Food Wastewater Research Articles

Wastewater Hydroponics for Pollutant Removal and Food Production: Principles, Progress and Future Outlook

As the global population reaches eight billion, large quantities of wastewater (domestic, industrial, livestock) need to be treated in an efficient, green, and environmentally friendly manner. Wastewater hydroponics technology (HP) can efficiently remove various pollutants (conventional and emerging pollutants, heavy metals, and microorganisms) and create economic benefits. This paper aims to systematically review the principles, applications, and limitations of wastewater hydroponics technology in the context of pollution and nutrient removal. Unlike constructed wetlands, wastewater hydroponics has been proven to be effective in removing pollutants through small-scale in situ restoration. For instance, the average removal of COD, total nitrogen (TN), total phosphorus (TP), copper (Cu), and zinc (Zn) was more than 70%, 60%, 80%, 64.2%, and 49.5%, respectively. However, HP technology still has the disadvantages of high energy consumption, complex control parameters, and low public acceptance of using wastewater for planting crops. Therefore, further research is needed to reduce system energy consumption. In addition, hybrid technologies, such as two-stage hydroponics that use aquatic plants (algae or aquatic floating weeds) to recycle pollutant-containing wastewater nutrients for hydroponics, should be further developed.

Water hyacinth as a green and sustainable material for carbon aerogel electrodes utilized in membrane capacitive deionization

AbstractWater hyacinth is a substantial and quick‐growing plant that can strongly invade and negatively affect the aquatic ecosystem, causing many problems to the water environment by consuming nutrients and oxygen from surface water. However, the hierarchical porous carbon derived from water hyacinth can be employed for the removal of oil spills, heavy metals, or wastewater nutrients. Recently, water‐hyacinth‐derived carbon aerogel has been utilized as electrode for the desalination of brackish water using membrane capacitive deionization (MCDI) technology. In this research, lignocellulose aerogels were synthesized from water hyacinth, which were then pyrolyzed to obtain carbon aerogel and then treated with KOH to acquire activated carbon aerogel, with the corresponding surface area of 51 and 100 m2 g−1. The desalination capacity of the MCDI device was also evaluated using a 200 ppm NaCl feed water solution with an applied potential of 1.2 V. A high salt adsorption capacity value of 14.69 mg g−1 was achieved after 3000 s. These results will lead a new research area of biomass and bio‐waste conversion to fabricate CDI‐utilized carbon aerogel electrodes.

An eco-sustainable and effective treatment practice by Pyracantha coccinea M. J. Roemer for food wastewater carrying synthetic dye

An eco-sustainable and effective treatment practice by Pyracantha coccinea M. J. Roemer for food wastewater carrying synthetic dye

Floating treatment wetlands using Vetiveria zizanioides and Heliconia psittacorum in aquaculture wastewater treatment

The most important things needed in aquaculture are good quality and quantity of water resources. The residue from the use of pellets as additives and the results of the excretion of aquatic biota will produce liquid waste characteristics with high nutrient and organic matter content. One of the efforts to treat wastewater is using floating treatment wetlands (FTWs). This study aimed to analyze the changes in nutrients and organic matter concentrations and the removal efficiency using Vetiveria zizanioides and Heliconia psittacorum in a sewage treatment system using FTWs by grouping water quality parameters as observational variables whose linear correlations are in the line to become one main component using the PCA (Principal Component Analysis). The research was conducted on a laboratory scale using tarpaulin ponds with a batch system, the source of wastewater from catfish ponds with 12 treatment variations namely plant type, surface area, and pond depth, and observed for 30 days. Parameters monitored include total nitrogen (TN), total phosphorus (TP), nitrate (NO3 −), nitrite (NO2 −), ammonia (NH4 +), orthophosphate (PO4 3-), chemical oxygen demand (COD), and in situ measurement of parameters such as dissolved oxygen (DO), pH, temperature, and conductivity. At the end of the experiment, it was seen that treatment pond 7 (Heliconia psittacorum, surface cover area 50%, depth 100 cm) effectively removed 75.35% of TN and 90.70% nitrate, treatment pond 1 (Vetiveria zizanioides, surface cover area of 100%, depth of 100 cm) effectively removed TP 92.55%, the treatment pond 5 (Heliconia psittacorum, the surface cover area of 100%, depth of 100 cm) effectively removed ammonia by 94.64% and nitrite by 97.93%. Almost all treatments tested can reduce COD concentrations, while the phosphate in the study showed a fluctuation until the end of the experimental period. Based on the PCA results on day 30, TN, TP, conductivity, phosphate, COD, nitrate, pH, and temperature can represent the characteristics of changes in the concentration of organic compounds and nutrients in aquaculture wastewater compared to other parameters.

