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Recent progress in integrated fixed-film activated sludge process for wastewater treatment: A review

Waqas S, Bilad MR, Man Z, Wibisono Y, Jaafar J, Indra Mahlia TM, et al.

J Environ Manage, 2020 Aug 15;268:110718.
PMID: 32510449 DOI: 10.1016/j.jenvman.2020.110718

Integrated fixed-film activated sludge (IFAS) process is considered as one of the leading-edge processes that provides a sustainable solution for wastewater treatment. IFAS was introduced as an advancement of the moving bed biofilm reactor by integrating the attached and the suspended growth systems. IFAS offers advantages over the conventional activated sludge process such as reduced footprint, enhanced nutrient removal, complete nitrification, longer solids retention time and better removal of anthropogenic composites. IFAS has been recognized as an attractive option as stated from the results of many pilot and full scales studies. Generally, IFAS achieves >90% removals for combined chemical oxygen demand and ammonia, improves sludge settling properties and enhances operational stability. Recently developed IFAS reactors incorporate frameworks for either methane production, energy generation through algae, or microbial fuel cells. This review details the recent development in IFAS with the focus on the pilot and full-scale applications. The microbial community analyses of IFAS biofilm and floc are underlined along with the special emphasis on organics and nitrogen removals, as well as the future research perspectives.

Matched MeSH terms: Waste Water*
Fulltext Contribution of Arab countries to pharmaceutical wastewater literature: a bibliometric and comparative analysis of research output

Zyoud SH, Zyoud SH, Al-Jabi SW, Sweileh WM, Awang R

Ann Occup Environ Med, 2016;28:28.
PMID: 27382475 DOI: 10.1186/s40557-016-0117-0

BACKGROUND: Recently, the pharmaceutical manufacturing industry has been growing rapidly in many countries in the world, including in Arab countries. Pharmaceuticals reach aquatic environments and are prevalent at small concentrations in wastewater from the drug manufacturing industry and hospitals. Such presence also occurs in domestic wastewater and results from the disposal of unused and expired medicines. Therefore, the objective of this study was to analyze and compare the quantity and quality of publications made by researchers in Arab countries on pharmaceutical wastewater.
METHODS: To retrieve documents related to pharmaceutical wastewater, we used the Scopus database on November 21, 2015. All documents with terms related to pharmaceutical wastewater in the title or abstract were analysed. Results obtained from Arab countries were compared with those obtained from Turkey, Iran and Israel.
RESULTS: Globally, a total of 6360 publications were retrieved while those from Arab countries, Iran, Turkey and Israel, were 179, 113, 96 and 54 publications respectively. The highest share of publications belonged to Kingdom of Saudi Arabia (KSA) with a total of 47 (26.2 %) publications, followed by Egypt (38; 21.2 %), Tunisia (17; 9.5 %) and Morocco (16; 8.9 %). The total number of citations was 1635, with a mean of 9.13 and a median (inter quartile range) of 3 (1.0-10.0). The study identified 87 (48.6 %) documents with 32 countries of international collaboration with Arab countries. It was noted that Arab researchers collaborated mainly with authors in Western Europe (54; 30.2 %), followed by authors from the Asiatic region (29; 16.2 %) and Northern America (15; 8.4 %). The most productive institution was King Saud University, KSA (13; 7.3 %), followed by the National Research Centre, Egypt (10; 7.3 %).
CONCLUSIONS: This study showed that KSA has the largest share of productivity on pharmaceutical wastewater research. Bibliometric analysis demonstrated that research productivity, mainly from Arab countries in pharmaceutical wastewater research, was relatively lagging behind. More research effort is required for Arab countries to catch up with those of non-Arab Middle Easter countries on pharmaceutical wastewater research.

Matched MeSH terms: Waste Water
Effects of wastewater type on stability and operating conditions control strategy in relation to the formation of aerobic granular sludge - a review

Hamiruddin NA, Awang NA, Mohd Shahpudin SN, Zaidi NS, Said MAM, Chaplot B, et al.

