done using an industrial‐type horizontal‐axis machine, two leading consumer heavy‐duty liquid laundry detergents, one I&I detergent formulation, and chlorine bleach. The technical feasibility of reusing laundry water at high levels without significant deterioration in detergency was established in this study. Warm water (40 °C) was used in the wash cycle, and cold water (29 °C) was used for three rinse cycles. In the integrated process, waters from wash and rinse steps were treated using tubular microfiltration units with 0.1 μm pore size to remove particles and emulsion droplets. These recovered waters were recycled to be reused. In addition, water recycled from the wash step contains surfactants that can be reused. In order to simulate a large‐scale industrial laundry operation at steady‐state, the batch process used here was operated six times in sequence; wash and rinse waters were filtered after each cycle and reused in the next wash cycle. The surfactant recovery is over 40%. Soiled test strips were used to measure the percentage of soil removal after the wash/filtration sequence for stains and various liquid or particulate soils. The soil removal remained practically constant under simulated steady‐state conditions even with water recoveries of nearly 90%. Softness of towels remained unchanged when recycled water was used in this process. Chlorine carry‐over from white laundry to the wash process was shown to be minimal. This is important to avoid color fading in mixed loads upon reuse since water is not segregated for colored laundry versus white laundry. Hardness ions can precipitate fatty acids which reduce flux during filtration and decrease surfactant recovery. Preliminary analysis of the different formulations used indicates that an all‐nonionic formulation may be best suited to this recycling process.