Knowledge Mapping of High-Rate Algal Ponds Research

High-rate algal ponds (HRAPs) are a highly promoted wastewater treatment system that uses sunlight as an energy source to provide the oxygen needed in the system through photosynthesis and has a high nutrient and organic matter removal capacity. In addition, the microalgae in the system can use wastewater as a growth substrate to produce valuable bioproducts, biomaterials, and bioenergy, so it is receiving more and more attention. This review uses bibliometric analysis to explore current research hotspots and future research trends in this emerging technology. By analyzing research papers related to HRAPs published in the Web of Science (WOS) from 1987 to 2021 based on the co-occurrence and clustering of keywords, it shows that the research hotspots of HRAPs are mainly focused on wastewater treatment, nutrient removal, microalgal biomass, biofuel, and biogas upgrading. In the future, in-depth research will continue to be added on the contribution of HRAPs to environmental sustainability, including E. coli removal, biogas upgrading and oxygen removal, treatment of aquaculture wastewater, purple phototrophic bacteria, aqueous biorefineries, and biorefineries. The results assist scholars in systematically understanding the current research status, research frontiers, and future trends of HRAPs from a macro perspective.

Decoupling solid and hydraulic retention times in microalgal biofilm reactors treating primary wastewater: performance and biodiesel potential

AbstractBACKGROUNDMicroalgal biofilm systems are a promising approach for wastewater treatment and for production of biodiesel precursors through simple biomass harvesting. However, the low concentration of nutrients in wastewater limits possible approaches for microalgal growth. The effective decoupling of the solid retention time (SRT) and the hydraulic retention time (HRT) in biofilm reactors as an alternative for increasing microalgae growth and biodiesel performance in low‐strength wastewater has not been investigated. In this study, we tracked how decoupling the SRT and the HRT influences the removal of organics and nutrients, the biomass productivity and the production of fatty acid methyl esters (FAME).RESULTSThree perturbations of the HRT, SRT and liquid level (LL) with regards to the base case condition (HRT 2.6 h; SRT 21 days, LL 5 mm) performance were analyzed. The base case showed the highest TN and TP removal (>50%) outcomes with high pH values (>10). A decrease of HRT and SRT from 2.6 to 1.3 h and 21 to 10 days, respectively, promoted an increment of microalgal productivity ≤5.8 ± 0.7 g m−2 day−1. A short HRT of 1.3 h enhanced the nitrogen removal rate up to 1.2 g N m−2 day−1, which triggered an increase in the FAME productivity and microalgal density on the biofilms without affecting their productivity.CONCLUSIONOur study demonstrated that the strategy of decoupling HRT and SRT allows operation at shorter HRTs, promoting microalgal growth without affecting FAME production in low‐strength municipal wastewater. © 2023 Society of Chemical Industry (SCI).

Nutrients in a circular economy: Role of urine separation and treatment

The increasing global population, over the last few decades, brought about the rise in synthetic fertiliser market prices along with explosive agricultural demand. Source separation of urine can be one of the most effective solutions for nutrient recovery as a fertiliser, transforming the conventional linear economy into a circular economy. The urine diversion from wastewater can improve conventional wastewater treatment plants to be energy-efficient and cost-effective, as a considerable quantity of nutrients in wastewater is derived from urine. The stabilisation and sanitisation of source separated urine have been studied earlier by applying physical, biological, chemical, and electrochemical treatment processes. Further processes such as evaporation, freeze-thawing, and membrane processes have been investigated to recover as well as concentrate nutrients as a urine-derived fertiliser. As such, this review discusses the urine diversion and collection systems as well as previous technologies for the urine treatment and nutrient recovery. In addition, the industrial research hub funded by Australian Research Council (ARC) which focuses on the Nutrients in a Circular Economy (NiCE) is introduced in this paper. The ARC NiCE hub aims to achieve four themes, including urine collection, processing, fertiliser optimisation, and fertiliser end-use, moving towards a closed circular nutrient economy.

