USE OF PLANT RAW MATERIALS FOR PURIFICATION OF INDUSTRIAL WASTE WATERS FROM COPPER AND IRON IONS.

N.G. Kalabegashvili, G.I. Balarjishvili, L.O. Samkharadze, D.K. Ioseliani, I.I. Mikadze and R.P. Tsiskarishvili. I. Javakhishvili Tbilisi State University, P. Melikishvili Institute of Physical and Organic Chemistry 31, Politkovskaia Str., Tbilisi, 0186, Georgia. ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History Received: 24 March 2019 Final Accepted: 26 April 2019 Published: May 2019


ISSN: 2320-5407
Int. J. Adv. Res. 7 (5), 1020-1025 1021 It was established through scientific investigations that systematic penetration of heavy metals into human body is especially hazardous for health, since they are characterized by biological peculiarities, such as: accumulation ability in the organism, mutagenic, carcinogenic, embryotoxic properties. Heavy metals' toxic effect is of a special nature in case of children and pregnant women. The copper accumulation in large quantities in human body causes the Wilson's disease that implies excessive copper accumulation in the brain tissues, skin, liver, pancreatic gland, eyes, and kidneys. It damages the liver and nervous system and frequently becomes the reason of a lethal outcome (Bokris,1982). The excessive iron content also has the negative impact on human body, it sometimes causes coma and even the death.
According to foregoing, the study and elaboration of simple processing methods of purification of waste (quarry) waters of industrial enterprises from HMI is of undoubted interest. Local enterprise "RMG Copper" (copperprocessing combine) of Bolnisi District (Georgia) faces this problem, too.
Kazretula River flows under the quarry tailing dumps and it is rich in ore elements (Cu, Zn, Fe, Cd etc.). The total content of heavy metals in Kazretula River considerably exceeds the maximum allowable concentrations for surface waters. It should be noted that the water of the mentioned river is used for irrigation of agricultural lands in Bolnisi district, creates a threat of agriculture production pollution with heavy metals and causes various severe illnesses.
There are known many traditional, up-to-date and non-traditional methods of waste waters (mine, quarry and under spoil waters) treatment, for instance: chemical, membranous, ion exchange, galvanogenic, electrochemical, sorption, extraction methods and so on. However, most of these methods have number of lacks, such as origination of the secondary pollution, necessity of the special complex devices and structures that makes the production nonprofitable (Kim,2005;Ahuwalia,2005). Taking into account the generalization of literature data, carried out explorary researches and RMG Copper's technological scheme we suppose that the role of geochemical barrier technologies, i.e. complex of protective measures and structures installed on the migration way of different toxicants, including HMI, increasingly grows in the solution of mentioned problem. A geochemical barrier is the area, on which in a short time a sharp fall of migration and concentration of chemical elements takes place. The essence of this method lies in the transition of polluting components into a less moving form. Geochemical barriers play "filtering function" kind of role. Significant part in these technologies is assigned to sorption barriers made of different sorbents (Perelman,1994).
There are developed and investigated the sorbents on the basis of a wide variety of mineral and organo-mineral raw materials, synthesized polymers, industrial and agricultural waste. In recent years in order to remove the heavy metal ions dissolved in the water the successful use of the sorption materials on the basis of vegetable waste has been started, namely: coconut and cedar nut shells, rice husk, buckwheat, wood chips, straw and many other wastes (Fiol et al.2006;Shukla et al.2015). The vegetable waste, such as sunflower, oat, buckwheat, rice husks contains cellulose (up to 30%) and lignin (up to 25%) in their chemical composition, i.e. substances, which are able to carry out the processes of physical sorption and chemosorption (Sciban et al.2008).
Sunflower husk is the easily-accessible large-tonnage waste at the relatively small price, that's why it is considered as a prospective raw material for production of sorption materials ( The use of these materials can reduce the expenses for waste water purification several times. The important economic factor is that the vegetable waste of agricultural enterprises serves as a raw material used for such prospective adsorbents. At the same time, it gives us an opportunity to relate the problem of their disposal with the improvement of ecological state of water resources. In the previous works related to the process of quarry waters purification from heavy metal ions we have studied natural, local alumosilicates, both clays (gumbrin, Askangel) and zeolites (clinoptilolite, mordenite) and also mineral brucite. There was shown that the above mentioned alumosilicates have sorption activity towards HMI