Water Sci Technol, 2021 Nov;84(9):2113-2130.
PMID: 34810301 DOI: 10.2166/wst.2021.415

Currently, research trends on aerobic granular sludge (AGS) have integrated the operating conditions of extracellular polymeric substances (EPS) towards the stability of AGS systems in various types of wastewater with different physical and biochemical characteristics. More attention is given to the stability of the AGS system for real site applications. Although recent studies have reported comprehensively the mechanism of AGS formation and stability in relation to other intermolecular interactions such as microbial distribution, shock loading and toxicity, standard operating condition control strategies for different types of wastewater have not yet been discussed. Thus, the dimensional multi-layer structural model of AGS is discussed comprehensively in the first part of this review paper, focusing on diameter size, thickness variability of each layer and diffusion factor. This can assist in facilitating the interrelation between disposition and stability of AGS structure to correspond to the changes in wastewater types, which is the main objective and novelty of this review.

Matched MeSH terms: Waste Water*
A review on geopolymers as emerging materials for the adsorption of heavy metals and dyes

Siyal AA, Shamsuddin MR, Khan MI, Rabat NE, Zulfiqar M, Man Z, et al.

J Environ Manage, 2018 Oct 15;224:327-339.
PMID: 30056352 DOI: 10.1016/j.jenvman.2018.07.046

The world water resources are contaminated due to discharge of a large number of pollutants from industrial and domestic sources. A variety of a single and multiple units of physical, chemical, and biological processes are employed for pollutants removal from wastewater. Adsorption is the most widely utilized process due to high efficiency, simple procedure and cost effectiveness. This paper reviews the research work carried out on the use of geopolymer materials for the adsorption of heavy metals and dyes. Geopolymers possess good surface properties, heterogeneous microstructure and amorphous structure. The performance of geopolymers in the removal of heavy metals and dyes is reported comparable to other materials. The pseudo-second order kinetics and Langmuir isotherm models mostly fit to the adsorption data suggesting homogeneous distribution of adsorption sites with the formation of monolayer adsorbate on the surface of geopolymers. Adsorption of heavy metals and dyes onto geopolymers is spontaneous, endothermic and entropy driven process. Future research should focus on the enhancement of geopolymer performance, testing on pollutants other than heavy metals and dyes, and verification on real wastewater in continuous operation.

Matched MeSH terms: Waste Water
Current advancements on the fabrication, modification, and industrial application of zinc oxide as photocatalyst in the removal of organic and inorganic contaminants in aquatic systems

Abdullah FH, Bakar NHHA, Bakar MA

J Hazard Mater, 2022 Feb 15;424(Pt B):127416.
PMID: 34655867 DOI: 10.1016/j.jhazmat.2021.127416

Industrial wastewaters contain hazardous contaminants that pollute the environment and cause socioeconomic problems, thus demanding the employment of effective remediation procedures such as photocatalysis. Zinc oxide (ZnO) nanomaterials have emerged to be a promising photocatalyst for the removal of pollutants in wastewater owing to their excellent and attractive characteristics. The dynamic tunable features of ZnO allow a wide range of functionalization for enhanced photocatalytic efficiency. The current review summarizes the recent advances in the fabrication, modification, and industrial application of ZnO photocatalyst based on the analysis of the latest studies, including the following aspects: (1) overview on the properties, structures, and features of ZnO, (2) employment of dopants, heterojunction, and immobilization techniques for improved photodegradation performance, (3) applicability of suspended and immobilized photocatalytic systems, (4) application of ZnO hybrids for the removal of various types of hazardous pollutants from different wastewater sources in industries, and (5) potential of bio-inspired ZnO hybrid nanomaterials for photocatalytic applications using renewable and biodegradable resources for greener photocatalytic technologies. In addition, the knowledge gap in this field of work is also highlighted.