Valorization of Human Urine with Mixed Microalgae Examined through Population Dynamics, Nutrient Removal, and Biogas Content

The majority of nutrients in municipal wastewater originate from urine. However, when flush water is used, the urine is diluted and mixed with other organic household waste, losing its high-value stream content. This study investigated the effect of source-separated human urine on the population dynamics, nutrient removal, growth, and biogas content of mixed microalgae grown in 250 L raceway ponds. Overall, a maximum biomass concentration of 1847 mg/L was reached, with up to 90% nitrogen and 80% phosphorus removal efficiencies, along with 254.96 L/kg vs. biogas production. The microbial community analysis identified Chlorella sorokiniana (Chlorophyta, Trebouxiophyceae) as the species with the highest abundance, after confirmation with four different markers (16S rRNA, 18S rRNA, 23S rRNA, and tufA). Moreover, principal component analysis was applied to capture the effect of environmental factors on culture diversity. The abundance of Chlorella sorokiniana increased almost sevenfold when the culture was exposed to open systems compared to the small-scale study carried out in 1 L Erlenmeyer bottles in laboratory conditions, both grown in urine and synthetic media (BBM). In conclusion, the present study contributes to the potential to valorize urine with microalgae by showing its high biogas content, and reveals that microalgae can adapt to adverse environmental conditions by fostering their diversity.

Nutrient consumption of green microalgae, Chlorella sp. during the bioremediation of shrimp aquaculture wastewater

Aquaculture products are among the biggest contributor to food supplies to meet the global food demands of the growing population over these past few years. For aquaculture to continue developing, an effective wastewater treatment is required to lessen the environmental effects. This study examined the potential of Chlorella sp. to reduce nutrients in shrimp aquaculture wastewater and correlate with the growth kinetics of the algae during the bioremediation process. Six different Chlorella sp. inoculation dosages ranging from 0 to 60 % (v/v) were used in this study. Marine water wastewater (MW) and Freshwater wastewater (FW) where the two types of shrimp wastewater were employed. Results indicated that the 30 % (v/v) and 40 % (v/v) were the optimum dosage for MW and FW. During the treatment, microalgae cell density increased more than tenfold compared to the initial value. Moreover, batch culture resulted in the specific growth rate concentration of 0.18 k day−1 and 0.15 k day−1, respectively. Those dosage also resulting the highest removal efficiencies with removal of ammonia, nitrite and orthophosphate of 96.77 %, 82.07 %, 75.96 % and 90.10 %, 87.09 %, 95.60 %, respectively. The application of FTIR spectroscopy was employed in this study to analyze the functional group in the microalgae biomass. The results of the scanning electron microscopy (SEM) and Energy Dispersive Spectroscopy Analysis (EDS) also included to further illustrate how microalgae biomass was affected by the treatment in this study. Therefore, the research from this study could be used in design novel microalgae treatments that offer a thorough and environmentally beneficial method of treating shrimp aquaculture wastewater.

Light and oxygen facilitating the directly treatment food wastewater and poly-β-hydroxybutyrate, 5-aminolevulinic acid, pigment productions by Rubrivivax gelatinosus.

