Organophosphates are one of the most common pesticides in the world. Among them, one can find malathion that is classified as carcinogenesis, and, as a result, should be appropriately removed since it is highly consumed and possesses a lot of pathogenicity. So far, several processes have been used to remove malathion from aqueous media. The present study investigates its removal by means of Fe3O4 iron oxide nanoparticles. Based on experimental-laboratory studies, using the Response Surface Methodology (RSM), the impact of independent variables such as pH, iron oxide nanoparticle concentration, and contact time on malathion removal efficiency have been investigated. Results show that the pH of the solution is the most important and effective parameter in the process. Optimal conditions of malathion removal based on the appropriate model, obtained from RSM, include 0.4 g/L iron oxide nanoparticles, pH of about 5 (acidic conditions), and contact time of about 1 h with ultraviolet radiation being equal to 82% malathion removal. The process, used in this study, can remove malathion from aqueous solutions according to the so-called conditions, and changing the laboratory conditions can effectively remove it. This process can also be recommended as an economic and scientific method to remove malathion from drinking water.

In this work, Fe3O4-SiO2 nanoparticles were synthesized, characterized, and applied as adsorbent material to remove methyl blue stain from an aqueous solution. The prepared nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and Brunauer–Emmett–Teller (BET) to determine the physical surface properties and correlate them to the adsorption efficiency. In addition, this study investigated the influence of several parameters on the removal percentage and adsorption capacity. Specifically, this study investigated the impact of changing the following parameters: pH (1 – 8), agitation speed (Uspeed; 100 - 350 rpm), initial methyl blue (MB) concentration (1 - 100 mg/L), adsorbent dose (0.05 to 0.15 g), and contact time (10 - 100 min). The characterization study reveals that the prepared material has an excellent surface area (385 ± 5 m2/g) and pore volume (0.31 cm3/g) which enhances the adsorption capacity. In addition, the prepared material showed excellent efficiency where the removal percentage reached 99.0±1% at the optimal operating conditions and the maximum adsorption capacity was 40 mg/g. This study delivers a full elucidation of the adsorption of MB dye by Fe3O4-SiO2 NPs which considers a promising inexpensive adsorbent. It also delivers important insight information about the adsorption process and the influence of each parameter, which fill the lack in this field.

Cities in developing countries like Shiraz in Iran face significant challenges due to a lack of an integrated solid waste management system. Climate change, soil, and water pollution are examples of environmental issues caused by improper Municipal Solid Waste Management Systems (MSWMS) in developing countries. The aim of this study is to find solutions for these environmental problems based on the experiences of developed countries. The data was collected using several methods such as visual observations, studying accessible documents of the current situation of the MSWMS in Shiraz, and participating in an interview with engineers the 'Shiraz Municipality Waste Management Organization' (SMWMO).  Results present the current functional elements of MSWMS in Shiraz, Shiraz waste diversion rate (0.22), and its Zero Waste Index (.015). Moreover, the results present some recommendations to find a way to transform cities like Shiraz into zero-waste cities. Results indicate that establishing zero-waste policies, legal frameworks, and financial strategies as well as convincing private sector involvements in installing waste-to-energy facilities and a proper sanitary landfill to move the city toward optimum recycling and zero landfilling in addition to reducing consumption and maximizing diversion rate and finally sustainable development by the cooperation of government, NGOs and media programs would solve many problems of the MSWMS and would solve environmental issues in many cities.

The problem of pollution of aquatic ecosystems with microplastics has been actively studied by the world scientific community. Most of this research has been devoted to marine ecosystems, whereas scant research has been conducted on fresh water bodies. Lake Baikal (Russia) is a unique natural reservoir. Previous studies devoted to the amount of microplastics in the waters of Lake Baikal were carried out singularly and were not of a systemic character; therefore, previously obtained data does not reflect a complete picture of the state of the lake. Within the framework of this study, our goal was to study the composition and morphological structure of microplastic particles in the ice of Lake Baikal at different distances from the coastline. To do this, a number of ice samples were taken from the upper and lower sides at five different points in South Baikal opposite the village of Bolshiye Koty. Later these samples were analyzed for the types of microplastics and their amount. In the samples taken, two types of microplastics were found—fragments and fibers—with fibers being predominant. The median values of the number of microplastics particles are higher in samples taken at the interface between water and ice, compared to samples taken from the ice surface. Presumably, main part of microplastic fibers found opposite the village of Bolshiye Koty were brought in by a constant circular current from the opposite east coast. In turn, the low number of fragments in the samples may be due to the freezing of the coastline.