Matched MeSH terms: Waste Water
Modified APHA closed-tube reflux colorimetric method for TOC determination in water and wastewater

Salihu SO, Bakar NKA

Environ Monit Assess, 2018 May 30;190(6):369.
PMID: 29850927 DOI: 10.1007/s10661-018-6727-y

The analysis of total organic carbon (TOC) by the American Public Health Association (APHA) closed-tube reflux colorimetric method requires potassium dichromate (K2Cr2O7), silver sulfate (AgSO4), and mercury (HgSO4) sulfate in addition to large volumes of both reagents and samples. The method relies on the release of oxygen from dichromate on heating which is consumed by carbon associated with organic compounds. The method risks environmental pollution by discharging large amounts of chromium (VI) and silver and mercury sulfates. The present method used potassium monochromate (K2CrO4) to generate the K2Cr2O7 on demand in the first phase. In addition, miniaturizing the procedure to semi microanalysis decreased the consumption of reagents and samples. In the second phase, mercury sulfate was eliminated as part of the digestion mixture through the introduction of sodium bismuthate (NaBiO3) for the removal of chlorides from the sample. The modified method, the potassium monochromate closed-tube colorimetry with sodium bismuthate chloride removal (KMCC-Bi), generates the potassium dichromate on demand and eliminates mercury sulfate. The semi microanalysis procedure leads to a 60% reduction in sample volume and ≈ 33.33 and 60% reduction in monochromate and silver sulfate consumption respectively. The LOD and LOQ were 10.17 and 33.90 mg L-1 for APHA, and 4.95 and 16.95 mg L-1 for KMCC-Bi. Recovery was between 83 to 98% APHA and 92 to 104% KMCC-Bi, while the RSD (%) ranged between 0.8 to 5.0% APHA and 0.00 to 0.62% KMCC-Bi. The method was applied for the UV-Vis spectrometry determination of COD in water and wastewater. Statistics was done by MINITAB 17 or MS Excel 2016. ᅟ Graphical abstract.

Matched MeSH terms: Waste Water/analysis; Waste Water/chemistry*
A simple method for chromium speciation analysis in contaminated water using APDC and a pre-heated glass tube followed by HPLC-PDA

Salihu SO, Bakar NKA

Talanta, 2018 May 01;181:401-409.
PMID: 29426532 DOI: 10.1016/j.talanta.2018.01.041

In this study, a simple sample preparation method was developed for the determination of tri-and hexavalent chromium in water samples. It utilizes a pre-heated customized glass tube (CGT), to supply the heat energy required for the reaction of Cr(III) with ammonium pyrrolidinedithiocarbamate (APDC). The products of the Cr complexes, tris(1-pyrrolidinecarbodithioato)chromium(III) and bis(1-pyrrolidinecarbodithioato)[1-pyrrolidinecarbodithio(thioperoxoato)]chromium(III) were chromatographed with Shimadzu LC-20AT and Zobax Eclipse C18 (150mm × 4.6mm, 5µm) column using ACN: Water, (7:3, v/v) as the mobile phase. The concentration of Cr(III) ranged from 0.06mgL-1to 0.09mgL-1and that of Cr(VI) was between 0.02mgL-1to 0.04mgL-1in the samples. Percentage recoveries from spiked real samples were between 87% (tap water) to 110% (wastewater) for Cr(III) and 92% (pond water) to 117% (tap water) for Cr(VI). The limits of detection (LODs) were 0.0029mgL-1and 0.0014mg/L-1for Cr(III) Cr(VI) respectively. While the limits of quantitation (LOQs), were 0.0098mgL-1and 0.0047mgL-1for Cr(III) and Cr(VI) respectively. Method precision (RSD (%)) was 3.3% and 3.5% for Cr(III) and Cr(VI) respectively. The developed method was applied for the speciation analysis of chromium in drinking water, tap water, wastewater, river water, and pond water samples. Our findings proved the method is simple and inexpensive. The method was validated by the analysis of a certified reference material (CRM) SLRS-4. The percentage recovery and RSD(%) from the spiked CRM were 91% and 115% and 0.32% and 1.4% for Cr(III) and Cr(VI) respectively.

Matched MeSH terms: Waste Water
Fulltext Optimization of Micro-Pollutants' Removal from Wastewater Using Agricultural Waste-Derived Sustainable Adsorbent

Alhothali A, Haneef T, Mustafa MRU, Moria KM, Rashid U, Rasool K, et al.