Rubrivivax gelatinosus has the advantage of using wastewater to realize biomass recovery. However, they still cannot be applied large scale because they cannot directly treat the wastewater containing macromolecular organics. Thus, this article investigated the effects of light-oxygen conditions on R. gelatinosus by directly recycling wastewater containing macromolecular organics to produce biomass, poly-β-hydroxybutyrate (PHB), 5-aminolevulinic acid (5-ALA), and pigment. Results showed that R. gelatinosus directly treated the macromolecule organic (soybean protein and starch) wastewaters and achieved biomass recovery under light-anaerobic and light-micro-oxygen in six conditions. Chemical oxygen demand, protein, and starch removals for two wastewaters all reached above 70%. Renewable bio-resources such as biomass, PHB, 5-ALA, and pigment production were 10 times the initial content. Theoretical analysis indicated that light activated the synthesis of protease and amylase. However, oxygen concentration decided the number of enzymes. When oxygen was at micro-oxygen or anaerobic, the aforementioned expression and synthesis were conducted. In summary, this study expanded the viewpoint ignored by traditional theory. It was realized that R. gelatinosus directly treated wastewater and accumulated nutrients (biomass, PHB, pigment, and 5-ALA) for recycling, which reduced the secondary pollution of excess sludge into the environment.

Modeling domestic wastewater pathways on household system using the socio-MFA techniques

This study discussed the Malaysian household consumer perception of domestic wastewater management from food waste. Moreover, the solutions for wastewater flow rehabilitation were established based on the Material Flow Analysis (MFA) model for Malaysian household systems. The research scope includes creating an allied scientific platform and introducing a socio-material analysis approach for urban-rural-scale wastewater flow management in Malaysia. In this approach, background information was collected from Mental Model (MM) observations on food flow. This model showed Malaysia's household agents' current state of conduct, beliefs, and action, supported by the MFA primary and secondary data. The leading research detailed an MFA diagram framework and a questionnaire conducted with selected household respondents residing in urban and rural areas. The study also contained in-depth interviews with selected stakeholders, who explained their views on the importance of understanding, knowledge, and social responsibility towards Malaysia's integrated wastewater management system. The solution developed identified a close gap to understand the context of ethnopedology literature and the empirical context in food wastewater flow management. This idea is specific for households based on the object, tool, and subject perspectives.

Effect of Addition of Zero-Valent Iron (Fe) and Magnetite (Fe3O4) on Methane Yield and Microbial Consortium in Anaerobic Digestion of Food Wastewater

Direct interspecies electron transfer (DIET), which does not involve mediation by electron carriers, is realized by the addition of conductive materials to an anaerobic digester, which then activates syntrophism between acetogenic and methanogenic microorganisms. This study aimed to investigate the effect of the addition of two conductive materials, zero-valent iron (ZVI) and magnetite, on the methane production and microbial consortium via DIET in the anaerobic digestion of food wastewater. The operation of a batch reactor for food wastewater without the addition of the conductive materials yielded a biochemical methane potential (Bu), maximum methane production rate (Rm), and lag phase time (λ) of 0.380 Nm3 kg−1-VSadded, 15.73 mL day−1, and 0.541 days, respectively. Upon the addition of 1.5% ZVI, Bu and Rm increased significantly to 0.434 Nm3 kg−1-VSadded and 19.63 mL day−1, respectively, and λ was shortened to 0.065 days. Simultaneously, Methanomicrobiales increased from 26.60% to 46.90% and Methanosarcinales decreased from 14.20% to 1.50% as the ZVI input increased from 0% to 1.50%. Magnetite, at an input concentration of 1.00%, significantly increased the Bu and Rm to 0.431 Nm3 kg−1-VSadded and 18.44 mL day−1, respectively. However, although magnetite improves the efficiency of methanogenesis via DIET, the effect thereof on the methanogen community remains unclear.

Study on application of electrohydraulic effect for disinfection and increase of water nutrient content for plants

This article describes the application of electrohydraulic effect to decontaminate wastewater and increase nutrient content in water for agricultural crops. It is characterized by the formation of chemical processes in water and electrohydraulic effect carried out using ultrasound and ultraviolet radiation. The nutrient content in water has increased from 1.1 mg/l to 2.23 mg/l, i.e. it has gone up by 102.7% after the preliminary water treatment by means of the electrohydraulic effect, while neutralization of coliform bacteria in the treated water has decreased from 3474 (RLU) to 610 (RLU), i.e. it has dropped to 82.55 over control. The increase of nutrient chemicals in water and coliform bacteria neutralization (Escherichia coli) depend on the treatment time, discharge voltage, capacitor capacity, discharge interval and the number of pulses if treated with electrohydraulic effect conducted by means of ultrasound and ultraviolet radiation causing a chemical reaction of electrohydraulic shock in water. The discharge voltage for increase is 9-15 kV, disinfection time - 100-120 minutes depending on the voltage of treatment. It is advisable to have the capacitor capacity of 0.8 μF and discharge interval of 10-12 mm.

