Tofu Wastewater Research Articles

Influence of Electrode Surface Area and Processing Time on Chemical Oxygen Demand (COD) and Total Suspended Solid (TSS) Reduction in Tofu Wastewater Using Electrocoagulation

Electrocoagulation is a wastewater treatment process that uses electrochemical working principles to remove contaminants in solutions or wastewater. Where at the anode (negative current) metal ions are released into solution, while at the cathode (positive current) an electrochemical reaction occurs, namely the release of H2 (hydrogen) gas. Factors that influence the electrocoagulation process include electrode type, current strength, electrode cross-sectional area, process time, voltage, stirring, distance between electrodes, and acidity level (pH). The objective of this research is to investigate the effect of the surface area of the electrode and processing time on the COD and TSS of tofu wastewater. In this research, tofu industry liquid waste was processed using the electrocoagulation method using fixed variables including, Fe-Fe type electrodes, 4 electrodes, acidity level at 4, tofu liquid waste temperature at 25 ̊ C, distance between electrodes 2 cm, electrode thickness 2 mm, test sample of 4 liters and current strength of 13 V. The changing variables used are electrode cross-sectional area (70 cm² and 60 cm²) and processing time (30, 45, 60, 75, 90 minutes). In this study, the best conditions for reducing COD and TSS levels were obtained with a cross-sectional area of ​​70 cm² and a process time of 60 minutes for reducing COD levels and 30 minutes for reducing TSS levels. With a reduction in COD levels of 690.66 mg/L and a reduction in TSS levels of 181.25 mg/L. The results of reducing COD levels do not meet the tofu industry wastewater quality standard of 300 mg/L, and the results of reducing TSS levels meet the tofu industry wastewater quality standard of 200 mg/L.

The kinetics of a two-stage completely stirred tank reactor for treating tofu wastewater by anaerobic digestion

ABSTRACT Tofu wastewater is an inevitable by-product of the bean curd production process. In this study, we used a two-stage continuous stirred tank reactor (CSTR) to treat tofu wastewater. The kinetic analysis of two CSTR reactors was conducted utilizing the material accounting model, microbial accounting model, and first-order kinetic model. The results demonstrated that the methane production coefficient of reactor 1 was 0.00573 LCH4·mg−1 greater than that of reactor 2, which is 0.00533 L CH4·mg−1. The first-order kinetic constants of reactor 1 were poorer than those of reactor 2, and their values are 0.15700 d−1 and 0.11574 d−1, respectively. The microbial yield coefficients of reactors 1 and 2 were 0.009648 and 0.060704, respectively. Under different organic loading rates, the average microbial concentrations were 25.24000 and 2.706667 mg·L−1 for reactors 1 and 2, respectively. The operational performance of the two-stage CSTR anaerobic digestion system was evaluated in order to design a novel and unique method as well as provide a new perspective for enhancing the performance of anaerobic digestion.

Acclimatisation process of biogas production from tofu industrial wastewater using biofilter in anaerobic baffled reactor (ABR)

A biofilter is a simple technology used in an anaerobic baffled reactor (ABR) to keep biological solids (inoculum) from being easily carried by the inlet substrate and to shorten the hydraulic retention time (HRT). The principle of a biofilter is to form a biofilm on the packed bed of the biofilter in ABR so that it contains immobilised microorganisms. This study aims to know the performance of the biofilter reactor on biogas production during the acclimatisation process. The results show biofilters shorten the HRT and effectively remove pollutants, increasing biogas production and methane quality. The total solid content decreases by around 44 %, from 0.38 % to 0.17 %. The biogas production during acclimatisation was 1806.41 L and COD removal was 95 %. The biogas composition of CH4 was 58.05 %, CO2 38.23 %, and N2 3.2 %. This study provides preliminary findings for further studies on the use of tofu wastewater as a biogas feedstock with different concentrate substrates, which is very useful for sustainability activities and improving the industry to become green.

