The Huatanay River in Cusco-Peru, is affected by wastewater discharges along its course. In order to evaluate this impact, we evaluate antibiotic residues and their impact on the increase of bacterial resistance in the city of Cusco treatment plant. For this purpose, water samples from the influent and effluent of the treatment plant were analyzed by chromatographic methods; additionally, sensitivity tests were performed with three bacterial strains (Escherichia coli, Salmonella sp., and Klebsiella sp.), which were isolated from the same place. Six antibiotic residues were identified (ceftriaxone, amoxicillin, trimethoprim, sulfamethoxazole, dicloxacillin, and lincomycin). Those found in the highest concentration were: amoxicillin (91495 and 0 µg/L) and lincomycin (33970 and 10800 µg/L) in the influent and effluent, respectively. There is more resistance in the effluent than the influent in the case of E. coli shows resistance in the effluent to cephalexin (30 µg) and azithromycin (15 µg). Salmonella sp. is resistant to amoxicillin (15 µg), dicloxacillin (1 µg), lincomycin (2 µg), ceftriaxone (30 µg), cephalexin (30 µg), and ciprofloxacin (5 µg). Finally, Klebsiella sp. is sensitive to ceftriaxone (30 µg), amoxicillin (15 µg), and cephalexin (30 µg). This confirms that the antibiotic residues contained in the wastewater of Cusco generate resistance in the isolated bacteria.

Elevated level of fluoride (> 1.0 mg/L) in drinking water leads to both dental and skeletal fluorides. Present research is dedicated to check the efficacy of duck shell dust towards removal of fluoride. Various analytical tools (XRF, XRD, SEM-EDAX and zero point charge) were used to characterize the present adsorbent. The entire batch mode study results were further optimized by Response Surface Methodology (RSM). The results revealed that Langmuire isotherm is best fitted (R2 = 0.819) with adsorption capacity 4.894 mg/g. However, kinetic study suggest that the fluoride adsorption followed pseudo-second-order kinetic equation (R2 = 0.956). Similarly, thermodynamic study revealed that the fluoride adsorption by duck shell dust is endothermic and entropy driven process. Finally, optimization study demonstrated the optimized condition such as initial concentration, adsorbent dose, contact time and pH are 89.29 mg/L, 1.112 g/100 mL, 42.5 min and 9.91, respectively. Therefore, it may be concluded that duck shell dust could be a promising adsorbent for decontamination of fluoride from contaminated body.

Hydrothermal carbonization is a thermal technique that offers numerous environmental benefits, particularly in managing solid waste streams by decomposing the raw materials of solid wastes and converting them into the renewable source of energy known as hydro-char. This study evaluates the heating value of hydro-char produced through the hydrothermal carbonization of cigarette butts, taking into account influential factors such as time, temperature, and pressure, as well as its benefits and economic implications, using a novel approach involving simulations aimed at reducing the number of required tests, saving time, and cutting costs.The range of 150 to 350 oC for temperature and 30 to 240 minutes for reaction time were considered and resulted in a thermal value range of 15.94 to 23.12 MJ/Kg for hydro-char, which makes its heat value greater than lignite coal and within the range of bituminous coal. The findings also indicated that temperature and time have a direct impact on the heat value, with time being the more influential factor, although high temperatures can expedite the reaction rate and should not be disregarded. Finally, the economic analysis of the project was conducted using the NPV method, which demonstrated that the viability of this method depends on the cost of coal, making it a promising alternative for accessing new and cost-effective fuel resources while considering environmental benefits. Besides, this study highlights the potential of hydrothermal carbonization as a viable and advantageous method for producing fuel resources from biomass and organic waste, and provides quantitative and comparable evidence of the applicability and benefits of the proposed hydrothermal carbonization methodology in comparison to conventional methods.

