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Water purification included the elimination of pathogenic organisms and the reduction of suspended substances in water, which was obtained by conventional methods of disinfection and filtration. But today, due to the increase in all kinds of pollution to water sources, the common methods are not fully able to properly purify water. Based on the results obtained from various studies, drinking water disinfection can increase antibiotic-resistant bacteria in water environments. Water treatment may extend antibiotic resistance in bacteria, and systems of water distribution may serve as a vital reservoir for antibiotic resistance spread to opportunistic pathogens. Treatment processes of drinking water cannot remove all ARGs from sources of drinking water, thus, supply systems of drinking water may be a primary release of ARGs route from the environment to the host, which poses potential hazards to human health. It is also known that some bacteria number increases with the chlorine increase in drinking water and the water purification process can not eliminate all antibiotics from drinking water. Therefore, it is essential to obtain more information about the frequency and amount of bacteria with antibiotic-resistant mutations. In this review article, the studies done on drinking water treatment, as well as the introduction of antibiotics used in everyday life through sewage and production effluents and their impact on the health of human society. [ABSTRACT FROM AUTHOR]

Nitrogen (N) and cerium (Ce) co-doped titanium dioxide (TiO2) supported activated carbon (AC) (N-Ce-AC/TiO2) were synthesized to remove antibiotic tetracycline from aqueous solution via adsorption and photodegradation. The sol--gel technique, aided by microwave radiation, was used to synthesize N-Ce-AC/TiO2. Central composite design under response surface methodology was used to optimize the variables comprising urea (N source) (A: 0.02-0.20 g), cerium(III) nitrate hexahydrate (Ce source) (B: 0.02-0.20 g), activated carbon (C: 0.10-0.50 g), and microwave power (D: 600--800 W), where the degradation of tetracycline was the response. Characterization of the produced catalyst was carried out by means of X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and the Brunauer--Emmett--Teller method for determining surface-texture parameters. N-Ce-AC/TiO2 prepared with 0.50 g activated carbon, doped with 0.02 g urea and 0.20 g cerium, and activated at microwave power 600 W for 15 min exhibited 91.08% tetracycline removal when subjected to 7 W of UV irradiation, according to the results of optimal variable preparation. [ABSTRACT FROM AUTHOR]

Various waste management strategies have been discussed by the above-mentioned collection of articles including the use of eco-enzymes, flood management, heavy metal pollution management, and the circular economy concept in waste management in developing countries. HEAVY METAL REMOVAL Heavy metal removal in the ecosystem is described in the following six articles. Ratnasari et al. ([19]) evaluated a powerful and flexible mathematical model, modified mass transfer factor model (MMTF), for describing the mechanism of numerous heavy metal and dye pollutants adsorbed onto various adsorbents. The special issue carries 27 articles exploring various aspects of environmental quality including nano adsorbent, waste management, wastewater treatment, and heavy metal removal. [Extracted from the article]

The area of polluted water expands day by day due to the rapid increase in agricultural activities. Application and the excessive amount of fertilizer in the agricultural activity can reduce the water quality. One of the alternative way to remove pollutants from polluted water is phytoremediation technique. This paper attempt to evaluate the potential of Azolla pinnata act as a phytoremediation to treat the agricultural water. Three types of media with different dosage which are tap water, water added with organic fertilizer (chicken manure: dosage range of 10-30 g), and water added with inorganic fertilizer (growing fertilizer: dosage range of 10-30 g) were employed. Media B10 (water added with 10 g organic fertilizer) had the highest removal efficiencies for NH3-N, PO3-4, and NO-3 with 25%, 38.5% and 30%. In addition, turbidity and pH value diminished to 15.65% and 18.6%, respectively. However, it indicated that Azolla pinnata has the potential as an agent of phytoremediation especially for water polluted with organic fertilizers. [ABSTRACT FROM AUTHOR]

Metribuzin is a triazine herbicide used in sugarcane fields to control broadleaf weeds. Metribuzin that is washed into waterways as runoff can be linked to hermaphroditism in frogs as well as algal and macrophyte death. Metribuzin degradation by bacteria is essential to reduce the half‐life of metribuzin in the environment. The objective of this study was to determine metribuzin degradation by various bacterial consortia developed from a sludge collected from a sewage treatment plant. The sludge was exposed to metribuzin under various electron acceptor conditions including, nitrate reducing, sulfate reducing, and mixed electron acceptor conditions. Results showed metribuzin was removed significantly under mixed electron acceptor condition when glucose served as a co‐substrate followed by sulfate reducing and nitrate reducing conditions. The major metabolites identified in metribuzin degradation were desamino‐metribuzin, diketo‐metribuzin, and desamino‐diketo‐metribuzin. Repeated exposure to metribuzin may help the bacteria to adapt and evolve metribuzin degrading enzymes. [ABSTRACT FROM AUTHOR]

On August 29, 2021, Hurricane Ida made landfall as a category 4 hurricane, bringing a torrent of wind, rain, and storm surge to Southeast Louisiana. This hurricane brought several feet of sediment into the residential areas of southeast Louisiana affecting homes and businesses. The sediment contains industrial waste and sewage sludge. A study was conducted to find the presence of antibiotic‐resistant bacteria (ARB) in the sediments. The results of this study show the presence of human polyomavirus BK in the sediments indicating the presence of human feces. The sediment also showed high levels of antibiotics such as tetracycline and sulfonamide. Presence of many multidrug resistant bacteria were found in the sediments along with the presence of various antibiotic resistance genes (ARGs) such as sul1 and sul2 for sulfonamide resistant and tetA gene for resistant to tetracycline. The heavy metal analysis revealed an elevated presence of heavy metal contamination. [ABSTRACT FROM AUTHOR]