An effective biological treatment method for marine aquaculture wastewater: Combined treatment of immobilized degradation bacteria modified by chitosan-based aerogel and macroalgae (Caulerpa lentillifera)

Aquaculture has expanded significantly in recent years, and the effluent it produces has had a significant negative impact on the environment. The survival and growth rates of aquaculture products may impact by the eutrophication of the water body if the effluent from aquaculture is not handled. In this study, chitosan-based aerogel was used as a carrier to immobilize the degrading bacteria, and the adsorption capacity of the carrier material for methyl blue was 1.30 mg·g−1. The Caulerpa lentillifera was added to the shrimp tank at the same time as a biofilter, and a composite in-situ treatment system using microbes and macroalgae was built to handle the effluent from the mariculture industry to test the reduction rates of the nutrients from the wastewater. The outcomes demonstrated that the immobilized bacteria used had reduction rates of COD, NH4+ and NO2− in wastewater that were 48.82%, 9.14% and 40.74% greater than those of the free bacteria, respectively. The reduction effect of macroalgae for nutrients in wastewater is also very ideal, in which the reduction rates of TP and TN reach 32.43% and 74.94% respectively. When the immobilized degrading bacteria and macroalgae are combined, the reduction rates of COD, TN and TP in water reach 68.61%, 59.03% and 34.25%. At the same time, the survival rate of shrimp and the biomass of macroalgae have increased to a positive extent, with increases of 12.5% and 140%, respectively. These results demonstrate that the introduction of immobilized degrading bacteria and macroalgae into the shrimp culture system can effectively reduce the accumulation of nutrients in the shrimp culture system and have a positive impact in a variety of ways.

Efficient removal of ammonium in aqueous solution by ultrasonic magnesium-modified biochar

Ammonium is one of the most important nutrients in agricultural wastewater, and its excessive existence will pose a threat to ecosystem and even human life. The cavitation effect generated by ultrasonic waves with huge energy can break the carbon bonds of biochar and thus increase the abundance of functional groups. In order to adsorb ammonium effectively in water, we used ultrasound to improve biochar or magnesium-loaded biochar performance in removing wastewater pollutant. Batch experiments with material characterization and adsorption models were conducted to assess adsorption characteristics. The nano-biochar (NBC) was obtained after the ultrasonic modification, with porosity, cation exchange capacity (CEC), zero point of charge (pHpzc), and functional groups (–OH, C–O, C–O–H, C–H) effectively being improved, indicating OH– and H+ were separated from water and bound to biochar to form functional groups during ultrasonic cavitation. The nano-Mg-biochar (NMBC) also increased the functional group of metal oxides. The ammonium adsorption of NBC and NMBC was dominated by intraparticle diffusion. The observed ammonium adsorption capacity of NBC and NMBC was best described by the Langmuir isotherm, implying the adsorption derived from the energetically homogeneous surface. Moreover, the maximum adsorption capacities for NH4+ on NBC, and NMBC were 13.589, and 23.777 mg·g−1, respectively. Ultrasound improved the maximum ammonium adsorption capacity of raw biochar and Mg-biochar through electron attraction and ion exchange, respectively. Notably, ultrasonic modification causes a more uniform distribution of chemical crystals in the biochar and broken carbon bond to combine with more functional groups, which would be a significant way to reorganize functional groups directionally and optimize the adsorption performance of materials.