Materials And Methods:-
In the given work there is studied purification of industrial waste quarry waters and Kazretula river waters from copper Cu 2+ and iron Fe +2 ions by adsorption method. The studied quarry water belongs to waters of average mineralization, composition of which is changed depending on seasons. Copper and iron concentration in quarry water studied by us was varied within ranges of 201,6-560,1 mg/l and 462-560 mg/l,, while in Kazretula River 2,5-4,0 mg/l and 8-11,2 mg/l, respectively, that exceeds the maximum allowable concentrations (MAC), especially in case of iron. MAC of drinking-service domestic waters is 3 mg/l for copper, and 2 mg/l for iron. Vegetable raw materials were used as adsorbents: oak bark, grape stalks, sunflower pellets, corn cob, spruce sawdust, walnut partition, plane tree leaves and pine cones.

Experimental Part
Study of sorption properties of mentioned sorbents was conducted under optimum conditions.
The water samples of the river Kazretula were taken at 2000 meters away from the quarry, and quarry water samples from the water dam, from which the quarry waters are headed for processing. Samples were taken in accordance with "The sanitary rules of taking water samples" of Ministry of Internally Displaced Persons from the Occupied Territories, Labour, Health and Social Affairs of Georgia №15/N (Law article 15 and 23). Samples were several times washed by distilled water for removal of dust and other admixtures and afterwards were dried at room temperature and grinded. 5 g weights of abovementioned sorption materials were placed into test flask with a capacity of 250 cm 3 , then 50 cm 3 of surveyed solution were added and a mixture stirred during an hour in the magnetic stirrer CSM305 at the 800 rpm rate, afterwards the adsorbent was removed via filtration, and copper and iron ions concentrations have been determined in the filtrate.
Analyses have been conducted by atomic-adsorption (AAC), Perkin-Elmer (Analyst-200), photometric (KFK-2) and chemical methods. We proceed each trial 3-times, then we take the average value and the results are given in table and drawings. Metal ions quantity absorbed per 1 g of sorbent -A (mg/g) and adsorption (purification) degree of solution R% were calculated by formulas mg/g , where initial concentration, mg/dm 3 ; Cconcentration after test; msorbent mass, g; Vvolume of purified solution, dm 3 .

