In 2004,ammonia concentration in raw water of Sitalakhya River at the eastern periphery of Dhaka was found higher than the expected rate of 4 mg/Lforecasted in feasibility studies,with a value of about 8 mg/L, which could not be removed by conventional treatment chain employed at Dhaka, hence, recentlyan ammonia removal plant has been constructed. This important background has ledto the current study on ammonia, a single quality parameter to understand the trend of deterioration, its probable causes, and the probable remedy.Water samples have been collected and tested for ammonia for a period of fifteen years, from 2002 to 2017, mostly in the laboratory of the existing plant. Ammonia levels have been found generally below 4 mg NH4-N/L in the wet season,though during the dry season they rise up to 20 mg NH4-N/L (sometimes more). The maximum and average values of concentration follow a more or less similar pattern with time, withboth average and maximum values, increasing around 1 mg/L annually,suggesting a similar trend in future which will make the existing treatment process inadequate. This needs attention in terms of both regulatory measures and proactive strategies on how to handle the resulting future challenges.

Water is one of the most crucial substances for life. In order to maintain their public health, each and every country has defined standards of drinking water quality, beyond which the water is considered harmful for human health. The current study compares physical, chemical, and biological standards of drinking water quality for the USA, EU, Japan, India, and Bangladesh, considering 4 physical parameters (namely, color, odor, taste, and turbidity), 35 chemical parameters (such as Calcium (Ca), Magnesium (Mg), Phosphate (PO43-), Sodium (Na), Phenolic compounds, Nitrite (NO2-), Arsenic (As), Aluminum (Al), etc.) and 2 biological parameters (i.e., Coliform (Fecal) and Coliform (Total)). The data has been collected from several secondary sources and since processes of data collection for water quality differ from one another, this aspect has been ignored. No variation has been found in biological water quality standards along with physical quality standards of the considered regions. In order to find out the differences in chemical parameters, standard ANOVA and pair-wise F-test have been conducted. There was no disparity among chemical parameters in ANOVA test. Moreover, thanks to the few excessive values of the standards (as in case of Bangladesh), the COD value is 4 mg/L, whereas in other countries this parameter is much less. However, the chemical parameters of water quality standards in Bangladesh vary significantly from other countries. Besides, there has been no variation among the standards of other countries, even though they are located in different continents. Most interestingly, despite being neighbors, Bangladesh and India differ significantly in this regard.

Traffic snarl-up or traffic jam is a common phenomenon in Puri, one of the imperative pilgrimage sites for Hindus as well as a popular tourist destination in India. Traffic congestion inevitably produces traffic noise, in turn annoying the drivers, leading to road rage. Keeping this in mind, the present article has monitored and assessed different noise descriptors in 7 different types of buses, totally involving 35 buses in and around Puri, for three years, from 2014 to 2016. The minimum and maximum noise levels have been more than 65.3 dB and 90 dB, respectively. Also, Leq is beyond 80dB, demonstrating a noisy environment inside the bus. The result of Karl Pearson’s Correlation Co-efficient clearly indicates that in general, the noise levels have gradually increased from 2014 to 2016. Furthermore, it has conducted a survey to reveal opinions of 156 passengers and 50 drivers of the buses concerning their annoyance from noise pollution.

Trace organic compounds (TrOCs), mostly found in secondary effluents have a potential impact on the environment including surface water, groundwater and especially aquatic ecosystems. This study focuses on oxidation of five selected TrOCs in column experiments simulating soil aquifer treatment (SAT) integrated with Fenton like reaction using granular ferric hydroxide (GFH) as a catalyst. In order to determine the effectiveness of removing TrOCs by water through this approach, experiments were carried out with ultrapure water containing different target compounds at pH 6 using different dosages of hydrogen peroxide and catalyst. In this study the optimal concentration of hydrogen peroxidefor removal of TrOCs was found to be 200 mg/L. However, observed overall removal was low for each target compound. Moreover, little increase in chemical oxidation of micropollutants was observed by increasing dosage of the catalyst. For an optimum concentration of hydrogen peroxidethe removal of 33, 34, 28, 29 and 35% were observed for benzotriazole, carbamazepine, phenytoin, primidone and meprobamate, respectively in 5h with a hydraulic retention time of 3h, respectively. Therefore, this treatment scheme might not be a promising option for oxidation of secondary effluents. Thus, other treatment options, such as decrease of pH, recirculation of effluent through columns to increase the hydraulic retention times, other types of catalyst and higher dosage of hydrogen peroxide need to be considered for more efficient removal of TrOCs within SAT integrated with Fenton-like.

Although the vulnerability assessment of forest parks is used to determine the threats they face, a rapid and holistic framework has not been established well. The primary objective of this study is to adopt a framework for rapid assessment of forest parks vulnerability, examined in Lavizan forest park in Tehran (Iran) as the case study. The vulnerability assessment has been conducted, using the evaluation matrix on the basis of landscape and ecological values and threats. In this model, the most important values and threatening factors of the Lavizan forest park have been identified and assessed, based on the intensity of their effect as well as occurrence probability. Finally, this article proposes five strategies to reduce the vulnerability. Results from this research indicate that the most important values have been air purifcation, wildlife, flora and fauna species, environment regulation, mental health, and scientific resources and the most important threats have included reduction of habitat diversity, intensive exploitation of the resources, fire, woodcutting, and reduction of ecological connectivity. Based on these vulnerabilities, the most important strategies propose the use of affordance strategy formulation framework to preserve and enhance ecological and landscape values of the park.

