Showing papers on "Effluent published in 2023"

Performance Evaluation Of Dye Wastewater Treatment Technologies: A Review

Abstract: Dye wastewater released from several dyes induced industries are harmful towards the living, non-living environment and human. Consequently, existence of dye in water bodies is becoming a rising concern to environmentalists and citizens. Dye wastewater should be treated prior to release in an open water body to minimize its negative impacts. A long term sustainable and efficient treatment methods should be established to reduce and overcome the impacts. Although there have been significant advances in the management and treatment of such effluent using physical, chemical and biological methods. However, due to lack of information on effective dye removal methods, it is difficult to decide on a single unique technique that resolves the prevailing dye wastewater. Therefore, this paper reviews recent research on various (physical, chemical, biological, advanced oxidation process (AOPs) and hybrid) dye removal methods to compare efficiency, evaluation performance, merits and demerits. Among the existing methods, most of them have a common disadvantage which is the generation of secondary pollutes, takes long time and costly. This paper especially highlights AOPs method for dye removal as these are known as one of the promising and most effective dye removal techniques these days. This paper also suggests the application of AOPs methods possess the best performance in terms of faster dye removing as well as cost effective, time oriented and environmentally friendly. Additionally, this paper addressed the difficulties and future prospects of this emerging method that links to sustainable development.

Occurrence and spatial distribution of pharmaceuticals and personal care products (PPCPs) in the aquatic environment, their characteristics, and adopted legislations

Abstract: Pharmaceuticals and personal care products (PPCPs) residues are known to occur widely in the aquatic environments of industrialized and developing countries. Considerable progress has been made regarding to study of their exposure and distribution in aquatic environment. The spatial distribution and transformation of PPCPs have been investigated in the aquatic systems of different countries covering the five UN regions. As a result, the objectives of this review are focused on: (a) the global occurrence of PPCPs residues in aquatic systems, particularly in drinking/tap water, surface water, groundwater, and wastewater treatment plants (WWTPs), (b) widely prescribed pharmaceutical classes such as antibiotics, antidepressants, β-blockers, lipid regulators, nonsteroidal anti-inflammatory drugs (NSAIDs), etc. due to their potential adverse influences on the aquatic ecosystems and human health, (c) the spatial distribution of PPCPs in water bodies based on recently published data, (d) different regions in the world (e.g., USA, China, and Mediterranean basin) as case studies of contaminated areas, (e) the relation of occurrences with specific characteristics of frequently detected compounds, (f) the legislation and regulations implemented by countries/states governments were summarized and discussed, and finally, (g) future perspectives for research on PPCPs in the aquatic environment, which are explained regarded to the research gaps in current knowledge. The findings of this review indicate that the concentrations of PPCPs in the influents and effluents of WWTPs of the selected regions are much higher than in other water matrices. Additionally, there are significant variations in PPCPs concentrations between different countries and regions due to certain reasons.

Toward Energy Neutrality: Novel Wastewater Treatment Incorporating Acidophilic Ammonia Oxidation

Abstract: Chemically enhanced primary treatment (CEPT) followed by partial nitritation and anammox (PN/A) and anaerobic digestion (AD) is a promising roadmap to achieve energy-neutral wastewater treatment. However, the acidification of wastewater caused by ferric hydrolysis in CEPT and how to achieve stable suppression of nitrite-oxidizing bacteria (NOB) in PN/A challenge this paradigm in practice. This study proposes a novel wastewater treatment scheme to overcome these challenges. Results showed that, by dosing FeCl3 at 50 mg Fe/L, the CEPT process removed 61.8% of COD and 90.1% of phosphate and reduced the alkalinity as well. Feeding by low alkalinity wastewater, stable nitrite accumulation was achieved in an aerobic reactor operated at pH 4.35 aided by a novel acid-tolerant ammonium-oxidizing bacteria (AOB), namely, Candidatus Nitrosoglobus. After polishing in a following anoxic reactor (anammox), a satisfactory effluent, containing COD at 41.9 ± 11.2 mg/L, total nitrogen at 5.1 ± 1.8 mg N/L, and phosphate at 0.3 ± 0.2 mg P/L, was achieved. Moreover, the stable performances of this integration were well maintained at an operating temperature of 12 °C, and 10 investigated micropollutants were removed from the wastewater. An energy balance assessment indicated that the integrated system could achieve energy self-sufficiency in domestic wastewater treatment.

