UTILIZATION OF RATS PURUN (ELEOCHALISTS OF DULCIS) AND WATER HYACINTH (EICHHORNIA CRASSIPES) TO REDUCE MERCURY LEVEL (HG) WITH PHYTOREMEDIATION METHOD

Metal mercury (Hg), has the chemical name hydragyrum which means liquid. Mercury metal is represented by Hg. In the periodic chemical elements Hg rank (NA) 80 and have atomic weights (BA 200,59). Rat Purun (Eleocharis dulcis) and water hyacinth (Eichhornia crassipes) are plants that are widely found in tidal swamp land. Both plants can be used as organic fertilizer, biofilter, and absorb toxic elements such as heavy metals Lead (Pb), Iron (Fe), Mercury (Hg), Sulphate (SO4). This study aims to determine the ability of rat purun plants (Eleochalis dulcis) and water hyacinth (Eichhornia crassipes) in reducing mercury (Hg) levels in water and to determine the effectiveness of rat purun plants (Eleochalis dulcis) and water hyacinth (Eichhornia crassipes) in absorbing mercury Hg. Sample analysis was carried out at the Bandar Lampung Standardization Research Center. The results obtained by rat purun plants (Eleochalis dulcis) can reduce mercury levels (Hg). The effectiveness of reducing heavy metal mercury (Hg) is 97.88%. Water hyacinth plants (Eichhornia crassipes) have effectiveness in reducing heavy metals mercury (Hg) which is equal to 96.66%.


INTRODUCTION
In Indonesia, development in the industrial sector continues to increase in line with the advancement of science and technology. Human activities in managing and processing the environment play a very important role in the sustainability of http://senjop.ppj.unp.ac.id/index.php/senjop Science and Environmental Journals for Postgraduate  December 2019 p_ISSN 2655-5085 e_ISSN  development. With the increase in development will be able to improve the quality of human life and community income. But on the other hand development can reduce environmental quality and community health status due to pollution.
In Law No. 32 of 2009 concerning Environmental Protection and Management, environmental pollution is defined as: Environmental pollution is the entry or inclusion of living things, substances, energy, and /or other components into the environment by human activities so as to exceed the environmental quality standards that have been set.
Likewise, the aquatic environment will be exposed to the effects of pollution from industrial processes from human activities in exploiting the environment, so that water will become polluted and cannot be used again by humans for their living needs.
An environmental order can be polluted or damaged due to many things and the main cause is waste, including chemical waste containing toxic materials such as heavy metals. One type of heavy metal is mercury (Hg) which is widely used by humans to meet needs such as in the mining sector. Where the community uses mercury to separate gold grains from rocks through the amalgam process. The influence of inorganic chemicals such as Pb, Cd, Hg in high levels can cause changes in water quality so that it cannot be used in accordance with its designation, besides causing the death of aquatic biota such as fish, plankton.
Traditional gold mining that is developing today by amalgamation which is the processing of gold minerals using mercury to bind gold, has the potential to cause the impact of pollution on aquatic environments such as rivers and seas. In the technique of operating waste rather than tailings containing mercury, it is immediately discharged into the river without being treated first and can pollute aquatic biota such as fish and other aquatic plants. Furthermore, it will damage the food chain in the aquatic environment.
Poisoning events due to contamination by mercury have occurred a lot.
One alternative that can be used to reduce mercury pollution (Hg) is the phytoremediation method (Mardekawati et al, 2012). Phytoremediation is the only method of processing waste that uses plants as an indicator, is easy to do or apply, does not cost much and the plants used are also widely available in nature. One plant that is able to reduce the level of impact of heavy metals on water caused by this gold mining is Rat Purun (Eleocharis dulcis) which is a wild plant that is widely found in tidal swamp   land. Rat Purun (Eleocharis Dulcis) can be used as organic fertilizer, biofilter, and absorb toxic elements such as lead (Pb), iron (Fe) and sulfate (SO4) (Asikin and Thamrin, 2012).

