The Feasibility of Family Biogas Production from Mixed

Pastures in general and in the eastern slopes in particular have a great role in local livestock sector. Recently, local pastures witnessed a great deal of deterioration. This affects local livestock operations. The objectives of this study were to examine the pastures through different aspects as the plant cover, habitat, problems of overgrazing and those related to the Israeli occupation authority. A well-constructed questionnaire was implemented to obtain data required from the total livestock farmers of about 1600. The study showed that only 20% of the pasture areas in the eastern slopes are accessible by farmers compared to the area before 1967. This limited area is not completely free for grazing as farmers in that district utilize some of the area in cultivation of some field crops. The study showed the limitation of water in the studied area where water is provided though water tanks. More than 70% of farmers in the area of the study are lacking in social, health and veterinary services. It was concluded from the study that plant cover in area is enough for only 10% of livestock population. Some recommendations were given to help improving the conditions of the eastern slopes pastures. Biogas technology is a technology that applied to produce biogas (energy source) and organic fertilizer by anaerobic digestion for organic materials, especially organic wastes that should be disposed off to give more socio-economic and environmental positive impacts. The success of biogas plants (projects) at an area depends on: - availability of organic materials, cost of constructing, founded energy sources and its costs, experience, knowledge, ambient climate conditions especially temperature, and acceptability for people constructing these plants. The research concerned with studying the feasibility of family biogas production from mixed organic wastes in Palestinian rural areas by field survey and experiment. The field survey data support the opinion about the importance of constructing family biogas plants in Palestinian rural areas where the average of rural family members’ number is (6.85) with high average monthly energy cost (45.97 JD) per family or (6.711JD) per capita. The field survey data also indicate the availability of organic wastes for rural families, since most of these families raise animals (72.47%), and of cultivation activities (87.45%), besides their generated domestic wastes. Moreover; these families follow useless or negative methods for disposing off their: - animals’ dung {collected to be disposed off later, 71.20%}, domestic solid wastes {disposed off in general containers, 75.80%} and waste water {drained off to the cess pits, 89.00%}, in contrast; these families fed their plants and crops residues to animals (70.80%) which is a positive disposing method. Field survey data reveal Palestinian rural people suffer from negative impacts of organic wastes {reply average percentage, 60.30%}. They have also a positive awareness toward wastes impacts and issues {average percentage, 65.2%}. Attitudes could enhance their acceptance {average percentage, 65.8%} for constructing biogas plants, especially if they provided with financial assistance and necessary knowledge about biogas technology and its benefits. Twenty samples (18 in barrel digesters each of 240 litter, and 2 in large digesters each of 1500 litter) of mixed organic wastes were tested at ambient conditions. The effects of organic waste type, stirring, enlargement and dilution factors on samples biogas production were studied. The pH- values for all samples (initially ranged between 6.52 and 8.12) drop slowly in the first days of the digestion process to below 6, then raise gradually to reach more than 7 at last days for all samples. The experiment data show all samples produce biogas at ambient temperature with an average biogas weight (51.9g) per kilogram of mixed organic wastes, and reach their maximum biogas production within a time interval of (24 to 36) days from the beginning of the experiment which continue for 60 days. Food residues produce the highest biogas quantity (67.3g/Kg waste),then mixed animals dung (59.5g/Kg dung) while wheat straw produce the lowest weight (37.2g/Kg straw). For animals dung types: - the chicken dung has the best biogas productivity (57.9g/Kg dung), the sheep and goat dung (53.8g/Kg dung) and finally the cow dung (48.7g/Kg dung). The biogas production enhanced by increasing sample water content (B11>B7>B10), and with stirring for the digester content where productivity of (D1) with stirrer is {58.93g} biogas /Kg waste while for (D2) without stirrer is {48.46g }biogas / Kg waste. Results indicate the Palestinian rural family will save monthly (23.07 JD) as a result of using biogas (instead natural gas) and using digested organic material as an organic fertilizer, if this family construct a 9m³ biogas plant with daily loading for (30.83 Kg) of organic wastes into the digester. It is recommended that: 1- More studies be done for providing more information to rural people about biogas technology. 2- More efforts must be done for enhancing their acceptability to this technology. 3- Enhance means for provide public with sufficient assistant for constructing biogas plants.