Organic Matter Removal Efficiency Research Articles

Characteristics of Organic Matters in Influents and Effluents of Sewage Treatment Plants in Gyeongsanbuk-do

Objectives : This study aimed to provide scientific information on the characteristics of organic matters in influents and effluents of sewage treatment plants (STPs) in Gyeongbuk province, Korea, for better performance of treatment processes in the plants.Methods : We selected six STPs with each capacity over 30,000 mZ3/day in Gyeongbuk province, and analyzed water quality data in influents and effluents of the plants from 2013 to 2020. Also, the removal efficiencies of pollutants were assessed with the operational data. In 2020, characteristics and origins of dissolved organic matters (DOM) in influents and effluents were investigated using the fluorescence excitation emission matrix (FEEM) analysis.Results and Discussion : The average BOD5/CODMn ratios of influents and effluents from the STPs were 1.60 and 0.27, respectively. High variability in BOD5/CODMn ratios was observed for both influents and effluents. The CODMn/TOC ratios of the influents and effluents were the same with an average of 1.6. Although the biological treatment process was different for each STP, the organic matter removal efficiency was similar, and the TOC removal efficiency was 86.5~91.7%. The representative spectra of DOM identified through FEEM analysis was peak C (humic-acid like substance) region, and under the same carbon concentration (2 mg-C/L) the fluorescence intensity of effluents was stronger than influents possibly due to the influence of soluble microbial products (SMP). It was found that DOM of both influent and effluent originated from microorganisms, and the difference in water quality of DOM was statistically significant.Conclusions : The characteristics and fate of organic matters in influents and effluents of the six STPs were similar regardless of plant location. The results of this study can be used as basic information to efficiently control organic matters in the STPs.

The Tolerance of Anoxic-Oxic (A/O) Process for the Changing of Refractory Organics in Electroplating Wastewater: Performance, Optimization and Microbial Characteristics

In order to investigate the tolerance of an anoxic-oxic (A/O) process for the changing of refractory organics in electroplating wastewater, optimize the technological parameters, and reveal the microbial characteristics, a pilot-scale A/O process was carried out and the microbial community composition was analyzed by high-throughput sequencing. The results indicated that a better tolerance was achieved for sodium dodecyl benzene sulfonate, and the removal efficiencies of organic matter, ammonia nitrogen (NH4+-N), and total nitrogen (TN) were 82.87%, 66.47%, and 53.28% with the optimum hydraulic retention time (HRT), internal circulation and dissolved oxygen (DO) was 12 h, 200% and 2–3 mg/L, respectively. Additionally, high-throughput sequencing results demonstrated that Proteobacteria and Bacteroidetes were the dominant bacteria phylum, and the diversity of the microbial community in the stable-state period was richer than that in the start-up period.

Investigating the working efficiency of natural wastewater treatment systems: A step towards sustainable systems

Abstract Globally, wastewater is a vital resource and requires appropriate treatment management strategies. Wastewater has become a major source of irrigation in the peri-urban areas of developing nations. With the increasing amount of wastewater generation, there are several complications in using treatment systems in terms of installation, operation and maintenance, and size in developing countries. Recently, natural treatment systems are gaining popularity due to less cost and maintenance and have been preferred in peri-urban settings. In this study, the working efficiency of the natural systems was assessed from case studies from Vizianagaram, Andhra Pradesh, India. The nutrient (Phosphorous and Nitrogen content) and organic matter removal efficiency of four natural treatment systems (NTS) having different operation, maintenance and loading rates were investigated. The study showed that natural treatment systems have good potential for peri-urban wastewater treatment. It was also observed that waste-stabilization based systems perform better than those based on duckweed and hyacinth plants. Regularly maintained and operated systems show removal efficiency on the order of 80% for organic and nutrients and performed better than others. The study indicates that decentralized, adequately maintained Waste Stabilization Ponds (WSP) offer a viable, self-sustaining and eco-friendly alternative for wastewater treatment to supply irrigation water in rural areas.

Digestate mechanical separation in industrial conditions: Efficiency profiles and fertilising potential.