Mercury Heavy Metal (Hg)
Mercury is very dangerous for health. As a result of Minamata disease in Japan in 1968, more than 1,000 people died, tens of thousands of people suffered from hereditary disability. Minamata gets its name from Minamata City, Kumamoto Prefecture in Japan, which is an area of this disease which began in 1958. At that time there was a problem with epidemics in the Japanese city of Mintamana. Hundreds of people die of strange diseases with symptoms of nerve palsy. Knowing this, health experts find problems that must be immediately observed and sought for causes.
Through in-depth observation of the symptoms of Japanese diseases and habits, including diet, a hypothesis is taken. The hypothesis is that the disease resembles those of heavy metal poisoning. Then from the local culture it is known that Japanese people have the habit of consuming large quantities of marine fish. From the hypothesis and habits of the diet then experiments were conducted to find out whether the fish in the Minamata Bay contain a lot of heavy metals (mercury).

Rat Purun Plants (Eleocharis Dulcis)
Rat purun (Eleocharis Dulcis) is one of the many wild plants found in acid sulphate tidal swamps. This type of grass has a short rhizome with stolon (an extension of shoots that grows horizontally to the surface of the ground) extending spherical, flat-tipped, brownish to black. Stems erect, unbranched, grayish to shiny green 10-200 cm long and 2-8 mm thick. The results showed, besides functioning as a plant that traps white rice stalks, rat purun can also be used as organic fertilizer, biofilter, and absorbing toxic elements.

Hyacinth Plants (Eichhornia Crassipes)
Although water hyacinth (Eichhornia Crassipes) is considered a weed in the waters, it actually plays a role in capturing heavy metal pollutants. A series of studies on the ability of water hyacinth (Eichhornia Crassipes) by Indonesian researchers include (Widyanto andSusilo, 1977 in Aulia, 2013)  hyacinth (Eichhornia crassipes) was able to absorb metal cadmium (Cd), mercury (Hg ), and nickel (Ni), respectively at 1.35 mg / g, 1.77 mg / g, and 1.16 mg / g if the metal does not mix. Water hyacinth (Eichhornia Crassipes) also absorbs Cd 1.23 mg / g, Hg 1.88 mg / g and Ni 0.35 mg / g dry weight when the metals are mixed with other metals. (Lubis andSofyan, 1986 in Widodo, 2014) concluded that chrom (Cr) metal can be absorbed by water hyacinth maximally at pH 7. In its research, the original Cr metal with a level of 15 ppm decreased to 51.85%.

METHOD
This type of research is a real type of research. The place for this research was conducted at the Malahayati University, Faculty of Engineering laboratory with artificial waste. Furthermore, sample analysis was carried out in the Bandar Lampung standardization research center laboratory. When this research was conducted in May 2015 until July 2015. Effluents from processing results are analyzed in the laboratory.
To find out its efficiency can be calculated by the formula: The reduction efficiency is the ratio of influent and effluent expressed in percent.

E=
C awal− C akhir C awal X 100 % Where : E = Efficiency C = Concentration

RESULTS AND DISCUSSION
Rat purun plants (Eleochalis dulcis) and water hyacinth (Elchhornia crassipes) used were taken in swamp areas near rice fields near the study site. In the process of extracting rat purun plants (Eleochalis dulcis) and water hyacinth plants (Elchhornia crassipes) plants are taken whose condition is still good and not deformed (torn, broken).
The plant was acclimatized in a tub containing Hg contaminated liquid waste for 1 week.
The rat purun plants (Eleochalis dulcis) which were acclimatized were then selected for plants that were ± 15 cm high, water hyacinth (Elchhornia crassipes) plants which had been acclimatized and then plants with leaves of 3-6 sheets were selected, plant height was 10-14 cm with plant conditions still green and has intact roots. Selection is done with good plant characteristics so that the absorption of plants is more optimal for absorbing heavy metals mercury (Hg).

