Food Wastewater Research Articles

Enhanced nitrogen and phosphorus removal from mariculture water using immobilized bacteria and macroalgae

With the vigorous development of the mariculture industry, the untreated wastewater from mariculture has exerted significant pressure on the water environment. The untreated N and P in the wastewater from mariculture can deteriorate the quality of the mariculture. In this study, a composite in situ treatment system involving macroalgae (Caulerpa lentillifera/Caulerpa sertularoides f. Longipes) and immobilized degrading bacteria was established to handle wastewater from shrimp culture. The changes in nutrients in aquaculture wastewater were studied by chemical analysis, and the microbial community structure was analyzed using molecular biology technology and high-throughput sequencing technology. The removal efficacy of nutrients in aquaculture wastewater and the composition of microorganisms in the wastewater were examined, and the primary causes for the alteration of the microbial community were analyzed. The results demonstrated that when the macroalgae in the system were Caulerpa lentillifera (CL), the removal efficiencies of TN, PO43--P, and COD from shrimp culture were 59.04%, 34.26%, and 68.61% respectively. When the macroalgae was Caulerpa sertularoides f. Longipes (CSF), the removal efficiencies of TN, PO43--P, and COD generated by experimental shrimp culture were 51.50%, 33.69%, and 50.88% respectively. The biomass (wet weight) of both macroalgae species also increased, facilitating the removal of nutrients from the wastewater. Additionally, both Proteobacteria and Bacteroidetes were the dominant bacteria in the three samples, and the addition of the composite in-situ treatment system had no impact on the dominant bacteria in the water. The results of FAPROTAX analysis indicated that compared with the untreated samples, the abundances of methyl-functional bacteria and amino acid-functional bacteria in the samples increased due to organic matter such as COD produced during shrimp culture and the addition of feed, suggesting that shrimp culture can influence the abundances of functional bacteria in the water. In conclusion, the combined in situ treatment system can effectively eliminate nutrients from aquaculture wastewater, and the combined effect of macroalgae and immobilized degrading bacteria plays a vital role in this process.

Extended photoperiods enhance the production and water treatment performance of algal-bacterial bioflocs from aquaculture wastewater

Reducing pollution and converting wastewater nutrients into useful biomass are major challenges of intensive aquaculture. We investigated the nitrogen and phosphorus metabolism, nutrient composition, and microbial community of algal-bacterial bioflocs (ABBs) produced under glucose addition and different photoperiods. This biomass was used for aquaculture wastewater treatment for 18 days. ABBs produced under longer photoperiods were smaller and more numerous, which facilitated nitrogen recovery and reduced nitrogen loss. Additionally, nitrogen and phosphorus-metabolizing enzyme activities, as well as the activity of overall microorganisms were positively correlated with the light duration. The removal rates of COD (96.89 %), DTN (93.57 %), and DTP (93.67 %) from wastewater by ABBs were highest when the photoperiod was 16L:8D during the production period. Moreover, the crude protein content (41.77 ± 0.11 %) was highest under a photoperiod of 12L:12D, and the rich amino acid and fatty acid profile of the ABB under this photoperiod enhanced its utility as a feed additive for aquaculture species. The high-throughput sequencing analysis revealed a high abundance of Hydrogenophaga at the genus level, highlighting its denitrification capacity of ABBs under the 16L:8D photoperiod. Redundancy analysis (RDA) demonstrated that photoperiod, as a key driver in the formation of microbial communities in ABBs, exerted a direct influence on water treatment efficiency and nutrient accumulation. This study provides new insights into the effects of photoperiod on the properties of ABBs, which has implications for the treatment and subsequent application of aquaculture wastewater.