Utilization of Tofu Wastewater for Environmental Conservation and Economic Improvement in Taman Village, Grujungan District, Bondowoso Regency

The processing of tofu wastewater into organic liquid fertilizer in Taman Village, Grujungan District, Bondowoso Regency, was conducted to utilize wastewater that often causes environmental issues. This study aims to evaluate the potential of tofu wastewater in producing organic liquid fertilizer using a Community-Based Research (CBR) approach. A descriptive qualitative research method was employed, including observation, interviews, documentation study, and literature review. Observations revealed that tofu wastewater is yellowish-brown, has an acidic odor, and contains organic materials such as proteins, carbohydrates, and fats. The production process of organic liquid fertilizer involves collecting wastewater, fermenting with EM4 and molasses, filtering, and packaging. The fermentation results in a liquid fertilizer that can improve soil fertility and reduce environmental pollution. The program also has the potential to increase community awareness of waste management and provide economic benefits through enhanced agricultural productivity. Thus, this study shows that tofu wastewater has significant potential as a raw material for effective organic liquid fertilizer, offering notable environmental and social benefits.

Mitigating environmental pollution from tofu industry wastewater: Case of Suyanto Tofu Factory, Mojokerto

Background: This research investigates the impact of tofu industry wastewater on water environments at Suyanto Tofu Factory, Mojokerto. The tofu industry generates liquid waste containing high pH, Total Suspended Solids (TSS), Biochemical Oxygen Demand (BOD), and Chemical Oxygen Demand (COD), potentially polluting local rivers. Despite Suyanto Tofu Factory having wastewater treatment facilities, these are currently non-functional, underscoring the urgent need for designing new wastewater treatment installations. Methods: In this context, the study aims to determine the volume of wastewater produced, analyze the levels of BOD, COD, TSS, and pH in the wastewater, and design sustainable wastewater treatment facilities using a Constructed Wetland system. Findings: This method is expected to minimize the environmental impact of tofu wastewater, protect surrounding aquatic ecosystems, and comply with environmental regulations. By proposing sustainable solutions, the research aims to enhance awareness and management of wastewater in the tofu industry, offering technology solutions appropriate to local conditions. Conclusion: In conclusion, implementing effective and sustainable wastewater treatment installations is crucial to safeguard water quality and river ecosystems around Suyanto Tofu Factory. Novelty/Originality of this Study: By proposing a Constructed Wetland system for tofu industry wastewater treatment, this research introduces an innovative, sustainable solution tailored to local conditions, potentially revolutionizing waste management practices in small-scale food industries.

Evaluation and Kinetics of Tofu Wastewater Bioreactor with Addition of Water Hyacinth

Evaluation and Kinetics of Tofu Wastewater Bioreactor with Addition of Water Hyacinth

Studi Pengaruh Pemberian Bakteri Probiotik Komersial Terhadap Perubahan Kadar BOD dan COD Pada Air Limbah Tahu Dengan Perbedaan Interval Waktu Inkubasi 8 Jam

Environmental pollution has become a serious problem in the world, including in Indonesia. Tofu waste is waste from processing soybeans and consists of solid and liquid waste. Solid waste in the form of dirt left over from cleaning is usually called tofu dregs, while liquid waste is water resulting from washing tofu. Industry knows that disposing of waste directly into water bodies can pollute those waters, because it can lower the pH of the air and affect aquatic biota. Therefore, the industry knows that it must carry out processing first to prevent environmental problems. In this study, researchers used commercial probiotic bacteria to reduce BOD and COD levels in tofu wastewater. The research was carried out by testing in the laboratory and using statistical data with graphic methods which can provide a comparison of the water content of tofu waste before and after it was given. The action given in the research was a ratio of 1:1, 1:2 and 1:3 water to tofu waste with commercial probiotic bacteria. Apart from that, researchers also added incubation times within each 8 hour interval, namely at 0 hours, 8 hours, 16 hours, 24 hours and 32 hours. The results of the research show that administering commercial probiotics can reduce BOD and COD levels in tofu wastewater. The most significant reduction occurred in a ratio of 1:3 in COD and BOD to 242.69 mg/lt and 148.00 mg/lt with an incubation time of 32 hours. This proves the commercial effect of probiotic bacteria to reduce BOD and COD levels so that it can help reduce environmental pollution, especially in the air.

