Conventional Water Filter ( Sand and Gravel ) for Ablution Water Treatment , Reuse Potential , and Its Water Savings

Ablution process consumes a huge amount of water especially in mosques for cleaning certain part of the body before performing prayers. The high volume of ablution water produced in mosques and its low strength in quality makes it a feasible option to be reused. This paper introduced an assessment of conventional filtration (sand and gravel) in treating ablution water for reuse purposes and its water savings potential in mosques. The treatment system has assessed its capability for reuse and its water savings potential. A pilot scale of filtration system was developed and was run with the ablution water from the Parit Raja mosque and the Pintas Puding mosque. The samples were taken during Friday noon prayer between January to March 2013. The efficiency of the conventional filtration system was tested for the effluent quality of NH3, TSS, COD, and BOD. The case study of water savings estimation for the proposed system was undertaken at Pintas Puding mosque. It was determined based on the quantity of ablution water, water consumption, water demand, and water bills record. The results deduced that the conventional sand filtration can improve the water quality parameters; 0.60-0.05mg/L reduction of nitrogen ammonia (NH3), 6.0-1.53mg/L of suspended solids (TSS), 3.12-0.15mg/L of chemical oxygen demand (COD), and 27.67-4.16mg/L of biochemical oxygen demand (BOD). The treatment system was projected to save water consumption by 41.73% and RM180.16 of water saving per month. Water consumption was estimated to be further reduced to 50.83% if reused activities such as irrigation and toilet flushing were applied. Hence, annual water savings could reach up to RM2161.92 per year. With the current instability of water resources, the implementation of the conventional filtration system for ablution water in the mosques provides water security and water resources conservation option for the country.


Introduction
The interests in reusing ablution water in most arid and semi-arid countries have been heightened due to the increase of water demand, water shortage, and prolong drought.This practice has become increasingly common in Saudi Arabia and Yemen with the installation of treatment system to reuse the greywater generated from hand and mouthwash (ablution) in most of their mosques.Ablution water is the water which has been used by worshippers in washing (wudhu) before performing prayers.Ablution involves cleaning certain part of the body with fresh water in a certain order as a religious right.A large amount of greywater is produced in the mosque from ablution activity.High amount of greywater is produced in more than 700000 mosques in Indonesia due to the large number of Muslims (Uteberta et al., 2011).On the other hand, water-rich countries have less value in reusing the ablution water due to the fact that they have water security from the rainfall.However, early this year, Malaysia faced water shortage which affected more than seven million consumers in Klang Valley in which resulted in the reduction of water level at Sungai Selangor dam.This indicated that even though Malaysia has been blessed with high rainfall, there is no guarantee for constant water supply.This issue has put into remark the importance of water conservation.Muslim countries such as Indonesia, Malaysia or Middle East countries can be ascertained that ablution water and mosques are one of big sources of greywater in the country (Uteberta et al., 2011).
In Malaysia, the ablution water from mosques is commonly discharged directly into drainage channels without treatment.Under certain circumstances, ablution water is combined with stormwater run-off into the waterways and carries pollutants subsurface into the water surface.Generally, ablution water is less contaminated but it still 102°44'27") and the Pintas Puding mosque (coordinate N 1°51'29" E 103°5'58") which were located in Parit Raja Town, 20 km from the main city of Batu Pahat, Johor Malaysia.Ablution water sampling was taken on 28 th February 2014, 7 th Mac 2014, and 14 th Mac 2014 by applying the grab technique at a fixed time which was 1.00 pm before the Friday prayer.These sites were chosen due to the number of worshippers preferred its strategic location where it is in the heart of Parit Raja Town, and near the university residents of Universiti Tun Hussein Onn Malaysia.Grabbed samples were obtained by filling a container of ablution water at a specific point and time.Therefore, the grabbed samples collected should be representing the ablution water that was flowing out through the drainage.Ablution water was collected in the container until it was full and then was neatly closed so that no air enters the vacant space.Samples were then kept in an ice container to control the temperature and were brought immediately to the laboratory for testing.
The preparation and preservation of the sampling container were carried out according to the Standard Method for Examination of Water and Wastewater (APHA, 2005).Raw ablution water was collected and the analyses for the following parameters were conducted: pH and conductivity by pH meter; total suspended solids (TSS) by the gravimetric method; biological oxygen demand (BOD 5 ) by five-day test; chemical oxygen demand (COD) by using COD reflux method(reactor digestion method), and nitrogen ammonia (NH 3 ) by the Salicylate method (reactor digestion method).