Removal of Copper Ions from Wastewater: A Review

Abstract: Copper pollution of the world’s water resources is becoming increasingly serious and poses a serious threat to human health and aquatic ecosystems. With reported copper concentrations in wastewater ranging from approximately 2.5 mg/L to 10,000 mg/L, a summary of remediation techniques for different contamination scenarios is essential. Therefore, it is important to develop low-cost, feasible, and sustainable wastewater removal technologies. Various methods for the removal of heavy metals from wastewater have been extensively studied in recent years. This paper reviews the current methods used to treat Cu(II)-containing wastewater and evaluates these technologies and their health effects. These technologies include membrane separation, ion exchange, chemical precipitation, electrochemistry, adsorption, and biotechnology. Thus, in this paper, we review the efforts and technological advances made so far in the pursuit of more efficient removal and recovery of Cu(II) from industrial wastewater and compare the advantages and disadvantages of each technology in terms of research prospects, technical bottlenecks, and application scenarios. Meanwhile, this study points out that achieving low health risk effluent through technology coupling is the focus of future research.

Performance Evaluation of Al-Rustamiya Wastewater Treatment Plant

Abstract: Al-Rustamiya sewage treatment plant (WWTP) serves the east side of Baghdad city (Rusafa) and is considered one of the largest projects.It consists of three parts (old project F0, first extension F1, and second extension F2) that treat wastewater and the effluent is discharged into Diyala river and thus into the Tigris River. These plants are designed and constructed with an aim to manage wastewater to reachIraqi effluent standard for BOD5, COD, TSS and chloride concentrations of 40, 100, 60 and 600 mg/L respectively. The data recordedfrom March till December 2011 provided from Al-RustamiyaWWTP, were considered in this study to evaluate the performance of the plant. The results indicated that the strength of the wastewater entering the plant varied from medium to high. The average concentrations of the effluent of BOD5, COD, TSS and chloride were within Iraqi effluent standards. The overall efficiency removalswere: For BOD5: 92.1, 90.31, and 92.96% for F0, F1, and F2 respectively COD: 88.23, 87.9, and 87.95% for F0, F1, and F2 respectively TSS: 86.98, 80.72, and 89% for F0, F1, and F2 respectively Chloride: 14.79, 15.37, and 15.31% for F0, F1, and F2 The mean value of BOD5/COD ratio of the raw wastewater was 0.67 as for typical untreated domestic wastes. The mean BOD/COD ratios of the treated sewage from F0 was 0.48, from F1 0.50 and from F2 0.38. These ratios did not confirm with the typical ratios indicating that the wastewaterneeds more treatment

A review of the antibiotic ofloxacin: current status of ecotoxicology and scientific advances in its removal from aqueous systems by adsorption technology

Abstract: It is estimated that the growth of the population, the augmented expectancy of life, and the emergence of new pandemics will significantly increase the consumption of pharmaceutical drugs in the coming years. Due to its high efficiency, the group of fluoroquinolones, where the antibiotic ofloxacin hydrochloride (OFL) is found, is widely used to combat bacterial infections in humans and animals. The big problem is concentrated in the effluents generated by industries and hospitals. Additionally, most of the drug is not absorbed by the body and is released directly into domestic effluents. On the other hand, treatment stations have removal limitations for small concentrations. This review analyzed all adsorbents developed and used in OFL removal, listing the main parameters influencing the process. In the end, the other existing technologies in the literature and the gaps and future prospects were described. OFL adsorption in most studies occurs under basic conditions (pH between 6.5 and 8). The increase in concentration provides an increase in adsorption capacity. The adsorbents analyzed showed moderate kinetics, reaching equilibrium before 250 min for most studies. The pseudo-second-order model showed the best statistical fit. In most of the studies, the increase in temperature (313, 315, and 328 K) favored the adsorption of OFL. The Langmuir monolayer model represented most of the isothermal studies. The adsorption capacity varied from 3702 to 0.3986 mg g−1. In this aspect, factors such as OFL concentration and textural characteristics of the adsorbent exerted great influence. The thermodynamic parameters were compatible with the isothermal data, where the endothermic nature of the studies was confirmed. Physical interactions (π-π stacking, H bonding, hydrophobic and electrostatic interactions) governed the main adsorption mechanism. Although some studies stated that chemosorption occurred, thermodynamic parameters cannot validate the same. Coexisting ions in the solution can positively and negatively influence OFL adsorption. The listed studies are all applied to batch processes, where fixed bed studies should be better explored. From this review, it can be concluded that adsorption is a promising technique for OFL removal. However, it is extremely necessary to break the laboratory scale barrier and analyze possible conditions for applying these materials in treating real effluents together with combining technologies.

