مجله پژوهش و فناوری محیط زیست
پیاپی 3 (پاییز و زمستان 1396)

In this study, the treatability of pulp and paper wastewater has been studied using a combined method (ultrafiltration and fenton) in a laboratory scale. First, the effect of membrane filtration on the removal of turbidity and COD, as well as membrane flux and membrane fouling were investigated, and then the advanced oxidation method was used to supplement the treatment and increase the removal efficiency of the pollutants. At the end of the membrane filtration operation, the removal efficiency of turbidity was 99%. Based on the results, the average COD of the filtration process with 41.8% removal efficiency was 906 mg/ l. Under optimal pressure conditions bar-1, the amount of membrane flux in the first backwash was equal to 1/99 L.m-2.h-1 which this amount reached to 1/26 L.m-2.h-1after the fourth backwash. the Fenton process removed 862/5 mg /L COD from the pretreated wastewater by UF membrane with an optimal dose of 1.5 mM for Fe +2 and 6 mM for a hydrogen peroxide at an initial pH of 3 and at a 17minute reaction time .In these conditions, the removal efficiency of COD, BOD5 and color was 95%, 90.3% and 92.1% respectively, These results shows high efficiency of the advanced oxidation process to remove contaminants in pulp and paper wastewater

Recognizing and determining the suitability and talent of the earth is one of the primary measures in spatial and environmental planning for physical and urban development. The aim of this research is to identify and determine the spatial distribution of suitable areas for physical development in Guilan province. Land suitability was determined by hierarchical process analysis (AHP) method and using seven natural criteria including gradient, altitude, cover, rainfall, distance from fault, rock, soil. The land suitability for physical development was divided into three large, moderate and low classes, and its zoning map was prepared. The results showed that, regardless of the protected areas and the wetland, about 62% of the study area is located in the class with a high proportion. With the consideration of other parameters, these areas can be considered for developmental planning by planners and policy makers.

In this research, the ability for removal of methylene blue cationic dye using Electro active polymers based on polypyrrole (PPy) and poly (3-methylthiophene) (P3MTh) in a batch system were studied. Sawdust (SD) was made from wood, after patching, as a holder for coating polymers and Sodium Dodecyl Sulfate Anionic Surfactant (SDS) was used to modify the surface of the sawdust. The effects of some important parameters such as pH, initial concentration of dye and contact time were investigated. To evaluate the obtained data, adsorption isotherm curves (Langmuir and Freundlich) were used. The adsorption efficiency for methylene blue was maximized at alkaline pH. Adsorption capacity increased with increasing initial concentration and contact time. In all cases, the adsorption process complies with Langmuir isotherm and represents the homogeneous and single-layer process. Also, the adsorption capacity obtained in SD/PPy, SD /PPy / SDS and SD / P3MTh polymers were 59/52, 400 and 1000 mg/g, respectively. Based on the studies and the results obtained in this study, it was found that these polymer materials can effectively be used in waste dyes, such as textile industry, which they have the great environmental significance.

Industrial and agricultural developments and the population of rural and communities led to excessive consumption of chemical detergents and fertilizers and increasing industrial wastwater which threaten water resources in last decades. Vulnerability of the water resources is a continuation of such trends. The first step in management of the groundwater resources is a determination of the vulnerable areas. The objective of this research was determin the vulnerability assessment of the central plain of Guilan using DRASTIC model. Principles of the model are based on overlaying of seven thematic maps of depth to water table, net recharges, aquifer media, soil media, topography, vados zone and hydraulic conductivity by considering appropriate weights and rates. The database was constructed by introducing the mentionec maps. Index of DRASTIC model for aquifer vulnerability of the central plain Guilan was ranged in 82-182. In this plain, there was not very much and very low vulnerability classes. The final map of DRASTIC model showed that % 48.64 of the area has high vulnerability and % 50.55 has medium vulnerability and only a small area of plain (% 0.81) has low vulnerability. Th estatistical summary of the DRASTIC model elements shows that the element of depth to groundwater table has the greatest impact on DRASTIC model. Also based on the map remove and single element sensitivity, depth to groundwater table is identified as the effective element in the central plain of Guilan. The results of the correlation between the elements of DRASTIC model and nitrate concenteration showed that there is the highest correlation between nitrate and depth to groundwater table. The average concentration of nitrates is 8.92 mg/lit in the wells studied at the Central Plains Guilan. In all wells studied, nitrate concentration was lower than the recommended level by US Environmental Protection Agency (45 mg/lit).

Crude oil is a mixture of pure compounds, from the chemical point of view, oil is a mixture of hundreds of molecular compounds called hydrocarbons. Therefore, in this article, various families of hydrocarbons are studied without going into organic chemistry. Then, oil hydrocarbons and in particular PAHs, which are the main subject of this research, are being examined. Moreover, an overview of the information gathered about the effects and toxicity of these compounds. The presence of oil pollution in many years in the seas and coastlines of the world has made this topic very much to be considered. Many studies have been conducted to investigate these contaminations, some of which are mentioned in this article. Oil pollution studies related to the Caspian Sea are widely discussed in this paper.

Increasing air pollution and global warming due to the excessive use of fossil fuels attracted public attention to climate change. Accordingly, the expected increase in demand for other alternative energy sources especialy renewable energy is predictable. While some research on renewable energy shows that these kind of energy also have undesirable environmental effects. In this study solar energy systems, wind power and hydroelectric power systems wew investigated and their effects on air, soil, sound and effect on wildlife were studied. The results show that although these kind of energy are called clean energy, they have negative environmental effects. This research also suggests ways to prevent the effects of destructive renewable energy sources.

EcoRA, which is aimed at appraising a wide range of undesirable impacts on ecosystems exposed to a possible eco-environmental hazard, has been highly recommended for environmental decision-making. In this paper reviews the development history of ecological risk assessment (EcoRA) and presents a perspective for EcoRA and management. In addition, regional EcoRA needs to make further efforts, especially in theoretical study, uncertainty analysis, integrated use of GIS software and comprehensive risk assessment at regional scale in the future work.