Int J Environ Res Public Health, 2021 11 01;18(21).
PMID: 34770021 DOI: 10.3390/ijerph182111506

Water pollution due to the discharge of untreated industrial effluents is a serious environmental and public health issue. The presence of organic pollutants such as polycyclic aromatic hydrocarbons (PAHs) causes worldwide concern because of their mutagenic and carcinogenic effects on aquatic life, human beings, and the environment. PAHs are pervasive atmospheric compounds that cause nervous system damage, mental retardation, cancer, and renal kidney diseases. This research presents the first usage of palm kernel shell biochar (PKSB) (obtained from agricultural waste) for PAH removal from industrial wastewater (oil and gas wastewater/produced water). A batch scale study was conducted for the remediation of PAHs and chemical oxygen demand (COD) from produced water. The influence of operating parameters such as biochar dosage, pH, and contact time was optimized and validated using a response surface methodology (RSM). Under optimized conditions, i.e., biochar dosage 2.99 g L-1, pH 4.0, and contact time 208.89 min, 93.16% of PAHs and 97.84% of COD were predicted. However, under optimized conditions of independent variables, 95.34% of PAH and 98.21% of COD removal was obtained in the laboratory. The experimental data were fitted to the empirical second-order model of a suitable degree for the maximum removal of PAHs and COD by the biochar. ANOVA analysis showed a high coefficient of determination value (R2 = 0.97) and a reasonable second-order regression prediction. Additionally, the study also showed a comparative analysis of PKSB with previously used agricultural waste biochar for PAH and COD removal. The PKSB showed significantly higher removal efficiency than other types of biochar. The study also provides analysis on the reusability of PKSB for up to four cycles using two different methods. The methods reflected a significantly good performance for PAH and COD removal for up to two cycles. Hence, the study demonstrated a successful application of PKSB as a potential sustainable adsorbent for the removal of micro-pollutants from produced water.

Matched MeSH terms: Waste Water
Augmented biohydrogen production from rice mill wastewater through nano-metal oxides assisted dark fermentation

Rambabu K, Bharath G, Thanigaivelan A, Das DB, Show PL, Banat F

Bioresour Technol, 2021 Jan;319:124243.
PMID: 33254466 DOI: 10.1016/j.biortech.2020.124243

This study highlights biohydrogen production enrichment through NiO and CoO nanoparticles (NPs) inclusion to dark fermentation of rice mill wastewater using Clostridium beijerinckii DSM 791. NiO (~26 nm) and CoO (~50 nm) NPs were intrinsically prepared via facile hydrothermal method with polyhedral morphology and high purity. Dosage dependency studies revealed the maximum biohydrogen production characteristics for 1.5 mg/L concentration of both NPs. Biohydrogen yield was improved by 2.09 and 1.9 folds higher for optimum dosage of NiO and CoO respectively, compared to control run without NPs. Co-metabolites analysis confirmed the biohydrogen production through acetate and butyrate pathways. Maximum COD reduction efficiencies of 77.6% and 69.5% were observed for NiO and CoO inclusions respectively, which were higher than control run (57.5%). Gompertz kinetic model fitted well with experimental data of NPs assisted fermentation. Thus, NiO and CoO inclusions to wastewater fermentation seems to be a promising technique for augmented biohydrogen production.

Matched MeSH terms: Waste Water*
Phycoremediation for carbon neutrality and circular economy: Potential, trends, and challenges

Rambabu K, Avornyo A, Gomathi T, Thanigaivelan A, Show PL, Banat F

Bioresour Technol, 2023 Jan;367:128257.
PMID: 36343781 DOI: 10.1016/j.biortech.2022.128257

Phycoremediation is gaining attention not only as a pollutant mitigation approach but also as one of the most cost-effective paths to achieve carbon neutrality. When compared to conventional treatment methods, phycoremediation is highly effective in removing noxious substances from wastewater and is inexpensive, eco-friendly, abundantly available, and has many other advantages. The process results in valuable bioproducts and bioenergy sources combined with pollutants capture, sequestration, and utilization. In this review, microalgae-based phycoremediation of various wastewaters for carbon neutrality and circular economy is analyzed scientometrically. Different mechanisms for pollutants removal and resource recovery from wastewaters are explained. Further, critical parameters that influence the engineering design and phycoremediation performance are described. A comprehensive knowledge map highlighting the microalgae potential to treat a variety of industrial effluents is also presented. Finally, challenges and future prospects for industrial implementation of phycoremediation towards carbon neutrality coupled with circular economy are discussed.

