Water Journal : Water Journal December 2011
water DECEMBER 2011 81 small wastewater systems samples taken, however, are within Class B limits. All effluent is currently discharged to the evaporation ponds. However, given the high quality of effluents, the WWTP management has begun looking into potential reuse for irrigating trees planted along the highways instead of using scarce fresh water. Approximately 400m3 of digested sludge has been drained from the settling/digestion reactors since the start of operations. These were then dried on sludge drying beds. Sampling has indicated the dried solids can meet requirements for all field classifications permitted under the Jordanian Bio-solids Reuse and Disposal Standards (JS 1145/2006). As such, it is the intention of the WWTP management to mix the dried sludge with the soils within the WWTP site and utilise it as a soil conditioner for nearby forest trees areas. North Shouneh WWTP As previously stated, the North Shouneh WWTP is designed for 1,200m3/d of septage. The North Shouneh WWTP is designed to continuously meet JS 893/2006 Class B reuse standards (presented previously in Table 4) and consists of the following unit process: septage receiving and screening station; two settling/anaerobic/denitrification reactors (each consisting of four 240m2 settling/digestion compartments, three 740m2 anaerobic compartments and three 120m2 denitrification compartments); two 3,800m2 facultative lagoons; 12 1,500m2 recirculating sand filters; and two 5,600m2 reed beds (see Figure 4). The facultative lagoons were designed for a 9.0 day HRT. The sand filters are divided into two trains. The sand filter design is based on an eight-hour work day. During this eight-hour work day, in general no more than two filters per train will be dosed every two hours, with no single filter dosed more than once per day. The maximum recycle rate from the sand filter effluent to the denitrification compartments is 6,000m3/d. The North Shouneh WWTP is currently under construction with completion projected in late 2011. Footnote: This paper is an edited version of a presentation to the IWA Convention at Singapore International Water Week, 4--8 July, 2011. The Authors Thor Young (email: Thor. Young@ghd.com) is GHD Inc's Service Line Leader for Wastewater Treatment and Recycling and Rip Copithorn is GHD's Global Technical Leader for Water, both located in the firm's Bowie, Maryland, US office. Joseph Karam is the President of Ecodit LLC and is located in the firm's Arlington, Virginia, US headquarters. Osama Abu-Rayyan is Ecodit's Chief of Party for the Jordan Small Communities Project and is based in Aman, Jordan. References Morocco Ministry of Agriculture: Assessment of the Reuse of Wastewater for Agriculture at the Treatment Station at Ben Sergao, 1996 (published in French). Pollution Control Division, Morocco Office National de l'Eau Potable (ONEP): Quantitative and qualitative assessment of the waste water treatment at Drarga in the Region of Agadir, February 2005 (published in French). United States Agency for International Development: Design Documents for Drarga, Shobak, and North Shouneh WWTPs, 1997 to 1998, and 2005 to 2008 (prepared by Stearns & Wheler/GHD under subcontract to ECODIT and IRG). United States Agency for International Development and the Water Authority of Jordan: Wastewater Treatment Facilities for Small Communities in Jordan: Shobak WWTP Operations, Maintenance, and Training Report No. 1, February 2011 (prepared by ECODIT under subcontract with IRG). United States Environmental Protection Agency: Guidelines for Water Reuse. EPA/625/R-04/108. September 2004. Effluent Storage Septage Receiving Nitrate Recycle Settling/Anaerobic/ Denitrification Reactor Reed Beds Recirculating Sand Filters Facultative Lagoons Reuse Water for Crop Irrigation Figure 4. North Shouneh Septage Treatment Plant Process Flow Schematic. Recirculating sand filters at Drarga.
Water Journal April 2012
Water Journal November 2011