Bioenergy Science

Abstract: In this study monthly aerosol samples collected at Erbil city, Iraq, throughout 2008-2009 yielded
significant concentration of viable (culture forming) bacteria and fungi only when the dust was present. The
results indicated the concentration of total bacteria was ranged from 3×104 to 36×106 CFU/g, and concentration
of fungi varied a wide range from 6×103 to 36×103 CFU/g. The dominant group of bacteria isolated from the
dust was Pseudomonas 25.6%, including P. corrugate, P. diminuta, P. marginata and P. agaramicus, followed
by Zanthomonas 17.9%, including Z. orgzae, Staphylococcus 12.8%, including S. xylosus, S. epidermidis,
S. homonis and S. cohini, Bacillus 10.2%, including B. subtilis and B. licheniformis, Curtobacterium,
Micrococcus and Streptococcus 5.1%, Ctrubacterium, Rhodococcus and Agrobacterium 3.4%. Our data also
confirms the existence of Aspergillus which comprised 23.4% of fungi colonies, followed by Penicillium
12.8%, Emerciella sp. 10.62%, Tetracoccosporium, Eurotium sp. 8.51%, Rhizopus sp., Sterile fungus,
Trichocladium sp. 6.4%, Alternaria sp., Phoma sp., Yeast, Curvularia sp., Ascochyta sp., Taeniolella sp.,
Trichophyton, Fusarium sp., 2.12% of total isolated fungi.

Since particulates are a sort air pollution and impact on environmental conditions seriously, considerable amount of program to assess and to control air pollution are regarded, since there are only a few study on dust deposition in Iraq and since there is a drought condition in last few years. Iraqi Kurdistan region, an experiment on dust accumulation as indoor and outdoor air pollution was made within Erbil city and surrounding areas from November 2008 to April, 2009. The amount of deposited dry dust in deferent studied location and surrounded area was between 9.1 and 48.3 gm.m2. per 2months. The results revealed that the concentration of some chemical characteristics like total acidity, total alkalinity and sulphat was ranged between 7 - 33, 50 - 88 and 15 - 180 mg/l respectively. Also determine elements in accumulated dry dust such as nitrogen, phosphorus, potassium and sodium was ranged from 20.3 - 95.3, 6.3 - 2.06, 8.02 - 66.7 and 0.9 - 43.6 mg/l respectively. However, heavy metals including Zn+2, Fe+3, Cr+3, CU+2 and Pb+2 was at rang of 0.54 - 3.8, 15.4 - 67.3, 0.04 - 1.22, 0.025 - 0.47 and 0.21 - 2.17 mg/l respectively. Finally radiation level was ranged from 0.02 to 0.08 msv/h (mile severt/hour).

Abstract. Over the past few years, the Erbil -Iraq city has produced 100 tons of solid waste daily yet there
is no sanitary land fill for ultimate disposal of solid waste. For a long time, it has been a common practice to
dispose of soil waste in open low-lying areas. Recently, the government commissioned a new process to
separate solid wastes in to organic and inorganic fractions. In the present study, particular interest are plastics,
because plastics are not eco-friendly as they are non-biodegradable or degrade very slowly, and could secrete
pollutants including heavy metals into the soil. The binding property of plastics in its molten state has helped
in discovering a method of safe disposal of plastic waste, which is their use in road laying. This study
determines some common heavy metals in soil at depths of 0-15 cm the concentration of heavy metals
including Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn were determined, and Fe recorded highest value comparing with
other metals. While, the main aim is to use the plastic waste to mix with bitumen. This mix has high Marshall
Value, low penetration value and resistance to water penetration.

This study examined the physical and chemical characteristics of rainwater from 15 sites in Kurdistan- Iraq between March and April 2009 and compared the growth of crop plants (Triticum duarium, Lens esculenta, Cicer arietinum and Bracica oleraceae) using rainwater.  Results were analyzed using a factorial experiment which was replicated three times using a randomized design set-up. Results revealed that plant growth varied with 22.89 ± 3.54 cm recorded at the Bahirk’s village site and 5.33 ± 0.764 cm recorded at the Erbil Kirkuk road site, respectively. Fresh shoot dry weight ranged between 1.181 ± 0.054 gm and 0.023 ± 0.011gm; fresh root weight was between 1.38 ± 0.07 gm and root dry weight was 0.0519 ± 0.021 gm respectively. Determination of nutrient content of rainwater revealed that N-3, P-3, K+, and Na+ concentrations ranged between  (6.98 -  3.53; 2.28 -  2.17; 106.51 - 38.41; and 19.55 - 12.94) mg/L, respectively. Results revealed that rainwater can be applied for agricultural purposes as plant characteristics and the nutrient content did not fundamentally change when compared with use of Tab water.

Pre-treatment is one of the key challenges in the conversion of lignocellulosic raw materials into bioethanol. Various pre-treatment strategies have been developed, such as dilute acid pre-treatment, alkali pre-treatment, steam explosion and ammonia explosion pre-treatment. These methods are energy intensive as these are normally operated at high temperature, high pressure or high chemical loading rate. Inhibitor formation during the pre-treatment is another concern in these methods, which significantly impacts the efficiency of the following fermentation processes.