Effects of different culture media on growth, composition, quality and palatability of the green algae Ulva sp. cultivated in cylindrical photobioreactors

Ulva spp. are valuable seaweeds with recognized commercial applications, including food, feed, and ecosystem services. Ensuring a sustainable and consistent supply of biomass with desirable profiles aligned with intended uses is fundamental for the successful applications of this seaweed. In this study, the growth rate, morphology, physiology, and composition of Ulva sp. produced by propagation in indoor cylindrical photobioreactors using four different culture media (lagoon water - LW, lagoon water enriched with Guillard medium (LF), with sea urchin wastewater - LU, and cow digestate - LD) was assessed; moreover, the nutrient uptake potential of the species was evaluated. The palatability and attractivity of the produced biomass towards the sea urchin Paracentrotus lividus were investigated. It was found that the media influenced all the parameters examined, the LF biomass weight was double compared to the other treatments and showed a slightly higher absorbance. Colorimetric analyses reported a significant darker color in Ulva sp. grown under enriched media. Ulva sp. showed higher nutrient removal potential in LF. The lipid content did not vary (2–3 % dry weight, DW), while the protein content ranged from 21 % in LF to 6–9 % in the other treatments. Carbohydrates and fiber content were significantly lower in LF (16 % and 30 %) compared to the other treatments, 27–34 %, and 41–48 %, respectively. Pigment content significantly varied, being higher in biomass grown in LF and LU. Sea urchins showed preferences for biomass grown under LU, followed by LD. This study shows how different nutrient sources affect the biochemical composition, growth, quality, and palatability of Ulva sp.. When cultivated under the synthetic enriched media (LF) the species exhibits characteristics better suitable for human consumption, although requiring a higher economic investment for production, while biomass derived from wastewater nutrients (LD, LU) confirms potential applications of the seaweed as valuable feed and for bioremediation services.

Impact of PCLNPG Nanopolymeric Additive on the Surface and Structural Properties of PPSU Ultrafiltration Membranes for Enhanced Protein Rejection

This research explored the use of a partially cross-linked graft copolymer (PCLNPG) as an innovative nanopolymer pore-forming agent to enhance polyphenylsulfone (PPSU) membranes for protein separation applications. The study systematically examined the impact of incorporating PCLNPG at varying concentrations on the morphological and surface properties of PPSU membranes. A thorough characterization of the resulting PPSU-PCLNPG membranes was performed, focusing on changes in morphology, water affinity, porosity, pore size, and pore size distribution. The experimental findings demonstrated that the use of PCLNPG led to a significantly more porous structure, as confirmed by SEM analysis, with notable increases in porosity and pore size (nearly double). Additionally, the hydrophilicity of the PPSU membrane was remarkably enhanced. Performance evaluations revealed a substantial improvement in pure water flux, with the flux nearly tripling. The BSA retention was directly correlated with the concentration of the PCLNPG pore former for a loading range of 0.25–0.75 wt.%. The incorporation of PCLNPG also reduced the membrane fouling propensity by reducing both cake layer resistance (Rc) and pore plugging resistance (Rp). These results underscore the potential of PCLNPG-PPSU membranes for wastewater reclamation and nutrient recovery applications.

Magnesium-modified starch cryogels for the recovery of nitrogen and phosphorus from wastewater and its potential as a fertilizer substitute: A novel nutrient recovery approach

Nitrogen (N) and phosphorus (P) are primary pollutants contributing to water quality degradation and eutrophication but are also indispensable resources for agricultural production. In this study, we synthesized porous MgO/Mg(OH)2-modified starch gels (SC-M/SC-OM) to facilitate the simultaneous removal of N and P from wastewater and address the challenges associated with separating and recycling powdered materials. By immobilizing magnesium powder within the matrix of starch gel, with the addition of 1.7 % w/w of MgO and 2.4 % w/w of Mg(OH)₂, the adsorbent can be efficiently recovered from the liquid phase, minimizing material loss. Due to their inherent pH-regulating capabilities, the modified starch gels exhibited excellent removal performance over a wide pH range. At the appropriate adsorbent dose, the maximum recovery of SC-M was 70.072 mg/g P and 25.517 mg/g N, whereas SC-OM was marginally inferior to SC-M. The pseudo-first kinetic model more accurately represented the adsorption of the two materials, showing that N and P concentrations mainly affected the adsorption efficiency, which benefits nutrient recovery at higher concentrations. Starch gels function as carriers for powdered magnesium and contribute to the synergistic removal of N and P, particularly enhancing P removal. SC-OM primarily facilitates the recovery of N and P by forming struvite. At the same time, the adsorption during the hydration process of MgO also plays a crucial role in the recovery with SC-M. Finally, the pot experiment confirmed the feasibility of using the recovered SC as a sustained release fertilizer. This study reveals the significant potential of SC-M/SC-OM for environmentally friendly nutrient removal and recovery, providing a promising approach for wastewater treatment and nutrient recycling.

