النشر العلمي

  • A challenge of sustaining water supply and sanitation under growing population: A case of the Gezira State, Sudan

The challenge of securing future water supply and sanitation services for an increasing population requires continued efforts to satisfy the future needs. This paper focuses on water availability and sanitation services under growing population taking Gezira State, Sudan, as the case. Future projection of the population was predicted based on the 2.2% growth rate. Data on water sources, quantities and sanitation was collected from Gezira State Water Corporation and various health and educational reports. The results calculated that the population is increasing by 14% from 2008 to 2014. Water stands are the main source of water in Gezira and yields 84% of the available water. The current consumption rates are 22.5 and 55 Liter per capita per day for rural and urban population, respectively. There is a gab in rural water supply and is expected to increase rapidly by 2025. Sanitation coverage in the state is 80% in schools and 88% in health facilities. The study recommended construction of new water sources to satisfy the rural consumption.

published in International Journal of Water Resources and Environmental Engineering , 7(9):132-138

  • اثر المواد الخام المستخدمة على الخواص الفیزیائیھ للورق

Abstract

 

تعتبر صناعة الورق من أقدم الصناعات التي عرفها الإنسان إذ يعود الفضل في اختراعها إلي الصينيين وذلك في القرن الأول الميلادي باستخدام سيقان نبات الخيزران المجوفة والخرق البالية . فالورق عبارة عن رقائق مستوية  تتكون من عدد كبير من الألياف الرقيقة القصيرة التي تشبه الشعيرات والتي تكون متداخلة مع بعضها ومتلاصقة مكونة سطحا متصلا أملس. تعتبر ألياف السليلوز هي الألياف الأساسية التي يتكون منها الورق .

من المواد الاخرى التي تكون الخلايا النباتية بجانب السليلوز الهيمو سليلوز، اللجنين والمواد الغروية ، فهذه المكونات لها اثر على خصائص الورق المصنع . فالهيمو سليلوز مادة عديدة السكر (polysaccharides) قليلة الوزن الجزئي ،فالهيموسليلوز يشبه السليلوز ولكن يختلف عنه في قصر السلسلة وذوبانه في القلويات كما أنه اكثر استعداداً  من السليلوز للتمؤ فهو يعمل على تقوية صفائح الورق كما ان له بعض الصفات السالبة التي تعمل على تقليل شفافية الورق ، ويزيد من الزمن المطلوب للتخلص من الماء كما انه يقلل من نسبة الاكسجين البايولوجي (BOD) (حسين واخرون,1988).

اما اللجنين (lignin)  فهو عبارة عن مخلوط مركب من المواد العضوية ذات الصبغة الاروماتية وتعتمد صلابة جدران الخلايا النباتية على وجود هذه المادة . يكون اللجنين 20-40 % من وزن الخشب في الاشجار وهو مادة بلورية بنية اللون .فاللجنين يعطي انسجة النبات وكل شعيرة على حده قدر من المتانة ويجعل جدار خلية الالياف الكثر صلابة.ويمنع الكاربوهايدريت من التلف نتيجة للعوامل الفيزيائية والكيميائية(Abdul Khalil et al,2006) هنالك ايضا المواد الصمغيه   والغروية وتعتمد كمية هذه المواد على نوعية النبات وعمره وهي تعطي الأشجار الطعم واللون والرائحة . هذه المركبات تتكون من الدهون والدهون الحمضية والأحماض     ومن السيانيد والترينز والفتوسترين والشموع ومن آثارها السالبة على الورق حاجتها لكميه من المواد الكيميائية للتخلص منها و تكسب السيليلوز اللون الداكن (حسين واخرون,1988) .ان التغيرات المناخيه وزيادة عدد السكان قد أسهما في الحد من الرقعه المخصصه للغابات الامر الذي قلل من كميه الأخشاب المستخدمة لصناعة اللب ومن ثم صناعة الورق (Bruenner,1994) هذا استدعى البحث عن مصادر بديله. تنتج المحاصيل

