Constructed wetlands (CWs) are man-made systems designed to treat a range of residential, commercial, and industrial wastewaters. The objective of the study was to evaluate the efficiency of wastewater treatment systems using constructed wetlands. The effectiveness of removing chemical and physical pollutants was also evaluated. The setup consisted of a hybrid flow system composed of upflow constructed wetland and a horizontal flow constructed wetland connected in series that is used for primary treatment of the influent of domestic wastewater. Two systems were analyzed: one cultivated with the ornamental species Canna Indica, and one cultivated with the cattail Cymbopogon flexuosus. It consisted of two treatment sections consisting of two plant species Cymbopogon citratus (lemon grass – first CW) and Canna xalapensis Horan (Canna Indica – second CW). The water quality parameters i.e., BOD, COD, TSS were analyzed according to APHA (American Public Health Association) by daily sampling. The CW was monitored for the quality of wastewater inflows and outflows and nutrient accumulation in plants. Results showed that the maximum COD removal for Lemon Grass and Canna Indica beds were 75% and 70% respectively at 200mg/L COD loading in the CW setup over a six-month period respectively. The maximum BOD removal found in Lemon Grass and Canna Indica beds were 73% and 64% respectively at a feed concentration of 200mg/L COD. Both the CWs together as one unit showed similar rates of TSS removal irrespective of the type of wetland plant species and were more efficient in treating wastewater.

The applicability of Polyetheretherketone/polyvinylalcohol nanocomposite modified with zinc oxide nanoparticles synthesis for the removal of benzyl butyl phthalate from wastewater. Identical techniques, including BET, FT-IR, XRD, and SEM, have to characterize this unknown material. The investigation shows the applicability of adsorbent PEEK/PVA/ZnONPs, as an available, suitable, and low-cost adsorbent for adequately removing the benzyl butyl phthalate from wastewater. The impacts of variables, including benzyl butyl phthalate concentration, adsorbent, pH, and time (15 mgL-1, 0.3 g, 5.0, and 60 min). Based on the received data, the adsorption of benzyl butyl phthalate on the PEEK/PVA/ZnONPs adsorbent agrees well with the Langmuir adsorption model isotherm (qm = 34.24 mgg-1). The results of the thermodynamic parameter showed a negative enthalpy (-77.0 KJ/mol), a negative Gibbs free energy (-11.7 KJ/mol), and negative entropy (-274.0 J/K.mol). This led to the conclusion that the adsorption process is energetically possible, and exothermic was also spontaneous. This work indicates that the PEEK/PVA/ZnONPs, used as an ecologically adapted, adsorbent holds promise for eliminating benzyl butyl phthalate from wastewater.

The goal of this research was to investigate the efficacy photocatalysis with natural solar radiation and artificial UV radiation for disinfecting total coliforms in biologically treated wastewater.   The effect of TiO2 dosage and irradiation time on total coliform inactivation as measured by log reduction values (LRV), removal of BOD, COD, turbidity, and effluent properties as measured by pH and conductivity was investigated. Two sets of experimental equipment were constructed, one for using solar UV light and the other for using artificial UV light. After four hours of irradiation with 60 mg/L TiO2, photocatalysis achieved LRVs of 1.4 and 1, respectively, under UV and solar radiation. COD and BOD were reduced by 67% and 50% respectively under UV and solar radiation after two hours of irradiation with 60 mg/L TiO2. Turbidity was reduced by 71%. Both conductivity and acidity of the effluent were reduced as TiO2 concentration was increased. Photocatalysis with natural solar radiation produced disinfection results that were comparable to that of efficient UV light exposure. Artificial UV light and natural solar radiation can be combined in photocatalysis process to form a hybrid process.