The Estimation of water savings
Water savings estimation was calculated based on the proposed treatment system.The water savings estimation used the Pintas Puding mosque as the case study.

• Determination of the number of worshippers
Worshippers who perform the ablution were calculated in each prayer (five times a day) for a month in Mac 2014 and the average was calculated.
• Determination of the average quantity of ablution water Ablution water was collected using the bucket method for a worshipper of an average of 10 people.This method involved filling a bucket and used a stopwatch to determine the length of time the ablution was performed.The volume of water for each person differs according to the activity.The measurement of water demand was determined using the bucket method.This method involved filling a bucket of known volume and used a stopwatch to determine the time taken to fill it up.The volume of the bucket divided by the time taken to fill up the bucket will yield the value of the flow.
• Determination of water consumption A water audit survey was done to determine the water consumption.A few activities were identified such as ablution, toilet flushing, irrigation, and reverse osmosis (RO) drinking water.
• Estimation of water savings The estimation of water savings was a projection achieved if the proposed ablution water was performed.The treated ablution water will be proposed to be reused for toilet flushing and water irrigation.The amount of water demand for irrigation and toilet flushing were estimated based on the water consumption activities.The water used was calculated and compared with the water bill obtained from the local water authority (SAJ).The total current water usage is then calculated using the SAJ link (http://www.saj.com.my/v2/calculatorbm.php).

Results and Discussion
The summary for the mean value of untreated and treated with sand + gravel filter at Parit Raja mosque and Pintas Puding mosque is presented in Table 1.In general, the mean concentrations of typical parameters of treated ablution water showed remarkable reduction of TSS, NH 3 , COD, and BOD concentration.Based on the National Water Quality Standard (NWQS), the maximum threshold limit of TSS for Malaysian irrigation (Class IV) is 300 mg/L.The TSS values in this study were within the limit and the TSS value from Parit Raja mosque has improved from 9.0mg/L to 6.0mg/L after being filtered through sand and gravel.Furthermore, treated ablution water from Pintas Puding mosque showed the level of TSS concentration was reduced from 10.67mg/L to 1.53 mg/L.Normally, the suspended solid were made of inorganic materials, through bacteria and algae which were due to the gargling activity during ablution (Fondriest, 2015).Previous study conducted by Khatun (2011) and Mohamed & Ali (2012) had demonstrated that the TSS concentration in raw ablution water was low which ranged between 5-146mg/L and 19-49mg/L respectively.Therefore, the ablution water from Parit Raja and Pintas Puding mosque has low strength of TSS and it was saved to be reused for irrigation.
Biochemical oxygen demand (BOD) concentration was reduced tremendously in both mosques in which the value reduced was 31 mg/L to 27.67 mg/Land 31mg/L to 24.16 mg/L respectively.According to NWQS, the BOD concentration of ablution water exceeded the permissible limits recommended as categorized as class IV for irrigation.The BOD was considered high compared to NWQS recommended value (12mg/L).The BOD levels represent the amount of organic matter that may be released during the ablution of cleaning certain part of the body like rinsing the palm, mouth, and washing nose by sniffing.Usually, the BOD concentration is associated with dissolved oxygen and high BOD value shows a reduction in DO (Al-Badaii et al., 2013).A large amount of organic matter enhances the microorganisms to consume more DO to complete the biological processes.From previous study, ablution water generated from the mosques in Egypt was found to be low in strength because the BOD varied between 17 mg/L-23 mg/L.The water quality of ablution water varies in quantity in a wide range depends on the usage patterns as well as on the sources and locations (Khatun et al., 2011).The chemical oxygen demand (COD) concentration of the ablution water samples were reduced after treated with sand and gravel filter which were 3.66 mg/L to 3.12mg/L at Parit Raja mosque and 3.50mg/L to 0.15 mg/L at Pintas Puding mosque.In addition, these results were within the standard allowable limit recommended by NWQS which is 100 mg/L or less and is classified as class IV.Comparing the COD concentration obtained from both mosques (Parit Raja and Pintas Puding) to a previous study by Pidou et al. (2007), the ablution water from Riyard City Mosque, Saudi Arabia showed high strength of COD which varied between 260mg/L to 280mg/L.Moreover, both mosques showed low level of COD when compared to Dhaka's mosque and Dhaka's residential area greywater in which the concentration were 51-60mg/L and 85-462mg/L respectively (Khatun et al., 2011).The value of COD may vary due to several reasons such as the number of the worshippers, the ablution steps, climate, and also the landform of the country.Generally, low COD level indicates a low level of pollution, whilst high level of COD points out high level of water pollution in the study area.
The ammonia (NH 3 ) concentration in the sample of ablution water from Parit Raja mosque was 0.77 mg/L before treated and 0.60 mg/L after being filtered.Meanwhile, the ammonia level at Pintas Puding mosque was reduced from 0.71mg/L to 0.05mg/L after treatment.According to the NWQS, the maximum threshold level of NH 3 for Malaysian water which is suitable for irrigation is 2.7mg/L.Nevertheless, the concentrations of NH 3 from both mosques were within this range and were classified as class IV.In addition, higher NH 3 value can be toxic to plants but in small concentration it could serve as the nutrients for excessive growth of algae (Al-Badaii et al., 2013).