Chromium VI is a frequent pollutant of industrial liquid effluents. It is a substance classified as a carcinogen group I. In this study, a Cr VI sorption mechanism was developed by using nanocellulose spheroids (hydrogel) obtained from ivory nut. Cr VI was detected in water by a colorimetric method, using 1, 5-diphenylcarbazide at λ 540 nm. Then, the sorption capacity of nanocellulose spheroids was tested by varying the solution's pH and temperatures. The outcome of the experiment shows that the most efficient pollutant’s adsorption conditions are occur at pH 4 and 25 °C. Removal percentages of Cr VI reached 91.29% (+/-1.36) and 95.33% (+/- 0.86). Additionally, the sorption kinetics showed that the adsorption reaction on the material reaches its equilibrium 20 to 30 minutes after the reaction starts. Finally, an analysis of adsorption isotherms showed a high adjustment with the Langmuir and Freundlinch isotherms. In this frame, this work’s results show that nanocellulose beads are an interesting alternative to efficiently reduce Cr VI from industrial and drinking water.

Exposure to household dust is a common occurrence in all countries and causes various diseases. This study provided information on the number, shape, size distribution, and elemental composition of household dust particles collected in urban homes in Agadir city in Morocco. Moreover, a potential human health risk of exposure has been identified based on current research. Samples were analyzed using computer-controlled scanning electron microscopy and ImageJ image processing program. A total of 3296 particles were analyzed for their size, and 76 particles were classified according to their size and elemental composition. Household dust particles were classified in six types: micro-aggregates (31.6%), biogenic (5.3%), spherical (17.1%), subrounded (7.9%), subangular (11.8%), and angular (26.3%). These particles were determined to have originated from a distant source (Trask classification index between 1 and 2.5). They were large (Skewness asymmetry coefficient > 1), and ranged from 0.2 to 363 µm with an average value of 22.8 ± 0.6 µm in diameter. Dust particles with diameters of 5-10 µm and 10-20 µm were the most abundant, while dust diameters of 10-20 µm, 20-30 µm, and > 100 µm were the highest in volume. The domestic dust deposition rate was 19.8 ± 7.4 g/m2 per year. Household dust is one of the major sources of PM10 in the residential environment (44.6% of the total number of particles), and the studied properties of house dust are highly related to human health. Household dust is a critical element to be considered in the occurrence of respiratory and cardiovascular infections.

Batch adsorption process was employed to remove copper(II) and cadmium(II) ions from contaminated water using dried orange peel powder as a cellulosic adsorbent, which supports circular economy and sustainability. Metal ion concentrations were determined using a flame atomic absorption spectroscopy (FAAS). Effects of pH, sorbate-sorbent contact time, metal ion concentration and adsorbent dose on the removal efficiency of the metal ions was investigated. The adsorption equilibrium was reached at 120 and 150 minutes for Cu(II) ions and Cd(II) ions, respectively. At optimized pH and biosorbent load, 10 mg L-1 of Cu(II) and Cd(II)  ions could be removed to the extent 96.9% and 98.1%, respectively, within 2 hrs. However, the percentage removal of metal ions decreased with increasing their initial concentrations. The observed adsorption data was also interpreted in terms of Langmuir and Freundlich adsorption isotherm models. The calculated equilibrium data fitted more adequately with Freundlich model (higher correlation coefficient, R2) than Langmuir model, indicating heterogeneity of adsorption sites due to different functional groups in cellulose. Cd(II) ions showed less binding affinity and less desorption than Cu(II) ions. The maximum adsorption capacity (qmax) of dried orange peel were 2.78 mg/g and 2.57 mg/g for copper(II) and cadmium(II) ions, respectively.

