Walid M. Alalayah

Sludge production from municipal wastewater treatment in sewage treatment plant

ABSTRACT Sewage sludge is obtained from wastewater treatment in sewage treatment plants. The sludge consists of two basic forms, sludge and secondary sludge, also known as activated sludge in the case of activated sludge process. Municipal sewage sludge (MSS) or only sewage can be a solid, semi-solid, or liquid muddy residue. It contains mainly proteins, sugars, detergents, phenols, and lipids and also includes toxic and hazardous organic and inorganic pollutants source. Sewage is a mixture of domestic and industrial wastes that contains above 99% water. It is produced by residential, institutional, commercial, and industrial establishments. Sludge is semi-solid slurry and can be produced as sewage sludge from wastewater treatment processes. The sludge consists of a wide range of harmful substances such as dioxins and furans, polychlorinated biphenyls, organochlorine pesticides, absorbed and extracted chlorine derivatives, polycyclic aromatic hydrocarbons, phenols and their derivatives, phthalate, and others. Sewage treatment is the process of removing contaminants from wastewater, primarily from household sewage. It includes physical, chemical, and biological processes to remove these contaminants and produce environmentally safe treated wastewater. The treatment is divided into three stages: pretreatment, primary treatment, and secondary treatment. In pretreatment, large solids and grit are removed by screening. In primary treatment, the water is left to stand so that solids can sink to the bottom and oil and grease can rise to the surface. In secondary treatment, the sludge is further treated in sludge digesters.

Analysis of petroleum coke from low grade oily sludge of refinery

ABSTRACT Petroleum coke is often shortened as pet coke. Petroleum coke or pet coke is a product obtained from oil of all kinds during the oil refining process. Petroleum coke is a carbon-rich solid originating from petroleum refining and is obtained by cracking process. Petroleum coke is a byproduct of the coking unit, a residual fuel upgrader. The coke quality depends on the crude oil processed in refinery. The mixture of oil, solids and water deposited at the bottom of the storage deposit is known as waste oil sludge. Oil sludge is one of the solid wastes produced in petroleum refinery and it is a complex emulsion composed of various petroleum hydrocarbons, heavy metals, solid particles, and water. As a result of the refining process of crude oil, the contaminated sludge is biodegraded and converted into waste products that damage the environment and human health. In the coke processing, the assessment of oil sludge fraction is based on the principle of heating to high temperatures and the removal of light fractions from the breakdown. If the oil sludge initially contains low levels of sulfur and metal, the resulting petroleum coke is then calcined before use. The high quality needle type coke produced on convenient conditions in the coking unit.

Gasoline- and diesel-like products from heavy oils via catalytic pyrolysis

ABSTRACT Heavy oil is less expensive than light crude oil, but heavy oil is more expensive to obtain light oil products. Conventional light crude oil resources are decreasing, therefore heavy oil resources will be needed more in the future. There are huge differences from field to field for heavy oil deposits. In terms of final productive use, heavy oil is considered as an unconventional resource. Heavy oil upgrading depends on four important factors: catalyst selection, heavy oil classification, process design, and production economics. Heavy and extra-heavy oils are unconventional reservoirs of oil. Globally, 21.3% of total oil reserves are heavy oil. Heavy oil is composed of long chain organic molecules called heavy hydrocarbons. The thermal degradation of the heavy hydrocarbons in heavy oil generates liquid and gaseous products. All kinds of heavy oils contain asphaltenes, and therefore are considered to be very dense material. The most similar technologies for upgrading of heavy oils are pyrolysis and catalytic pyrolysis, thermal and catalytic cracking, and hydrocracking. The amount of liquid products obtained from pyrolysis of heavy oil was dependent on the temperature and the catalyst. Pyrolytic oil contains highly valuable light hydrocarbons as gasoline and diesel components range. The constant increase in the use of crude oils has raised prices of the most common commercial conventional products and consequently seeking for new alternative petroleum resources, like some unconventional oil resources, becomes an interesting issue. The mass contents of gasoline, diesel, and heavy oil in the crude oil are 44.6%, 38.3%, and 17.1%, respectively. The gasoline yield from the heavy oil catalytic (Na2CO3) pyrolysis is higher than the diesel efficiency for all conditions. The yield of gasoline products increases with increasing pyrolysis temperature (from 230°C to 350°C) and percentage of catalyst (from 5% to 10%). The yields of gasoline-like product are from 21.5% to 39.1% in 5% catalytic run and from 32.5% to 42.5% in 10% catalytic run. The yields of diesel-like product are from 9.3% to 29.8% in 5% catalytic run and from 15.5% to 33.7% in 10% catalytic run.