The growing number of biogas plants has resulted in problems with the digestate management. In the studies carried out in industrial conditions in the biogas plant fed with sugar beet pulp, the influence of the decanter centrifuge operating parameters such as the retention time and differential speed on the effectiveness of digestate mechanical separation was evaluated. During the studies, the impact of the addition of cationic polyacrylamide flocculants with different charge density on the liquid and solid fraction composition was also determined. It was shown that the dry matter and organic matter concentrations in the solid fraction were about 88.80 g/kg FM and 66.20% DM, respectively and in the liquid fraction 25.50 g/kg FM and 77.00% DM after the centrifugation of the digestate without flocculant at an optimal retention time of 225s and differential speed of 4rpm. The removal efficiency of dry matter and organic matter was 32.00% and 39.39%. The best separation results were obtained centrifuging the digestate with addition of 20 g/kg DM flocculant with a charge density of 80%. The flocculant addition increased the removal efficiency of dry matter and organic matter in comparison to centrifugation without flocculant by 49.60% and 46.86%, respectively. After centrifugation and flocculation, about 60.83% of nitrogen, 74.55% of potassium and 33.23% of phosphorus remained in the liquid fraction. The liquid fraction contained lower concentrations of nickel, lead, cadmium and chromium in comparison to solid fraction.

Acclimation of microorganisms for an efficient production of volatile fatty acids and biogas from mezcal vinasses in a dark fermentation process.

Mezcal is an alcoholic artisanal drink made from agave plants in Mexico. Its production causes the generation of wastewater called vinasses, which are highly polluting residues due to its concentration of organic matter as chemical oxygen demand (COD) (35,000-122,000 mg/L) and acidity (pH < 4). Due to their organic content, these residues can be used in dark fermentation to obtain biogas, which is rich in hydrogen. In this work, the acclimation of inoculum by means of a dark fermentation process, in the presence of toxic compounds from mezcal vinasses was studied. The strategy of increasing the initial concentration of vinasse in each treatment cycle in a sequencing batch reactor (SBR) reactor was applied. It was possible to obtain a maximum biogas production of 984 ± 187 mL/L, from vinasses (18,367 ± 1,200 mg COD/L), with an organic matter removal efficiency of 20 ± 1%. A maximum generation of volatile fatty acids (VFA) of 980 ± 538 mg/L equivalent to a production of 74 ± 21% of the influent concentration and removal rate of organic matter of 1,125 ± 234 mg COD/L d-1 equivalent to a removal efficiency of 20 ± 4% was obtained from vinasses with a concentration of 19,648 ± 1,702 mg COD/L.

Formaldehyde biodegradation in an ASBR-SBR system: an effective treatment solution for furniture industry painting booth wastewater

Formaldehyde (HCHO) is a toxic organic compound with carcinogenic properties which is present in the furniture industry painting booth wastewater (PBW) and does not receive adequate treatment in its industrial environment. This effluent treatment commonly occurs by physicochemical processes that do not remove formaldehyde, while advanced treatment methods are costly for industrial scale application. This study assessed a system consisting of an anaerobic sequential batch reactor (ASBR) followed by an aerobic sequential batch reactor (SBR) for the PBW treatment. The system performance was evaluated by the gradual increase of HCHO concentration from 34 ± 5 to 232 ± 10 mg HCHO L−1, and chemical oxygen demand (COD) from 585 ± 8.4 to 3960 ± 100 mg O2 L−1, performed with cycle time of 4 days in ASBR and 2 days in SBR, evaluating the formaldehyde potential toxicity on anaerobic biomass. The ASBR-SBR system removed 99% of COD and HCHO until initial concentration of 180 ± 7 mg HCHO L−1. The HCHO concentration increase to 232 ± 10 mg L−1 reduced the removal efficiency of organic matter to 72% in ASBR due to partial inhibition of microorganisms caused by formaldehyde toxicity. However, under these conditions, the SBR was efficient and removed the remaining organic matter by 98%. The performance of ASBR-SBR showed that this simple system was suitable for the PBW treatment at the evaluated concentrations.

