REMOVAL OF HEAVY METALS FROM LUBRICANT INDUSTRIAL WASTE WATER

REMOVAL OF HEAVY METALS FROM LUBRICANT INDUSTRIAL WASTEWATER

Abstract: This research aims to remove heavy metals that are carcinogenic to humans and harmful to the aquatic ecosystem from the industrial wastewater in lubricant industries. Adsorption has been proved to be the best process of water treatment because of its significant advantages. Clays and their minerals are abundant and cheap material successfully used for decades as an adsorbent for removing toxic heavy metals from aqueous solutions . The presence of heavy metals in water for human use or consumption represents a major risk to human health. It is therefore important to find materials to remove or minimize the concentration of these pollutants. Clays and their minerals, both in its natural and modified forms, effectively remove various heavy metals from aqueous solution, as extensively discussed in this review. This detailed review compiles thorough literature of current research over the last ten years (2000–2016) and highlights the key findings of adsorption studies that use clay minerals as an adsorbent. The adsorption process for the removal of heavy metals is favored by the use of low-cost materials that exhibit a porous structure and a high cation exchange capacity such as zeolites and clays.

CHAPTER ONE

• BACKGROUND OF STUDY

Environmental regulation and public health concerns require that wastewater collected from municipalities and communities must be treated to a set standard before it is returned to surface waters or land or even reused (Jiang et al. 2004).

Municipal wastewaters are still very important in the issue in waste management systems within Southeast Asia and the rest of the world. The COD, turbidity, Total

Suspended Solids (TSS), and major cations are the main concerns of the characteristics of municipal wastewaters. Generally, high levels of COD results in  low Dissolve Oxygen (DO) in water and this can lead to mortality of aquatic life.

In addition to that, suspended solids such as organic and inorganic materials can

result in the water being contaminated by dirt and odour.

Environmental pollution control has been a concerned issue in many countries. The most concerned environmental pollution is air pollution and wastewater pollution. Air pollution usually comes from open burning especially the forest and vehicles combustion while wastewater pollution comes from the industrial effluent and also from the domestic sewage. It is an interesting issue since it is one of the most public health concerns.

Wastewater pollution gives bad effects on public water supplies which can cause health problem such as diarrhea. While air pollution can cause lung diseases, burning eyes, cough and chest tightness.  Additionally, it is also an esthetic concern coursed by odours and discolouration which interferes bathing facilities and recreation. It is also can cause property damage such as the discharge of sewage affects industrial water supplies by changing the character of the water. It is also affect real estate by causing paints to discolor as well as damage to boat, andpollution of the aquatic environment by heavy metals has been considered a major threat to the aquatic organisms (Saeed and Shaker, 2008).

Industrial activities is on the increase everyday which has a direct proportional relationship to increase in the level of effluent from these industries like paint industries, petroleum industries, chemical industries, oil and lubricant industries.With the need for disposal of both domestic and industrial effluents, industrialization and urbanization have accelerated pollution in the water bodies environment, hence treatment before disposal and reuse of industrial treated wastewater is becoming of extreme importance (Xujie Lu et al., 2010).

The demand for lubricants is continually increasing with the increase in the establishment of factories and the tremendous increase in the number of vehicles and other means of transportation has led to more wastewater pollution issue.  These wastewater generated is characterized by oily water, sludge, acidity, presence of heavy metals; zinc, mercury, iron, cadmium, lead.These heavy metals are the non-degradable metals, many studies have shown also that these heavy metals are toxic even at low concentration hence the need for treatment of the wastewater before disposal. The presence of these toxic metals can cause in turn, accumulative poisoning, destroy liver, cancer and brain damage when found above the tolerance level (Pescod, 1992).

Presently, heavy metals are be removed from wastewater by several methods include ion exchange, solvent extraction, foam flotation, filtration, coagulation, electro deposition, chemical precipitation and membrane reverse osmosis, adsorption. Among these methods, adsorption by clay is the most extensively used due to its considerable effective and cost as compared to more expensive water treatment method such as ion exchange.

• PROBLEM STATEMENT

Several industrial wastewater streams may contain heavy metals such as Sb, Cr, Cu, Pb, Zn, Co, Ni, etc. including the waste liquids generated by petroleum or the mineral processing industries. If the wastewaters were discharged directly into natural waters, it will constitute a great risk for the aquatic ecosystem, while the direct discharge into the sewage system may affect negatively the subsequent biological wastewater treatment. It is also important to ensure there are no harmful heavy metals in the water stream because it can accumulate in the environmental elements such as the food chain and pose a significant danger to human health. Adsorption is one of the several unit operations which by used to achieve these heavy metal separation from lubricant industries, due to its advantage of Flexibility and simplicity of design, ease of operation and insensitivity to toxic pollutants. Clay is used as an adsorbent in this research to investigate its adsorption efficiency at different temperature.

• AIM  AND OBJECTIVE OF THE RESEARCH WORK

This research aims to remove heavy metals that are carcinogenic to humans and harmful to the aquatic ecosystem from the industrial wastewater from the lubricants producing industry.

OBJECTIVES

1. Characterization of the clay using XRD, XRF, CEC, and SEM.
2. Evaluation and optimization of clay mineral for their removal capabilities, kinetics and mechanisms for wastewater treatment.
3. Characterization of the industrial wastewater before and after treatment.

• SIGNIFICANCE OF RESEARCH WORK

The rationales of significances of this study are:

1. To prevent the heavy metal concentration release to the water stream which causes foul odor and toxicity that can be a potential hazard to human health and environment.
2. To reduce the cost of wastewater treatment by using clay as an adsorbent in the adsorption process on heavy metal degradation.
3. To open up opportunities to increase the demand for wastewater treatment by using adsorption with natural absorbent; clay as proven by researchers that have a lot of benefits.
4. To reduce the danger of polluted water in the environment as we know that wastewater from lubricant industries is carcinogenic and very harmful.