Portable System for Field-Feeding Greywater Remediation and Recycling

摘要

The Army requires a portable greywater treatment system to remediate and recycle dirty sink water from its field feeding and sanitation operations. A greywater recycling system is expected to reduce field kitchen demand for fresh water by 55% and wastewater hauling expenses by 80%. Under an Environmental Security Technology Certification Program (ESTCP) funded project, three systems were demonstrated at Ft. Lee, VA, in August 2004 as part of the Log Warrior Training Exercise. The field test lasted two weeks and each of the three systems was operated out-of doors treating water created during actual field feeding operations. Water samples were taken before and after treatment. Systems were evaluated for water quality, percent reduction of contaminants, permeate flow rate, weight, and size. There are no firm Environmental Protection Agency (EPA) regulations regarding the quality of recycled greywater for use in ware washing, so for the purposes of this study, the water was considered to be recyclable if it met the EPA Secondary Treated Water Quality (part of the Clean Water Act) outlined in the Code of Federal Regulations, 40 CFR 133.102 1 . This is defined by the following: biological oxygen demand (BOD) of 30 mg/L or less; total suspended solids (TSS) of 30 mg/L or less; pH between 6 and 9. In addition recyclable water should have a turbidity of 5 NTU or less. The rational for specifying Secondary Treated water is twofold; if the treated greywater is accidentally discharged to surface water such as a lake or stream, the water would be considered clean enough to do so. Secondly, most states with greywater reuse regulations 2 base their water quality standards on the Secondary Treatment standard. In addition, each system s process rate was required to be fast enough to process the entire bulk of greywater before the next meal. The following tables summarize the results and indicate if the treatment systems passed or failed to meet any of the requirements.