Water pollutionis one of the major environmental problems worldwide caused as a result ofvarious factors. At present, Thailand is facing a critical water pollutionproblem.
One of the main causes of water pollution arises from wastewater thatcomes from the textile industries. Over 10,000 pigments and dyes used in thesetextile industries are toxic and harmful to human and aquatic life (Charoenlarp& Choyphan, 2009). The dyes degrade and produce products that are toxic andcarcinogenic to humans and animals (Carmen & Daniel, 2012). Colors and dyesare extremely important in all aspects of human life. Everything that meets thehuman eye consists of a variety of colors. In general, colorful clothes tend tobe more attractive to most people than the dull black and white combination.Therefore, the dyeing process is essential in all textile industries (Ratna& Padhi, 2012).
During the dyeing process, about 10-25% of textile dyes arelost and 2-20% are released as aqueous effluents in different environmentalcomponents. The dyes released usually escape traditional wastewater treatmentprocesses and remain in the environment for a long time as they have highstability to light, temperature, chemicals and bleach as well (Joshi et al.,2004). Consequently, the turbidity of water increases which reduces lightpenetration that is required for photosynthetic activity. This in turn disruptsthe mechanism of oxygen transfer at air water surface and therefore decreasesthe level of dissolved oxygen (Kant, 2012). As a result, plants can’t maketheir own food and they eventually die. This also leads to a major disruptionof food chain in the ecosystem (Upadhyay & Mahajan, 2014).
Moreover, theconcentration of dyes that are discharged have many effects on differentorganisms. For example, it can cause irritation to the respiratory tract aswell as causing ulceration of skin, and mucous membrane (Lavanya et al., 2014). Asaforementioned, the dye containing wastewater affects aquatic organisms.
However, these dye containing wastewater can be treated using different methodsincluding physical and chemical processes like adsorption, oxidation processes,microbiological or enzymatic decomposition (Khandare & Govindwar, 2015).Even though there are many treatments, these methods are usually very expensiveand produce secondary pollutant (Tahir et al., 2016).
An alternative techniquethat is environmental protective known as phytoremediation is now a commonmethod used to remove pollutants in water (Saravanan et al., 2015). Accordingto Salt et al. (1998), phytoremediation is a process in which green plants areused to rid of the pollutants present in the environment. This is a costeffective as well as environmental friendly method that is easy to carry out. Phytoremediationcan be used to remove organic and inorganic pollutants present in both solidsubstrates like soil and liquid substrates like water. The processes includedin phytoremediation are phytodegradation (breakdown pollutants),phytostabilization (lowers the bioavailability of pollutants),phytovolatilization (clears pollutants) and rhizofiltration (using the roots ofplant to absorb pollutants).
Nonetheless, the main key for phytoremediation tobe favorable is to be able to identify plants that can withstand highconcentration of chemicals and pollutants present in the surrounding. Hence, thisresearch aims to study different plants to see which one best absorb eosin, anacidic dye, present in the water. The different plants that will be use in thisexperiment are Eryngium foetidum- plantgrown on soil, Ipomoea aquatica- semiaquatic plant, Hydrilla verticillata- anaquatic plant. The plant that shows the most decrease in optical density ofwater containing eosin dye, for a given period of time, is considered to be themost effective in using for the process of phytoremediation. Lastly, differentconcentrations of eosin in water would be used see the effect of toxicity onthe organism, Artemia salina.