Evaluation of Coffee Sludge as an Adsorbent of Cations and Chlorides from Mangrove Sediments

The sludge is a residue from the processing of soluble coffee and represents, on average, 48% of the amount of green coffee used in the process. The high volumes of this waste reflect environmental problems for industries. This research aimed to study the use of coffee grounds with a view to the adsorption of chemical elements from the mangrove sediment irrigated with desalination waste. Under laboratory conditions, an experiment was carried out with PVC tubes, where 1.5 kg of mangrove sediment was added. Soon after, 300g of coffee grounds was applied to the surface and also incorporated into the sediment, with irrigation with desalinator waste twice a week. The extract was collected every 15 days until 60 days, where Cl were determined in each collection, with an indication that at 15 days of contact of the coffee sludge incorporated in the mangrove sediment, it presents a greater adsorption of the determined elements sodium (3285.0mg/l), calcium (282.0mg/l), magnesium (316.0mg/l), chloride (3731.0mg/l); and potassium (24.0mg/l) at 30 days of contact.

beach, it receives Ariquindá and its affluent União, two important components of its basin. Along its route it receives domestic waste and residues from the sugar agribusiness [11]. The salinization of waters in the Northeast of Brazil has been revealed as a phenomenon as worrying as low rainfall. After the water desalination process, part of the solutes that were obtained in the process produces a by-product, a wastewater called tailings, with a much higher salt concentration than the original brackish water and polluting power for the soil, fauna, and flora. In some places, the waste reaches 75% of the original volume and one of the environmental problems found in this process is the disposal site, since it can cause damage to the environment [12][13][14].
Sludge is a waste produced in large quantities in the soluble coffee industries, and represents an environmental problem, as it contains carbohydrates (cellulose, hemicellulose, sugars), some proteins and other compounds that represent a large organic load, and, consequently, demand a high oxygen content for its degradation, despite its high moisture content. In addition, the residue still contains caffeine, tannins, and polyphenols [15].
Various destinations have been proposed for this residue, including use as fertilizer, animal feed, burning, and even as a raw material for obtaining biodiesel and alcohol [16]. Due to its richness in several constituents, this residue began to be studied, being an organic matter with excellent physical-chemical characteristics that make it possible to be valued and characterized as a coffee by-product, with a lot of potential to be explored, including as an adsorbent.
This work's objective was to evaluate the efficiency of adsorption of chemical elements of the mangrove sediment, using coffee sludge.

Materials and Methods
The experiment was conducted at the Analytical Chemistry

Results and Discussion
The results obtained for the determination of Na + , K + , Ca 2+ , Mg 2+ and Clare shown in (Figures 1 to 5). (Figure 1) shows the influence of the incorporated coffee sludge (IC) in the mangrove sediment for sodium adsorption (3285.0mg/l), up to 15 days of contact, with the highest leachate value when the coffee sludge was placed on the surface -SC (7633.0 mg/l), indicating less adsorption. When the coffee sludge on the surface -SC was in contact for 30 days (2590.0mg/l), 45 days (2397.0mg/l) and 60 days (2400.0mg/l) it was more promising in the sodium adsorption reaction in the sediment of mangrove. According to [17] it has been found through laboratory tests that seeds with crushed or ground Moringa      The analyzes related to the potassium adsorption process [19] obtained results distributed in two blocks: the first, with a slight adsorption in T1 (sediment after eight days of contact with the residues), despite being below the values found for T0 (control) for The percolated calcium in the survey by [18] showed lower values at 15 days (214.7mg/l), 45 days (128.2mg/l) and 60 days (114.8mg/l) when the moringa seed incorporated into the mangrove sediment was used. At 30 days, Ca 2+ showed a value equal to 171.5mg/l when the moringa was placed on the surface of the mangrove sediment, indicating increasing calcium absorption. In (Figure 4), it can be seen that magnesium was adsorbed in greater quantity when the leachate showed lower value (316.0 mg/l) at 15 days, with coffee sludge incorporated in the mangrove sediment. A study carried out by [20] reached the same result: the researcher proved that the powder of Moringa oleifera seeds in contact with the organic material of the well water reduces the hardness value in the period of 24 hours. Chloride presented, at 15 days of contact with coffee sludge incorporated into the mangrove sediment, less value in the leachate (3731 mg/l), which indicates greater adsorption of this ion. According to [12] it has been found through laboratory tests that seeds with crushed or ground Moringa husks are equally effective at adsorbing chloride from 6.997.5 mg/l to 6.782.4 mg/l (1.8%).

Conclusion
In view of the results obtained, it can be inferred that there is a tendency to recommend coffee sludge when incorporated into mangrove sediment, as it favors the adsorption of ions, since they presented the lowest values in the percolate at 15 days of contact: sodium (3285.0mg/l), calcium (282.0mg/l), magnesium (316.0mg/l), chloride (3731. 0mg/l); and at 30 days of contact, potassium (24.0mg/l).