The role of extracellular organic matter on the cyanobacteria ultrafiltration process

The membrane fouling caused by extracellular organic matter (EOM) and algal cells and organic matter removal of two typical cyanobacteria (M. aeruginosa and Pseudoanabaena sp.) during ultrafiltration (UF) process were studied in this work. The results showed that EOM had a broad molecular weight (Mw) distribution and the irreversible membrane fouling was basically caused by EOM. Moreover, humic acid and microbial metabolites were major components of EOM of two typical cyanobacteria. Since EOM could fill the voids of cake layers formed by the algal cells, EOM and algal cells played synergistic roles in membrane fouling. Fourier transform infrared spectroscopy analysis indicated that the CH2 and CH3 chemical bonds may play an important role in membrane fouling caused by EOM. Interestingly, the cake layer formed by the algal cells could trap the organic matter produced by algae and alleviate some irreversible membrane fouling. The results also showed that although the cake layer formed by the algal cells cause severe permeate flux decline, it could play a double interception role with UF membrane and increase organic matter removal efficiency. Therefore, when using UF to treat algae-laden water, the balance of membrane fouling and organic matter removal should be considered to meet the needs of practical applications.

Alkylphenols and Chlorophenols Remediation in Vertical Flow Constructed Wetlands: Removal Efficiency and Microbial Community Response

This study aims to investigate the effect of two different groups of phenolic compounds (the alkylphenols nonylphenol (NP) and octylphenol (OP), and the chlorophenol pentachlorophenol (PCP)) on constructed wetlands (CWs) performance, including on organic matter, nutrients and contaminants removal efficiency, and on microbial community structure in the plant bed substrate. CWs were assembled at lab scale simulating a vertical flow configuration and irrigated along eight weeks with Ribeira de Joane (an urban stream) water not doped (control) or doped with a mixture of NP and OP or with PCP (at a 100 μg·L−1 concentration each). The presence of the phenolic contaminants did not interfere in the removal of organic matter or nutrients in CWs in the long term. Removals of NP and OP were &gt;99%, whereas PCP removals varied between 87% and 98%, mainly due to biodegradation. Microbial richness, diversity and dominance in CWs substrate were generally not affected by phenolic compounds, with only PCP decreasing diversity. Microbial community structure, however, showed that there was an adaptation of the microbial community to the presence of each contaminant, with several specialist genera being enriched following exposure. The three more abundant specialist genera were Methylotenera and Methylophilus (methylophilaceae family) and Hyphomicrobium (hyphomicrobiaceae family) when the systems were exposed to a mixture of NP and OP. When exposed to PCP, the three more abundant genera were Denitromonas (Rhodocyclaceae family), Xenococcus_PCC_7305 (Xenococcaceae family) and Rhodocyclaceae_uncultured (Rhodocyclaceae family). To increase CWs efficiency in the elimination of phenolic compounds, namely PCP which was not totally removed, strategies to stimulate (namely biostimulation) or increase (namely bioaugmentation) the presence of these bacteria should be explore. This study clearly shows the potential of vertical flow CWs for the removal of phenolic compounds, a still little explored subject, contributing to promote the use of CWs as nature-based solutions to remediate water contaminated with different families of persistent and/or emergent contaminants.

Optimization of airflow and aeration cycles in a new structured bed reactor configuration for carbon and nitrogen removal

ABSTRACT The Structured Bed Reactor with Recirculation and Intermittent Aeration (SBRRIA) is a reactor configuration that presents high efficiency of organic matter and nitrogen removal, besides low sludge production. However, operational parameters, as the recirculation rate, aeration time, and airflow, are not fully established. A bench-scale structured bed reactor with intermittent aeration was fed with synthetic effluent simulating the characteristics of sanitary sewage. The reactor was operated for 280 days with an operational hydraulic retention time (HRT) of 10 h. The reactor was operated without effluent recirculation for the first time since this approach was not yet reported, and was named Structured Bed Reactor with Intermittent Aeration (SBRIA). The COD removal was higher than 81% for all operational conditions, and the total nitrogen removal ranged from 10 to 80%. The highest efficiencies were obtained with an aeration time of 1 h 45 min (total cycle of 3 h) and an airflow rate of 4.5 L.min−1. Different nitrification and denitrification behaviours were observed, resulting in nitrification efficiencies over 90% when the reactor was submitted to higher aeration times and denitrification efficiencies above 90% when the reactor was submitted to low aeration times. The airflow ranges tested in this study affected the nitrification and the total nitrogen efficiencies. Even without effluent recirculation, the temporal profile showed that there were no peaks in the concentration of the nitrogen forms in the reactor effluent, saving electrical energy up to 75% due to pumping.

