Environmental Sciences
Year:2005 | Volume:3 | Issue:9|Papers Count:9

Removing nitrogen, one of the most common and abundant pollutants of surface and ground water, is very important. For this purpose, biological nitrification and denitrification as the most economical method should be considered. The feasibility of high load COD (Chemical Oxygen Demand) (800-2000 mg/lit) and NH4 (250-1000 mg/lit) industrial wastewater treatment, at different Hydraulic Retention Times (HRTs), was studied in 9-lit anaerobic-aerobic systems in the post-denitrification mode. The Ultracompacted Biofilm Reactor (UCBR) is a new system, with all the advantages of activated sludge and fluidized fixed bed processes, without the disadvantages of each system, so that the biofilm production takes place on the packings, moving along the height of the reactor. From the experiments carried out using this system, it can be said that higher ammonia removals take place at higher ammonia and lower organic loads. Denitrification increases at higher nitrification rates because of the effect increasing of NO3- entering to anaerobic reactor. Despite the fact that nitrifying bactefoia are more sensitive than COD and NO3- or removing bacteria, after toxic shock by phenol as an organic source, the nitrification rate increases and COD removal decreases according to the damaging effect of phenol on COD-removing bacteria. Total COD removal during the study varied between 70-98%, this value changing between 50-90% for ammonia and 55-90% for nitrate.

One of the most pressing questions in the current debate about global climate change is what will happen to organic carbon sequestered in organic matter in soils if global warming occurs. This paper aims to study the potential effect of changes in temperature and precipitation on organic carbon sequestered in global soils. Interpolated data from a General Circulation Model (GCM), predicting temperatures and precipitation as well as world vegetation data set were used in a soil organic carbon decomposition model to study the likely effects of climatic change on organic carbon in soils over the next 100 years under three different scenarios. Results show that levels of organic matter in global soils will decrease as a result of an increase in global temperatures and precipitation. Results also show that different climatic zones of the Earth appear to be affected differently by global warming. Results from the research, as with climatic change modeling itself, represent only one of many possible outcomes. Results from only one GCM were studied in this study. The project results depend largely on a number of justifiable but major assumptions in the theoretical models and sets of data that were used in the study. Moreover, many environmental processes in the atmosphere, oceans and on land are not well understood. As a result, most if not all physical attempts to model the coupled effects of an atmosphere-soil system will contain significant errors. Although the results show (as with previous works) that the level of organic matter in global soils will decrease as a result of an increase in global temperatures and precipitation, such an outcome is by no means certain.

In this experiment the use of different organic waste materials - poplar tree bark, palm fibre and sewage sludge compost (Biosolid) - as substrates in the production of ornamental plants was studied, with a special interest in the suitability of palm fibre as growing substrate for conifer plants. The plant species tested were Pinus densiflora, Cupressus arizonica and C. sempervirens and the substrate mixtures were: (1) poplar tree bark, (2) poplar tree bark with 15% of sewage sludge compost, (3) poplar tree bark with 30% of sewage sludge compost, (4) palm fibre, (5) palm fibre with 15% of sewage sludge compost and (6) palm fibre with 30% of sewage sludge compost. The substrates were physically and chemically well characterized and 75-cm plants were grown on them for one year. For each species, the experimental design consisted of six random blocks with 60 plants per substrate grown in 7-I capacity pots. The plant and substrate status were periodically tested during the experiment. Since biosolid recycling is the main objective of the present work, mixtures with 30% of composted sewage sludge will be the most convenient substrate to use. Plant growth in palm fibre substrates mixed with biosolid showed similar results as those grown in poplar tree bark based substrates. For C. sempervirens and C. arizonica, a mixture of poplar tree bark or palm fibre and 30% biosolid compost in volume gave the best results. However, the lower cost of the poplar tree bark than the palm fibre substrate indicated the use of the PB+30% CSS. Also, the results showed that palm fibre substrate alone was not a good growing media for Cupressus plants.

Diversity of dominant marine bacteria was studied in nine different shoreline sites from Qeshm Island to Genaveh, in Northern Persian Gulf. Samples were collected from surface water and pelagic sediments. The total number of culturable bacteria in these sites ranged between 3.7x105 and 4.3x107, as determined by culture dilution method. These results showed relatively high concentration of marine bacteria. Serial dilution cultures were prepared from each sample on oligothrophic medium agar plates, made with filter sterilized natural seawater, and two isolates that were dominant in the number of colonies were chosen for identification. Using morphological and biochemical tests and determination of guanine plus cytosine content of DNA, members of the genera Pseudomonas, Vibrio, Alteromonas, Flavobacterium, Bacillus, Mycobacterium and Alcaligenes were identified and seemed to be abundant in investigation area.

