The present work investigates nitrate and phosphate removal from synthetic treated slaughterhouse wastewater in a novel open raceway pond with sedimentation zone. For this purpose, microalgae Chlorella salina has been cultivated in synthetic wastewater and sedimentation zone has been added to enhance both algae separation in the system and nutrient removal. The effectiveness of Chlorella salina to treat nitrate and phosphate has been tested in open raceway ponds with harvest system. It has been found that Biomass concentration of the Chlorella salina is 1.35 g/L during 11 days of experiment. Also, maximum specific growth rate of the species in the pond has been 0.74 day-1. Throughout the cultivation period, nitrate and phosphate have been analyzed to show that their average removal efficiencies were 100% and 45%, respectively. It can be concluded that the growth of Chlorella salina in novel open pond system is an effective way to reduce nitrate and phosphate levels in slaughterhouse synthetic wastewater. Also, wastewater is suitable for algal growth.

Lipases have many applications in biotechnology, thanks to their ability of acylglycerides hydrolysis. They alsp possess the unique feature of acting at the lipid-water interface, which distinguishes them from esterases. Commercially useful lipases are produced by microorganisms with the extracellular lipase being produced by many bacteria including Pseudomonas. The greatest production of lipase takes place under optimum conditions such as appropriate temperature, suitable carbon, nitrogen sources, etc. This study tries to collect lipase-producing bacteria from the soil of oil-extraction factories and identify isolated bacteria, while creating optimum conditions for lipase production by bacteria. Having collected three soil samples from an oil extraction factory, lipase-producing bacteria have been identified, based on biochemical and morphological tests. Finally the optimal conditions for lipase production as well as molecular analysis has been evaluated. During the study, among the different bacteria, the strain to produce highest lipase has been selected. It has been found out that the optimal conditions for lipase production by this strain is as follows: 48 hours of incubation; incubation temperature of 37 °C; pH of 7; agitation speed of 150 rpm; peptone extract as the nitrogen source; and olive oil as a carbon source. A lipase-producing bacterium has been identified based on morphological, physiological, and biochemical characteristics as well as 16S rRNA analysis, identified as Pseudomonas spp.

Heavy metals that enter marine environment and remain in the water as well as the sediments are accumulated by aquatic organisms, thus becoming highly good indicators to monitor metal accumulation in the long run. Metals are potentially harmful to humans and most organisms at varied levels of exposure and absorption. Northern East Mediterranean Sea is a crucial region as it is an area, shared by numerous aquatic species with pollutant factors such as heavy marine traffic, transportation ports, industry plants, iron and steel works, oil pipeline installation, and other small factories. While the previous part of this review (Review of heavy metal accumulation on aquatic environment in Northern East Mediterranean Sea part I: some essential metals) evaluated the data from previous studies concerning toxic effects of selected essential metals on seawater, sediment, and different tissues of aquatic animals, collected from different areas in Northern East Mediterrenean Sea since the 1990s, the present part intends to evaluate the data from previous studies on toxic effects of selected non-essential metals. For this purpose, 94 articles and 6 theses have been examined and a good deal of information has been gathered to open a forward-looking view of the studied area’s pollution. Althought there has not been any harmonization, when comparing heavy metals investigations in the bay, all studies have shown that consumption of aquatic species from the region causes no problem to human health.

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.

The association of the emergence of bacterial resistance to clinical environments is common; however, aquatic environments, especially the polluted ones, also play a key role in this regard. Aquatic environments can act as facilitator for the exchange of mobile elements, responsible for resisting antibiotics. They even may stimulate the emergence and selection of these elements through contaminants or the natural competition between bacterial phyla. Currently there is a large number of highly-reliable resistance genes, which is selected in aquatic environments, mostly due to several types of pollution, such as the mcr-1 gene that causes resistance to one of the antibiotics, available in the market, namely colistin. Thus, the present review aims to show a range of impacts capable of selecting bacterial resistance in the environment, thus clarifying this environment's role in dispersion of resistance.

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.

The current study aims at modelling the dispersion of two pollutants, namely CO (carbon monoxide) and SO2 (sulfur dioxide) released from District 7 of Tehran Municiaplity, from 20 main line sources, by means of CALPUFF modeling system. CALPUFF is a non-steady state puff modeling software which employs meteorological, terrain, and land-use data to effectively simulate air pollutants' dispersion from a given source. CALMET software has been applied to provide meteorological conditions within the study domain. The study has been carried out on September 30, 2012 and shows that the modeled concentrations have been below both Iranian air ambient standard and NAAQS standard for CO and SO2. It also compares the measurements from the monitoring station of Setad Bohran, showing that the simulated hourly mean concentrations of the SO2 and CO do not follow similar temporal patterns for measurement values. For the absolute value, model results seem to be highly underestimated, compared to the monitored data (R2 = -0.41).

The present study aims at designing a promising Microbial Fuel Cell (MFC) to utilize wastewater in order to generate electricity. Two types of salt bridge have been used in MFC (KCl and NaCl). The maximum electricity generation with 1M KCl and NaCl has been 823 and 713 mV, respectively. Varied salt concentrations (0.5M, 1M, 2M, and 3M) of salt bridge in MFC have been analyzed with different factors like temperature, type of electrode, configuration, and surface area of electrode being studied. The optimum temperature is found to be 32Co, with the optimum type of electrode being graphite rod, while the optimum configuration and surface area of electrode is graphite plate with surface area of 183.6 cm2. Artificial Neural Network (ANN) has been employed to predict voltage production of MFC and compare it with the experimental voltage. Multiple   correlation methodology has optimized the voltage production with the correlation coefficient (R2) being 0.999.

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.