جستجوی مقالات مرتبط با کلیدواژه "standard" در نشریات گروه "محیط زیست"

Many of the pollutants in water are known to be harmful for human health and toxic for environment. Among these pollutants, Arsenic is more important because millions of people are exposed to contaminated drinking water. The World Health Organization (WHO) has identified the permitted limit of below 0.01 mg/L (10 micrograms per liter) for arsenic in drinking water and the same amount for arsenic has been reported in Iran's 1053 standard. In this study, various techniques have been investigated for removing Arsenic and efficiency of different nanoparticles in treatment of Arsenic from drinking water. Common methods of removing Arsenic from water sources are including oxidation, coagulation and flocculation, reverse osmosis and ultrafiltration, ion exchange, phytoremediation and new technologies based on the use of nanoparticles. The findings showed that despite of the high arsenic removal percentage using different methods such as oxidation, ion exchange and floating with dissolved air, these methods are not economic and a lot of time is required to achieve optimal efficiency. Recently, the use of nanoparticles has become very popular, so that metal oxide nanoparticles such as magnetic iron, Zinc, Copper, Serum, and Aluminum can completely eliminate Arsenic soluble with a high concentration of 50 mg/L in water sources and after the adsorbent is saturated, it is possible to use the regeneration of adsorbents, repeatedly by adsorbing the pollutant into the adsorbent. As a result, the use of nanoparticles is better than chemical processes and is economic due to their high efficiency in a short time.

Greywater (GW) is defined as wastewater from kitchen, bath and laundry excluding streams from toilets. GW can be classified as either low-load GW (excluding kitchen and laundry) or high-load GW (including kitchen and/or laundry). In recent years many studies have been carried out on GW treatment.

This review provides information on the GW characteristics, existing guidelines for wastewater reuse and the present state of art in GW treatment as well as their advantages and limitations.

This article revealed that GW quality is highly variable and dependent on the source of production. Physical processes have been shown to achieve only a limited treatment of the GW, therefore the use of these methods alone is recommended in the low strength GW. The chemical treatments were reported to provide good removal of the suspended solids, pathogens and surfactants in the low strength grey water but could not efficiently remove the BOD. Biological processes achieved good general treatment of GW, but the nutrient imbalance of GW limits the performance of these systems.

However, the combination of aerobic biological process with physical pretreatment and disinfection is recommended in the high strength GW as the most economical solution.

Lead pollution due to toxic effects is one of the biggest problems of natural resources and environment. The current research have been done in winter 2012 till summer 2012, in order to measure the rate of pollution in the heavy metal, lead, in the water and the tissues of Lenkoran (Capoeta capoeta gracilis) fish (liver, gills and muscles) in Palangrood river, located in Abatar city of Somesara, Gilan province.
Water and fish samples have been collected from three specific stations. Water sampler and net vetch were used respectively for taking samples from water of the river and catching fish. After carrying out tests on the samples, we analyzed them statistically by excel software; also regression test was used for the study of cohesion.
The density of lead in gills, liver and muscles are respectively 50.7 mg/kg, 34.2 mg/kg and 24.3 mg/kg; according to data, lead density is higher than WHO, FAO, USFDA and NHMRC standards.
The results are showed that rates of the measured element in the samples higher than limitations of discussed standards and the region is densely polluted with the lead heavy metal.

The optimal management of hospital waste is essential to protect the public health and environment. The aim of the present study is to investigate the variables of hospital waste management in terms of their compliance with the ISO 14001 standard. In addition to identivying the weaknesses of waste management, some strategies are presented overcome them.
This study was carried out in 2013. The required data for hospital waste sector were obtained using a questionnaire and the Tables designed by World Health Organization (WHO). Condition of the environmental management of the wastes was described using the questionnaire, the environmental management system standard (ISO 14001), the national standard of Iran, and Likert range. All the data were analyzed by SPSS 16.
Findings: Results showed that the conditions in the studied hospitals were lower than the hypothetical average (3) in terms of some variables such as identification of environmental aspects, planning for achieving the macro and micro goals; receiving the necessary training, drafting functions and responsibilities of waste management, and preparation for emergency response. In order to identify the environmental aspects of hospital waste, results showed that from 2307.82 Kg of the waste produced in hospitals daily, 62.23% were general waste, 36.17% were infectious waste and 0.58% were sharp substances. There was a significant correlation between the numbers of provided services in hospitals and the rate of daily generated waste (r= 0.992¡ P=0.008). Moreover, there was a significant regression relation between the overall area of hospitals and the rate of daily generated waste (P=0.02).