Treatment of contaminated wastewater

ABSTRACT The environmental impacts of petroleum are often negative because they are toxic to almost all lifestyles, and there is a possibility of causing climate change. Oil pollution in the air and in the water can be toxic and dangerous to the human body. Preliminary researchers have thoroughly studied and discussed the methods of treatment of oily wastewater. Removing oily wastewater from the oil without damaging the environment is an important problem for the oil industry. The three-phase solid, water, and oil blends can be separated from each other when a continuous oil–water separator system is used. Oil contaminated wastewater is generally treated by gravity sedimentation, coagulation, flotation, coagulation composite flotation, demulsification, membrane separation, flocculation treatment, chemical precipitation, and biological treatment and filtration.

Kinetics of biological hydrogen production from green microalgae Chlorella vulgaris using glucose as initial substrate

ABSTRACT In this study, the kinetics of chemical reaction was studied based on the correlation between the rate of degradation of glucose by the microalgae and the rate of hydrogen gas formation. Bio-photolysis was carried out algal strain Chlorella vulagaris in order to produce hydrogen gas (H2) using glucose as an initial substrate. Algal strain C. vulgaris was used in this study. The strain was grown in the Bold’s basal culture (BBC) medium. Hydrogen was produced by degradation of glucose stored in a bioreactor. Produced gas was analyzed by gas chromatography (GC) to detect pure hydrogen gas production. The GC equipment was equipped with a column filled with molecular sieve 5A column containing argon as a carrier gas. During the experiment, the glucose concentration in the medium was determined by a blood-glucose analyzer. The initial glucose concentration plays an important role in the yield of hydrogen production. The results show that the highest hydrogen production over time was observed at varying glucose concentrations when the initial glucose concentration was 10 g/L. pH of medium is a critical factor in the hydrogen production process. A series of tests with pH ranging from pH 6.0 ± 0.2 to 9.0 ± 0.2 was performed. The results showed that the highest hydrogen yield was obtained by increasing the molar nitrogen and phosphate content by 10%. All experimental runs were carried out at 22°C. Essentially, the glucose uptake rate versus the hydrogen production rate is compared in this study, because the production rate of hydrogen depends on the rate of glucose depletion. For the glucose consumption, the order of reaction (n = 0.942) was first order. The reaction rate constant (k) was 7.037 × 102 s−1 for the glucose consumption. For the hydrogen production, the order of reaction (n = 0.954) was also first order, while the reaction rate constant (k) was 3.890 × 102 s−1 for the hydrogen production.

High Hydrogen Yield by Fermentation Using Clostridium Saccharoperbutylacetonicum N1-4

High hydrogen yield was carried out using Clostridium saccharoperbutylacetonicum N1-4 (ATCC 13564). The ability of this Clostridium on hydrogen production was studied in 250 mL batch culture with glucose as the sole organic carbon source. The effect of initial substrate concentration, initial medium pH, addition of Fe2+ and temperature were investigated. Results show that the highest yield (Yp/s ) of hydrogen produced was about 3.10 mol (mol glucose)−1 when the initial glucose concentration was 10 gL−1 , initial pH of 6.0 ± 0.2 and temperature 37°C. The yield of hydrogen produced decreased when higher initial glucose concentration was applied. The yield of hydrogen was increased when 25 mg L−1 Fe2+ was added to the medium.Copyright