Proceso Fenton-adsorción para lixiviados de dos rellenos sanitarios (karstico-arcilloso)

Tests were carried out to analyze the efficiency of organic matter removal by Fenton/adsorption treatment of leachate from two landfills. The Fenton process was optimized with the following conditions: pH = 4, reaction time = 60 min, and ratios [COD/ H2O2] = 9, [Fe2+/H2O2] = 0.6. The treatment was tested in leachate from the city of Tuxtla Gutiérrez, Chiapas, Mexico (clays) and compared with the removals previously obtained in the leachate from the landfill of the city of Mérida, Yucatán, México (karstic). In both, removals higher than 99% were obtained in chemical demand for oxygen, total organic carbon and color. In this research, it was found that the optimization of the Fenton process depends directly on the concentration of organic matter measured as chemical oxygen demand.

PÓS-TRATAMENTO DE LIXIVIADO ESTABILIZADO POR CICLO COMPLETO, ADSORÇÃO E OXIDAÇÃO QUÍMICA

The leachatefrom landfillhas high concentrations of organic matter, humic and nitrogenous compounds, heavy metals and inorganic salts, which requiresproper treatment for its final destinationand does not cause damage to the environment. Studies show that the biologically treated effluent requires an association of physical-chemical techniques.Thisstudy aimed to evaluate the application of complementary techniques to thebiological treatmentsuch as coagulation-flocculation-sedimentation(CFS)andFenton's reaction oxidation(FR), followed by adsorption. The CFS with ferric chloride and FRpost-treatments isolated had100% and 87,9%, organic mattercorrelated with true color removal and 53,6% and 67,0% of CODremoval,which meetwiththe requirements of CONAMA 357/05 e 430/11 for disposal in water bodies. The adsorption after Fenton reaction resulted in 84,5% organic matter correlated with true color removal and 67,0% of CODremoval. Adsorption after coagulation-flocculation-sedimentation was able to reduce 76,9% of COD. CFSshowed higher removal efficiency of organic matter correlated to the true color, while RFobtained higher removal efficiency of NKT, N-ammoniacal and COD parameters. The biologically treated leachate did not show significant toxicityacute to the test organism saline artemia, however, after the post-treatment, acute ecotoxicity in the limits established by CEMA 81/10.

Vertical flow constructed wetland as a green solution for low biodegradable and high nitrogen wastewater: A case study of explosives industry

The removal of nitrogen compounds from a pretreated explosives wastewater in vertical flow constructed wetland planted with Vetiveria zizanioides (0.24 m2 × 0.70 m), filled with light expanded clay aggregates (Leca®NR 10/20), was studied. Experiments under constant hydraulic load, 50 ± 4 L m−2 d−1 and 83 ± 5 L m−2 d−1 without and with flooding level (25%), respectively, were made at different ammonium (3–48 mg NH4+-N L−1), nitrate (56–160 mg NO3−-N L−1) and nitrite (0.3–1.1 mg NO2−-N L−1) concentrations. Results indicate that without flooding level (unsaturated) the removal efficiencies obtained were 30 ± 9, 7 ± 1 and 96 ± 2%, respectively to NH4+-N, NO3−-N and NO2−-N. When using flooding level and an external carbon source (C/N ratio from 1.3 ± 0.19 to 2.5 ± 0.20), the organic matter (COD) removal efficiencies were above 90%, 75% for NH4+-N and 55% to NO3−-N. Increasing the C/N ratio from 2.9 ± 0.21 to 4 ± 0.22 did not contributed to upgrade the efficiencies of COD, NH4+-N and NO3−-N removal. The denitrification process was occurred in aerobic conditions and nitrite production have ben occurred, probably due to the presence of aerobic conditions that inhibited partially denitrification.