Nutrient removal in floating and vertical flow constructed wetlands using aluminium dross: An innovative approach to mitigate eutrophication

On global scale, eutrophication is one of the most prevalent environmental threats to water quality, primarily caused by elevated concentration of nutrients in wastewater. This study utilizes aluminum dross (AD), an industrial waste, to create a value-added material by improving its operational feasibility and application for removing phosphate and ammonium from water. The operational challenges of AD such as its powdered nature and effective operation under only extreme pH conditions were addressed by immobilizing in calcium alginate to form calcium alginate aluminium dross (Ca-Alg-Al dross) beads. These Ca-Alg-Al dross beads were further tested for phosphate and ammonium removal from natural wastewater in two different aqueous environment systems: (i) vertical flow constructed wetlands (VF-CWs) followed by Ca-Alg-Al dross beads fixed bed system and (ii) Ca-Alg-Al dross beads mounted floating constructed wetlands (FCW) for remediating polluted lentic ecosystems. Our results show maximum phosphate and ammonium removal of 85 ± 0.41 % and 93.44 %, respectively, in VF-CWs followed by Ca-Alg-Al dross beads fixed bed system. The Ca-Alg-Al dross beads mounted FCW system achieved maximum phosphate removal of 79.18 ± 8.56 % and ammonium removal of 65.45 ± 21.04 %. Furthermore, the treated water from the FCW system was assessed for its potential to inhibit algal growth by artificially inoculating treated water with natural algae to simulate eutrophic conditions. Interestingly, treated water from the FCW system was found capable of arresting the algal growth. Besides, scanning electron microscopy with energy dispersive X-ray (SEM-EDX) and Fourier transform infrared (FTIR) spectroscopy confirmed the functional groups and surface properties and probable participation of multiple mechanisms including ion exchange, electrostatic attraction, and ligand complexation for phosphate and ammonium removal. Overall, these results offer a promising way to utilize AD for high-end applications in wastewater treatment.

Removal of organic matter from food wastewater using anaerobic digestion at low temperatures enhanced by exogenous signaling molecule N-hexanoyl-homoserine lactone enhancement: Insight to extracellular polymeric substances and key functional genes

This experiment aimed to study the effects of adding the exogenous signaling molecule N-hexanoyl-homoserine lactone (C6-HSL) on the anaerobic digestion of food wastewater at low temperature (15 °C). Daily addition of 0.4 μmol C6-HSL increased the average chemical oxygen demand removal from 45.98% to 94.92%, while intermittent addition (adding 2 μmol C6-HSL every five days) increased it from 45.98% to 72.44%. These two modes of C6-HSL addition increased protease and acetate kinase activity by 47.99%/8.04% and 123.26%/127.91% respectively, and increased coenzyme F420 concentrations by 15.79% and 63.16%, respectively. The regulation of loosely bound extracellular polymeric substances synthesis was influenced by C6-HSL, which increased protein and polysaccharide content in sludge. The relative abundance of Firmicutes and Bacteroidetes increased following addition of C6-HSL. After continuous addition of C6-HSL, the relative abundance of related functional genes such as amy, apgM, aceE, and accC increased, indicating that methanogens obtained sufficient substrate. The abundance of glycolysis-related functional genes such as glk, pfk, pgi, tpiA, gap, pgk, gpmA, eno, and pyk increased after the addition of C6-HSL, ensuring the efficient transformation and absorption of organic matter by anaerobic sludge at low temperatures. This study provides new comprehensive insights into the mechanism behind the enhancement of food wastewater anaerobic digestion by C6-HSL at low temperature.

