Adsorptive Removal of Congo red dye from wastewater using Fenugreek Powder

The present study analyzed the efficiency of a naturally derived fenugreek powder for removal of Congo red dye from the aqueous solution. The flocculation Studies on Congo Red (CR) a hazardous, textile dye onto Fenugreek Powder and its adsorption was analyzed. Fenugreek Powder is Eco-friendly, biodegradable and locally available in the market. The dye adsorption process was performed in different batches at varying pH, dye concentration, adsorbent concentration and contact time to get the best results. The result showed that the maximum removal of dye was 42.4% with 10mg/l of Fenugreek powder at pH 4.


Introduction
Industries such as cosmetics, paper, food and textiles use different kinds of dyes to color their products which creates one of the most detrimental problem of wastewater, as color is the foremost pollutant in the water to be recognized, thus most of the countries have mandated to decolorize the wastewater before its discharge into water bodies (Pal et al, 2014). In textile industry, reducing wastewater production is a critical environmental challenge . Textile industry comes next to agriculture in employment Congo red is an azo group of dyes which is anionic in nature. Congo red has been extensively used in textile industry and it has number of harmful effects on environment and human. It is carcinogenic and causes irritation in human respiratory system (mohammadietal, 2020).Fenugreek being botanically called as Trigonellafoenumgraecum is also known as methi in Hindi.
Fenugreek is an edible seed and is an annual crop mainly cultivated in India. 2002) reported the use of fenugreek in the treatment of textile water effluent.As far as we know there are numerous advantages of these low cost, eco-friendly natural polysaccharides. The flocculation behavior of fenugreek for removal of Congo red has not yet been studied therefore; an effort has been made by utilizing these natural polysaccharides in removal of Congo red, a hazardous dye released from textile industry.

Fenugreek
Fenugreek is a natural polysaccharide and used as a direct food additive. It is very similar to clover in appearance, grown in North Africa, Asia Minor, India and Pakistan. The small brown seed of fenugreek are medicinally very important. The mucilage is obtained by extraction of milled seeds with cold water. The natural polysaccharides are low-cost materials fairly shear stable and easily available from reproducible agricultural resources and they act as good flocculating agents.

Flocculation Studies
The flocculation efficiency of natural polysaccharides with dye solution was determined at

Effect of Contact Time
The effect of % removal of dyes with contact time is shown in Fig (3.2).The maximumremoval of the dye Congo red was found after four hours. After this duration the percent removal becomes constant or the maximum slightly decreases.

Fig (3.2) % Removal of dye with varying contact time with dye concentration of
5mg/L at 10mg/L polysaccharide dose

Effect of Dye Concentration on % Removal
The effect of dye concentration on % removal is presented in Fig. (3.3,) It showed that variation in the concentration of dye from 1 -10 mg/L, the percent removal decreases from 41.8 to 0 % for Congo red at polymer dose at 10 mg/L respectively. Data related to % removal with varying concentration of dye given.

Effect of pH on % Removal
Effect of pH on % removal of dye is shown in Fig. (3.4). The maximum removal of dye was found to be 46.18% for Congo red at acidic pH.

Conclusion
In this study, flocculants based on natural polysaccharides has been assessed for removal of Congo red dye. Natural polysaccharides Fenugreek was chosen for this purpose. A series of contact time experiments were conducted for testing their efficiency as flocculants.
Flocculation studies were conducted to assess the different variables such as concentrations of natural polysaccharides and dye and pH. The maximum removal of Congo red dye observed was 42.4% with Fenugreek. The optimum time for removal was 4 hours. The maximum removal of dye was found at acidic pH.

Table.2. Flocculation capacity of Fenugreek for removal of Congo red dye
The present study covers only Congo red dye for the treatment by the flocculants Fenugreek. It is therefore, recommended to perform flocculation studies on effluents of various industries.