Compost is extracted from the Latin word “Compositus”, meaning compound or mixture and sometimes it is known as mixed fertilizer in Persian language. Regarding the economic values of spoilable substances, producing fertilizer from waste not only will help to ues this value, but also in this way, the waste and its recycling can be controlled. Thus, construction of compost factories for hygienic repulsion and production of valuable fertilizer, are the main preferences of urban waste management in the country. Objective of this study is evaluation of physical and chemical quality of compost fertilizer, produced in Zahedan Factory, and its comparison with the standards in Iran and the world.
In this study, the compost fertilizer produced in Zahedan Factory was investigated during 9 months. To determine the physical and chemical characteristics of the compost produced in this factory, the factors such as pH, electrical conductivity, organic carbon, azoth, phosphor, lead, cadmium, zinc and copper were evaluated. Microbial specifications of the produced compost are also specified by determination of culiferoum, Salmonellae, and parasite zygote.
Evaluated factors are: average percentage of carbon (4.2 ppm), percentage of azoth (1.98 ppm), percentage of lead (89.98 ppm), percentage of cadmium (2.695 ppm). The microbial quality of the produced compost was in B level of Environmental Protection Organization of America.
Results demonstrated that the produced compost, in terms of heavy metals, was in the range of UN, America and Canada standards (AAFC, CCME, and BNQ) and was reasonable according to the National Standards of Iran. Carbon and azoth percentages meet the compost standards in most cases. However, considering that the ratio of carbon is higher than the ratio of azoth, it is necessary to add vegetable and fruit wastes - that contain higher nitrogen - to the compost ingredients. Amount of phosphor is placed in rank 2 of National Standards of Iran. pH is almost higher than standard levels; in this case adding a little sulfur will solve the problem. Compost fertilizer samples are applicable as soil reclamation factor. Waste segregation at source and establishment of thermophilic conditions in mass are two effective strategies that should be concentrated to improve the quality of compost fertilizer.

Public consumption of lemon juice and best-selling market makes adulteration by jobbers to reducing of production costs which caused to dangerous problems in people's health and relevant regulatory authorities. Previous studies showed none of the proposed methods by the Standard Organization of Iran could not able to identify adulteration in lemon juice due to changed via adding of some synthetic materials. Therefore, all of proposed methods are actually incapable in detection of adulteration including: mixing of some rough straw with lukewarm water, using of extracts in lemon juice production , adding of citric acid , dilution with water and mineral acid adding. Unfortunately, the type of adulteration in lemon juice in Iran is different with other countries. lemon juice is completely synthetic production which caused to gastrointestinal side effects as well as damage to the enamel teeth and public health. It seems that the IRIS should be revised due to incapable in response to adulteration discoveries. Therefore, it supposed the necessary proceeding in solving of this problem which used as main seasoning and important source of vitamin C in throughout the years. This review shows the advantages and disadvantages of alternative methods in industries to provide differences in natural lemon juice for the first time to provide adequate research in finding of effective methods in identifying of lemon juice.

In this research entitled noise standards for passenger cars in Iran, in order to identify the permissible levels of sound for passing-by noise and the noise from vehicle exhausts and horns, through a step processing method, at first the real current situation of vehicles was obtained through different tests carried out on 100 vehicles of different types. The results have been analyzed statistically using the ATATGRAPHICS PLUS Version 2.1 software. The second step has been the study of other countries’ standards and regulations as well as the European Commission Directives 70/15/EEC and 70/388/EEC which have formed the basis of this study. According to the test results analysed and the Directives mentioned above, the permissible sound levels that have been identified are as follows: 77 dB (A) for passing-by noise of the M1 class; 80 dB (A) for the N1class; 86 dB (A) for exhaust noise and 87 dB(A) TO 112 dB(A) for horn noise for all types of vehicle.