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The study presented the occurrence of antibiotics in 16 different hospital effluents, the removal of antibiotics in urban wastewater treatment plant (WWTP), and the potential ecotoxicological risks of the effluent discharge on the aquatic ecosystem. The total concentration of antibiotics in hospital effluents was ranged from 21.2 ± 0.13 to 4886 ± 3.80 ng/L in summer and from 497 ± 3.66 to 322,735 ± 4.58 ng/L in winter. Azithromycin, clarithromycin, and ciprofloxacin were detected the highest concentrations among the investigated antibiotics. The total antibiotic load to the influent of the WWTP from hospitals was 3.46 g/day in summer and 303.2 g/day in winter. The total antibiotic contribution of hospitals to the influent of the WWTP was determined as 13% in summer and 28% in winter. The remaining 87% in summer and 72% in winter stems from the households. The total antibiotic removal by conventional physical and biological treatment processes was determined as 79% in summer, whereas it decreased to 36% in winter. When the environmental risk assessment was performed, azithromycin and clarithromycin in the effluent from the treatment plant in winter posed a high risk (RQ > 10) for the aquatic organisms (algae and fish) in the receiving environment. According to these results, the removal efficiency of antibiotics at the WWTP is inadequate and plant should be improved to remove antibiotics by advanced treatment processes.

Wastewater treatment plant (WWTP) effluent has been identified as a potential source of microplastics in the aquatic environment. Microplastics have recently been detected in wastewater effluent in Western Europe, Russia and the USA. As there are only a handful of studies on microplastics in wastewater, it is difficult to accurately determine the contribution of wastewater effluent as a source of microplastics. However, even the small amounts of microplastics detected in wastewater effluent may be a remarkable source given the large volumes of wastewater treatment effluent discharged to the aquatic environment annually. Further, there is strong evidence that microplastics can interact with wastewater-associated contaminants, which has the potential to transport chemicals to aquatic organisms after exposure to contaminated microplastics. In this review we apply lessons learned from the literature on microplastics in the aquatic environment and knowledge on current wastewater treatment technologies, with the aim of identifying the research gaps in terms of (i) the fate of microplastics in WWTPs, (ii) the potential interaction of wastewater-based microplastics with trace organic contaminants and metals, and (iii) the risk for aquatic organisms.

In this study, three coagulants (ferromagnetite (F), alum (A), and eggshells (E)) and their hybrids (FA, FE, and FEA) were investigated as possible cost-effective coagulants for the treatment of industrial wastewater. Scanning electron microscopy (SEM) coupled with energy-dispersive X-ray (EDX) was used to characterize the morphological and elemental compositions of the coagulants. The effects of coagulant dosage (10–60 mg/L) and settling time were investigated for the removal of turbidity, color, and total suspended solids. A jar tester (JTL6) operating at conditions of 150 rpm for 2 min (rapid mixing) and 30 rpm for 15 min (slow mixing) was employed. Results from the characterized supernatant showed about 80% removal of the contaminants. The prospects of F were proven to be the most effective as compared to the binary (FA > FE) and the ternary hybridized (FEA) coagulants. At an optimum dosage and settling time of 20 mg/L and 30 min, respectively, the treatability performance of F was clearly proven to be viable for wastewater treatment.

With a 270 million Indonesian population, domestic wastewater is one of the major contributors to wastewater generated from human activities. This review aimed to give an overview of the current state of domestic wastewater generation, characteristics and treatment systems in Indonesia. Overall, grey water quantity in Indonesia was 1 to 4 times higher than black water quantity, while the quantity of untreated grey water was 3 to 6 times higher than untreated black water. Parameters of concern include suspended solids, biochemical oxygen demand, chemical oxygen demand, oil and grease, nitrogen and coliforms. Our analysis shows that grey water can be a significant source of water pollution due to the large quantity and lack of treatment. In addition, black water treatment that relies mainly on on-site treatment is often inadequate due to the lack of quality control for the infrastructure, operation and maintenance. An incentive or penalty scheme to build and ensure the quality of domestic wastewater treatment is required and can be applied at the household, community or central (city) level.