الحقليه قدر كبير من السيقان تشكل عائقا للعمليات الفلاحيه اللاحقه لذا بداء التفكير في التخلص منها والاسنفادة منها في صناعة الورق بدلا عن الخشب (Veseth,1987).تتاثر خواص الورق المصنع من الأخشاب والمحاصيل الحقليه بكل من ظروف الإنبات والتلاعب بالجينات,فكثير من الدراسات أظهرت ان التركيب الكيميائي للقمح يختلف باختلاف الموقع والجينات وظروف الإنبات.فان الكاربوهيدريت يختلف بحوالي(+5%)واللجنين بحوالي((+2% والرماد بحوالي((+3%والسيليكا بنفس النسبة(Utne and Hegbon,1992). ينتج الاتحاد الأوربي سنويا75 مليون طن من الورق. 34مليون طن من جملة الورق المنتج يستخدم فيه الورق الراجع .ان إعادة تصنيع الورق توفر استخدام  50-60مليون طن من الاخشاب سنويا ويقلل من المخلفات بنحو 165مليون متر مكعب سنويا (Report,2001).تعتمد متانة الورق على الماده السيليلوزية للنبات,فالنباتات التي تحتوي على 34%  فأكثر من الفاسيليلوز تصنف من النباتات الواعدة لإنتاج اللب وصناعة الورق (Nieschlag et al,1990)

published in Gezira Journal of Engineering and Applied Sciences Vol3 No1

  • ). Reduction of Pesticides in Agricultural Products.

      Food is the basic necessity of life, and food contaminated with toxic pesticides is associated with severe effects on the human health. Hence, it is pertinent to explore strategies that address this situation of food safety, especially for the developing countries where pesticide contamination is widespread, due to indiscriminate usage, misuse and abuse , and a major part of population lives below poverty line . It is, therefore, of significance to evaluate simple, cost-effective strategies to enhance food safety from harmful pesticides for poor populace.  Agricultural production has been accompanied by continuous growth in the number and quantity of agrochemicals applied to crops. Pesticide use is associated with environmental contamination and human health problems worldwide. Currently, >800 pesticide A.I.s in a wide range of commercial products are registered for use in agriculture to meet food supply demands. Pesticides are essential in modern agricultural practices but, due to their biocide activity and potential risk to the consumer, the control of pesticide residues in foods is a growing source of concern for the general population and environment. Over 98% of sprayed insecticides and 95% of herbicides reach a destination other than their target species, including non-target species, air, water and soil. Particular uncertainty exists regarding the long-term effects of low-dose pesticide exposures. Current surveillance systems are inadequate to characterize potential exposure problems related to pesticide usage or pesticide-related illnesses. Associations between non-Hodgkin lymphoma, leukemia, prostate cancer, multiple myeloma, and soft tissues sarcoma have been reported in studies, with less association found for other cancers. Pesticide residues in or on plants may be unavoidable, even when pesticides are used in accordance with Good Agricultural Practice (GAP) . Most of the applied pesticides find their way as ‘residue’ in the environment into the terrestrial and aquatic food-chains, where they undergo concentration (biomagnification) and exert potential, long -term, adverse health effects. Pesticide residues are influenced by processing or household preparation stages,  e.g. washing, peeling and cooking etc. Processing studies allow a better estimate of the consumer exposure to the residues. Studies into effects of storage and some commercial processing techniques on residues in food are a part of the registration requirements for pesticides in many countries. Reviewing the extensive literature showed that in most cases these steps lead to large reductions in residue levels in the prepared food, particularly through, washing, and peeling, fermentation, refrigeration and some other operations. Food processing techniques implies the set of methods and techniques used to transform raw ingredients into food or to transform food into other forms for consumption by humans or animals either in the home or by the food processing industry. The most common food processing techniques can aid in pesticide reduction. The techniques that will be discussed are: baking, dairy product manufacture, drying, fermentation,  freezing and refrigeration, infusion, juicing, malting, milling, peeling, storage, thermal processing (canning and cooking), washing, wine making.

published in The 9th ANCAP Symposium to be held at the University of Nairobi, Kenya, from the 21st to the 23rd of November 2016 .

  • Storage Stability of Some Insecticides in Common Use under the Sudan Gezira Conditions.

