INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCE AND TECHNOLOGY (IJEST)
Year:2004 | Volume:1 | Issue:2|Papers Count:10

To assess the susceptibility of five varieties of tobacco to ozone, nine rounds of fumigation experiments were performed. These tobacco varieties were exposed to a range of ozone concentrations in a single-pass chamber fumigation system for short periods. A dose of 7.5 pphm did not produce visible injury in any tobacco variety. Tobacco cultivars; Bel-B, Weather Fleck and ZZ100 exhibited no visible injury up to 26 pphm. However, doses in excess of 16 pphm caused visible injury in cultivars Bel-W3 and Dynes. Awareness of the susceptibility levels of these cultivars to ozone assist biological monitoring process in field experiments. Biomonitoring is considered to be a valuable method for ozone assessment for situations where air pollution monitoring by instruments in remote locations is too expensive.

Mnemiopsis leidyi, native to America, Invaded the Caspian Sea in 1999. By the end of 2000, the entire sea was accupied with them. In parallel, a sharp decline in pelagic fish such accurrred.This survey was studied the relationship between the M. leidyi and this decline. Dietary analysis was conducted on anchovy sprat (Clupeonnela engrauliformis) and M. leidyi from August 2001 to October 2002 in the coastal water in the southern parts of Caspian Sea, in Iran. M. leidyi was caught by plankton net, (the mesh size ~5 mm), at three depth at 5, 10 and 15 m. Sprat was caught by fisheries boat at Babolasar fishery harbor. Samples were not fixed in M. leidyi common fixative, 96% Ethanol were used. The Schoener index analysis reflected a similar diet composition of both species, with an critical level of overlap (>89 in Babolsar samples and >84 in Noushahar samples). This competition is one of the reasons for the decline of anchovy sprat. also, the results show M. leidyi is feeding on fish eggs, but effects of this factor on anchovy population is less than feeding competition. Controlling of M. leidyi population is reducing the pressure of its invasion and the effective approach is introduces a predator to the Caspian Sea.

There are still many difficulties for developing the projects of using treated effluents. In this study, the efficiency of chlorine deoxide in the process of preparing the effluent of Sahebgharanieh Plant of Tehran for reuse purposes has been determind. Major results are as follows: Total COD reductions resulted from effluent treatment by ClO2 solutions having concentrations equal to 1/4, 1/2 and 1/1 of COD samples at one hour contact time have been about 42%, 49% and 59% respectively. Total suspended solids were also reduced by treatment with ClO2 solutions having the certain concentrations mentioned, and the reductions were about 37% ,47% and 58% respectively. Besides total and fecal coliforms results indicated that ClO2 apllied was quite efficient in effluent disinfection. The conclusion is that reasonable reductions would be expected in the amounts of remained major pollutants and so reuse applications for some non-potable purposes may become possible. The acidification of chlorite has been used for ClO2 generation as it is better suited to small treatment systems.

In this research, physical, chemical and biological treatability of Tehran solid waste leachate was studied. Results indicate that the amount of COD for the fresh raw leachate of Tehran is equal to 66,608 mg/l. The leachate is transferred to an equalization tank for storage and pH control process. After neutralization, leachate is introduced to an up flow and down flow anaerobic reactor. The effluent of anaerobic reactor is conducted to a sequencing batch reactor. Sequence batch reactor (SBR) effluent was pumped in to sand and activated carbon filters, after chemical coagulation and clarification. Results showed that anaerobic reactor with detention time of 3 days had a 35% COD removal and increasing the detention time to 4.5 days would improve the COD removal to 45%. Nutrient adjustment with phosphorus and nitrogen increased the initial 23% efficiency of sequence batch reactor to 44%. The effluent COD of SBR reactor was 21,309 mg/l. Recycling of aerobic reactor effluent with incoming feed to anaerobic reactor reduced the anaerobic reactor influent COD to 20,000 mg/l and this caused 53% and 57% COD removal in the anaerobic and aerobic effluent, respectively. The total systems COD performance increased to 80% and SBR effluent COD eventually reduced to 4,000 mg/l. Coagulation, flocculation and sedimentation processes were practiced to make the 4,000 mg/l effluent COD comply with environmental standards of Iran. The optimum coagulant found to be ferric chloride with the dosage of 50 mg/l at pH of 12, which reduced 10% of COD to an amount of 3,676 mg/l. The effluent was stored in a tank and then pumped in to pressure sand filter and afterwards to activated carbon filter. The COD removal was three and 90% for sand and activated carbon filters, respectively. The total process reduced the remaining COD to 36 mg/l, which is in compliance with environmental standards of Iran.