Pengolahan Limbah Industri Tahu dengan Tanaman Kenaf (Hibiscus cannabinus L.) untuk Menurunkan Kadar Nitrat (Utilization of Kenaf Plant (Hibiscus cannabinus L.) to Reduce Nitrate Levels in Tofu Industrial Wastewater)

Tofu industry waste is rich in nutrients so it can pollute the environment if there is no processing or remediation of soil contaminated by tofu waste. One technology that can be used is phytoremediation, which uses plants to reduce organic and inorganic pollutants in soil, sediment or water. Kenaf plants (Hibiscus cannabinus L.) have the ability to reduce pollutants so they can be used in the phytoremediation process. This research uses bed evapotranspiration with a batch system to measure the reduction in nitrate levels. The variables used in this research were kenaf plant varieties (KR 12 and KR 15), age (30 days and 45 days) and tofu wastewater concentrations of 50% and 75%. The results of pH observations on day 3 ranged from 7.1 - 7.7. Nitrate analysis observations were carried out every 7 days for 28 days. It is known from research results that kenaf 15 plants aged 45 days have the highest removal efficiency.

Performance of salt‐bridge microbial fuel cell (SB‐MFC) with various microorganism cultures on the generation of electricity from tofu wastewater

A suitable wastewater treatment system is required due to the high organic compound content in tofu wastewater, which can harm the environment. Biological treatment methods are effective for treating tofu wastewater due to its characteristics. Microbial fuel cells (MFCs) represent one such biological treatment option, effectively removing organic contaminants while generating low‐power electricity through bioenergetic reactions. In MFCs, microorganisms are used as biocatalysts to degrade the organic compounds present in wastewater. This study aimed to assess the efficacy of Salt‐bridge microbial fuel cells (SB‐MFC) using various acclimatized microbe cultures for reducing organic compounds and generating energy from tofu wastewater. Tofu wastewater was sterilized prior to introduction into the reactor. Additional microbes, including the native microbe consortium from tofu wastewater, Escherichia coli, Saccharomycopsis fibuligera, and a mixed culture of E. coli and S. fibuligera, were then introduced as biocatalysts. Carbon electrodes were utilized as both the anode and cathode. The results indicate that the mixed culture of E. coli and S. fibuligera significantly reduced COD and BOD5 levels, with removal rates of 82.74% and 76.53%, respectively, after 48 h. Furthermore, the culture generated a voltage of 676 mV, a current of 2.53 mA, a power density of 428 mWatt/m2, and 4.789×10‐2 kWh of energy. This study contributes to the advancement of SB‐MFC by utilizing wastewater and a combination of bacteria and yeast as biocatalysts.

Website-Based Monitoring System for Methane (CH4) Concentration, Humidity, and Temperature

Abstract The research developed a monitoring system that focuses on the development of a system and the acquisition of its readings into a simple website. This research was conducted in an effort to obtain data that can be used for managing methane gas pollution in the environment. Methane gas (CH 4) is a natural gas consisting of one carbon atom and four hydrogen atoms. Methane gas is one of the greenhouse gases that contribute to global warming, while humidity and temperature can increase or decrease methane gas productivity. Therefore, in this research, a monitoring system was created for methane gas concentration using TGS2611 sensor, humidity and temperature using DHT11 sensor through the creation of a chamber connected to test materials such as cow dung digesters and tofu wastewater as a source of methane gas production. The results obtained indicate that, in the development of the monitoring system as a measuring tool, it successfully detects the concentration of methane gas, humidity and temperature for each test material using calibration through characteristic equation V = 0,5591 ln(n) − 2,2657. For data acquisition in the form of methane gas concentration parameter readings by the TGS2611 sensor, humidity and temperature by the DHT11 sensor to the ESP8266 microcontroller to be displayed on the serial monitor, LCD, and the website that has been created in real-time. To display the data acquisition of the monitoring system, each component of the system is connected. Starting from software, hardware, and test materials. Data acquisition begins with sensor readings by ESP8266 through a program from Arduino IDE displayed on the serial monitor and LCD. Once connected to wifi or a hotspot and the data is successfully sent, the data will be checked by notepad++ and entered into the phpMyAdmin website database for storage. From this database. The data will then be displayed on the website that has been created in real-time. Additionally, humidity and temperature affect the increase and decrease in methane gas concentration productivity.

