Determina on of Fe Ions Content in Well Water Samples from Dumai Timur Subdistrict of Dumai Municipality

One of the raw water sources in Indonesia is well water. However, the water mostly smells, turbit, and dirty. Dumai Timur is one of the subdistricts in the Dumai municipality that have bad quality water. People use well water for daily ac vi es but the water is the smell and the color is yellowish and leaves rust stain in func onal par ons. This rust stain es mated as iron ion (Fe and Fe). Iron ion needed in red blood cell forma on; however, if it exceeds the defined level, this ions is harmful. This research aimed to iden fy the iron ions level in well water used by people at Kecamatan Dumai Timur. Samples obtained from some well water in Dumai Timur that consist of five Kelurahan. Technique sampling was random sampling and the iron ion was detected in a laboratory using SNI 6989.4:2009. The result compared with the defined level by the Minister for Public Health No. 416/1990.


Introduc on
The func on of water for human life cannot be replaced by other compounds [1] [2]. Water as a component of the environment will affect and influenced by other components. Poor quality water will result in adverse environmental condions that will affect the health and safety condions of humans and other living things [3] [4].
Water quality, in general, shows the quality or condi on of water associated with a par cular ac vity or need. For example, the quality of water needed for drinking and cooking needs will be very different from the quality of water used for aquaculture purposes. Water used for consump on must have good quality, both from the physical quality and chemical quality of water [5] [6].
Dumai Timur Subdistrict is one of the subdistricts in the Dumai Municipality that has poor quality water. The condi on of the well water used usually smells and is brownish yellow and leaves yellow marks on the walls of the well. The yellow color thought to be ferrous ions (Fe) which are Fe 2+ and Fe 3+ . Iron ion-containing water, if le in the open air, will form a precipitate. This sediment will s ck to the reservoir and if used for household purposes such as washing, it will leave stains on the laundry cloth [7]. The body needs iron ion in small amounts in the process of metabolism and red blood cell forma on [8]. Lack of iron ion levels in the body will cause anemia, but excess iron ion will cause vomi ng, diarrhea, and intes nal damage [9][10] [11]. Therefore, this research carried out to determine the levels of Fe ion contained in well water used by the people in the Dumai Timur Subdistrict area. So, if it turns out that the well water contains Fe ions that exceed the threshold set by the government, the community can be more careful in its use.

Experimental
Instruments and Materials. The instrument used in this study is the Atomic-Absorp on Spectrophotometer, pH-meter, plas c bo les, goblets, and dropper pipe es. The material used is water samples from several residents' well water in Dumai Timur Subdistrict and nitric acid.
Methods. The sampling process in this study carried out randomly (random sampling), wherein each village contained in the Subdistrict of Dumai Timur taken as many as 5 points that are considered to be representa ve of the whole. Dumai Timur Subdistricts in the Dumai Municipality with a land area of 47.52 km 2 ( Figure 1). Lies the Subdistrict of Dumai Timur right in the middle of the Dumai Municipality Subdistrict capital Teluk Binjai. Characteris cs of the subdistrict of Dumai Timur according to eleva on (height above sea level/dsl) is located between 0-25 m.
The whole region is the land and the topography is rela vely flat. Dumai Timur Subdistrict consists of 5 villages, namely Buluh Kasap, Bukit Batrem, Jaya Muk , Teluk Binjai, and Tanjung Palas Village [12]. These samples are put into plas c bo les and nitric acid is added to maintain its durability before the measurement process. Fe total content measurements as Fe 2+ and Fe 3+ ions were carried out in the laboratory using the Atomic Absorp on Spectrophotometer (SSA) (SNI 6989.4:2009) [13].

Result and Discussion
Results. The results of ions Fe measurements in well water samples used by residents in the Dumai Timur Subdistrict seen in Table 1. In each village, 5 points taken that were considered to represent the whole. The measurement results compared with the quality standards set by the government. The quality standard for clean water contained in the Regulaon of the Minister of Health of the Republic of Indonesia Number 416 of 1990, where the permi ed Fe ions content is only 1.0 mg / L.

Discussion.
Humans need low levels of iron ions in the process of metabolism and red blood cell forma on. The amount of iron needed by the body per day is around 7 .0-35 mg, which is not only obtained from water [15]. Iron deficiency can cause a decrease in red blood cells or known as iron deficiency anemia. Iron deficiency anemia is a health problem in society because it can cause various complicaons such as impaired cogni ve func on, decreased endurance, changes in behavior, decreased producvity, and stunted growth and development for children. Although the body needs iron ions, excessive amounts will cause various diseases such as damage to the intes nal wall [16], cause chronic effects such as hemochromatosis which will cause cirrhosis of the liver and pancrea c damage [17] [18].

ALKIMIA Jurnal Ilmu Kimia dan Terapan
Based on the data in Table 1, it can be seen that almost all regions in Dumai Timur Subdistrict have water with very high Fe ions content. Of the five exis ng villages, only one village whose water can be said to be decent as clean water. Four other villages have Fe ions content far above the quality standards set by the government. However , unfortunately, people connue to use this water as their raw water source.
The highest concentra on of Fe ions is found in Jaya Muk Village at sampling point 3.
The measurement results show that the value of Fe ions is 9.8971 mg / L. In addi on to Jaya Muk Village, the largest Fe ions concentra on was also found in Buluh Kasap Village at sampling point 2 with a value of 7.5193 mg / L, Tanjung  The presence of Fe ions in groundwater caused by several factors, including origina ng from the soil itself or from other sources such as corrosion of iron pipes, industrial wastes, biological reacons under anaerobic condi ons, and pH values that tend to be acidic [19]. Under low pH condi ons, iron dissolves well in water [20].

ALKIMIA Jurnal Ilmu Kimia dan Terapan
Based on Table 2, seen the pH value of the residents' well water samples found in the Dumai Timur Subdistrict is at a low acid / pH condi on. The Government in the Regula on of the Minister of Health RI No. 416 of 1990 set the standard quality value for clean water to have a pH between 6.5-9.0. This low water pH value is one of the causes of the high levels of ferrous ions found in groundwater in the Dumai Timur Subdistrict.

CONCLUSION
Based on the results of the research and analysis above, it concluded that almost all well water used by the community in Dumai Timur Subdistrict had not met the clean water requirements s pulated by the Government in the Republic of Indonesia's Minister of Health Regula on No. 416 of 1990. The well water has a very high iron ions content so it is not suitable for use as raw water.

ACKNOWLEDGMENT
The authors say to the Directorate of Research and Community Service of the Directorate General of Strengthening Research and Development of the Ministry of Research, Technology and Higher Educa on who have funded the research and publica on of the results of this research and to LPPM UIR who have supported the implementa on of this research ac vity.