الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Water pollution, contamination of water bodies by substances harmful to living things as a result of increasing technological development and industrialization has been known to disrupt and destroy the fragile ecology through indiscriminate discharge of industrial and municipal wastes into water bodies. The development of industries such as paint, coating, smelting and electric battery manufacturing, alloy preparation, wood preservation, plating, tanning, corrosion inhibition has resulted in potentially toxic heavy metals and some toxic organic compounds which finding its way into natural bodies of water.
Lead, cadmium, cobalt, nickel, etc., can affect the formation of blood cells, cause malfunctions in the liver, kidneys, the circulatory system, and the movement of nerve signals. Some heavy metals are highly carcinogenic. However, the environmental contamination and human exposure to toxic metals have dramatically increased during the past century. Along with the persistence against chemical and biological degradation, heavy metals have high environmental mobility and ability for bioaccumulation in the food chain. Also, nitro phenol compounds have been found in National Priorities List sites identified by the Environmental Protection Agency (EPA) Acute (short-term) inhalation or oral exposure of 4-nitrophenol in human’s causes, headaches, drowsiness, nausea, and cyanosis (blue color in lips, ears, and fingernails) and Contact with eyes causes irritation.
Therefore, nowadays, more attention is directed towards discovery of more efficient wastewaters treatments. Conventional wastewater treatments have proved to be more unfavorable than beneficial. Hence, in the past two decades rise of the environmental awareness led to the development of new, ecofriendly technologies for wastewater
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purification. This period can be considered as the beginning of biosorption.
Many studies have suggested biosorbents derived from waste biomass such as agricultural residues, as a promising alternative agent for the treatment of heavy metals and organics, while reducing both preparation and running costs. And many literatures relevant to pollutants release from industrial wastes like heavy metals and organic pollutants in the environment and uses of biochar which prepared from agricultural residues to adsorb these pollutants. That described biochar definition, properties, production, and activation, application of biochar for water treatment, the environmental occurrence, biochar and environment. It also points out some important characteristics of organic and heavy metals and provides some insights into their environmental adverse effects and toxicity criteria.
We aimed at: 1) reviewing the characteristics of biochar to better understand its efficiency in metal and organic sorption, 2) discussing the dominant sorption mechanisms of individual metals and organic by biochar, 3) describing biochar modification to enhance its metal and organic removal from aqueous solutions, and 4) applied fixed bed column for treatment of simulated wastewater sample.
The chapter of materials and methods includes; Preparation of biochar by pyrolysis method as a potential adsorbent for nitro phenol, cadmium, zinc, lead, nickel metal ions, characterization of the as prepared biochar and identification of its structure, preparation and analysis of the synthetic solutions used in the adsorption tests and, adsorption experiments including: batch adsorption, kinetic studies and adsorption isotherms. In this work, we carried out wastewater treatment of inorganic and organic pollutants. An adsorption technique was used for this treatment. Preparation of a suitable adsorbent for decontamination
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of wastewater. We removed Pb, Zn, Ni and Cd ions as an example of inorganic pollutants and 4- nitro phenol as an example of organic pollutants.
Biochar was prepared through direct pyrolysis of maize cob to be used for the removal of heavy metals from water. A range of experiments were conducted to evaluate the sorption ability of the biochar to Pb, Zn, Ni and Cd ions in aqueous solutions. The steps of this work were as follows: (1) preparation and characterization of biochar; (2) assessment of the adsorption ability of the biochar to lead, zinc, nickel and cadmium; and (3) determination of the effects of contact time, pH, concentration of metal ions and nitro phenol and sorbent dosage, on the adsorption of the heavy metal ions and organic compounds onto the biochar.
It was concluded that biochar was possibly prepared from low cost agricultural waste (corncob), and it was used for decontamination of water from metals ions; Cd, Ni, Pb, and Zn and nitro phenol via adsorption process. The removal of Cd, Ni, Pb, and Zn ions via adsorption from wastewater by biochar is studied under different conditions. Dose of 2 g/L is chosen as optimal amount for metals adsorption. For metals ions, maximum removal% reached to 38 to 63% after 90 minutes at pH 6.5, dose of biochar of 2 g/L. It was noticed that capacity removal increases with increasing of initial metal ion concentration. The results also of present study indicated that removal efficiency rate increased from 73.4% after 5 minutes of contact time to 98.8% after 90 minutes of contact time for 4- nitro phenol. The more chance of collision of nitrophenol molecules with the surface of biochar so adsorption increased with increasing the dose of biochar. The amount of rise of removal percentage from 2 g/L to 3 g/L biochar dose was only 2%. from economical point of view, the optimum dose of adsorbent is 2 g/L of biochar which was outstanding dos