The performance of extracted coagulant from the sugarcane bagasse was tested using synthetic wastewater for turbidity removal. Sugarcane bagasse was selected because it is available in abundance as a waste. This study was carried out to analyze the effect of the extraction process in optimizing the active coagulant agent of bagasse as a natural coagulant for optimum turbidity removal. Bagasse was characterized in terms of physical, chemical and morphological properties. The results showed bagasse has very high polysaccharide content which can act as an active coagulant agent together with hemicellulose and lignin. The extraction process for degradation of lignin and hemicellulose was run based on two different solvents (NaOH and H2SO4) with varying concentrations from 2% to 10% at different extraction temperatures varied from 60 °C to 180 °C for various extraction times (0.5 h to 3 h). The optimum polysaccharide content extracted from bagasse was 697.5 mg/mL by using 2% NaOH at 120 °C for 2 h extraction. The coagulation process using extracted bagasse showed the removal of suspended solids up to 95.9% under optimum conditions. The concentration of polysaccharides as the active coagulant agent plays a vital role where high polysaccharides content removes most turbidity at a lower dosage. Bagasse has the potential to be an alternative coagulating agent due to its efficiency, and eco-friendly properties for the treatment of wastewater. [ABSTRACT FROM AUTHOR]

Wastewater recycling plays an important role in minimizing water loss. The recycled wastewater can be utilized for many purposes from irrigation to portable water supply. Numbers of wastewater treatment system have been applied in Malaysia to achieve quality in meeting the intended purpose of wastewater recycling. Although there are many studies reported on the efficiency of the treatment technologies, comparative assessments including the significant purpose until the estimation of operational expenditure for each of the treatment technologies are lacking. Therefore, this brief review aims to critically discuss each of the treatment technologies from the secondary treatments, tertiary treatments, to the advanced treatments. Based on our review, the conventional activated sludge system has high potential for wastewater recycling due to lower cost in terms of population equivalent and shows great removal efficiency among secondary treatment while sand filtration and activated carbon is the better options for tertiary and advanced treatment. Therefore, it can be concluded that conventional activated sludge system, sand filtrations and activated carbon process is the most feasible in terms of removal performance and cost effectiveness for secondary, tertiary and advanced treatments. [ABSTRACT FROM AUTHOR]

Currently, development of an efficient natural adsorbent to remove pollutions becomes crucial since adsorbents derived from chemicals have several shortcomings such as their potential as a new pollution in the environment. Therefore, this study aims to investigate the capability of sewage sludge biochar for the removal of dye. Sewage sludge biochar was synthesized by pyrolysis at different temperatures, which were 350°C, 450°C, 550°C, 650°C, 750°C, and 850°C. The characterization of biochar was conducted by analyzing the percentage yield, ash content, moisture content, Fourier-transform infrared spectroscopy, and pH zero charge. This study found that as the pyrolysis temperature increased, the percentage yield along with moisture content decreased meanwhile the ash content increased. For kinetic studies, pseudo-second-order model gave better result than pseudo-first-order model indicating that adsorption mainly takes place on chemical adsorption. The applicability of adsorption isotherm analyses indicates that the adsorption mechanism followed Freundlich isotherm compared to Langmuir as Freundlich give value of R2 nearer to 1 (0.9962). It showed that adsorption mechanism behaves in a multi-molecular layer and the adsorption sites are heterogenous on the sewage sludge biochar. [ABSTRACT FROM AUTHOR]

This study proposed a novel and low-cost adsorbent prepared from dredging sediment (DSD) for effective removal of dye in aqueous solutions. The adsorption efficiency and behavior of the DSD adsorbent toward the crystal violet (CV), a cationic dye, were investigated via batch experiments. The results showed that DSD samples contain mainly clay minerals (illite and kaolinite) and other mineral phases. In addition, DSD is a mesoporous material (Vmesopore = 94.4%), and it exhibits a relatively high surface area (~39.1 m2/g). Adsorption experiments showed that the solution's pH slightly affects the adsorption process, and a pH of 11 gave a maximum capacity of 27.2 mg/g. The kinetic data of CV dye adsorption is well described by the pseudo–second-order and the Avrami models. The Langmuir and Liu isotherm models provide the best fit for the adsorption equilibrium data. The monolayer adsorption capacity of Langmuir reached 183.6, 198.0, and 243.6 mg/g at 293, 308, and 323 K, respectively. It was also found that the adsorption process was spontaneous (−ΔG°), exothermic (−∆H°), and increased the randomness (+∆S°) during the adsorption operation. The primary mechanisms in CV dye adsorption were ion exchange and pore filling, whereas electrostatic attraction was a minor contribution. In addition, three steps involving intraparticle diffusion occur at the same time to control the adsorption process. The results of this study highlight the excellent efficiency of DSD material as an ecofriendly sorbent for toxic dyes from water media. [ABSTRACT FROM AUTHOR]