Plastic pollution of the aquatic environment is a major concern considering the disastrous impact on the environment and on human beings. The significant and continuous increase in the production of plastics causes an enormous amount of plastic waste on the land entering the aquatic environment. Furthermore, wastewater treatment plants (WWTPs) are reported as the main source of microplastic and nanoplastic in the effluents, since they are not properly designed for this purpose. The application of advanced wastewater treatment technologies is mandatory to avoid effluent contamination by plastics. A concrete solution can be represented by membrane technologies as tertiary treatment of effluents in integrated systems for wastewater treatment, in particular, for the plastic particles with a smaller size (< 100 nm). In this review, a survey of the membrane processes applied in the plastic removal is analyzed and critically discussed. From the literature analysis, it was found that the removal of microplastic by membrane technology is still insufficient, and without the use of specially designed approaches, with the exception of membrane bioreactors (MBRs).

The presence of heavy metals in water bodies is linked to the increasing number of industries and populations. This has serious consequences for the quality of human health and the environment. In accordance with this issue, water and wastewater treatment technologies including ion exchange, chemical extraction, and hydrolysis should be conducted as a first water purification stage. However, the sequestration of these toxic substances tends to be expensive, especially for large scale treatment methods that require tedious control and have limited efficiency. Therefore, adsorption methods using adsorbents derived from biomass represent a promising alternative due to their great efficiency and abundance. Algal and seaweed biomass has appeared as a sustainable solution for environmentally friendly adsorbent production. This review further discusses recent developments in the use of algal and seaweed biomass as potential sorbent for heavy metal bioremediation. In addition, relevant aspects like metal toxicity, adsorption mechanism, and parameters affecting the completion of adsorption process are also highlighted. Overall, the critical conclusion drawn is that algae and seaweed biomass can be used to sustainably eliminate heavy metals from wastewater.

Photocatalysis is an ecofriendly technique that emerged as a promising alternative for the degradation of many organic pollutants. The weaknesses of the present photocatalytic system which limit their industrial applications include low-usage of visible light, fast charge recombination, and low migration ability of the photo-generated electrons and holes. Therefore, various elements such as noble metals and transition metals as well as non-metals and metalloids (i.e., graphene, carbon nanotube, and carbon quantum dots) are doped into the photocatalyst as co-catalysts to enhance the photodegradation performance. The incorporation of the co-catalyst which alters the photocatalytic mechanism was discussed in detail. The application of photocatalysts in treating persistent organic pollutants such as pesticide, pharmaceutical compounds, oil and grease and textile in real wastewater was also discussed. Besides, a few photocatalytic reactors in pilot scale had been designed for the effort of commercializing the system. In addition, hybrid photocatalytic system integrating with membrane filtration together with their membrane fabrication methods had also been reviewed. This review outlined various types of heterogeneous photocatalysts, mechanism, synthesis methods of biomass supported photocatalyst, photocatalytic degradation of organic substances in real wastewater, and photocatalytic reactor designs and their operating parameters as well as the latest development of photocatalyst incorporated membrane.

Dyes are used in various industries as coloring agents. The discharge of dyes, specifically synthetic dyes, in wastewater represents a serious environmental problem and causes public health concerns. The implementation of regulations for wastewater discharge has forced research towards either the development of new processes or the improvement of available techniques to attain efficient degradation of dyes. Catalytic oxidation is one of the advanced oxidation processes (AOPs), based on the active radicals produced during the reaction in the presence of a catalyst. This paper reviews the problems of dyes and hydroxyl radical-based oxidation processes, including Fenton’s process, non-iron metal catalysts, and the application of thin metal catalyst-coated tubular reactors in detail. In addition, the sulfate radical-based catalytic oxidation technique has also been described. This study also includes the effects of various operating parameters such as pH, temperature, the concentration of the oxidant, the initial concentration of dyes, and reaction time on the catalytic decomposition of dyes. Moreover, this paper analyzes the recent studies on catalytic oxidation processes. From the present study, it can be concluded that catalytic oxidation processes are very active and environmentally friendly methods for dye removal.

Levels of Mercury (Hg), Lead (Pb), Cadmium (Cd), Chromium (Cr), Nickel (Ni) & Thallium (Tl) were established in wastewater & soil samples obtained from 8 sites in open drainage channels at Nairobi industrial area, Kenya. Ultra-trace inductively coupled plasma mass spectroscopy (ICP-MS) was used for metal analysis. Temperature, pH & turbidity of wastewater ranged from 16.75 to 26.05 °C; 7.28 to 8.78; 160.33 to 544.69 ppm respectively and within World Health Organization (WHO) allowable limits. Wastewater conductivities in 4 sites ranged from 770 to 1074 µ S/cm and above WHO limits at 25 °C. The mean concentrations of the metals in wastewater ranged from 0.0001 to 0.015 ppm in an ascending order of Tl

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