Effective denitrification of water using photocatalytic reaction of active TiO2 particles doped with different oxides and metals has been the subject of numerous studies. For a particular research area, the potential of silica bond and its silicate based matrices with titanium dioxide and improving the photocatalytic performance using more economic methods is still challenging, and research in this field is attractive and ongoing. In this study, the effect of cement matrix and its complex bonds with industrial grade TiO2 particles was evaluated on the rate of water denitrification in a fixed bed circulating flow photoreactor. For this purpose, silica fume was substituted for cement in constant percent of 10 as a rich source of amorphous silica. Industrial grade TiO2 was added to the mix as5, 10 and 15 percent weight of cementitious materials (CM). Nano TiO2 was considered as a supplementary photocatalytic material with a constant 1% weight of CM in two mix designs. The results implied that the addition of 5% TiO2 increased the rate of nitrate concentration reduction by up to 10 times. Also, the specimen including 10% TiO2 increased denitrification rate by 107% compared to the previous content, which had much less impact. Also, the addition of nanoTiO2 increased denitrification rate up 113%.

Aquatic macroinvertebrates play significant roles in the benthic zone of the aquatic ecosystem and they have different tolerance level to pollution. Globally, macroinvertebrates are usedas bioindicators in determining the ecological health and water quality status of aquatic ecosystem. Therefore, this study focused on the community structure of benthic macroinvertebrates in River Ugbalo, south-south Nigeria. Macroinvertebrates and physicochemical parameters were sampled in three marked out stations between March 2018 and February 2020. Physicochemical parameters were analyzed following standard procedures, while macroinvertebrates were collected with Kick net and Van Veen grab. Physicochemical parameters showed that the water quality of the three stations sampled were fair considering the values of pH, turbidity, sulphate, nitrate, phosphate, DO, BOD, and EC which were within the World Health Organization and Federal Environmental Protection Agency of Nigeria. Cluster analysis based on Bray- Curtis similarity showed that macroinvertebrates were clustered by stations rather than seasons. A total of 5,580 macroinvertebrates individuals were recorded showing high biodiversity in the river. Diptera was the most abundant Order with 2,488 individuals followed by Odonata with 697 individuals. The least represented Order was Lepidoptera with 13 individuals. The diversity indices showed that Margalef index (5.93), Simpson diversity (0.95), Evenness (0.63), and Shannon-Weiner index (3.30) were highest in Station 1. This research work showed that the water quality of the studied stations was fair and station 3 was the most perturbed station.  We recommend the enactment and enforcement of policies that will lead to aquatic ecosystem restoration.

Substrates play a major role to filter, adsorb, sediment, flocculate, precipitate, and exchange ions. In CW (Constructed wetland), selecting substrate or bed materials is not difficult, as locally accessible, cost-effective, and environment-friendly materials can be used based on size, hydraulic conductivity, texture, porosity, etc. CW substrates undergo a multitude of purification processes, including physical filtration and sedimentation, sorption, ion exchange and microbial degradation, precipitation, and bio-immobilization in the substrate, in addition to uptake and metabolism by macrophytes. With constructed wetlands, treatment facilities with well-defined substrates, vegetation species, and flow patterns can be built with greater control than with natural systems. This report details investigations of some of the locally available substrates that all fit the requirements. Based on analysis of parameters which are pH, water absorption capacity, hydraulic conductivity, porosity, surface area, bulk density, particle size distribution, D10 particle diameter, D60 uniformity coefficient, permeability and specific gravity, a comparison of four materials is presented in this paper. The study found that the construction waste materials evaluated showed satisfactory physical properties for use as filler media in constructed wetlands for wastewater treatment.

Improper management of wet waste in cities located in temperate, humid regions with abundant rainfall leads to the production and spread of leachate across ecosystems. This not only pollutes soil and surface water but also contributes to the emission of greenhouse gases, negatively impacting both ecosystem and human health. Effective waste management can transform these wastes into valuable products, such as fertilizer and biogas, while also preventing environmental damage. In this study, we focus on a region with moderate weather conditions, which offers the potential for efficient waste management at a reasonable cost. By evaluating various technologies and methods, as well as considering global implementation approaches, anaerobic digestion emerges as a more suitable solution for waste management compared to conventional methods like burying and burning. Apart from waste reduction, anaerobic digestion offers several advantages, including reduced greenhouse gas emissions, prevention of soil, air, and water pollution, decreased toxicity and heavy metal contamination, and eradication of pathogenic organisms. Numerous types of digesters have been developed to date, and factors such as geographical location, substrate availability, construction materials, climatic conditions, cost and capital requirements, and energy consumption influence the design of these digesters. In this study, we estimate the design, construction, and management of a small-scale digester for a town with a population of 2000 people. By providing reliable information, this research aims to assist executive officials of towns and villages in establishing such units within their communities, promoting sustainable rural development.