Avaliação da qualidade das águas superficiais e do sistema de tratamento do esgoto sanitário do município de Rio Claro/SP

A manutenção da qualidade da água é fundamental, tendo em vista que somente uma parcela reduzida do seu volume total está disponível para utilização direta. O lançamento de efluentes fora dos padrões de qualidade pode agravar significativamente esse cenário. O gerenciamento correto de águas residuárias torna-se ainda mais importante em períodos de crise hídrica, para a qual uma solução é o reuso por meio de tratamento avançado. Assim, foi objetivo deste trabalho avaliar o padrão de qualidade de águas do município de Rio Claro (SP). Ao longo dos rios Corumbataí e Ribeirão Claro, cinco pontos foram analisados em relação a diversos parâmetros de qualidade de águas, em trechos que abrangiam tanto a montante de pontos de captação de água, quanto a jusante de lançamento de esgotos tratados.Os resultados obtidos foram comparados às legislações vigentes sobre os temas, para averiguar a conformidade com os padrões estabelecidos. O Índice de Qualidade das Águas foi apresentado com a classificação boa em praticamente todos os pontos, exceto o ponto mais a jusante do município que obteve a classificação regular. As concentrações de alumínio dissolvido e ferro dissolvido apresentaram-se acima dos limites estabelecidos pela legislação no ano de 2018 em todos os pontos, especialmente no período chuvoso. Nos períodos de 2010-2014 e 2013-2017: os valores de Escherichia coli ultrapassaram os limites legais também para todas as localizações, com os piores resultados para os dois pontos a jusante; os valores mais elevados para condutividade elétrica, demanda bioquímica de oxigênio e fósforo total foram obtidos nos dois pontos a jusante, acima dos limites. Para os dados referentes ao sistema de tratamento de esgoto do município, foram demonstradas elevadas eficiências na remoção de matéria orgânica.

Trade-off control of organic matter and disinfection by-products in the drinking water treatment chain: Role of pre-ozonation

Ozone is a strong oxidant commonly used in drinking water treatment, but its role in the transformation/formation of organic matters (OMs) and disinfection by-products (DBPs) in the drinking water treatment chain had not been systematically studied. In this work the occurrence and building up of OMs, DBPs of trihalomethanes (THMs) and nitrosamines (NAs) during water purification steps under different pre-ozonation dosages have been studied through lab-scale and pilot-scale studies. Results indicated that 0–0.4 mg/L of pre-ozonation dosage could reduce organic load of following-up process steps but insufficient to control DBPs. Seasonal performances of a pilot plant indicated that the accumulation of DBPs was much less in summer than in winter. Furthermore the formation potential of NAs was higher in winter than summer when 0.4 mg/L pre-ozonation was dosed while the maximum removal efficiency of organic matter was found at a pre-ozonation dosage of 0.8 mg/L in summer. Finally a seasonal trade-off control strategy for both OMs and DBPs was proposed with an elucidated role of pre-ozonation in the drinking water treatment chain. This study provided working principles on optimizing pre-ozonation dosage and a seasonal control strategy for trade-off control of both OMs and DBPs in drinking water treatment plants.

A microwave radiation-enhanced Fe-C/persulfate system for the treatment of refractory organic matter from biologically treated landfill leachate.

In this study, a microwave (MW) radiation enhanced Fe–C/PS system was used to treat refractory organic matter in biologically-treated landfill leachate. The effects of important influencing factors on the refractory organic matter in biologically treated landfill leachate were explored, and the main reactive oxygen species produced in the system were verified. The mechanism by which humus was degraded was investigated by analyzing effectiveness of organics removal in different systems, and comparative analysis was conducted on the Fe–C materials before and after the reaction. The results showed that degradation capacity and reaction rate of the system could be improved with an increase in the Fe–C/PS dosage and MW power, while initial acidic conditions were also conducive to the degradation of organic matter. Under the conditions of an Fe–C of 1 g L−1, PS dosage of 30 mM, MW power of 240 W, and reaction time of 10 min, the UV254, TOC, and CN removal efficiencies were 51.48%, 94.56%, and 51.59%, respectively. In the MW/Fe–C/PS system, a large amount of and a small amount of ˙OH were generated by the thermal activation of PS to remove organic matter. The removal efficiency of organic matter could be further improved via the homogeneous catalytic oxidation and heterogeneous adsorption catalytic oxidation of Fe–C materials. In addition, the MW/Fe–C/PS system was effective for removing refractory organic matter from the leachates from four typical treatment systems: DTRO, SAARB, MBR, and NF. The MW/Fe–C/PS system has the potential to be widely applied for the treatment of landfill leachate.