Matched MeSH terms: Waste Water
The short- and long-term inhibitory effects of Fe (II) on anaerobic ammonium oxidizing (anammox) process

Mak CY, Lin JG, Chen WH, Ng CA, Bashir MJK

Water Sci Technol, 2019 May;79(10):1860-1867.
PMID: 31294702 DOI: 10.2166/wst.2019.188

The application of the anammox process has great potential in treating nitrogen-rich wastewater. The presence of Fe (II) is expected to affect the growth and activity of anammox bacteria. Short-term (acute) and long-term effects (chronic) of Fe (II) on anammox activity were investigated. In the short-term study, results demonstrated that the optimum concentration of Fe (II) that could be added to anammox is 0.08 mM, at which specific anammox activity (SAA) improved by 60% compared to the control assay, 0.00 mM. The inhibition concentration, IC50, of Fe (II) was found to be 0.192 mM. Kinetics of anammox specific growth rate were estimated based on results of the batch test and evaluated with Han-Levenspiel's substrate inhibition kinetics model. The optimum concentration and IC50 of Fe (II) predicted by the Han-Levenspiel model was similar to the batch test, with values of 0.07 mM and 0.20 mM, respectively. The long-term effect of Fe (II) on the performance of a sequencing batch reactor (SBR) was evaluated. Results showed that an appropriate Fe (II) addition enhanced anammox activity, achieving 85% NH4+-N and 96% NO2--N removal efficiency when 0.08 mM of Fe (II) was added. Quantitative polymerase chain reaction (qPCR) was adopted to detect and identify the anammox bacteria.

Matched MeSH terms: Waste Water
Fulltext Biosorption of Pb (II) ions by immobilized cells of Pycnoporus Sanguineus in a packed bed column

Mashitah Mat Don, Yus Azila Yahaya, Bhatia, Subhash

Pertanika Journal of Science & Technology, 2009;17(1):-.
MyJurnal

The removal of heavy metals like lead, copper and cadmium from wastewater streams is an important environmental issue. The capability of immobilized Pycnoporus sanguineus (P. sanguineus), a white-rot macrofungi to remove heavy metals from aqueous solution in a packed bed column was investigated. Lead (Pb (II)) biosorption by immobilized cells of P. sanguineus was investigated in a packed bed column. The experiments were carried out by considering the effect of bed height (5-13 cm), flow rate (4-12 ml min-1) and initial lead (II) concentration (50-300 mg L-1). The breakthrough profiles showed that the saturation of metal ions was achieved faster for 5 cm bed height and 12 ml min-1 influent flow rate. However, the breakthrough time decreased as the initial metal concentration increased from 50 to 300 mg L-1. The column was regenerated using 0.1M HCl solution and biosorptiondesorption studies were carried out for 2 cycles. The results showed that the breakthrough time decreased as the number of cycle was proceeded.

Matched MeSH terms: Waste Water
Fulltext A comprehensive review on the use of algal-bacterial systems for wastewater treatment with emphasis on nutrient and micropollutant removal

Oruganti RK, Katam K, Show PL, Gadhamshetty V, Upadhyayula VKK, Bhattacharyya D

Bioengineered, 2022 Apr;13(4):10412-10453.
PMID: 35441582 DOI: 10.1080/21655979.2022.2056823