Carbon sources influence on heterotrophic ammonia assimilation: Performance and mechanism

Different carbon contents of organic carbon sources can be used as the reaction substrates of heterotrophic ammonia assimilation (HAA), which effectively dominates the recovery of available nutrients in wastewater. However, the influences of organic carbon sources on nutrient metabolism, degradation kinetics, and functional microbes of HAA were largely unknown. Here, HAA bioreactors fed with acetate, glucose, sucrose, starch, methanol, and sludge alkaline fermentation liquid (SAFL) were constructed to compare the nitrogen recovery performance, kinetic analysis, sludge characteristics, and microbial community structure. Higher COD and NH4+-N removal efficiencies were found in bioreactors supplied with acetate, glucose, and SAFL. Kinetic analysis showed that the acetate-fed bioreactor had more efficient organic utilization for assimilation. Corynebacterium, Pseudohoeflea, and Methylophaga emerged as the primary assimilation bacteria for typical carbon sources of organic acids, sugars, and alcohols, whereas Halomonas, Corynebacterium, and Marinobacter dominated in SAFL. Acetate- and SAFL-supported sludge particles displayed enhanced internal and external oxygen mass transfer, along with heightened sedimentation performance and deconsolidation ability. High-quality assimilative gene expression, assimilative enzyme activity, and assimilated organic nitrogen product synthesis with direct effects were observed in a reactor supplied with acetate and SAFL. The cost-effectiveness of SAFL preparation positions it as a promising candidate for practical engineering applications. This research underscored the pivotal role of different carbon contents in the nutrient recovery process of the HAA reaction, providing essential insights for optimizing wastewater treatment strategies and enhancing environmental sustainability.

Sea Purslane's (Sesuvium portulacastrum) role in nutrient removal and microbial community dynamics of the mariculture wastewater bioremediation systems

The development of intensive mariculture requires effective wastewater treatment solutions, and mariculture wastewater bioremediation systems (MWBSs) are increasingly used for this purpose. One important part of these systems is the macrophyte unit. In this study, we established a MWBS consisting of four sections: sedimentation, biofilm, shellfish, and macrophytes, to investigate the role of sea purslane (Sesuvium portulacastrum) in nutrient removal and microbial community dynamics through controlled experiments (CE) and in situ observations (ISO). Our findings revealed the removal rates of CODMn in the low-density and high-density groups were 45.18 ± 5.42% and 48.25 ± 5.70% in CE, respectively. Furthermore, the removal rate of CODMn in the ISO was 85.28 ± 4.09%. Sea purslane notably enhanced microbial diversity and overall species count in the water. The bacterial community experienced three successional stages in the water and demonstrated more stability in the root system in CE. The stochastic processes were critical in shaping the community assembly. The bacterial dispersal in sea purslane treatment groups was higher than in the control group. Importantly, stochastic processes contributed more to the microbial community in the root system. Furthermore, the influence of stochastic processes was stronger in ISO than in CE. Therefore, it is speculated that the sea purslane demonstrated a substantial impact on microbial community structure and exhibited positive effects on wastewater nutrient removal. This study provided a reference for optimizing treatment areas within comprehensive wastewater treatment systems.

Separation and recovery of elements from drainage water arising in soilless tomato cultivation − Application of electrocoagulation