Analysis of the chemical components of Municipal solid waste (MSW) indicated that the presence of high concentrations of toxic heavy metals. The aim of this study was to select the best leaching condition, in order to generate a compost product, which adheres to the environmental standards for safe use. To determine the role of organic acids produced in the bioleaching process, chemical leaching experiments were compared using inorganic (H 2 SO 4) or organic acids (oxalic, and gluconic acids). These results revealed that addition of H 2 SO 4 correlated with a lower retained yield when comparing with addition of the other acids. Bioleaching was then studied by culturing fungi on the MSW. Addition of Aspergillus niger correlated with an efficient removal of heavy metal elements. The effect of pH was also determined and assays at pH 5.5 using a clay medium (32.4%) or at pH 2.5 using a sorghum medium (28%) were characterised by a lower retained yield. In the above conditions, we looked at elemental ions which have been deemed beneficial to the environment (P and K) and those which are toxic (Cd, Cu,Cr, Ni, Pb and Zn), these elements were measured in the solid fractions.

Analysis of the chemical components of Municipal solid waste (MSW) indicated that the presence of high concentrations of toxic heavy metals. The aim of this study was to select the best leaching condition, in order to generate a compost product, which adheres to the environmental standards for safe use. To determine the role of organic acids produced in the bioleaching process, chemical leaching experiments were compared using inorganic (H 2 SO 4) or organic acids (oxalic, and gluconic acids). These results revealed that addition of H 2 SO 4 correlated with a lower retained yield when comparing with addition of the other acids. Bioleaching was then studied by culturing fungi on the MSW. Addition of Aspergillus niger correlated with an efficient removal of heavy metal elements. The effect of pH was also determined and assays at pH 5.5 using a clay medium (32.4%) or at pH 2.5 using a sorghum medium (28%) were characterised by a lower retained yield. In the above conditions, we looked at elemental ions which have been deemed beneficial to the environment (P and K) and those which are toxic (Cd, Cu,Cr, Ni, Pb and Zn), these elements were measured in the solid fractions.

Treatment of Municipal Solid Waste (MSW) becomes an increasing problem worldwide; however, MSW contains high lignocellulosic content that can be further processed for the generation of electricity, transportation fuel and other commercially important products. This study aims to explore the possibility of hydrolyzing MSW into a sugar solution, which could then be fermented into liquid biofuels, such as bioethanol. Two commercial cellulase enzymes, Cellic® CTec2, and a fresh prepared fungal filtrate were used to hydrolyse MSW. Results revealed that CTec2 displayed the best hydrolysis efficiency. Use of an alkali pre-treatment on MSW before enzymatic hydrolysis failed to show any improvement in terms of release of sugars, an assessment of the efficacy of addition of surfactants revealed that addition of tween 80 or polyethylglycol had a no significant effect on release of sugars. Results revealed that by increasing the solid liquid ratio the amount of glucose increased, Data generated by this study was analysed using design expert stat program.

Bioleaching can be considering a simple and effective technology for removing metals from waste which is rich in heavy metals. Bioleaching of these metals by microorganisms offers an economical and eco-friendly approach. In this study Saccharomyces cerevisiae NCYC2592, was used to remove metals from municipal solid waste (MSW). The tolerance of S. cerevisiae against the metals was determined using phenotypic microarrays using artificial hydrolysate containing various metals. Parameters such as one and two way methods or process, yeast strains, pH and mediums were studied and optimized. The results revealed that two-way methods and S. stipitis strain among five strains, using artificial media correlated with better performance at pH 5.5, while at pH 4 Correlated with sorghum media which showed lowest retained yield %.

Worldwide significant amounts of food waste are generated daily causing serious environmental issues, occupying land and requiring expenditure of resources for its treatment. A smart method for handling this food waste problem is the development of novel processes targeting the conversion of this waste into value added products. Although valorization of food waste to biofuels, biochemicals and bio-polymers have been widely investigated, the utilization of food waste streams into biofertiliser has not been intensively reviewed. Conversion of food waste, especially agriculture residues into biofertiliser would reduce its environmental impact, improve nutrition levels of the soil, decrease requirements for synthetic chemical fertiliser and have a direct benefit on food production. This paper reviews recent progress in the field regarding the production of biofertiliser from food waste, using anaerobic digestion, aerobic composting, chemical hydrolysis, in situ degradation and direct burning methods. This review also highlights the latest field applications of biofertiliser derived from various food waste streams. It confirms that the technology for the conversion of food waste to biofertilisers is viable, but the production efficiency could be improved with better process control strategies, strict quality controls, development of a smart product distribution system and adoption of advanced technologies. Field tests have indicated that biofertilisers which are obtained in proper managed AD plants are safe and could partially replace the use of chemical fertilisers in field application.

Energy is an important requirement for population growth, technological progress and urbanisation. Worldwide energy demand has been projected to increase 5-fold by 2100. Fulfilment of these energy requirements cannot be solely reliant on fossil fuels, such as oil, coal and natural gas, on account of their adverse environmental impacts and concomitant depletion of natural resources. As a result multiple approaches for generating alternative energy are being explored globally.In this review paper, focused on the viability of waste especially MSW being a source for bioenergy products such as methane gas, bio-enzyme, biofuel and bio-fertiliser production. This review also focuses on the environmental impacts of MSW, the effect of MSW pre-treatments and properties (physical and chemical) on bioenergy products production.