Biological Reduction of Organic Matter in Buji River Sediment (Shenzhen, China) with Artificial Oxygenation

In this work, artificial oxygenation treatment (pure oxygen aeration or oxygen enriched water injection) combined with the introduction of exogenous microorganisms was employed to purify urban river sediment for the first time. Results showed that the developed in situ remediation strategy could increase the dissolved oxygen (DO) concentration and oxidation-reduction potential (ORP) value of the sediments. Benefiting from the increase of DO concentration, the bacterial diversity was enhanced. The highest removal efficiencies of organic matter were 18.4% and 22.3% through pure oxygen aeration and oxygen enriched water injection, respectively. More importantly, overlying water quality was not affected. By comparison, oxygen enriched water injection treatment could achieve better performance on sediment purification. Introducing exogenous microorganisms further reduced the organic matter content of the sediment. In short, the current work not only proposed a promising strategy for controlling urban river sediment pollution, but also provided novel insight for the understanding of river sediment containing highly concentrated organic matter.

Green sustainable technology for biotreatment of actual dairy wastewater in constructed wetland

AbstractBACKGROUNDDue to the environmental problems caused by food processing wastewaters and their complex and expensive treatment methods, it becomes mandatory to seek a sound, sustainable and environmentally friendly solution such as constructed wetland (CW). This study aimed to investigate the potential of treating real dairy wastewater in CW. Six horizontal subsurface flow CW microcosms were set up using different conventional and cost‐effective supporting media, which were gravel, soil and sand. All the CWs were fueled continuously with real fresh dairy wastewater. Five of the six CW microcosms were planted with Canna indica. The remaining CW microcosm was kept unplanted and was considered as a control microcosm.RESULTSThe results revealed significant removal efficiencies of organic matter (as chemical oxygen demand) up to 89.92%, 97.6%, 95.8%, 97.2%, 97.3% and 98.2%, for CW1, CW2, CW3, CW4, CW5 and CW6, respectively. Also, high removal efficiencies of ammonium were observed in the range of 98.4–82.0%, whereas removal efficiencies of total suspended solids were in the range of 99.2–93.4%.CONCLUSIONThe results demonstrated that the dominant mechanisms for organics and ammonium removal were biodegradation processes. These promising results confirmed the validity of using constructed wetland as a sustainable cost‐effective approach for dairy wastewater treatment. © 2020 Society of Chemical Industry

Pre-coagulation with cationic flocculant-composited titanium xerogel coagulant for alleviating subsequent ultrafiltration membrane fouling by algae-related pollutants

In-line coagulation-ultrafiltration is reliable to achieve the safe disposal of algae-laden water with alleviated membrane fouling. Poly(diallyl dimethyl ammonium chloride) (PDADMAC)-composited titanium xerogel (TXC) coagulant (abbreviated as P-T) was reported to possess better resistance to organic matter loads, and its mitigation effect on subsequent ultrafiltration efficiency towards algae-related pollutants was investigated in this study. Results showed that P-T coagulation effectively mitigated membrane fouling over pH 5.0–9.0, whereas TXC only worked better under acidic condition. Acidic environment facilitated algae and organic matter removal by pre-coagulation, thus greatly improving ultrafiltration efficiency. Under neutral and alkaline conditions, PDADMAC portion in P-T enhanced the coagulation removal towards algae and protein constituents, and simultaneously promoted the formation of flocs with unique porous structure, which jointly contributed to its high-efficient alleviation ability. Nevertheless, PDADMAC increased adhesion force between P-T coagulated flocs and membrane surface, thus slightly reducing the recovery rate of membrane flux at pH 5.0. Pearson correlation analyses implied that removing algae cells would prevent reversible fouling-induced flux decline, whereas eliminating organic matter could greatly promote ultrafiltration efficiency via mitigating irreversible fouling. Therefore, elevating removal efficiency of organic matters is still the major objective for ultrafiltration pretreatment technologies and the optimization direction towards TXC-based coagulants.