Utilization of tofu wastewater and Nannochloropsis oceanica for eutrophication mitigation and eicosapentaenoic acid valorization: Advancing carbon neutrality and resource recycling

Seeking environmentally-friendly and resource-recycling strategies for tofu wastewater (TFW) treatment could effectively mitigate harsh ecological impacts and resource wastage caused by direct discharge. This study investigated the feasibility on the utilization of Nannochloropsis oceanica (N. oceanica) for TFW eutrophication mitigation and eicosapentaenoic acid valorization. The findings demonstrated that employing N. oceanica resulted in significant removal rates for total phosphorus, total nitrogen, ammonia nitrogen, and chemical oxygen demand by 88.60 %, 97.02 %, 94.22 %, and 98.02 % under fed-batch treatment mode. Such nutrients removal efficiency met discharge permit standards while accomplished a superior biomass at 26.37 g/L and EPA yield at 43.5 mg/g by N. oceanica, representing 2.61- and 2.52-fold more than that of batch treatment mode. Furthermore, TFW feeding enhanced the cytomembrane fluidity of N. oceanica and promoted TFW nutrients uptake into cells consequently boosted the nutrients removal efficiency. Simultaneously, TFW feeding upregulated enzymes such as antioxidases, desaturases and elongases responsible for EPA biosynthesis in N. oceanica to collectively protect EPA from oxidation stress and stimulate proactive accumulation. EPA derived from TFW-fed N. oceanica exhibited promising in vitro antihyperlipidaemia efficacy in constructed hyperlipopyte HepG-2 cells. Further, the molecular docking indicated that the hypolipidemic activity partly contributed to that EPA inhibited PPARα signaling to trigger fatty acids β-oxidation and cholesterol transport suppression. The outcomes present a viable route that utilization of microalgae for TFW eutrophication mitigation and EPA valorization to advance carbon neutrality and resource recycling.

Analysis of Anaerobic Digestion Installation Testing for Tofu Liquid Waste Utilization into Biogas with the Addition of Cow Manure Variations

The purpose of this study is to convert tofu wastewater into biogas using an anaerobic digester with varying cow dung mixtures (10%, 15%, and 20%). The study method entails creating digesters including independent, dependent, and controlled variables. Variations in pH, temperature, biogas pressure, and biogas volume were detected throughout the course of a 15-day fermentation. The data show that in the 10% fluctuation, the greatest pH was on day 7 (7), whereas the highest temperature was 32°C on days 6 and 7. Biogas pressure emerged on day 6 (89.2 cmHg), resulting in a volume of 90 liters by day 15. In the 15% variation, the highest pH (7.2) occurred on day 8, with the highest temperature (34°C) on days 9 and 10. Biogas pressure began on day 5 (89.9 cmHg), with a biogas volume of 95 liters on day 15. The 20% variance resulted in the highest pH (7.4) on day 8 and the highest temperature of 35°C from days 9-11. Biogas pressure began on day 5 (90.7 cmHg), resulting in a biogas volume of 100 liters on day 15. This study sheds light on how to manage tofu waste into biogas with varying degrees of effectiveness and efficiency.

Pengolahan Limbah Cair Industri Tahu Menggunakan Teknologi Ultrafiltrasi Dengan Sistem Monitoring Berbasis Internet of Things

Waste from the tofu industry is a byproduct of the tofu production process that can have negative environmental impacts if not managed properly. CV. Dapur Tahu still discharges liquid waste directly into the river, posing a potential threat of river water pollution. Although a new reservoir and waste disposal channel are under construction, there is currently no effective waste treatment facility in place. To address this issue, a tofu wastewater treatment facility utilizing filtration technology is proposed due to its simplicity of operation, durability, and high efficiency in removing organic contaminants. The technology comprises a multi-stage filtration process involving sand filters (pumice, zeolite, and activated charcoal) combined with ultrafiltration membrane technology, complemented by a monitoring system consisting of TDS, pH, and temperature sensors. The multi-stage filtration process is capable of reducing TDS levels to 160 ppm, resulting in visibly clearer wastewater compared to the initial turbid white condition. The installation of IoT-based monitoring devices in the wastewater treatment process significantly aids in real-time water quality monitoring, accessible via mobile phone screens.