Application of environmental management system (EMS) in urban environment provides a city with orderliness, regularity, quietness and freshness environment. Besides, it contributes sustainable development and optimization in life level index of the city. If the whole urban districts design and establish an environmental management system ISO 14001, the development will be faster and more sustainable. Municipality of Tehran, District-22 has been found and started an activity under the command of Sterling Council of Iran Urbanization and Architecture in order to regenerate the urbanization concealed concepts and also to control and organize the excessive constructions in west and northwest of Tehran since 2000. As a result of human undergoing development activities, the process of urbanization during many years has caused various environmental impacts. Thus, decision makers and managers considered urban sustainable development as a main strategy. District-22, has taken the required steps in providing sustainable development, safety and health of the organization and citizens in the related district. Environmental policy and commitment of top management (Mayor of the District-22) are to keep environmental conservation, in a well organized manner. In this study, dominant environmental aspects, impacts and legal requirements of the related activities and services are identified. Subsequently, environmental objectives and targets and also environmental management programs have been determined. Besides, training, internal and external communication, operational control, emergency preparedness and responsibility, obligations to follow environmental rules and achieving certification of ISO 14001; 1996 standard are the most important highlights at this study. The planning process, establishing and the method of operation has also been studied.

Twenty-six cowpea cultivars were tested for yellow mosaic virus resistance at NIAB Faisalabad. NCPM-1, Elite, IT-84-552, No.44, P-518, S.A. Dandy, IT-97k-350-4, IT-93K-452, IT-97K-1042-8 and IT-97K-497-2 showed resistant reaction to yellow mosaic virus disease. As the study was aimed to select disease resistant and high yielding cultivars. Five cultivars viz. NCPM-1, Elite. S.A. Dandy, IT-97K-497-2 and IT-97K-1042-8 were chosen and evaluated at five different ecological zones during the year 2003. At each location, the experiment was laid out in a randomized complete block design keeping 7.2 m2 plot size in three repeats. At maturity the seed yield was collected and subjected to analysis of variance following stability parameters, varieties, environment and varieties x environment showed significant differences. Significant and highest seed yield (880 kg/ha) was observed in NIAB cowpea mutant-1 followed by Elite (729 Kg/ha). The highest yielding genotypes i.e. NIAB cowpea Mutant-1 and Elite showed non-significant differences of regression coefficient from one. Moreover these genotypes also exhibited non-significant difference of standard deviation to regression from zero. Based on three parameters i.e. high mean seed yield, regression coefficient and standard deviation to regression, these genotypes showed excellent and trustworthy stable performance over different environment. Hopefully these genotypes will definitely be helpful for increasing one local production of cowpea crop.

Ammonia nitrogen compounds in the wastewaters and effluents have harmful effects on water resources. Ion exchange with zeolites is a separation process for ammonia removal from effluents. The objective of this research was to study the efficiency of an ammonia removal and the factor affecting to this process. The Clinoptilolite was obtained from Semnan mines at the north part of Iran. The samples were grounded and sieved based on the U.S. standard mesh number 20, 30, 40 and conditioned by ammonia sulfate and sodium chloride solutions. The characteristics of samples for ammonia removal and the selectivity sequence for adsorbing interfering cations were then determined. Results shown that the average ion exchange capacity of zeolite in batch and continuous systems were 6.65-16 and 16.31-19.5 mg NH4+ /g zeolite weight, respectively. In study on the zeolite for selective cations showed the ranking of K+, NH4+, Na+, Ca2+ and Mg2+ respectively. Results indicated that high level of regeneration (95-98%) might be achieved with NaCl solution. Based on the results, Clinoptilolite may be effective applied in wastewater treatment, both from technical and economical aspects.

Riverine sediments and suspended matters have been subjected to several bench scale tests for the evaluation of adsorption potential of heavy metals. For this purpose water, sediment and suspended particulate matters of Tadjan River (southern part of the Caspian Sea) were collected. In the vicinity of the river many polluting sources were recognized; for instance, pulp and paper mill, dairy factory and municipal sewage that can introduce various amounts of heavy metals into the river water. Bottom sediments and suspended particulate matters have been individually subjected to adsorption tests. The results of analysis showed that riverine bottom sediments have greater potential for adsorbing heavy metals than suspended matters. However the trend of adsorption in both sediments and suspended matters are similar. Maximum adsorption capacity of heavy metals (in terms of mg of metal per kg of sediments and suspended matters) by sediments and suspended matters are as: Sediments: Cu (2200)> Mn (2000)> Ni (1400)> Zn (320) Suspended matters: Cu (2100)> Ni (1500)> Mn (1200)> Zn (310) Further, results revealed that increasing concentration of metals would cause desorbing Cadmium from both sediments and suspended matters.

A mathematical and computer model for the transport and transformation of solute contaminants through a soil column from the surface to the groundwater is presented. The model simulates selenium species such as selenate, selenite, and selenomethionine as well as pesticides and nitrogen. This model is based on the mass balance equation including convective transport, dispersive transport, surface adsorption, oxidation and reduction, volatilization, chemical and biological transformation. The governing equations are solved numerically by the method of implicit finite difference. The simulation results are in good agreement with measured values. The major finding in the present study indicates that as the time of simulation increases, the concentration of different selenium species approaches the measured values.

Natural ecosystems provide an array of critical but largely undervalued goods and services. Because these are seldom included in benefit-cost calculations of land use change, the value of wild land development nearly always appears greater than protecting wild nature. The following paper introduces a theoretical framework within which environmental economists evaluate ecosystem services. This is followed an assessment of three types of ecosystem services with particular relevance to the developing world pharmaceutical drug development from native plants, the economics of non-timber product extraction, and the benefits and costs of ecotourism as a development strategy. We conclude with an overview of recent attempts to provide a global estimate of the value of nature`s services.