This paper examines the economic impacts of tourism and considers, in particular, how the benefits to the local economy from ecotourism development can be maximised. Although it does not directly address them, this is a discussion of relevance to the growing interest of developing countries (including Iran) in developing their tourism sectors as a source of foreign currency income. It also relates to the approach of Agenda 21 (UNCED, 1992b) in which tourism is viewed as a form of land use with potential significance for improving both the economic and environmental sustainability of a region if it is correctly developed. The World Summit on Sustainable Development (Johannesburg, 2002) placed ecotourism development for the preservation of biodiversity as one of its five major areas of action. It can provide a suitable response to the need for economic regeneration and job creation in remote areas where the traditional industries can no longer satisfy these needs on their own. The aim of this paper is to analyses the economics of ecotourism development on the macro and micro levels in order to address the question of how far ecotourism development can provide the basis for local economic development. To this end, the economic impacts and the scale of the ecotourism industry worldwide are examined. This examination serves to clarify the way in which tourism projects should be developed to ensure both economic and environmental sustainability. There is an intriguing paradox relating to the economics of ecotourism that is worth some exploration. On the face of it, the small-scale character that typifies ecotourism projects would appear to be in contradiction to the desire of governments to realize significant returns on their investment in the tourism industry. However, experience would suggest that (a) mass tourism is a very unreliable source of income over the medium- to long-term (due to the fickle nature of the industry) and (b) well managed, quality ecotourism products can be very profitable for economy of the destination and its region. Thus ecotourism can offer not only an environmentally sustainable option but also, potentially, a more economically sustainable one. In order to illustrate certain points and as an aid to analysis, a case study of ecotourism development in Scotland – a country heavily reliant on agriculture and the fishing industry - is presented.

Study of floristic composition of vegetation is crucial for biodiversity and conservation management by providing habitats for wildlife and contributing to the ecologically sustainable management of natural resources. Miankaleh peninsula considered of high conservation value owing to its floral and faunal characteristics. A study was carried out in Miankaleh, in 2002, to determine floristic composition and available vegetation types carrying a central importance in foods and shelter habits of the wildlife. Therefore, the total 70 quadrats of the size 100 and 25 sq.m., based on defining minimal area, were located in the area and each predefined homogenous unit was received 10 quadrats. Plant species and their abundance and dominance were recorded. Seven vegetation types viz. Plantago indica-Carex nutanse, Pure Punica, Punica-Rubus, Punica-Juncus, Juncus-Rubus, Pure Juncus and Frankenia hirsuta-Plantago coronopus were recognized in the area. Vegetation profile of each type was also depicted. In Plantago indica-Carex nutanse (Psamophyte) vegetation type, a strip planted by alder species (Alnus subcordata) could supports as a nest for Falco subbuteo. Pure Punica (Pomegranate) vegetation type that occupied most of the central part of the peninsula has been covered mostly by Punica granatum. It is a good habitat for black francolin cocks (Francolinus francolinus), Isabel shrike (Lanius isabellinus), robins (Erithacus rubecula), Phasianus colchicus, Otis tarda, Chlamydotis undulate, Coturnix coturnix and Scolopax rusticola. Some plant species are important elements of the food chain in Miankaleh.

Phonetic studies were performed on 25 populations of 8 Bromus species and varieties of the section Genea concerning intra and inter-specific variations. Interspecific relationships and the most variable morphological characters useful in the species delimitation were also determined. Descriptive statistical analysis showed that the range of quantitative characters is much different from what is given for description of Bromus species and varieties in different flora. The species studied differed significantly in most of the quantitative characters studied and using the mean of such characters may be of use in the species delimitation. The clustering showed distinctness of the Bromus species and principal components analysis identified the most variable morphological characters among the species studied. The present study suggests the use of some ratio characters along with other quantitative and qualitative characters in taxonomy of the Bromus.

The real development would be achieved only when all of Social, cultural, economic and political sectors are developed simultaneously. Different programs related to these sectors are implemented via a communicative process. In this process, the development agents send some messages as new technologies to customers via some media. Furthermore, beyond this communicative process, development programs should meet environmental concerns too. This paper based on an analytic research method conducted to explain Rural Environmental Sustainability from communication changes perspective. If we suppose a communication model consists of some components such as sender; message; media; receiver and feedback system, to reach environmental sustainability in rural areas, all of them should be changed in one way or another. For example, about organizational part as senders; decentralization, privatization, activation of NOGs, and customers' sharing in costs of development programs should receive enough attention. Customers or receivers; rural women, youth and poor should be putted first. Media: using interactive media such as folk media and new information technologies are recommended. For Feedback- evaluation system; participation and empowerment of rural people should be considered. The content of messages; environmental considerations such as preserving living diversity in one hand, and minimizing the usage of un-renewable/ natural resources, pastures, chemical materials, air, water and land pollutions, and erosion in the other hand should be considered. Furthermore, with regard to holistic view, environmental problems should be considered in parallel to social systems. So, social elements such as decrease the rate of migration from rural areas; social gap; improving people's income, employment, housing and educational opportunities; providing communicative infrastructures and stability of cultural patterns are really important in the process of Rural Environmental Sustainability. This article has investigated and analyzed the above components and it has also introduced an alternative communication model for rural areas' sustainability.