The use of pesticides in the Sudan started in the mid forties in the Gezira. Science that time the quantity was steadily increasing with the increase of cotton area. In season 1978/79 the total cultivated area was 540,000 feddans (F), and the average number of sprays per season 1987/88 was ca. $60 million. The stocking for the required pesticides is determined by the Pest & disease Committee. The committee normally recommends five spray/season, but caters for two more excess sprays as a reserve. Part of the stocked pesticides could sometimes be carried over into the following seasons. the study attempts to answer the questions of whether, how and to what extent the storage condition in the Gezira scheme affect the pesticides physical and chemical properties. Four commonly used insecticides were chosen for the study from the fresh stocks: Dursban 4 EC (chlorpyrifos), Decis 2.5% EC (Deltamethrin), Thimul 50% EC (endosulfan), and a ULV mixture of Thimul/Dimethoate 500/200 (endosulfan/dimethoate). They were subject to the different pre-specified storage conditions for one year. The same four insecticides were also chosen from the carried over stocks of the foregone season  that have already spent one air in storage in the open air. The latters were kept for another year in the open air. Sample from both the fresh insecticides and the carry over were drawn at regular internals to check if any changes in the physical or chemical properties have taken place. Treatment (1): indoors (shed storage for one year; (2): storage under open shed for one year; (3): Storage in the open air for one  year, and (4): Storage in the open air for two years. The methods of CIPAC were adopted to test for the physical properties. GLC was used  to test the active ingredient (a.i.) content. The study also included the determination of the water hardness of the irrigation water in the scheme as important for ECs application. It was found to be 83 ppm as calcium carbonate (i.e. soft water). Emulsion quality of Dursban have not changed significantly. Same observations were noted as far as specific gravity (sp. Gr.) is concerned. Water-content  and free acidity have considerably increased, and as a result, the flash point also increased. By the end of the 2nd year of storage in the open, the a.i. content decreased by 3.9%. the sp. Gr., the emulsion stability, and the a.i. content of deltamethrin did not show any significant changes under the different condition and durations. The water-content, free acidity, and flash point have increased during storage. Thimul behaved rather differently: the sp. Gr. And the emulsion properties have deteriorated; no remarkable change in the total endosulfan content. The deterioration is attributed to the increase in the free acidity.

The sp. gr. viscosity, and flash point of the ULV mixture exhibited significant increase during storage. There was a striking decreased in dimethoate content of this mixture (up to 10.3% one yr in open air). The deterioration reached 26.7% in dimethoate stored in open air for two years.

published in The Indian Agric. Research Center (ICAR), Delhi

  • Storage Stability of Some Insecticides in Common Use under the Sudan Gezira Conditions.

The use of pesticides in the Sudan started in the mid forties in the Gezira. Science that time the quantity was steadily increasing with the increase of cotton area. In season 1978/79 the total cultivated area was 540,000 feddans (F), and the average number of sprays per season 1987/88 was ca. $60 million. The stocking for the required pesticides is determined by the Pest & disease Committee. The committee normally recommends five spray/season, but caters for two more excess sprays as a reserve. Part of the stocked pesticides could sometimes be carried over into the following seasons. the study attempts to answer the questions of whether, how and to what extent the storage condition in the Gezira scheme affect the pesticides physical and chemical properties. Four commonly used insecticides were chosen for the study from the fresh stocks: Dursban 4 EC (chlorpyrifos), Decis 2.5% EC (Deltamethrin), Thimul 50% EC (endosulfan), and a ULV mixture of Thimul/Dimethoate 500/200 (endosulfan/dimethoate). They were subject to the different pre-specified storage conditions for one year. The same four insecticides were also chosen from the carried over stocks of the foregone season  that have already spent one air in storage in the open air. The latters were kept for another year in the open air. Sample from both the fresh insecticides and the carry over were drawn at regular internals to check if any changes in the physical or chemical properties have taken place. Treatment (1): indoors (shed storage for one year; (2): storage under open shed for one year; (3): Storage in the open air for one  year, and (4): Storage in the open air for two years. The methods of CIPAC were adopted to test for the physical properties. GLC was used  to test the active ingredient (a.i.) content. The study also included the determination of the water hardness of the irrigation water in the scheme as important for ECs application. It was found to be 83 ppm as calcium carbonate (i.e. soft water). Emulsion quality of Dursban have not changed significantly. Same observations were noted as far as specific gravity (sp. Gr.) is concerned. Water-content  and free acidity have considerably increased, and as a result, the flash point also increased. By the end of the 2nd year of storage in the open, the a.i. content decreased by 3.9%. the sp. Gr., the emulsion stability, and the a.i. content of deltamethrin did not show any significant changes under the different condition and durations. The water-content, free acidity, and flash point have increased during storage. Thimul behaved rather differently: the sp. Gr. And the emulsion properties have deteriorated; no remarkable change in the total endosulfan content. The deterioration is attributed to the increase in the free acidity.

The sp. gr. viscosity, and flash point of the ULV mixture exhibited significant increase during storage. There was a striking decreased in dimethoate content of this mixture (up to 10.3% one yr in open air). The deterioration reached 26.7% in dimethoate stored in open air for two years.

published in The Indian Agric. Research Center (ICAR), Delhi

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