Pretreatment of Biogas Slurry by Modified Biochars to Promote High-Value Treatment of Wastewater by Microalgae

High concentrations of contaminants such as ammonia nitrogen and organic matter in full-strength wastewater severely inhibit the growth of microalgae, contributing to lower biomass accumulation and contaminant removal efficiency. To overcome this limitation, modified biochars prepared from pine sawdust and sugarcane bagasse were used in this study as an adsorbent–desorbent for the pretreatment of wastewater to promote the growth of microalgae. The results showed that the two modification methods (acid/alkaline modification and magnesium salt modification) used in the experiment could increase the abundance of oxygen-containing functional groups. Moreover, magnesium salt modification could effectively improve the pore structure of biochar surfaces and increase the specific surface areas. Compared with the pristine biochars, the adsorption performance of the modified biochar was found to be significantly higher for nutrients in wastewater. The adsorption capacity of the acid/alkaline-modified pine sawdust biochar reached 8.5 and 16.49 mg∙g−1 for ammonia nitrogen and total organic carbon in wastewater, respectively. The magnesium salt modified pine sawdust biochar achieved a more comprehensive nutrients adsorption capacity of 15.68, 14.39, and 3.68 mg∙L−1 for ammonia nitrogen, total organic carbon, and total phosphorus, respectively. The mechanism of ammonia nitrogen adsorption was mainly the complexation of surface -OH functional groups, while the adsorption mechanism for phosphate was mainly the complexation of -OH and Mg-O functional groups and the chemical precipitation of MgO or Mg(OH)2 attached to the surface.

Species- and diet-specific aquaculture wastewater nutrient profile: Implications for aquaponics and development of sustainable aquaponics diet

Aquaponic (AQP) systems use aquaculture wastewater to supply the nutrients for plant growth. Recent fish meal (FM) production and price trends call for adopting of financially and environmentally sustainable protein sources for fish feed. However, different protein sources can alter the macro-and micro-nutrient effluxes from fish tanks and their nutritional value for plant growth. Early attempts to formulate the AQP diets have focused on enhancing nutrient efflux via dietary additives such as potassium diformate or potassium chloride. Here we present an alternative approach. We tested the effect of four aquafeeds differing in protein sources (complete substitution of FM with black soldier fly meal, BSFM; poultry blood meal, PBM; and hydrolyzed feather meal, HFM) on nutrient efflux in the water from Colossoma macropomum and Clarias gariepinus. The water from PBM and HFM-fed fish showed the highest efflux of TN (0.106 and 0.097 mg.L−1.g of feed, respectively), while the efflux of soluble reactive phosphorus and calcium was highest in FM-fed fish (0.012 and 0.028 mg.L−1.g of feed, respectively). BSFM-fed fish had the highest efflux of magnesium and potassium (0.008 and 0.023 mg.L−1.g of feed, respectively). Regarding macronutrients, the species-specific effects were observed only in sulphur, with higher efflux from C. macropomum. Iron efflux was not affected by diet, while higher efflux was observed in the trial with Clarias gariepinus. Effluxes of other micronutrients showed diet- and species-specific effects, except for zinc and manganese, with similar effluxes between species. In general, we found that it is possible to manipulate the nutrient efflux from RAS using alternative sustainable aquafeed components.

Optimization and mechanism of coupling process between algal ponds and constructed wetlands for wastewater polishing and nutrient recovery

Due to the lack of influent carbon source and the limited adsorption of the substrate, constructed wetlands (CW) could not achieve satisfactory removal of nitrogen and phosphorus. In this study, the coupling process between algal ponds (AP) and constructed wetlands (AP-CW) was proposed to enhance wastewater purification performance. The results showed that when 10.6 mg/(L‧d) microalgae were added into the CW, the best TN removal reached 90.3% and 1 g microalgae averagely promoted 0.291 g N removal in CW. In addition, a coupled model of AP-CW was established to find the optimal range of critical parameters. Based on effluent purification and nutrient recovery, the optimal parameters were determined as: 5 d HRT of AP and 0.4% microalgae reuse rate. With optimal parameters in AP-CW, the TN and TP removal were 94.18% and 85.80% respectively. For the engineering application, the microalgae suspended-attached mixed culture in AP was presented and the microalgae production was increased by 32.1%. Moreover, microalgae were suggested to be consecutively added to the CW daily to reduce the fluctuation of effluent pollutants. Based on the above optimization conditions, the nitrogen and phosphorus removal of optimized AP-CW increased by 110.4% and 416.4% respectively compared with a single CW, and 55.6% TN and 83.9% TP were recovered as bioresource. This study provides theoretical guidance and technical support for efficient sewage purification and nutrient recovery.

