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.

Kharg Island in the Persian Gulf is the place for the major oil export terminals of Iran and hosts several large oil related industries. Coastal environment of the Kharg Island is rich in coral reefs. This paper presents concentrations and sources of aliphatic and aromatic hydrocarbons in the sediments from the coastal area of the island. The concentration of hydrocarbons in 14 seabed sediment samples from water depths of 13-20 m around the island were measured by gas chromatography (GC). Total Petroleum Hydrocarbon (TPH) concentrations in sediment samples ranged from less than 1 to 133 μg/g indicating low to moderate levels of oil pollution. Spatial distributions of TPH concentrations indicated no oil pollution in the southern part of the island, higher oil pollution levels near oil terminals and correlation with fine particles. Total Polycyclic Aromatic Hydrocarbons (∑PAHs) concentrations in sediment samples ranged from near zero to 6210 ng/g, indicating non to highly, but mainly moderately polluted levels. SPAHs concentrations, except at one station, were all less than the NOAA sediment quality guideline value for the effects range low. Developed indices for pollutant origins showed that hydrocarbons in all sediment samples collected in the study area had petrogenic origin. The results also indicated that the emissions from gas flares in the island were the main source of aromatic compounds in the sediment samples.

The sediments of Saf-Saf river (North eastern of Algeria), were studied in order to evaluate their degree of contamination by trace metal elements. Six heavy trace metals (Cd, Cr, Cu, Fe, Mn and Ni) were researched at the surface sediments of nine study stations. Since these different metallic elements appear as tracers of anthropogenic pollution; various evaluation indices of metallic contamination were studied (Igeo, FC, DC, IPS and PEC). The results of these indices are consistent and reveal a polymetallic sediment contamination by several heavy metals essentially by Fe, Mn and Cd, with an abundance of Fe and Mn. Sediment pollution index, indicates that sediments at all stations are hazardous (IPS ˃ 20). The environmental quality of Saf-Saf river sediments, were realized by comparing the metal contents with the values of the TEC and the PEC has showed that the metals Cd, Cu and Mn present a great danger of toxicity.

The quality of the water from Lake Bosomtwe was assessed to aid in the conservation decision on the lake. Twenty-six parameters of physico-chemical, bacteriological, and organic effects and major and trace ions were evaluated using the principal component analysis. The levels of these parameters were also compared with surface water benchmarks of Ghana EPA, WHO, EU, US EPA and CCEM. As prescribed by the benchmarks of these regulatory bodies, the mean levels of temperature, pH, dissolved oxygen, total suspended solids, total dissolved solids, nitrates, phosphate, biochemical oxygen demand, chemical oxygen demand, total hardness, conductivity, alkalinity, turbidity and fluorine did not signal any lake pollution, but sulphate, total and faecal coliforms, chlorophyll-a, cadmium and mercury showed pollution tendencies. Temperature, pH, dissolved oxygen, total suspended solids, total dissolved solids, nitrates, phosphate, sulphate and total coliform bacteria were found to be the main parameters that drive 71.2% of the limnological characteristics of the lake water and deserve careful consideration in designing conservation strategies for the lake.

The current study determines the concentrations of trihalomethanes (THMs), and the cancer risk associated with them. The tap water sampling was done from the command area of nine water treatment plants (WTPs) of Delhi, India. THMs levels in the water samples from eighteen distribution points were investigated for one year. The cancer risk (CR) related to THMs by different exposure routes i.e., ingestion, dermal absorption, and inhalation, was assessed for males and females. The THM levels varied between 11.41 µg/L to 175.54 µg/L in the distribution system, having a mean level of 77.58 µg/L. The average concentrations of THMs exceeded the maximum permissible limit given by Indian Standards. The concentration of chloroform was maximum, followed by bromodichloromethane, dibromochloromethane, and bromoform. For males and females, the mean value of total CR was 5.09E-05 5.70E-05, respectively. As the THMs levels were high, the total CR value was also more than the negligible level of risk i.e., 1.0 x 10-6 through all exposure routes.

Worldwide there is an immense demand for plastic material that results in “white pollution”. Petrochemical-based plastic is used all over the world which leads to adverse impacts on every sphere of the earth. However, many steps have been taken to control this plastic pollution globally, such as chemical treatments, plastic waste incineration, sanitary landfilling, and 7 R programs. Still, plastic pollution is one of the major international problems. Non-biodegradable plastic would not eradicate from our environment until we have an economically feasible and more biodegradable substitute. In recent years algae, especially microalgae, have got attention worldwide, owing to their various applications. Microalgae is one of the sustainable ways of bioplastic synthesis as during cultivation it also purifies wastewater. This review paper has summarized various species of microalgae used for the synthesis of bioplastic, their cultivation system, and methods for bioplastic production by using microalgae biomass, followed by multiple challenges, solutions, and future prospects.

Humans spend close to 90% of their time within the indoor environment. Deteriorating indoor air quality, especially high PM10, PM2.5 and PM1 is slowly becoming a major concern. A study was carried out, for two years, to characterize the spatiotemporal variation of PM in the indoor-outdoor environment across different residential setups (R1, R2, R3, and MC) in the Delhi region. The study established correlation between monthly variations of Indoor/Outdoor (I/O) ratios and meteorological factors. The results showed Spatio-temporal variation in the average mass concentrations of PM10 recorded peak values during the winter season (avg. 514± 72.15 µg/m3) and minimum concentration was observed during monsoon (avg. 91.41± 22.64 µg/m3) months. Among all the sites, the mixed cluster (MC), a residential cum commercial zone reported the highest particulate matter concentration (avg. 308.10 ±37.23 µg/m3) and while R2 reported the least concentration (avg. 244.9± 27.65 µg/m3) within the indoor environment. The I/O ratios of particulate matter were observed to be highest in January (I/O ratio1.6) and lowest in June month (I/O ratio 0.8). PM10, PM2.5, and PM1 dynamics were found to be critically influenced by meteorological factors, regular household activities, and diverse building designs. The short- or long-term exposure of particulate pollutants (beyond the permissible limits) can increase the probability of acute health effects, so there is an utmost requirement to collect better and systematic information about actual exposure levels experienced in different urban residential environments.