Performance of a membrane bioreactor and a moving bed biofilm reactor–membrane bioreactor treating table olive processing wastewater: a comparative study

AbstractBACKGROUNDTwo laboratory‐scale experimental systems – a membrane bioreactor (MBR) and a moving bed biofilm reactor–membrane bioreactor (MBBR‐MBR), both treating real high‐strength, saline wastewater from a table olive processing plant – were operated under identical conditions to comparatively evaluate their performance for three different hydraulic retention times (HRTs) of 88, 96 and 104 h.RESULTSThe biological process of both systems, after appropriate biomass acclimatization, was stable and the removal efficiencies were rather high; i.e., regarding total organic carbon (TOC) ≥86.4% and ≥85.6% for the MBR and MBBR‐MBR, respectively, and ≥89.1% regarding total polyphenols (TPh) for both systems. Concerning TOC and TPh removal, no statistically significant difference (p &lt; 0.05) was observed between the two systems. Reduction of HRT resulted in a slight decrease in mean TOC removal efficiency, but the mean TPh removal was practically unchanged. No membrane chemical cleaning was applied to either system during the 85‐day long continuous operation.CONCLUSIONThe comparative assessment showed that both systems (i.e., MBR and MBBR‐MBR) are effective for the advanced biological treatment of table olive processing wastewater and can achieve quite high removal efficiencies of organic matter and TPh. However, direct effluent reuse for irrigation purposes seems to be hindered by its high salinity. No significant differences were observed in the performance of these systems, apart from the increased aeration (and related energy costs), which is necessary to keep the biofilm carriers floating in the case of the MBBR‐MBR. © 2020 Society of Chemical Industry

Use of probiotics in fish feed and clams (Pilsbryoconcha exilis) as biofilter components of aquaponic system in archipelagic dryland

Abstract. Santoso P, Sunadji. 2020. Use of probiotics in fish feed and clams (Pilsbryoconcha exilis) as biofilter components of aquaponics system in archipelagic dryland. Trop Drylands 3: 46-50. Aquaponics is a combination system between aquaculture and hydroponic. It is water-use efficient and suitable to be developed in the archipelagic dryland. This study aimed to determine the effect of adding probiotics in fish feed and the use of clam (Pilsbryoconcha exilis) as additional components in the aquaponic system on feed conversion ratio, productivity of catfish (Clarias gariepinus) and aquatic spinach (Ipomoea aquatica), and removal efficiency of organic matter suspended in the aquaculture water. This study was an experimental study using a factorial treatment laid out in a completely randomized design with three replications. The treatments applied were administration of probiotics with concentrations of 2 mL kg-1, 4 mL kg-1, and 6 mL kg-1 in feed to improve feed efficiency in catfish, thus minimizing metabolite discharges, and the use of clam in biofilter systems with a density of 50 clams m-2, 100 clams m-2, and 200 clams m-2 to improve the efficiency of absorption of cultivation effluents in the form of suspended particles. The results of ANOVA showed that the treatment of adding probiotics in the fish feed had a significant effect (P&lt;0.05) on improving feed conversion ratio, increasing the production of catfish, and the removal efficiency, but had no significant effect (P&gt;0.05) on aquatic spinach biomass production. Whereas the use of clams as biofilter significantly (P&lt;0.05) improved feed conversion ratio, increased the production of catfish and aquatic spinach, also efficiently removed organic matter in the aquaponic system. The interaction of these two factors had a significant effect (P&lt;0.05) on feed conversion ratio and aquatic spinach production, however, it had no significant effect (P&gt;0.05) on the production of catfish and the organic matter removal efficiency. Post hoc LSD test showed that the best interaction effect was the treatment of probiotic 6 mL kg-1 and biofilter 200 clams m-2 because it generated a combination of the lowest feed conversion ratio (1.07) and the highest of aquatic spinach production (5.28 kg m-2).