Concentration of Mercury (Hg) in Wastewater
The concentration of mercury (Hg) in wastewater can be seen in Table 1. The average value of decreasing mercury (Hg) in water can be seen from Table 2.

Source: Bandar Lampung Standardization Research Center
The average value of mercury (Hg) concentration in plants can be seen from Table 5.  (Table 4.3) for rat purses (Eleochalis dulcis) and water hyacinth (Elchhornia crassipes) this shows that the decrease (loss) of Hg in liquid waste, all absorbed by rat purun plants (Eleochalis dulcis) or water hyacinth (Elchhornia crassipes). There is no Hg in evaporated liquid waste. This is in accordance with the nature of Hg which is difficult to evaporate at ambient temperature. Measurement of Water Acidity (pH). Measuring the acidity of water (pH) is carried out on the first day and day 15. The degree of acidity in the three treatments can be seen in Table 7.  (Haryati, 2012in Natalina, 2013. Photosynthesis is a physiological property possessed by plants. The increase in pH is due to photosynthesis from plants where CO2 will be reduced to carbohydrate. Decreasing the amount of free CO2 in wastewater has a correlation with increasing pH (Suardana, 2005in Natalina, 2013.
The decrease in pH and resistance to the nitrification process showed a positive correlation with the growth of rat purun (Mulyani, 2005in Belami, 2013. These results indicate that the acidity level in wastewater that is not too high affects the presence of mercury contained in wastewater. According to (Palar, 1994in Belami, 2013, low water pH will cause mercury in the waters to be stable, whereas if the water pH is high it can reduce the solubility of metals in water. The increase in pH can change the stability of mercury from a form that is easily absorbed by plants and becomes difficult to absorb by plants by forming bonds with particles in the water that will settle.

Temperature Measurement of Water
During the phytoremediation treatment measurements were also made on the temperature present in liquid waste.

Visual Observation of Plants
Direct observations made with the aim to see the physical changes that occur in plants which are indicators in the phytoremediation method on mercury waste (Hg), visual observations of plants can be seen in Table 8. No changes in plants from day 0 to day 7, the condition of the plants is still good 2.
8-10 It has begun to appear small yellow spots on old leaves.
Experiencing changes in leaves and stems with more yellow spots than rat puruns. 3.
11-13 Experiencing changes in the old stems, with brown stems with yellow spots.
Old plants have undergone changes in dead leaves and some are yellowish in color. 4.
14-15 Old leaves and stems undergo changes that are partially dead and withered. However, plants that are still alive are seen from the presence of new shoots in plants.
Old leaves and stems undergo changes, namely wilting, and some die, so that the water experiences odor, which is caused by decay in dead leaves.

Source : Primer Data
Direct observations were intended to see the condition of rat purun plants (Eleochalis dulcis) and water hyacinth (Elchhornia crassipes) during the phytoremediation process. From day 8, rat purun plants (Eleochalis dulcis) and water hyacinth (Elchhornia crassipes) undergo changes in the leaves with characteristics that begin to wither and the presence of yellow spots. Within 15 days the plants were still alive even though some had withered. Mercury absorbed by plants has an effect on plants, including shoots and plant roots will dry up, chlorophyll content in leaves decreases, protein content will also decrease, and the concentration of Ca and K in plant tissues will decrease, (Azad and Kafilzadeh, 2012 )

CONCLUSION
The conclusions obtained from this study are: (1) Rat Purun (Eleochalis dulcis) and water hyacinth (Elchhornia crassipes) can be used to reduce Hg content by phytoremediation method. This is indicated by the efficiency of decreasing the Hg content of 97.88% for rat purun (Eleochalis dulcis) and 96.66% for water hyacinth (Elchhornia crassipes), (2) Efficiency in decreasing rat purun plants (Eleochalis dulcis) is better than that of water hyacinth plants (Elchhornia crassipes), this is due to rat purun plants