Abatement technologies for copper containing industrial wastewater effluents – A review

Abstract: The extensive application of copper in numerous industries leads to its accumulation in the environment, imposing severe toxic and carcinogenic health effects to human. In this article, the recent advances of abatement technologies for copper containing industrial wastewater were reviewed, including adsorption, electrochemical, and precipitation/crystallization processes. Adsorption is effective in treating dilute copper wastewater. Several adsorbents derived from biomass and clay have been developed, as well as the nano-sized and composite adsorbents. Electrochemical treatments such as electrodialysis, electrocoagulation, and capacitive deionization are also in demand due to its versatility, minimal use of chemical reagents, and compact design. Precipitation and crystallization techniques, including the emerging fluidized bed homogeneous crystallization process, are improved not only to provide effective removal but also to recover copper as sparingly soluble salts which can be further utilized for other industrial and scientific purposes. The abatement technologies for Cu(II) were compared to provide guidelines for the selection of processes based on the characteristics of wastewater. Ultimately, the limitation of the processes was summarized to reveal the perspectives in future research.

Current status of the direct detection of MPs in environments and implications for toxicology effects

Abstract: Microplastics (MPs) have received much more attention as a novel breed of pollutant due to their tiny size and difficulty to degrade in natural conditions. MPs are produced from primary sources that are purposefully engineered to be small in magnitude and subsequently discharged into the earth after usage, like resin pellets seen in microplastic factory spills. MPs can also be produced by secondary sources such as the breakdown of macro debris and breakdown of particles, or dust released during the wear and tear of artificial garments, tires, and brake pads. Since rivers meander through municipalities and cities, as well as transporting effluent from plastic-related enterprises and other sewer pollutants into them, which automatically causes MP's contamination in a river to intimately tie to the land environment. Current reports suggest that the amount of plastic trash produced in the upstream watershed can be positively correlated to the amount of plastic waste in the river. While there are currently several sensing approaches for MPs today, there are still several restrictions such as lengthy sensing times, an elevated false sensing rate, and costly sensing apparatus that make detecting microplastics in natural environments difficult. Direct, quick, effective, and precise sensing techniques for microplastics are direly required to enhance environmental conditions. This study focused on the current analysis methods for the detection of MPs. Direct detection methods for MP pollution in water and sedimentary environments are also outlined. Finally, the toxic impacts of MPs on aquatic life and other living organisms are discussed.

Feasibility of rapid gravity filtration and membrane ultrafiltration for the removal of microplastics and microlitter in sewage and wastewater from plastic industry

Abstract: Wastewater treatment plants (WWTPs) act as barriers in reducing uncontrolled microplastic and microlitter (MP-ML) emissions from both urban and industrial wastewaters. Despite removing most of the MP-ML, large quantities of this waste still enter the environment through WWTP effluents, which means further post-treatment technologies are needed. This study contains a technical evaluation of MP-ML removal from urban wastewater (UWW) and from the wastewater from the recycling plastic industry (PIWW) using two different pilot-scale post-treatment systems: rapid gravity filtration (RGF) and ultrafiltration (UF) membranes. The MP-ML mass concentrations contained in UWW and PIWW were measured by a simplified method adapted for the long-term monitoring of WWTP operations. The method was validated on standard samples. Despite the RGF system consumed less energy than UF treating UWW (0.097 kWh·m−3 and 0.156 kWh·m−3, respectively), RGF was not efficient enough to properly decrease the risk of MP-ML emissions (39.5 ± 34.6 % of MP-ML removal). With respect to PIWW, the energy consumption of the UF plant decreased up to 0.059 kWh·m−3. The combination of RGF and UF technologies was expected to reduce membrane fouling but it did not show significant differences in the mid-term operation.