Removal of organic matter from tofu wastewater using a combination of adsorption, Fenton oxidation, and ultrafiltration membranes

The production of tofu results in wastewater from the soaking, washing, and pressing processes. Owing to its unique composition and quality, tofu wastewater treatment involves a complex set of challenges. Wastewater from tofu production has a significantly high organic content because it contains many soybean residues and other products. This study aimed to determine the removal efficiency of tofu wastewater contaminants for a combination of adsorption, Fenton oxidation, and ultrafiltration membrane processes. The best strategy for turbidity removal, with a removal value of 99.78%, was an integrated system combining adsorption and ultrafiltration membranes. The most optimal method for reducing organic matter contained in tofu wastewater is Fenton oxidation with TSS, COD and turbidity removal values of 81.11%, 95.13% and 62.42%. Moreover, microphotography analysis using scanning electron microscopy showed an irregularly shaped surface layer with the particles spaced far apart when granular active carbon adsorption was integrated with an ultrafiltration membrane. The results were inversely proportional when Fenton oxidation was integrated with ultrafiltration membranes. After granular active carbon adsorption, the spacing between the granules or crystals increased, whereas the granular dimensions decreased.

Utilization of Moringa Seed Powder (Moringa Oleifera) as a Natural Coagulant for Reducing Pollution Parameters in Tofu Wastewater

The wastewater generated from the tofu industry often contains elevated levels of COD and TSS pollutants. One effective method for treating this wastewater is through the coagulation-flocculation process. Moringa seeds, recognized as a biomass with natural coagulant properties, contain a bioactive compound known as 4αL-rhamnosyloxy-benzyl-isothiocyanate, capable of adsorbing particles present in wastewater. The objective of this study is to assess the efficiency of reducing pollutant parameters (COD, TSS, and Turbidity) in wastewater from the tofu industry by utilizing Moringa seeds as a natural coagulant. The research was conducted using a jar test apparatus with coagulation stirring at 100 rpm and flocculation at 40 rpm for 12 minutes. The study involved varying coagulant doses (2, 3, 4, 5, and 6 g/L of tofu wastewater) and coagulation stirring times (1, 3, and 5 minutes). Based on the results obtained, the optimal stirring duration and dose, as well as the efficiency of reducing each pollutant parameter, were determined. For COD, the optimal conditions were found to be 3 minutes stirring time with a dose of 4 g/L, resulting in an efficiency of 64.88%. Similarly, for TSS parameters, the optimum conditions were achieved with 3 minutes of stirring time and a dose of 4 g/L, yielding an efficiency of 52.71%. Lastly, for turbidity, the most effective conditions were observed with 3 minutes of stirring time and a dose of 4 g/L, with an efficiency of 58.85%.

COD’s Level Reduction of Tofu Industrial Wastewater by Using Activated Coal Fly Ash as Adsorbent

Tofu wastewater contained a high concentration of COD and will be dangerous if directly discharged into the environment without any pre-processing. In this research, tofu wastewater is processed using an adsorption process to determine the amount of COD reduction in tofu wastewater using coal fly ash. To maximize the adsorption process by enlarging the fly ash’s pores and removing the impurities, fly ash is activated first by using 2 M of H2SO4 100 mL. Fly ash was tested with XRD (X-Ray Diffraction) to know its crystal structure and tested with XRF (X-Ray Fluorescence) to determine the difference in the elemental composition of fly ash before and after the activation process. The research on the effect of time on the adsorption process was carried out with time variations of 15, 30, 45, 60, 75, 90, 105, and 120 minutes. The results showed that the intensity of silica in the fly ash after the activation process was more significant than before the activation process. The optimum time for fly ash to adsorb tofu wastewater was 105 minutes with eficiency of 79,71%.

Tofu Wastewater Treatment Using Biocoagulant Moringa Seed Powder (Moringa Oleifera L)

Indonesia has various types of vegetation which are used as natural coagulants or biocoagulants. Coagulants can be divided into chemical coagulants and natural coagulants (biocoagulants). Biocoagulants are more environmentally friendly and can be obtained from natural ingredients, both animals and plants, one of which is Moringa seeds. Moringa seeds or with the Latin name Moringa oleifera are a type of plant from the Moringaceae family. From several previous studies, Moringa seeds were used as a more economical and environmentally friendly wastewater treatment method. Moringa seed biocoagulant in powder form is made from ripe and old moringa seeds and contains less than 10% water. Moringa seed biocoagulant contains 4αL-rhamnosyloxy-benzylisothiocyanate and is a determinant of coagulation effectiveness. This active substance is able to absorb pollutants in waste water. This research aims to treat tofu waste with moringa seed biocoagulant in reducing pollutant parameters, namely TSS (Total Suspended Solid) and COD (Chemical Oxygen Demand). Results of the removal of pollutants from moringa seed powder biocoagulant in tofu waste water the efficiency value obtained for each TSS parameter, and the COD for the TSS parameter is 54.4%. and for the COD parameter of 14.6%, it can be concluded that the efficiency value for each parameter still does not meet the effectiveness value.