Mangrove ecosystems have many functions for coastal areas, including ecological, social, and economic services. These functions have a systemic impact on the environment of other coastal ecosystems and human life. The mangrove ecosystem covering an area of 197.92 ha in Bedono, Demak Regency, Central Java was threatened due to the wave abrasion and high tides. Some parts of Bedono Village had become inundated and flooded permanently, zink as part of the ocean. This research was conducted to quantify water pollution in the mangrove ecosystem of Bedono Village using the Storage and Retrieval (STORET) method and the pollution index (PI). The fieldwork was conducted June 2022, by collecting water samples for laboratory analysis tests and in-situ water quality measurement. The parameter of the water quality that exceeded threshold of the Government Regulation of the Republic of Indonesia Number 22 of 2021 are the dissolved oxygen (DO) ranges between 4.39-8.78 mg L-1, BOD ranges between 30-32.4 mg L-1, phosphate ranges between 0.063-0.074 mg L-1, ammonia ranges between 0.148-0.48 mg L-1, Cr ranges between 0.071-0.21 mg L-1, and Pb ranges between 0.071-0.21 mg L-1. Based on the STORET method, the water quality in the mangrove ecosystem was found to be in the category of moderately (-16, for harbor function) – heavily polluted (-80, for tourism and -90, marine biota), whereas based on the PI index it was lightly polluted (1.77-4.12, for harbor function) – moderately polluted (11.06-13.83for tourism, and 9.96-11.85, marine biota).

The biodegradation rates of single-use blended bioplastic packaging nylon, nylon 6, and cellulose polymer were assessed in aquatic environments in an attempt to identify real biodegradable bioplastics (RBB). The natural biodegradation rates of the test samples in freshwater and marine water were assessed by respirometric method following the procedure of the American Standard Testing and Materials. The experimental design was arranged thrice in a completely randomized design of 2x4x3. The physicochemical parameters were obtained using the standard methods while the rates of biodegradation were obtained by titration method. Data obtained were analyzed using descriptive statistical method. At the end of 120 days, there were steady increase in the rates of biodegradation of cellulose and bioplastic samples across the fourth month in both freshwater and marine water. However, the rate of biodegradation in marine water were higher than in freshwater following the trend cellulose in marine (342 %) > cellulose in freshwater (259%) > bioplastics packaging nylon in marine (193%) > bioplastics packaging nylon in freshwater (175%). For nylon 6, the rate (-14) of retardation in the biodegradation process in Nylon 6 soaked in marine water is greater than that of Nylon 6 soaked in freshwater (-13). Consequently, nylon 6 was recalcitrant to biodegradation both in freshwater and marine water. The study concluded that the blended bioplastic packaging nylon is a real biodegradable bioplastic and could be suggested as a feasible and environmentally-friendly option to replace traditional plastics in the society.

Contamination of ground and surface water resources with Nitrate (NO3), Fluoride (F), Trihalomethanes (THMs), radon, and heavy metals is the most important global concern due to its possible health risks to people. This study reviews the drinking water contaminants and their health outcomes examined in Iran. A review search was conducted using Scopus, Web of Knowledge, PubMed, and Embase databases for associated released articles from 2014 to 2023, resulting in 86 articles relevant to the objective of this study. According to the results of this review, different emerging contaminants were found in potable water, including THMs, NO3, F, radon and heavy elements (i.e., As,  Pb, Ni, Cd, Zn, Cu, and Cr). Health outcomes of exposure to radon, F, NO3, THMs, and heavy metals in potable water have been expressed in various epidemiological research studies. More than 65% of the studies reported hazard index (HI) or hazard quotient (HQ) of heavy elements to be greater than one in potable water in Iran for infants, children, teenagers, and adults. Children and infants are at higher health risk than adults in these areas. The level of Arsenic, Cadmium, Lead, Nickel, Zinc, and Chromium, in 26, 26, 17.39, 13.04, 8.69, and 4.3% of the papers was more than the allowable limits, respectively. Various groups of emerging pollutants have been found in potable water in Iran, while epidemiological research studies on their health outcomes are still insufficient.