Performance of a combined low-consumption biotreatment system with cost-effective ecological treatment technology for rural domestic sewage treatment

Abstract: Treating rural domestic sewage has always been a hard task for rural vitalization in China. To overcome this problem, high-efficiency, easy-maintenance and low-consumption treatment technologies are urgently needed. To meet the requirements of rural sewage treatment, a new combined bio-ecological system was proposed in this study, including the anoxic filter (ANF), novel integrated guide-plate rotating biological contactors (NIGPRBC) and constructed wetland (CW). Key parameters of “ANF-NIGPRBC” system including hydraulic residence time (HRT), reflux ratio (RR) and rotational speed (RS) were identified founded on the organic matter and nitrogen removal performance for further application. In addition, the combined bio-ecological system was lasted for the 90 days at optimal operating parameters to confirm its performance on pollutant removal. The optimal operating parameters were determined to be 5 h HRTNIGPRBC, 100 % RR and 3 r/min RS. Under the optimal operating parameters, average 95.14 ± 1.31 % COD, 79.07 ± 4.32 % TN, 93.42 ± 2.16 % NH4+-N and 83.39 ± 3.46 % TP were removed during the 90-day operation. The operating results of the combined bio-ecological system indicate that the effluent meet local rural domestic wastewater pollution discharge standard. The microbial community results also helped to better explain the process performance of the whole system by high-throughput sequencing analysis. Proteobacteria and Bacteroidetes were the dominant phylum existing widely in this system. Denitrification-related genera were abundant both in ANF and CW. Overall, the new combined bio-ecological system is one of the priority choices for treating rural wastewater owing to its economic benefits, integrated design concept and convenient operation.

Simultaneous determination of dissolved organic nitrogen, nitrite, nitrate and ammonia using size exclusion chromatography coupled with nitrogen detector.

Abstract: Accurate quantification of dissolved organic nitrogen (DON) has been a challenge due to the cumulative analytical errors in the conventional method via subtracting dissolved inorganic nitrogen species (DIN) from total dissolved nitrogen (TDN). Size exclusion chromatography coupled with an organic nitrogen detector (SEC-OND) has been developed as a direct method for quantification and characterization of DON. However, the applications of SEC-OND method still subject to poor separations between DON and DIN species and unsatisfied N recoveries of macromolecules. In this study, we packed a series of SEC columns with different lengths and resin materials for separation of different N species and designed an independent vacuum ultraviolet (VUV) oxidation device for complete oxidation converting N species to nitrate. To guarantee sufficient N recoveries, the operation conditions were optimized as oxidation time ≥ 30 min, injection mass (sample concentration × injection volume) < 1000 µL × mg-N/L for macromolecular proteins, and neutral pH mobile eluent. The dissolved O2 concentration in SEC mobile phase determined the upper limit of VUV oxidation at a specific oxidation time. Compared to conventional HW50S column (20 × 250 mm), HW40S column (20 × 350 mm) with mobile phase comprising of 1.5 g/L Na2HPO4·2H2O + 2.5 g/L KH2PO4 (pH = 6.85) could achieve a better separation of DON, nitrite, nitrate, and ammonia. When applied to river water, lake water, wastewater effluent, groundwater, and landfill leachate, the SEC-OND method could quantify DON as well as DIN species accurately and conveniently even the DIN/TDN ratio reached 0.98.

Optimization of atmospheric carbonation in the integrated treatment immediate one-step lime precipitation and atmospheric carbonation. The case study of slaughterhouse effluents

Abstract: Long carbonation time has been a common feature in the integrated process composed by immediate one-step lime precipitation and atmospheric carbonation. This work aims to understand how carbonation time can be influenced by reaction pH, as well as how reactor area/volume ratio affects carbonation time and ammonia removal, using slaughterhouse wastewater due to its variable characteristics. In the integrated immediate one-step lime precipitation and atmospheric carbonation process, the immediate one-step lime precipitation results showed that the reaction pH and the type of slaughterhouse wastewater influenced the removal, however, removals were the highest at reaction pH 12. In atmospheric carbonation process, the carbonation time required to reach pH 8 was independent of the reaction pH used. Additionally, at reaction pH 12, the reactor area/volume ratios applied (from 0 to 155.4 m2/m3) showed that higher reactor area/volume ratios caused lower carbonation time, but ammonia removal was not affected. For reactor area/volume ratios of 5 and 155.4 m2/m3, 15 and 1 days were spent to reduce the pH from 11.9 to 8.2, with removals of 71 and 82.6% for NH4+ and 10 and 79.1% for calcium, respectively. High removals of total Kjeldahl nitrogen (≥71%), biological oxygen demand (≥80%), ammonium nitrogen (≥52%), total phosphorus (98%), total suspended solids (≥52%), turbidity (≥62%), absorbance at 254 nm (≥87%), absorbance at 410 nm (≥83%) and oils & fats (≥47%) were obtained using immediate one-step lime precipitation and atmospheric carbonation integrated process to treatment slaughterhouse wastewater, indicating that the these process is an efficient pretreatment for slaughterhouse wastewaters.