Soilless tomato cultivation requires significant water and nutrient inputs, resulting in the generation of drainage water (DW) with varying macro- and micronutrient compositions. This poses challenges for effective nutrient’s reuse due to technological and economic constraints. This study investigates the feasibility of using electrocoagulation, employing aluminum electrodes, to treat DW. The experiment involved three different current densities (2 A/m2, 4 A/m2, and 8 A/m2) and a 24-hour hydraulic retention time (comprising 4 h of electrocoagulation followed by 20 h of stirring). Treatment performance, kinetics, sludge characteristics, and energy consumption were evaluated. The elemental composition of the electrocoagulation-treated DW, including P, N, S, Cl, Ca, Mg, K, Na, Mo, Mn, Fe, Zn, Cu, B, organic compounds, and Al, was analyzed. The results showed that higher current densities resulted in increased pollutant removal rates and efficiencies. Importantly, the electrocoagulation process facilitated phosphorus recovery at pH < 7.0, ranging from 95.3 ± 0.6 % (at 2 A/m2) to 99.9 ± 0.1 % (at 8 A/m2), with corresponding energy consumption between 6.03 kWh/kgP and 29.98 kWh/kgP. Electrocoagulation as a drainage water treatment not only offers phosphorus recovery, but can also recovery B, and – to a certain extent – S, Mg, K, Mn, Zn and Cu. Other elements, such as Na and Cl, remained at stable levels. This allows for the separation of valuable elements (P) from those that interfere with cultivation (Na, Cl). This research could contribute to the development of a precise treatment process to address nutrient and pollutant management challenges in agricultural wastewater.

Validity of zinc oxide nanoparticles biosynthesized in food wastes extract in treating real samples of printing ink wastewater; prediction models using feed-forward neural network (FFNN)

In the present study, biosynthesized ZnO nanoparticles in food wastewater extract (FWEZnO NPs) was used in the photocatalytic degradation of real samples of printing ink wastewater. FWEZnO NPs were prepared using green synthesis methods using a composite food waste sample (2 kg) consisted of rice 30%, bread 20 %, fruits 10 %, chicken 10 %, lamb 10%, and vegetable 20%. The photocatalysis process was optimized using response surface methodology (RSM) as a function of time (15–180 min), pH 2–10 and FWEZnO NP (20–120 mg/100 mL), while the print ink effluent after each treatment process was evaluated using UV–Vis-spectrophotometer. The behaviour of printing ink wastewater samples for photocatalytic degradation and responses for independent factors were simulated using feed-forward neural network (FFNN). FWEZnO NPs having 62.48 % of the purity with size between 18 and 25 nm semicrystalline nature. The main functional groups were –CH, CH2, and –OH, while lipid, carbon-hydrogen stretching, and amino acids were the main component in FWEZnO NP, which contributed to the adsorption of ink in the initial stage of photocatalysis. The optimal conditions for printing ink wastewater were recorded after 17 min, at pH 9 and with 20 mg/100 mL of FWEZnO NPs, at which the decolorization was 85.62 vs. 82.13% of the predicted and actual results, respectively, with R2 of 0.7777. The most significant factor in the photocatalytic degradation was time and FWEZnO NPs. The FFNN models revealed that FWEZnO NPs exhibit consistency in the next generation of data (large-scale application) with an low errors (R2 0.8693 with accuracy of 82.89%). The findings showing a small amount of catalyst is needed for effective breakdown of dyes in real samples of printing ink wastewater.

Ammonia recovery via direct contact membrane distillation: Modeling and performance optimization

Ammonia recovery from wastewater has positive environmental benefits, avoiding eutrophication and reducing production energy consumption, which is one of the most effective ways to manage nutrients in wastewater. Specifically, ammonia recovery by membrane distillation has been gradually adopted due to its excellent separation properties for volatile substances. However, the global optimization of direct contact membrane distillation (DCMD) operating parameters to maximize ammonia recovery efficiency (ARE) has not been attempted. In this work, three key operating factors affecting ammonia recovery, i.e., feed ammonia concentration, feed pH, and DCMD running time, were identified from eight factors, by a two-level Plackett-Burman Design (PBD). Subsequently, Box-Behnken design (BBD) under the response surface methodology (RSM) was used to model and optimize the significant operating parameters affecting the recovery of ammonia though DCMD identified by PBD and statistically verified by analysis of variance (ANOVA). Results showed that the model had a high coefficient of determination value (R2 = 0.99), and the interaction between NH4Cl concentration and feed pH had a significant effect on ARE. The optimal operating parameters of DCMD as follows: NH4Cl concentration of 0.46 g/L, feed pH of 10.6, DCMD running time of 11.3 h, and the maximum value of ARE was 98.46%. Under the optimized conditions, ARE reached up to 98.72%, which matched the predicted value and verified the validity and reliability of the model for the optimization of ammonia recovery by DCMD process.