Wastewater Treatment of Solid Waste Leachate and Production of Proteinaceous Biomass Using Duckweed Vegetation ( Lemna minor )

Tekoğul, H., 2023. Wastewater treatment of solid waste leachate and production of proteinaceous biomass using duckweed vegetation (Lemna minor). Journal of Coastal Research, 39(2), 296–302. Charlotte (North Carolina), ISSN 0749-0208. Phytoremediation provides cost–effective wastewater treatment and recovery of wastewater as rich biomass by aquatic plants and produces bioenergy and various important by-products. This study was carried out to treat solid waste leachate with Lemna minor L. and convert wastewater nutrients into protein-rich biomass by this aquatic plant. To create the experimental setups, L. minor was produced in wastewater at six dilution ratios: 100% (T1), 75% (T2), 50% (T3), 25% (T4), Hoagland medium with Lemna (T5c), and 100% wastewater without Lemna (T6). At the end of the 45-day study,the pH 7.00 (T5c) and 8.81, the protein yield rate (crude protein) in the trial groups was found to be T1 = 40.10%, T2 = 67.53%, T3 = 75.24%, T4 = 42.72%, and T5c = 85.00%. In the study, the T3 group showed the best performance in terms of initial weight, final weight, total biomass, specific growth rate, relative growth rate, and protein ratio in wastewater groups. The highest and lowest removal rates in leachate ranged between 85.40% (T4) and 56.50% (T1) for the NH4 +-N value, 14.20% (T4) and 4.73% (T2) for NO2-N, 16.96% (T4) and 6.53% (T3) for NO3-N, and 23.10% (T3) and 16.08% (T1) for PO4–3-P. The total biomass of the trial groups showed an average 50.55% increase from the baseline level. Although 46% biomass was obtained in the Hoagland medium with vegetative growth, a very high biomass of 61% was obtained in the T3 group of solid waste leachate containing dilute wastewater. As a result, phytoremediation is recommended as a solid option for the management of wastewater resources. This efficiency has shown that aquatic plants can be used in the treatment of wastewater and the obtained high protein biomass can be used in various ways, such as animal feed and bioenergy.

Performance of Sediment Microbial Fuel Cells in Generating Electricity using Fish Wastewater and Shrimp Wastewater as a Nutrient and Their Effect on Waste Quality

Sediment Microbial Fuel Cell (MFC) is a technology that can convert chemical energy into electrical energy through the process of nutrient degradation by microbes. Sediment taken from the bottom of shrimp ponds was added as a source of microbes, while fish and shrimp wastewater were used as a source of nutrients for microbes. This study aims to measure the performance of the SMFC system on fish effluent and shrimp effluent to produce bio-electricity while reducing the waste load. The research method was experimental laboratories. The treatment given was the different types of electrodes, namely zinc-copper and aluminum-copper. In addition, 0.2 M KMnO4 electrolyte solution was used. This study consisted of four stages: the manufacture of nutrients from fish and shrimp wastewater, the manufacture of a dual chamber MFC bioreactor, the measurement of electrical values, and the analysis of waste quality. Experiments were carried out for 30 days by measuring electricity every 24 hours. The average value of electricity generated in the nutrients of fish wastewater with Zn/Cu electrodes was 0.705 V and Al/Cu was 0.472 V. Meanwhile, the average value of electricity in shrimp wastewater nutrients with Zn/Cu electrodes was 0.630 V and Al/Cu was 0.625 V. The number of colonies after adding sediment in the shrimp wastewater sample were 8.9 x 106 CFU/mL, the fish wastewater sample was 9.5 x 106 CFU/mL. It indicates the presence of microorganisms that play a role in the SMFC system