The present study aims at phytoremediation of Lemna gibba L. in aqueous solutions with different concentrations of TC and Degradation Products (DPs). It also tries to determine whether there are differences in TC, ETC, EATC, and ATC levels, accumulated by Lemna gibba L. Exposure concentrations of 50, 100, and 300 ppb have been selected for TC and DPs, showing that the highest TC50, TC100, and TC300 concentrations in the plant have been 23.5+1.1, 80.1+3.9, and 274+13 ppb, respectively, while the highest ETC50, ETC100, and ETC300 have proven to be 39.5+1.9, 47.8+2.4, and 168+8.4 ppb, respectively. The highest EATC50, EATC100, and EATC300 concentrations in the plant have been 45.3+2.3; 65+3.0 and 173+9.0 ppb, respectively, whereas the highest ATC50, ATC100, and ATC300 concentrations in Lemna gibba L. have been 34.7+1.7, 39.6+0.2, and 114+5.6 ppb, respectively. TC, ETC, EATC, and ATC concentrations in Lemna gibba L. have increased with the increase of initial TC, ETC, EATC, and ATC concentration.

One of the most comprehensive tools to show the changing trend in urban ecosystems is by providing periodic State of Environment Report (SoER) for cities in national programs, wherein it is quite essential to have a truthful and realistic view of the current state of the environment as well as significant human impacts. Developing countries like Iran are faced with incoherent and deficient SoER; due to lack of data, which originates from neglecting environmental issues such as poverty, overpopulation, etc. The present study makes a comparative assessment of Tehran and Sydney's SoER in terms of sustainable urban environment indicators with the purpose of recognizing the weaknesses and strengths as well as finding the most important gaps in Tehran's SoER, which can be a useful resource for decision-makers. Results indicate the necessity of establishing integrated urban environmental management. On the whole, this paper recommends programs of environmental development and implementation as suggested strategies to reduce uncertainty and increase the reliability of SoER in the study area.

The extensive use of pesticides leads to accumulation of a huge amount of residues in the environment. As such, the present study investigates the potentiality of Pleurotus pulmonarius to bioremediate dichlorvos pesticides (2,2-dichlorovinyldimethylphosphate) in contaminated soil. DDVP-polluted soils have been contaminated in five concentrations (5% v/w, 10% v/w, 15% v/w, 20% v/w, and 25% v/w), and the soil samples have been inoculated and incubated with pure culture of growing spawns of P. pulmonarius, obtained from commercial mushroom laboratory of Federal Institute of Industrial Research Oshodi, Lagos. The control, however, has not been inoculated. Each treatment has been in triplicates with the soils, analyzed for total amount of DDVP at day 0 and day 60, using gas chromatography and mass spectrometry. Also, pH, moisture content, and total organic matter of the soil have been determined. Results show that the rate of DDVP degradation in the soils with Pleurotus pulmonarius has been higher than the soil samples without mushroom after 60 days. However, for the control without mushroom (loss due to natural attenuation) and those inoculated with P. pulmonarius (bioremediation) the loss percentage of DDVP ascended with the percentage of pesticide from 5% to 25%. The DDVP loss across all different concentrations of mushroom inoculation have been significant (p<0.05); however, for natural attenuation, it has not been significant (p>0.05), except for the lowest pesticide level (5%). Activities of mycelia have decreased soil pH, moisture content, and total organic matter. There has been a very minimal pesticide bioaccumulation in mushroom tissue, which has not been significant (p>0.05), but considerable at p<0.001, indicating that P. pulmonarius has the potential to degrade DDVP pesticides in soil.

Nitrate is a major contributor to water contamination, which can affect humans' and animals' health. Due to increased sewage production, growth of agricultural activities, and development of urbanization, recent years have seen an increase of Nitrate in water resources. Drinking water resources in both rural and urban areas of Jiroft City are supplied by water wells, scattered throughout the region. Thus the present research analyses the Nitrate pollution of 31 drinking water wells in summer and winter of 2016, in the urban area of ​​Jiroft City and by means of GIS as well as statistical analysis, presents the results as zoning and survey maps. It also studies and evaluates the effect of rainfall and soil type on the amount of Nitrate. Results from statistical analyses show that the amount of water pollution to Nitrate is independent from the type of land use as well as the soil type. Furthermore, statistical results show that the amount of Nitrate in the wells under test is affected by precipitation, being higher in the winter. Therefore, considering the agricultural density in this area and the untapped use of nitrogen fertilizers, it is necessary to take into account the use of chemical fertilizers for proper management, scientific and practical control, and maintenance of the wells' health safety.

This study aims at evaluating the improved facultative ponds performance in pilot scale. Wastewater has been collected from primary settling basins of Ahvaz wastewater treatment plant. Treatment efficacy of the four systems (three systems in parallel with a control system) has been evaluated over a period of 12 months at various hydraulic retention times (HRT) and organic loading rates (OLR). There has been no baffle and no attached growth media (AGM) in the control system (S0), while other three systems (S2, S3, and S4) have been equipped with different numbers of baffles and AGM packages, containing the mineral shells. Results show that efficiency of BOD5 removal for S0, S2, S3, and S4 are 53.4%, 60.8%, 64.7%, and 67.6%, respectively, while for COD these rates alter to 28.1%, 37.7%, 45.8%, and 50.1 % and of coliform to 66.7%, 76.6%, 80.7%, and 83.4%. Filtered BOD5 in the effluent of S0, S2, S3, and S4 is 32.5, 27.6, 24.6, and 22.3 mg/l, respectively and 60.2, 52.1, 47, and 44.3 mg/l for TSS. Also the 10-day HRT has been optimum among applied HRTs. As such, attached growth-baffled ponds function better than conventional ones, making the technique, examined in the present paper a low-cost process to establish new wastewater treatment plants or upgrading the existent WSPs, especially in case of warm areas of southwestern Iran.