Flushing Out Homeowner Perceptions to Improve Voluntary Septic to Sewer Conversion With Social Marketing

Background Septic systems are recognized as a contributor to water quality degradation. Septic to sewer conversion programs are being implemented to mitigate nutrient pollution but success of voluntary programs is dependent on homeowner participation. The purpose of this study was to identify elements of potential social marketing strategies that could advance the voluntary adoption of septic to sewer conversion programs. Focus of the Article This study used formative survey research to assess residents’ knowledge, attitudes, and perceived benefits of and barriers to septic systems conversion in Florida, USA to inform future interventions promoting this major, costly home infrastructure change that reduces wastewater nutrient contamination. Research Question This study attempts to answer the following questions: (1) Does septic system conversion status (mandatory vs. voluntary) influence homeowners’ knowledge, attitudes, and perceived benefits and barriers to septic to sewer conversion? (2) What social marketing variables are the best predictors of attitude about septic to sewer conversion? Importance to the Social Marketing Field In contrast to inexpensive, repeated habits which are the target of many social marketing campaigns, costly one-time behaviors have been minimally explored by social scientists and social marketers. This study demonstrates how social marketing research can be applied to advance the adoption of costly, one-time infrastructure improvements, with septic to sewer conversions serving as the study context. There are substantial opportunities for social marketers to support local government and other organizations in their promotion of major technologies, including, but not limited to septic system conversions. Methods 518 adult Florida residents who were also septic system owners completed an online survey instrument that assessed subjective and objective knowledge, attitudes about septic to sewer conversion, and motivators and barriers to conversion. Results Septic system homeowners are largely supportive of septic conversion programs; however, the greatest perceived benefits are personal and not associated with environmental improvements. Despite many septic to sewer conversion projects being initiated for environmental purposes, behavior change efforts should promote the benefits of conversion as perceived by the homeowner. The primary barrier is the upfront cost, and alternative funding structures should be investigated. Recommendations for Research or Practice This study indicates that target audience outreach is an essential component of the environmental planning process. Considering the costs and complexity of water quality infrastructure projects, environmental management professionals should consider a robust audience-specific social marketing program as part of the implementation and planning process. The findings presented here suggest opportunities for social marketers to partner with environmental management professionals tasked with encouraging septic to sewer conversion or other costly and significant one-time behaviors.

Circular economy approach: Nutrient recovery and economical struvite production from wastewater sources by using modified biochars

The enrichment of phosphorus (P) and nitrogen (N) in aquatic systems can cause eutrophication. Moreover, P rocks may become exhausted in the next 100 years. A slow-release fertilizer called struvite (MgNH4PO4.6H2O) can reduce surface runoff. However, the high cost of raw material or chemicals is a bottleneck in their economical production. Therefore, incinerated sewage sludge ash, food wastewater, and bittern were combined as the sources of P, N, and Mg, respectively. Sawdust biochar was used to enhance the adsorptive recovery of nutrients. First, recovery kinetics was studied by comparing bittern-impregnated biochar (BtB) with the Mg-impregnated biochar (MgB). Subsequently, the synergistic physical and chemical interactions were observed for P and N recovery. Almost complete PO43–P recoveries were achieved within 10 min for both biochars. However, NH4+-N recovery was stable after 2 h, with 26% recovery by MgB and 20% recovery by BtB. Biochars activated with steam (steam-activated biochar) and KOH (KOH-activated biochar) gave superior activities to those of unactivated biochars and activated carbon (AC) nutrient recovery and struvite purity. Moreover, the activated biochars showed a lower risk of surface runoff, similar to that of AC. Therefore, activated biochars can be used as an alternative to AC for economical struvite production from a combination of wastewater sources.