Olive mill wastewater is the main by-product derived from olive mills using the three-phase extraction process,displaying a serious environmental risk due to its notable content in organics and phenolics Olive oil production, an agro-industrial of vital economic particularly in Mediterranean countries, is unfortunately associated with the generation of large quantities of OMW (Olive Mill Wastewater) and solid wastes. The OMW is considered a major environmental problem, it is a powerful pollutant rejected in nature without any prior treatment. This research work aims to study the treatment of OMW by a new ecological and economic system, which consists of the use of the following components: gravel, sawdust, soil, activated carbon, bamboo, and the valorization of the solid residues. HPLC analysis showed that hydroxytyrosol is the most abundant biophenol. Many other biophenols were identified (Tyrosol, gallic acid, and eleonic acid). The comparison between before and after filtration by the new system showed an essential degradation of phenolic compounds after treatment and found a new compound resulting from their degradation.

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.

This paper is the first to report on the role of a wastewater treatment plant (WWTP) in Sari, as a source of microplastics (MPs) in the Caspian Sea. Composite 270-liter/24-hour samples were taken the treated effluent of the WWTP in winter and spring, two seasons with different levels of human activity. The effluent contained 380±52.5 and 423±44.9 MPs/m3 in winter and spring, respectively, with the total numbers of MPs/m3 not differing between the two seasons. The dominant type of MPs in the effluent was microfibers with 237±68.7 and 328±33.4 per m3 in winter and spring, respectively. In both seasons, fiber sizes of

This study was undertaken to evaluate a novel aerobic wastewater treatment model for the remediation of refinery effluents and to assess the removal efficiency of Bulkholderia cepacia strain AJI and Corynebacterium kutscheri strain AJ2 to clean oil waste from petrochemical company. Wastewater quality parameters including pH, BOD5, COD, TDS, OIL & GREASE, PHENOL concentration, TPH and THC were monitored at 5, 10 and 15 days of treatment and the removal efficiencies were calculated. Results indicated that the raw oily wastewater effluents used during this study had extremely high levels of all the tested parameters. The mean values  of  all physicochemical parameters  of the wastewater from primary tank at different treatment period were statistically different (P˂0.001) After 15 days of biological treatment, BOD5 ,COD, TDS, Phenol, TPH, Oil & grease level of the refinery wastewater were reduced by 95.60 %, 98.40 % , 66.34 % , 100 %, 97.60 %  and 96.20 % respectively. The detection of the catabolic genes in the bacterial isolates recovered from primary tank using polymerase chain reaction revealed that both Bulkholderia cepacia strain AJ1 and Corynebacterium kutsheri strain AJ2 carried alk B and C23O but C12O was not detected in both isolates. Naphthalene dioxygenase was detected in Bulkholderia cepacia strain AJ1 but not found in Corynebacterium kutscheri strain AJ2. After treatment the waste water was filtered in the secondary tank. The results of physicochemical parameters in the outlet vessel essentially confirmed that the mixed culture in the two column model successfully carry out bioremediation of refinery wastewater. Therefore, aerobic treatment model for the bioremediation of refinery Petroleum refineries generate great amounts of wastewaters that may become seriously dangerous, leading to the accumulation of toxic products in the receiving water bodies with potentially serious long term effects to aquatic biota. Due to extreme toxicity of contaminants in refinery wastewater, there is a need to develop an economical technique to remove the pollutants from the wastewater is highly recommended owing its environmental friendliness.

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.

Natural quartz mineral was examined as a new sorbent for Hg(II) removal from synthetic wastewater systems. Batch adsorption experiments of Hg(II)  onto quartz mineral were conducted under various conditions such as solution pH, sorbent dosage, contact time, initial Hg(II)  concentration. Adsorption experiments results of Hg(II) by quartz mineral showed good achievement after 180 min with 1.0 g/L sorbent mass at pH of 2.0, agitation speed of 200 rpm and a temperature of 25°C. Moreover, the Hg(II) concentration was directly related to increases the adsorption capacity, the maximum Hg(II) uptake by quartz  sample was 16.52 mg/g for 80 mg/L (C0 (Hg(II)].  Langmuir isotherm and pseudo-second-order kinetics (R2 > 0.99) were found to be the most appropriate models to describe the adsorption of Hg(II) by quartz mineral. The intra-particle diffusion model and the calculated Dubinin–Radushkevich adsorption energy (Eads = 0.78 kJmol-1), confirms a physisorption adsorption reaction occurring in three stages.

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.