The scarcity of water resources and environmental pollution have highlighted the need for sustainable wastewater treatment. Existing conventional treatment systems are energy-intensive and not always able to meet stringent disposal standards. Recently, algal-bacterial systems have emerged as environmentally friendly sustainable processes for wastewater treatment and resource recovery. The algal-bacterial systems work on the principle of the symbiotic relationship between algae and bacteria. This paper comprehensively discusses the most recent studies on algal-bacterial systems for wastewater treatment, factors affecting the treatment, and aspects of resource recovery from the biomass. The algal-bacterial interaction includes cell-to-cell communication, substrate exchange, and horizontal gene transfer. The quorum sensing (QS) molecules and their effects on algal-bacterial interactions are briefly discussed. The effect of the factors such as pH, temperature, C/N/P ratio, light intensity, and external aeration on the algal-bacterial systems have been discussed. An overview of the modeling aspects of algal-bacterial systems has been provided. The algal-bacterial systems have the potential for removing micropollutants because of the diverse possible interactions between algae-bacteria. The removal mechanisms of micropollutants - sorption, biodegradation, and photodegradation, have been reviewed. The harvesting methods and resource recovery aspects have been presented. The major challenges associated with algal-bacterial systems for real scale implementation and future perspectives have been discussed. Integrating wastewater treatment with the algal biorefinery concept reduces the overall waste component in a wastewater treatment system by converting the biomass into a useful product, resulting in a sustainable system that contributes to the circular bioeconomy.

Matched MeSH terms: Waste Water/chemistry
Biochar-based geopolymer nanocomposite for COD and phenol removal from agro-industrial biorefinery wastewater: Kinetic modelling, microbial community, and optimization by response surface methodology

Jagaba AH, Lawal IM, Ghfar AA, Usman AK, Yaro NSA, Noor A, et al.

Chemosphere, 2023 Oct;339:139620.
PMID: 37524265 DOI: 10.1016/j.chemosphere.2023.139620

Agro-industrial biorefinery effluent (AIBW) is considered a highly polluting source responsible for environmental contamination. It contains high loads of chemical oxygen demand (COD), and phenol, with several other organic and inorganic constituents. Thus, an economic treatment approach is required for the sustainable discharge of the effluent. The long-term process performance, contaminant removal and microbial response of AIBW to rice straw-based biochar (RSB) and biochar-based geopolymer nanocomposite (BGC) as biosorbents in an activated sludge process were investigated. The adsorbents operated in an extended aeration system with a varied hydraulic retention time of between 0.5 and 1.5 d and an AIBW concentration of 40-100% for COD and phenol removal under standard conditions. Response surface methodology was utilised to optimize the process variables of the bioreactor system. Process results indicated a significant reduction of COD (79.51%, 98.01%) and phenol (61.94%, 74.44%) for BEAS and GEAS bioreactors respectively, at 1 d HRT and AIBW of 70%. Kinetic model analysis indicated that the Stover-Kincannon model best describes the system functionality, while the Grau model was better in predicting substrate removal rate and both with a precision of between R2 (0.9008-0.9988). Microbial communities examined indicated the abundance of genera, following the biosorbent addition, while RSB and BGC had no negative effect on the bioreactor's performance and bacterial community structure of biomass. Proteobacteria and Bacteroidetes were abundant in BEAS. While the GEAS achieved higher COD and phenol removal due to high Nitrosomonas, Nitrospira, Comamonas, Methanomethylovorans and Acinetobacter abundance in the activated sludge. Thus, this study demonstrated that the combination of biosorption and activated sludge processes could be promising, highly efficient, and most economical for AIBW treatment, without jeopardising the elimination of pollutants or the development of microbial communities.

Matched MeSH terms: Waste Water*
Aerobic sludge granulation at high temperatures for domestic wastewater treatment

Ab Halim MH, Nor Anuar A, Azmi SI, Jamal NS, Wahab NA, Ujang Z, et al.

Bioresour Technol, 2015 Jun;185:445-9.
PMID: 25851807 DOI: 10.1016/j.biortech.2015.03.024

With inoculum sludge from a conventional activated sludge wastewater treatment plant, three sequencing batch reactors (SBRs) fed with synthetic wastewater were operated at different high temperatures (30, 40 and 50±1°C) to study the formation of aerobic granular sludge (AGS) for simultaneous organics and nutrients removal with a complete cycle time of 3h. The AGS were successfully cultivated with influent loading rate of 1.6CODg(Ld)(-1). The COD/N ratio of the influent wastewater was 8. The results revealed that granules developed at 50°C have the highest average diameter, (3.36mm) with 98.17%, 94.45% and 72.46% removal efficiency observed in the system for COD, ammonia and phosphate, respectively. This study also demonstrated the capabilities of AGS formation at high temperatures which is suitable to be applied for hot climate conditions.