Consumption of polythene is unavoidable in this era and it is increasing day by day. Polythene’s hazardous waste is adversely effecting environment. In fact any form of polythene is a nuisance to the environment because of strong resistance against degradation thus; they remain in nature for a very long time. Biodegradation is the only promising solution to overcome this problem.  Fungi, a group of saprophytic organisms are evolved to adapt for almost every environment, specially marine and freshwater source. This property drives fungi to grown on polythene even in adverse environment. So, present study was planned to compare biological degradation of low density polythene [LDPE] and biodegradable polythene by potential fungus to find out an eco-friendly and economic solution of polythene waste. Ten fungal strains were isolated from rotting polythene debris those are Penicillium chrysogenum, Rhizopus nigricans, Chaetomium murorum, Memnoniella echinata, Aspergillus fumigatus, Stachybotrys chartarum, Aspergillus niger, Chaetomium globosum, Aspergillus flavus and Fusarium oxysporum, in which Penicillium chrysogenum, Rhizopus nigricans, Aspergillus fumigatus, Aspergillus niger and Aspergillus flavus showed greatest results in terms of degrading both Low density polythene and biodegradable polythene. These isolates also showed good enzymatic reaction and weight loss. SEM analysis of polythene surface was also in support of these findings.

Dairy industries generate enormous volumes of waste water which are significantly rich in organic compounds; contributing to high BOD, COD and sulfates. As a mandate to ‘treat’ effluents generated by different unit operations in a dairy industry, current treatment methods rely on physico-chemical, mechanical and conventional biological interventions. This approach remains unviable because of cost intensiveness and excessive energy usage. Additionally, the significant lowering of pollution indicators remains a daunting task with inlet and outlet parameters. With these identifiable gaps, our study was aimed to screen bio-efficacious, naturally attenuated fungal isolates to lower exceeding levels of sulfate in effluents released by dairy industry. Effluent samples were collected from Effluent Treatment Plant (ETP) of Jaipur Dairy, Rajasthan Dairy Co-operation Limited (RCDF), Jaipur. For mycological investigations, qualitative screening was carried out in Potato Dextrose Agar (PDA) supplemented with Calcium Sulfate (CaSo4) (0.1g/L). The most promising fungal isolates belonging to Aspergillus sp. was characterized based on its cultural and microscopic characteristics. Microcosm study was conducted by supplementing Aspergillus sp. in Untreated Dairy Effluent (UDE) for a period of 7 days at Room Temperature (RT) under static conditions. Following the incubation phase, mycelial mesh (plug) was indicative of exponential fungal growth. Effluent seeded with Aspergillus sp. and abiotic controls were spinned at 5000 rpm for 15 minutes to eliminate biomass. Sulfate estimation was carried out in Cell Free Extract (CFE) of both experimental and control group. A significant reduction of 67.3% was observed (p<0.05) with respect to positive control and 8.4% when contrasted with abiotic control.

This study utilized kinetic models to study the treatment efficiencies of a laboratory-scale up-flow biological aerated filters reactor (UBAF). The treatment efficiency of a model reactor was studied using different operating conditions of the hydraulic retention times, organic loading rates, and kinetic parameters. As a result of the calculations, the second-order and modified Stover/Kincannon models are appropriate. The substrate removal rate constant K2(S) was 1.7 per day for the reactor, with a correlation coefficient of 0.9979. Utilizing the modified Stover/Kincannon model, the coefficient of the determined concentration was 0.9987; 0.9265; and 0.9685 for Chemical oxygen demand (COD); ammonium nitrogen (NH4+-N); and Total Nitrogen (TN), respectively. The calculation of the saturation value constants and maximum utilization rate for Chemical oxygen demand (COD); ammonium nitrogen (NH4+-N); and Total Nitrogen (TN) was performed using the modified Stover-Kincannon model were 178.57 and 201.80 for COD; 1.876 and 4.6 for NH4 +-N; 3.823 and 6.644 for TN, respectively. It is possible to determine the kinetic parameter for removing COD, NH4+-N, and TN from wastewater by using the modified Stover-Kincannon model.