Results And Discussion:-
Regularities of quarry and river (Kazretula) waters purification from copper and iron ions by adsorption methods are researched. The impact of plant raw materials adsorption degree on contact time, environment pH, preliminary processing of adsorbent in relation to heavy metals sorption is studied. The dependence of copper and iron ions adsorption from the species of plant raw materials (adsorbents) in quarry water is shown in Tables 1. Research results of dependence of adsorption degree on contact time for sawdust, oak bark and damp pine cones in relation to copper and iron are shown in Fig. 1.   Fig 1:-Contact time influence on adsorption degree for Cu 2+ and Fe 2+ (pH = 3,0, ratio of adsorbent : solution volume -1:10); 1, 2oak bark, 3, 4pine cones.  -Cu 2+ x -Fe 2+ As is seen from diagrams, quarry water purification runs effectively after 30 minute contact and the maximum value of adsorption degree is reached within an hour, and afterwards they negligibly go up and weak dependence between them is observed.
The maximum value of Cu 2+ and Fe 2+ ions adsorption degree is reached in case of oak bark and is 55 and 60%, respectively, in comparison with damp pine cones, for which it equals to 43 and 57%, respectively, when pH = 3.
According to some authors, the bark of some southern species of wood contains moderate quantity of tannins. It is shown that when purifying model solutions with the use of oak bark the metal ions enter into reaction with tannincontaining substances and form insoluble complex compounds with them (Kunnambath and Thirumalaisamy,2015). It is probably one of the reasons of relatively high values of purification degree by oak bark compared with other adsorbents (Table 1).
It is known that adsorption degree of sorbent is substantially depended on environment (solution) pH (Willaescusa et al.,2004;Zhang et al.2000), and due to this reason there was studied an impact of environment acidity on adsorption of sorbing materialsoak bark and damp pine cones. Adsorption degree in relation to Cu 2+ and Fe 2+ on mentioned sorbents are given in Fig. 2.  Fig 2:-Impact of environment pH on adsorption degree of Cu 2+ and Fe 2+ ( = 1 hour, ratio of adsorbent: solution volume -1:10); 1, 2oak bark, 3, 4pine cones.  -Cu 2+ x -Fe 2+ As is seen from the diagrams, the dependence of adsorption degree on pH for copper and iron on both sorbents are almost of the same nature; they gradually go up. It is shown that maximum adsorption degree in relation to Cu 2+ and Fe 2+ ions in neutral environment (pH = 6) is observed in case of oak bark and is equal to 70 and 85%, while in case of pine cones it equals to 53 and 80%, respectively. Sorption degree on both sorbents in neutral environment is slightly higher than in acid medium, regarding both copper and iron.
It is established that this nature of sorption degree dependence on environment pH is related with change in state of active centers of sorbents. In case of low values of pH hydrogen ions totally dominate, and takes place promotion of sorbent surface that assists electrostatic repulsion of metal ions and reduction of their adsorption. At higher values of pH active centers of tannin-containing compounds (oak bark, grape stalks, pine cones) undergo dissociation and form corresponding phenolate anions, which are able to bind with metals ions and form chelate complexes (Shaikhiev and Bagauva,2014).
In order to compare the effect of preliminary alkali treatment on adsorption degree, the adsorbent (pine cones) was preliminary treated with 1N NaOH solution. It was shown that after alkali treatment adsorption degree in relation to Cu 2+ and Fe 2+ increases by 8 and 12%, respectively. Experimental data show that adsorption degree for all enumerated adsorbents regarding iron is higher than in relation to copper. Probably this is because of radius size of adsorbed cations, which plays important role. According to authors data copper cation radius is bigger than of iron cation and they equal to 73 r/P m and 70 r/P m , respectively (Wells,1984). Similar works have been carried out for the water of Kazretula River(see table2). Test results showed us that the oak barks (Cu -60%, Fe -73%), damp pine cones (Cu -48% and Fe -64%) and corn cobs (Cu -56%, Fe -60%) have purified the Kazretula water from heavy metals relatively well (Table 2). In case of oak barks Kazretula river was purified up to MAC. It is known that the efficiency of adsorption processes depends not only on sorbent properties and quantity, but also on chemical nature and concentration of adsorbed substance. The more is the substance concentration in polluted water, the more quantity is adsorbed per each gram of the sorbent (A, mg/g). This fact is clearly seen from Tables 1 and 2, in case of reduction of heavy metal ions quantity in sorbent phase in Kazretula River and quarry waters.

Conclusion:-
On the basis of foregoing materials, one can recommend the use of geochemical sorption barriers as of obstacles on the way of migration of different heavy metal ions, where the cheap natural raw materials, such as oak bark, grape stalks, pine cones, corn cobs, and sunflower husk can be used as adsorbents. When using the mentioned raw materials as adsorbents the copper adsorption degree in case of quarry water comprised 54,5% for oak bark, 30,4% for grape stalks, 43% for damp pine cones, and 38,9% for corn cobs; while the iron adsorption degree was 60,0; 40,9; 56,6 and 70%, respectively.