Matched MeSH terms: Waste Water*
Influence of high temperature on the performance of aerobic granular sludge in biological treatment of wastewater

Ab Halim MH, Nor Anuar A, Abdul Jamal NS, Azmi SI, Ujang Z, Bob MM

J Environ Manage, 2016 Dec 15;184(Pt 2):271-280.
PMID: 27720606 DOI: 10.1016/j.jenvman.2016.09.079

The effect of temperature on the efficiency of organics and nutrients removal during the cultivation of aerobic granular sludge (AGS) in biological treatment of synthetic wastewater was studied. With this aim, three 3 L sequencing batch reactors (SBRs) with influent loading rate of 1.6 COD g (L d)(-1) were operated at different high temperatures (30, 40 and 50 °C) for simultaneous COD, phosphate and ammonia removal at a complete cycle time of 3 h. The systems were successfully started up and progressed to steady state at different cultivation periods. The statistical comparison of COD, phosphate and ammonia for effluent from the three SBRs revealed that there was a significant difference between groups of all the working temperatures of the bioreactors. The AGS cultivated at different high temperatures also positively correlated with the accumulation of elements including carbon, oxygen, phosphorus, silicon, iron, aluminium, calcium and magnesium that played important roles in the granulation process.

Matched MeSH terms: Waste Water/chemistry
Fulltext Column-based removal of high concentration microplastics in synthetic wastewater using granular activated carbon

Amirah Mohd Napi NN, Ibrahim N, Adli Hanif M, Hasan M, Dahalan FA, Syafiuddin A, et al.

Bioengineered, 2023 Dec;14(1):2276391.
PMID: 37942779 DOI: 10.1080/21655979.2023.2276391

Microplastic (MP) is an emerging contaminant of concern due to its abundance in the environment. Wastewater treatment plant (WWTP) can be considered as one of the main sources of microplastics in freshwater due to its inefficiency in the complete removal of small MPs. In this study, a column-based MP removal which could serve as a tertiary treatment in WWTPs is evaluated using granular activated carbon (GAC) as adsorbent/filter media, eliminating clogging problems commonly caused by powder form activated carbon (PAC). The GAC is characterized via N2 adsorption-desorption isotherm, field emission scanning electron microscopy, and contact angle measurement to determine the influence of its properties on MP removal efficiency. MPs (40-48 μm) removal up to 95.5% was observed with 0.2 g/L MP, which is the lowest concentration tested in this work, but still higher than commonly used MP concentration in other studies. The performance is reduced with further increase in MP concentration (up to 1.0 g/L), but increasing the GAC bed length from 7.5 to 17.5 cm could lead to better removal efficiencies. MP particles are immobilized by the GAC predominantly by filtration process by being entangled with small GAC particles/chips or stuck between the GAC particles. MPs are insignificantly removed by adsorption process through entrapment in GAC porous structure or attachment onto the GAC surface.

Matched MeSH terms: Waste Water
Performance evaluation of a hybrid system for efficient palm oil mill effluent treatment via an air-cathode, tubular upflow microbial fuel cell coupled with a granular activated carbon adsorption

Tee PF, Abdullah MO, Tan IA, Mohamed Amin MA, Nolasco-Hipolito C, Bujang K

Bioresour Technol, 2016 May 28;216:478-485.
PMID: 27268432 DOI: 10.1016/j.biortech.2016.05.112

An air-cathode MFC-adsorption hybrid system, made from earthen pot was designed and tested for simultaneous wastewater treatment and energy recovery. Such design had demonstrated superior characteristics of low internal resistance (29.3Ω) and favor to low-cost, efficient wastewater treatment and power generation (55mW/m(3)) with average current of 2.13±0.4mA. The performance between MFC-adsorption hybrid system was compared to the standalone adsorption system and results had demonstrated great pollutants removals of the integrated system especially for chemical oxygen demand (COD), biochemical oxygen demand (BOD3), total organic carbon (TOC), total volatile solids (TVS), ammoniacal nitrogen (NH3-N) and total nitrogen (TN) because such system combines the advantages of each individual unit. Besides the typical biological and electrochemical processes that happened in an MFC system, an additional physicochemical process from the activated carbon took place simultaneously in the MFC-adsorption hybrid system which would further improved on the wastewater quality.

