JOURNAL OF ENVIRONMENTAL SCIENCE AND TECHNOLOGY
Year:2002 | Volume:- | Issue:14|Papers Count:8

The materials including keratinous fibers, such as, wool and hair are able to adsorb the metal ions from solution. In this case, by applying a suitable chemical pretreatment the elimination capacity for these ions will increase.In this study, by using three pretreatment methods including, NaOH, 0.1 N, Na2S 0.1 N as well as mixed NaOH and Na2S 0.1 N the human hair fibers have also been taken under pretreatment. In this research, the efficiency of pretreatment methods, have been investigated in increasing the efficiency and adsorption capacity of Lead Ion by means of human hair in laboratory scale.The regression tests showed that the elimination of lead by applying NaOH 0.1 N pretreatment for both the nitrate and acetate compound of Pb+2, had better deficiency than the other pretreatment methods like Na2S 0.1 N and mixed NaOH and Na2S 0.1 N.

Study of the ecological status and evaluation of the ecological competence of Lavasanat region, with reiteration upon Meygoon and Fasham regions, as tourist attractions and a location for Tehranian Citizen people to the regions vicinity and existence of natural attractions, took place in the year 2001.Different study phases, including identification of physical and environmental resources, integration of the data, coding of ecological units and, finally evaluation of the environment competence, with the application of slope, direction, altitude, land formation, pedological, vegetation types, vegetation coverage density percentage and climate maps, with the scales of 1:100,000 took place. At the identification stage, physical sources of climatic parameters, water resources, land formation and pedology were considered, while completing an additional study of .environmental flora resources. Integration and summing up of data, were in fact the main and at the same time, the most complicated ecological competence assessment in this study. The basis of this method was mainly, combination of the related data and information of the physical and environmental resources, which specified the regulated and disciplined groups of data summing up groups.These determined groups are, in fact. The ecological units, which have been compared with the well developed tourism model in lavasanat, Meygoon and Fasham region. In this comparison, the competence of each of the ecological units of the said region, specified for application of the well developed tourism model, in separate classifications of appropriate, average and / or inappropriate competences. The result of the study, shows that in the investigated region, from a total of 342 ecological units, there were 71 units Proportionate to the first class well-developed tourism and 183 units, in proportion to the second calss well-developed tourism.Therefore, 88 ecological units were not compatible with the well-developed tourism model, and were located as Class third.Field studies showed that steep slopes, vulnerability and sensitivity of soil in regard to erosion, has caused restrictions upon promotion of well-developed tourism model.

The emitted Nitrogen oxides concentration from the stack of Ramin Thermal power plant were measured in 10 sampling stations from 100 to 2200 m around the power plant.The results indicated that the measured concentration in different distances from the stack including Cmax (max. conc. of Nax) were lower than the national standards for nitrogen oxides except in statien 5 and 6 where the nitrogen concentrations howed a sudden increase.

The formation of biological compact granules is essential in the stabilization of up flow anaerobic sludge blanket (UASB) bioreactor. Granulation plays a key role in the behavior of reactor, as well as setlleability and activity of biomass and cellular retention time. These parameters explain and define the basic conditions for high rate anaerobic reactors. Therefore the mechanism of granulation has been a major point of consideration which could effect the behavior of the reactor directly.In this research~ the mechanism of granulation of thermophilic bacteria in a UASB reactor treating the effluents of an alcohol production plant has been studied. The results indicated that the granulation process can be divided into three phases, namely acclimation, granulation and maturation.Acclimation is followed by formation of anaerobic bacteria in reasonable concentrations to form granules. Initially formed granules have low stability and only adhere loosely together. In granulation phase, the loosely adhered granules are strengthened by extracellular polymers produced by bacteria to form firm granules.Low feed concentration or other limitations, reduce the rate of granulation, which is resumed when the unfavorable conditions are removed. The bacterial decay inside granules due to feed or nutrient limitation and production of methane inside the granules coupled to external shear stress is a major cause of disintegration of large molecules. The affect of biogas release inside the granules is also considered to be an important factor in disintegration of large granules.The presence of calcium and carbonate ions at high concentration in alcohol production wastewater, is responsible for precipitation of calcium salts at high pH. The bacteria can adhere to these deposits to form the basic nucleus of granules. Experimentation has indicated that the core of the granules is mainly composed of calcium carbonate.

Improper use and useless consumption of various pesticides will cause serious damage to our environment and all the ecosystems living things. Making use of Butachlor herbicide in rice farms located in northern parts of our country will cause the remains of poisons remained in environment have their routs into Caspian sea shores via agriculture waters Gammarus is from Pontogammarus maeoticus species and belongs to Amphipodas family living in southern shores of Caspian sea .They are living in sea shore regions. Gammarus which is the main article of food for many fishes living in Caspian Sea. In fact Gammarus exposed to danger by means of improper use of Butachlor herbicide. Butachlor is belong to chloroacetanilide herbicides and is used for a quick control in rice and barley farms whenever an unexpected growth of one year grasses or broad leaf grasses have appeared. For studying Butachlors effect on Gammarus , at first step we ought to sample Gammarus got from Darya-kenar region about 5km distance from Babolsar and then make a stockpile solution through Butachlorine technical material with pure degree 89.7% testing the amplitude or range will be done during the 96 hour time intervals. After performing nine test, determining Butachlorine Toxicity, viscosity amplitude between 0.5 ppm to 2.5 ppm could be measured. Original tests which have been resulted during 9 day intervals at four tests time repeats. We shall analyze those statistics regarding the casualties caused by Gammarus death as a result of poisoning Butachloring with probit analaysis program computer we shall be able to have important results such as viscosity s logarithm, regression linear model value of LC50. By making use of aforesaid factors, various graphs such as toxicity line, toxicity curve, sharpness and multiple x-y plot could be drowned as well as LC50 mean table can be drowned too. With increasing toxicity viscosity in environment, the death rate will increase too and as passing time the value of LC50 decreased as a result the most lost values of LC50 will be in the test s first 24 hours. Its absorption by organism body will increase, as a result a little value of toxicity viscosity is sufficient for killing the organism.

In this research, the adsorption of some heavy and poisonous metal ions such as Hg2+, Pb2+, Cd2+ from aqueous solutions using activated carbon (ac.c), has been investigated. Activated carbon employed was in the form of finely powdered form and the system was batch. In our preliminary investigation, it was found that powdered carbon is more effective than granule form in the adsorption of these metal ions.Powdered activated carbons have more sudace area and higher mass transport properties than granules.So it is more prefer for adsorption of medium to high MW poisonous materials from water and waste waters. In this research, it was observed that with increasing the size of metal ions under investigation, the rate of adsorption by ac.c increases too. Metal ions as simple and hydrated form have not much tendency for adsorption by ac.c. However, with impregnation of ac.c.by some suitable chemicals, it is quite possible to increase the rate of adsorption considerably. We also found that impregnated ac.c. With compounds that have sulfur atoms in their structure such as dithizone or methylene blue (a textile dye), considerable improvement in adsorption of these dangerous heavy metal ions is achieved.