Dataset on the spent filter backwash water treatment by sedimentation, coagulation and ultra filtration

During operation of most water treatment plants, spent filter backwash water (SFBW) is generated, which accounts about 2–10% of the total plant production. By increasing world population and water shortage in many countries, SFBW can be used as a permanent water source until the water treatment plant is working. This data article reports the practical method being used for water reuse from SFBW through different method including pre-sedimentation, coagulation and flocculation, second clarification, ultra filtration (UF) and returned settled SFBW to the beginning of water treatment plant (WTP). Also, two coagulants of polyaluminum ferric chloride (PAFCl) and ferric chloride (FeCl3) were investigated with respect to their performance on treated SFBW quality. Samples were collected from Isfahan's WTP in Iran during spring and summer season. The acquired data indicated that drinkable water can be produced form SFBW by applying hybrid coagulation-UF process (especially when PAFCl used as coagulant).


a b s t r a c t
During operation of most water treatment plants, spent filter backwash water (SFBW) is generated, which accounts about 2-10% of the total plant production. By increasing world population and water shortage in many countries, SFBW can be used as a permanent water source until the water treatment plant is working. This data article reports the practical method being used for water reuse from SFBW through different method including pre-sedimentation, coagulation and flocculation, second clarification, ultra filtration (UF) and returned settled SFBW to the beginning of water treatment plant (WTP). Also, two coagulants of polyaluminum ferric chloride (PAFCl) and ferric chloride (FeCl 3 ) were investigated with respect to their performance on treated SFBW quality. Samples were collected from Isfahan's WTP in Iran during spring and

Value of the data
The data presents the quality of raw water and produced spent filter backwash water in Isfahan-Iran water treatment plant.
This data show the ability of two coagulant as traditional and pre polymerized for SFBW treatment. The data present the quality of treated SFBW with coagulation -UF process and returned the settled SFBW to the WTP entrance.

Experiment protocol
In this study SFBW was treated by continues processes including primary sedimentation, coagulation, flocculation, secondary sedimentation and UF process. Entrance flow for all sections of the pilot, except UF membrane was 10 l/h. Also, hydraulic retention time (HRT) was 60, 6, 48 and 192 minu, respectively (Fig. 1). According to our previous study, coagulation with PAFCl and FeCl 3 was conducted at pH 8.3 [1]. Both PAFCl and FeCl 3 used as coagulants (Figs. 2 and 3). A pre-determined dosage of PAFCl (10 mg/L) and FeCl 3 (30 mg/L) was continuously and individually added into the rapid mixer basin (mixing speed: 80 rpm, HRT: 6 min). Then coagulated water passed through two-flocculation tanks with a mixing intensity of 40 rpm. After that, the effluent was introduced to a secondary sedimentation basin, and then directed to a UF membrane module. The UF module filtration was 8 L m −2 h −1 at a trans-membrane pressure of 300 Pa. It was operated in a cycle of 60 min filtration and 1 min backwashing [2][3][4][5]. The importance of such treatment processes for SFBW is that in case there are some concentrations of pollutants being accumulated in the SFBW they will be Table 3 Mixing of settled SFBW with raw water that entered to Isfahan's WTP.

Parameter
Mixing settled SFBW with raw water entered to WTP  removed to much lower concentrations [7][8][9]. Data of this article attained from experimental work and all experiments were conducted according to the standard method for the examination of water and wastewater. Total organic carbon (TOC) was analyzed by Phoenix 8000 system. Turbidity, UV 254 , true color, Total dissolved solid (TDS), Electrical Conductivity, and pH were measured by TN-100 (EUTECH) Turbidimeter, DR 5000-HACH LANGE, EC meter SENSION5 (HACH-LANGE, Germany), and pH-meter model CG 824, respectively. Dissolved organic carbon (DOC), UV254, and the true color were analyzed after filtration through a 0.45 μm membrane. Fe, Pb, As, and Cd were analyzed by inductively coupled plasma (ICP).