Matched MeSH terms: Waste Water
Fuzzy inference optimization algorithms for enhancing the modelling accuracy of wastewater quality parameters

Abunama T, Ansari M, Awolusi OO, Gani KM, Kumari S, Bux F

J Environ Manage, 2021 Sep 01;293:112862.
PMID: 34049159 DOI: 10.1016/j.jenvman.2021.112862

To ensure the safe discharge of treated wastewater to the environment, continuous efforts are vital to enhance the modelling accuracy of wastewater treatment plants (WWTPs) through utilizing state-of-art techniques and algorithms. The integration of metaheuristic modern optimization algorithms that are natlurally inspired with the Fussy Inference Systems (FIS) to improve the modelling performance is a promising and mathematically suitable approach. This study integrates four population-based algorithms, namely: Particle swarm optimization (PSO), Genetic algorithm (GA), Hybrid GA-PSO, and Mutating invasive weed optimization (M-IWO) with FIS system. A full-scale WWTP in South Africa (SA) was selected to assess the validity of the proposed algorithms, where six wastewater effluent parameters were modeled, i.e., Alkalinity (ALK), Sulphate (SLP), Phosphate (PHS), Total Kjeldahl Nitrogen (TKN), Total Suspended Solids (TSS), and Chemical Oxygen Demand (COD). The results from this study showed that the hybrid PSO-GA algorithm outperforms the PSO and GA algorithms when used individually, in modelling all wastewater effluent parameters. PSO performed better for SLP and TKN compared to GA, while the M-IWO algorithm failed to provide an acceptable modelling convergence for all the studied parameters. However, three out of four algorithms applied in this study proven beneficial to be optimized in enhancing the modelling accuracy of wastewater quality parameters.

Matched MeSH terms: Waste Water*
Antimicrobial resistance patterns and genotypic diversity between clinical and water systems isolates of Pseudomonas aeruginosa in Cali, Colombia

Chávez M, Cabezas AF, Ferauds M, Castillo JE, Caicedo LD

Trop Biomed, 2020 Sep 01;37(3):650-662.
PMID: 33612779 DOI: 10.47665/tb.37.3.650

Pseudomonas aeruginosa is considered an opportunistic pathogen, causing a wide variety of infections in compromised hosts, also frequently develops multi-resistance to antibiotics and can colonize various habitats, including water systems. The main aim of this study was to investigate antibiotics susceptibility pattern, genotypic diversity and detection of resistence genes in P. aeruginosa isolates from clinical and aquatic environment sources. Of the 220 P. aeruginosa isolates examined, 48 were clinical isolates and 172 isolates from wastewater and freshwater. Susceptibility to eight antimicrobial agents was carried out by disk diffusion method. Clinical and environmental isolates were screened for the presence of the genes encoding blaKPC-2, blaCTX-M-9, blaPER-1, blaOXA-10, blaIMP-1, blaVIM-2 and blaampC by polymerase chain reaction (PCR). Isolates were examined with PCR-SSCP analysis of partial DNAr 16S sequence. Isolates were mainly resistant to cefoxitin. Multidrug-resistant P. aeruginosa (MDRPA) strains were found in 70% and 90.3% of the clinical and environmental isolates, respectively. The prevalence rates of â-lactamase genes were recorded (blaKPC-2 41.3%, blaVIM-2 36.8%, blaIMP-1 13.6%, blaCTX-M-9 10.9% and blaampC 10.5%,). The PCR-SSCP analysis showed three conformational patterns. All clinical isolates and most environmental isolates were grouped into a single cluster. In this study, we found that P. aeruginosa strains recovered from city water systems must be considered potential reservoir for ESBL genes, especially blaKPC-2 and blaVIM-2.

Matched MeSH terms: Waste Water

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