Enhancing pollutant removal and desalination in microbial desalination cells using a rotating algal biofilm cathode

Currently, most photosynthetic microbial desalination cells (PMDCs) employ suspended algae as cathode organisms to produce oxygen. However, this method requires expensive platinum as a catalyst to catalyze the binding of oxygen to cathode electrons. In this study, a PMDC using a rotating algal biofilm (RAB) as a biocathode was demonstrated. RAB not only generates enough oxygen as an electron acceptor but also enhances the combination of oxygen and electrons on the cathode. Furthermore, the RAB-MDC system exhibited excellent performance in pollutant removal and desalination. When using simulated wastewater as anolyte and catholyte, the RAB-MDC achieved impressive removal efficiencies for COD, TOC, and NH4+-N, reaching 91.0 ± 0.1 %, 74.7 ± 0.03 %, and 95.0 ± 0.05 %, respectively. The power density reached 89.5 mW/m3 at an external resistance of 1000 Ω, while the desalination efficiency was 36.0 %, with a desalination rate of 190.9 mg/d. Additionally, high-throughput 16S rDNA sequencing was employed to assess the relative abundance of microorganisms in the RAB-MDC device, facilitating guided culture in subsequent studies. In conclusion, this research demonstrates the potential of RAB as a biocathode in MDCs for comprehensive wastewater treatment, desalination, power generation, and nutrient recovery.

Progress on the Use of Hydroponics to Remediate Hog Farm Wastewater after Vermifiltration Treatment

Hog farm wastewater may require novel biological treatment techniques to improve efficiency and reduce costs. Previous studies combining vermifiltration with downstream hydroponics showed the need for a balanced wastewater nutrient content, particularly the nitrogen-to-phosphorus ratio. Here, a deep-water culture hydroponic system, growing lettuce as model culture, was used to remediate hog farm wastewater after an initial vermifiltration stage, aiming to produce an effluent suitable for irrigation. Supplemented vermifiltered wastewater (SVW) with added nutrients was tested against unsupplemented vermifiltered wastewater (VW) over 35 days, using a synthetic nutrient solution (NS) as a control. Supplementation was shown to improve lettuce growth, light use efficiency, and water use efficiency. Nutrient analysis over time showed a better-balanced phosphorus and nitrogen removal in SVW than in VW; in all treatments nitrogen and phosphorus content was reduced to legally acceptable levels for treated wastewater reuse in irrigation: nitrate 5 mgN L−1 in VW and undetectable in SVW and NS; ammonia undetectable in all treatments; and total phosphorus 2.4 mg L−1 in SVW, 0.9 mg L−1 in NS and undetectable in VW. Coliforms increased in VW and SVW during hydroponic treatment, which should be solved by disinfection. Overall, combining vermifiltration with downstream hydroponic culture proved to be a promising treatment to remediate nutrients in hog farm effluent to make it suitable to be reused for irrigation.

Combining pre-fermentation and microbial electrolysis for efficient hydrogen production from food wastewater

Energy-rich food wastewater (FWW) offers a sustainable feedstock for bioelectrochemical hydrogen production. However, its complex characteristics and high suspended solids content hinder its direct utilization in dual-chamber microbial electrolysis cells (MECs) for producing high-purity hydrogen. This study explored pre-fermentation under uncontrolled pH conditions as a method to improve the exoelectrogenic utilization of FWW in dual-chamber MECs. Across 2–5 d hydraulic retention times (HRTs), pre-fermentation was effective in conditioning FWW to a more favorable composition for exoelectrogenic utilization. Short-chain organic acids and ethanol constituted 48–72% of the total chemical oxygen demand (COD) in pre-fermentation effluents, a substantial increase from 27% in raw FWW. In subsequent MEC experiments, the MECs fed with pre-fermentation effluents exhibited significantly higher current-generating and hydrogen-producing performance compared to those fed with raw FWW. The MECs fed with the 2-d HRT pre-fermentation effluent showed the highest hydrogen yield of 911 mL/g COD fed, which represents a 34.4% increase compared to the MECs fed with raw FWW, resulting in a 1.28-fold higher recovery of chemical energy from organic matter in raw FWW as hydrogen. The anode bacterial community was dominated by exoelectrogenic Geobacter in all MECs, with its abundance being significantly higher when utilizing pre-fermentation effluents (69.0–78.0%) compared to raw FWW (20.6–39.2%). Overall, pre-fermentation proved an effective conditioning approach for enhancing the exoelectrogenic utilization of FWW in MECs.