Water Savings Estimation
Water is a limited resource in arid countries and water conservation becomes important (Rose et al., 1991).In Malaysia, the excessive use of water has affected the availability of the resource (Hamilton et al., 2007).One way of conserving water is by recycling the ablution water from mosque.Table 2 shows the quantity of ablution water per person in performing the wudhu and the method showed that one worshipper uses about 5 L of greywater in 48.5 seconds averagely.People seldom close the taps while performing wudhu' and half of the water flows directly into the drain without any contamination (Al-Mamun et al., 2014).Water wastage can be avoided during ablution.It occurs when some worshippers left the water flow running without being fully utilized and take a relatively long time to perform ablutions.There are also some cases where some worshippers open the tap at maximum flow for ablutions.Figure 2 shows the frequency of worshippers for a month (March).The number of the worshippers visited Pintas Puding mosque was calculated.The number of worshippers during Friday prayer was recorded to be high.Therefore, it is estimated that the ablution water consumption produced at Pintas Puding mosque for a month is about 83.45 m 3 .The high number of worshippers may also be affected by the location of Pintas Puding mosque in which it is located near residential colleges and industrial areas.Figure 3 shows the percentage amount of water consumption in Pintas Puding mosque daily.There were five main water sources that contributed to the main water consumption in Pintas Puding mosque, namely ablution water, toilet pipe, 6 flushing toilets (without sinks), 4 bathrooms, 1 RO drinking water, 6 hand wash basins, and irrigation.Based on the pie chart, an ablution activity contributes the highest percentage of greywater with 92.56% of total water demand, due to the number of worshippers who come to perform their prayer at the mosque from nearby student hostels.Normally, the number of worshippers that come to the mosque consists of 50% hostel parameter of6.0 ± 1.73, NH 3 parameter of 0.60-0.02mg/L,COD parameter of 3.12-0.41mg/Land BOD parameter of 27.67-1.53mg/L.Meanwhile, for the Pintas Puding mosque, the TSS parameter was 1.53-1.53mg/L,NH 3 parameter was 0.05-0.05mg/L,COD parameter was 0.15-0.15mg/L,and BOD parameter was 24.16-4.16mg/L.The proposed treatment system was capable of reducing water consumption by 41.73% with monthly water bill saving of RM 180.16.The water savings can be further reduced up to 50.83% if the treated ablution water is reused for irrigation and toilet flushing.Hence, a huge amount of cost saving up to RM2161.92 can be achieved.

Figure 2 .
Figure 2. Frequency number of users for a month (data collected March 2014) Figure 5 sh It can be discharge convention water for r which the reduced fr

Table 1 .
The summary for the mean value of untreated raw sample and treated ±StDev at two mosques in Parit Raja during the sampling period from 28 February to 14 March 2014

Table 2 .
The quantity of ablution water per person during performing wudhu