Process of Bacterial Cellulose Production from Tofu Wastewater Without Pretreatment Using Acetobacter xylinum

Bacterial cellulose (BC) is an alternative cellulose source that warrants more investigation due to its limited efficiency and high production costs. This research aims to investigate the generation of bacterial cellulose from tofu wastewater using Acetobacter xylinum without pretreatment. The experiment was run on two media: tofu wastewater with and without additional sugar. The fermentation was run in a dark cabinet using a static batch method in numerous fermenter trays, each with a working volume of 1000 mL. Each experiment used 900 mL of tofu wastewater medium plus an extra 100 mL inoculum (equal to 10% v/v), which was then cultured at room temperature and harvested on days 6, 12, 18, 24, and 30. The weight of nata de soya, BC, and residual sugar were all measured from the samples. The results of the experiments revealed that the best incubation time was 18 days. The fermentation employing tofu wastewater medium with added sugar yielded nata de soya of 227.3 g/L and BC of 32.2 g/L, while the medium without added sugar yielded 103.9 g/L and BC of 9.3 g/L. The medium with added sugar yielded higher BC productivity, 1.79 g/L.day, compared to 0.57 g/L.day in the medium without added sugar. On the other hand, the BC results per sugar consumption were 0.62 g BC/g sugar and 0.36 g BC/g sugar, respectively, for the medium with and without added sugar.

Advanced Treatment of Tofu Wastewater using Multilevel Filtration and TiO2 Photocatalysis as Promising Approach for Effective Wastewater Remediation

Tofu production is known to generate large amounts of wastewater containing a variety of organic compounds, chemicals, and potentially hazardous substances. It is very important to apply proper treatment of harmful substances that impact this wastewater. The aim of this study is to explore advanced techniques for treating tofu wastewater by combining multilevel filtration and TiO2 photocatalysis methods. To evaluate the efficiency of the treatment process, influent and effluent parameters, including pH, total suspended solids (TSS), and chemical oxygen demand (COD), are carefully monitored and measured. The results clearly demonstrate the impressive removal efficiency achieved through the combined use of multilevel filtration and TiO2 photocatalysis in treating tofu wastewater. The treated wastewater showed a promising efficiency in pH (100%), a significant decrease in TSS (40%), and COD (72%). the final measurements of pH met the standards set by government regulations, indicating successful remediation of these specific parameters. Even though TSS and COD haven't met the standard limits, each of them shows a very promising efficiency improvement. Towards the end of this study, it is suggested that the combination of these methods holds promise for effectively remediating tofu wastewater.

Utilization of magnetic GAC adsorbent for the removal of COD and BOD parameters in tofu wastewater

The tofu industry in Indonesia has mainly not processed its waste before it is discharged into the environment. This study seeks to ascertain the effectiveness of granular activated carbon magnetic adsorbents in removing pollutant characteristics from tofu wastewater. The effectiveness of the allowance resulting from the processing procedure will be assessed using variations in the mass of magnetic granular activated carbon and adsorption time. Granular Activated Carbon (GAC) and magnetic GAC production are activated using a modified green coprecipitation approach. Tofu wastewater samples used in this study contained COD of 5080 mg/L and BOD of 828 mg/L. The magnetic GAC variations with an adsorbent mass of 7.5 g/L and an absorption duration of 60 minutes, a COD value of 2930 mg/L, and an allowance ability of 42.32%, have the best ability to remove COD, according to the research done for the COD test. The allowed for the BOD parameters that produced the best results was 345 mg/L, and the 45-minute absorption time treatment with a GAC concentration of 10 g/L resulted in a removal efficiency of 58.38%.