Role of biochar addition to improve anaerobic membrane bioreactors to resist oil stress in synthetic food wastewater treatment

This study investigated biochar addition to improve the performance and stability of anaerobic membrane bioreactor (AnMBR) to resist different oil contents in food wastewater treatment. Results show that an increase in oil content in synthetic food wastewater from 2 to 4 g/L of oleate-Na aggravated AnMBR performance in terms of methane (CH4) production and membrane fouling as showed by an obvious increase in transmembrane pressure (TMP). The reduced performance was caused by the accumulation of volatile fatty acids (VFAs) to inhibit the growth and activity of Methanobacterium in response to increased oil content. Nevertheless, biochar addition improved AnMBR resistance to against oil increase. The dominance of Methanobacterium and their potential mutualism with genus T78 were enhanced by biochar to sustain CH4 yield. Moreover, biochar reduced the production of extracellular polymeric substance (EPS) to alleviate membrane fouling.

Pengembangan Integrasi Budidaya Ikan Lele Dan Tanaman Herbal Di UPR Doa Mandeh

The catfish cultivation business carried out by UPR Doa Mandeh since 2015 still requires support in the form of assistance and training for its development. Meanwhile, the availability of fish seeds in South Sumatra is still very dependent on other regions, such as Lampung, Jambi and West Java. The lack of use of appropriate catfish cultivation technology and the use of commercial feed has an impact on the low production of fish seeds produced. Apart from that, there has been no effort to treat waste water which has the potential to have a negative impact on the surrounding environment. For this reason, community service (PPM) is carried out, which applies lecture materials, research and publications that have been carried out by the proposing team in the form of application of biofloc technology, making liquid fertilizer and cultivating herbal plants. The aim and benefits of carrying out this activity are to develop the catfish cultivation business, increase seed production, utilize waste water from catfish rearing media into liquid fertilizer products that can be used to develop herbal plant cultivation which will ultimately increase the income of cultivators at UPR Doa Mandeh. The activity model is in the form of empowerment, development and assistance which is implemented using counseling, training and technical/production assistance methods. The results of this activity are high survival and growth rates for catfish, water quality is in the optimal range, and the richness of nutrients in wastewater from the biofloc system can be used as liquid fertilizer for herbal plants. Keywords: biofloc; catfish; herbal plants; liquid fertilizer

Microalgal-bacterial treatment of ice-cream wastewater to remove organic waste and harvest oil-rich biomass.

The diversity of microalgae and bacteria allows them to form beneficial consortia for efficient wastewater treatment and nutrient recovery. This study aimed to evaluate the feasibility of a new microalgal-bacterial combination in the treatment of ice cream wastewater for biomass harvest. The bacterium Novosphingobium sp. ICW1 was natively isolated from icecream wastewater and the microalga Vischeria sp. WL1 was a terrestrial oil-producing strain of Eustigmatophyceae. The ice cream wastewater was diluted 4 folds for co-cultivation, which was relatively less inhibitory for the growth of Vischeria sp. WL1. Four initial algal-bacterial combinations (v:v) of 150:0 (single algal cultivation), 150:1, 150:2, and 150:4 were assessed. During 24days of co-cultivation, algal pigmentation was dynamically changed, particularly at the algal-bacterial combination of 150:4. Algal growth (in terms of cell number) was slightly promoted during the late phase of co-cultivation at the combinations of 150:2 and 150:4, while in the former the cellular oil yield was obviously elevated. Treated by these algal-bacterial combinations, total carbon was reduced by 67.5 ~ 74.5% and chemical oxygen demand was reduced by 55.0 ~ 60.4%. Although single bacterial treatment was still effective for removing organic nutrients, the removal efficiency was obviously enhanced at the algal-bacterial combination of 150:4. In addition, the harvested oils contained 87.1 ~ 88.3% monounsaturated fatty acids. In general, this study enriches the biotechnological solutions for the sustainable treatment of organic matter-rich food wastewater.