Biofilter based Treatment of Domestic Wastewater: A Systematic Review of Aerobic and Anaerobic Processes for the Reduction of Biological Oxygen Demand (BOD)

Introduction: Domestic wastewater significantly contributes to environmental degradation due to its elevated Biological Oxygen Demand (BOD), indicating the concentration of organic contaminants that deplete oxygen in aquatic ecosystems. Biofilter-based treatment technologies, both aerobic and anaerobic, have emerged as sustainable alternatives; nonetheless, their comparative efficacy remains inadequately investigated. Discussion: This systematic study, adhering to PRISMA principles, evaluates the efficacy of aerobic and anaerobic biofilters in diminishing BOD levels in home wastewater. A thorough literature search utilizing Publish or Perish software across five databases Scopus, DOAJ, ScienceDirect, PubMed, and Google Scholar was conducted to find pertinent articles published from 2019 to 2025. Of the 1210 articles initially discovered, ten satisfied the inclusion criteria according to the PICOS framework. Research indicates that both aerobic and anaerobic systems markedly decrease BOD values. Aerobic biofilters provide quick organic matter decomposition and superior removal efficiency, while anaerobic systems are beneficial for energy conservation and diminished sludge production. Numerous studies underscore the improved effectiveness of hybrid or sequential biofilter systems, demonstrating a synergistic impact when both approaches are utilized together. Conclusion: Both aerobic and anaerobic biofilters effectively reduce BOD levels in home wastewater. Hybrid systems offer a notably advantageous solution by amalgamating the qualities of both methods. Future study must concentrate on refining operational parameters and assessing the long-term scalability of integrated biofilter technology to enhance sustainable wastewater management.

Domestic wastewater in the culinary area is waste water produced from several restaurants. The problem of liquid waste needs to get serious attention, because it has complex characteristics and the remaining results of these activities can cause the volume of wastewater with a high contaminant load that flows continuously over a long period of time. One way to manage the environment is through physical processing, namely by pre-treatment of sedimentation and biological treatment by biofilter anaerobic processes. Anaerobic biofilter is a biological treatment, which uses media as a place to grow and develop microorganisms, with no oxygen in the reactor. The parameters in liquid waste processing consist of three, namely physical parameters, chemical parameters and biological parameters. In the method of combating liquid waste here uses chemical parameters, namely BOD and TSS. Where BOD ( Biochemical Oxygen Demand ) is the number of milligrams of oxygen needed by aerobic microbes to decompose karon organic matter in 1 L of water for 5 days at a temperature of 20EsC ± 1EsC. Whereas for TSS ( Total Suspended Solid ) as the residue from total solids held by a filter with a particle size of maximum 2I¼m or greater than the size of colloidal particles, which include TSS are mud, clay, metal oxides, sulfides, algae, bacteria, and fungi . The aim of this research is that the liquid waste from the activity can be reused as clean water by anaerobic biofilter method using BOD and TSS parameters. The variables used are operational time. Reactor I and reactor II contain media arranged from the bottom up, namely rock fragments, gravel, shells and gauze. The operational time variations used are 0 hours as t0 or the first time the waste exits the reactor, and the time is 2 hours, 4 hours, 6 hours, and 8 hours is a periodic observation of operational time. The results showed that anaerobic biofilter has the ability to reduce the concentration of BOD ( Biological Oxygen Demand ) and TSS ( Total Suspended Solid ). Based on the Regulation of the Minister of Environment and Forestry of the Republic of Indonesia Number P.68 / Menlhk / Setjen / Kum.1 / 8/2016 concerning Domestic Waste Water Quality Standards, the characteristics of wastewater are obtained before treatment (pre treatment) which is 28- 31 ° C; pH 9,3-10; BOD 30 mg / L; and TSS 29 mg / L. Decreasing the initial state in reactor I for BOD is 25 mg / L. Whereas for the decrease in TSS is 16 mg / L. The results showed that anaerobic biofilter with pumice, gravel and clam shell media had the ability to reduce BOD and TSS concentrations significantly. The percentage decrease in concentration in reactor I was greater than that of reactor II, with an operational time of 6 hours for BOD allowance of 73,54%. While the operational time of 8 hours for TSS is 81,39%.

Hill fires have the potential to influence dissolved organic matter (DOM) in water bodies, yet fewer studies have investigated the effects of hill fires on DOM within watersheds in karst areas. In this study, we employed the three-dimensional fluorescence-parallel factor analysis (EEM-PARAFAC) method to analyze the DOM fluorescence peaks, component compositions, fluorescence indices, and sources within the water body of the Yuanteng River sub-basin, which was impacted by the hill fire, serving as our primary research focus. The results indicate the presence of three primary fluorescent fractions in the water body of the Yuanteng River: C1, resembling humic acid (fulvic acid); C2, consisting of biopolymers and microbial by-products; and C3, containing proteins such as tyrosine and tryptophan. The Yuanteng River exhibited elevated levels of humus-like substances, diminished concentrations of protein-like substances, and demonstrated higher biogenic, freshness, and humification indices compared to unaffected water samples, reflecting the impact of the hill fire. Elevated levels of exogenous humic acid-like inputs into the waters of the Yuanteng River, along with exogenous inputs of DOM, were primarily influenced by stable, high-molecular-weight organic matter. Additionally, agricultural effluent, domestic sewage, and anthropogenic activities contributed to these inputs to a lesser degree. The impacts of endogenous inputs are mainly related to the restoration of ecosystems. The occurrence of hill fires has significantly influenced the composition of dissolved organic matter in the waters of the Yuanteng River. A comprehensive analysis of the impacts of hill fires on dissolved organic matter in water bodies can serve as a valuable reference for characterizing DOM in the water bodies of the Yuanteng River. Furthermore, it can inform strategies for environmental protection, facilitate the traceability of pollutants in water bodies, and contribute to environmental and ecological restoration efforts following hill fires in the region.

Biochemical oxygen demand (BOD) is the measurement of the amount of dissolved oxygen used by aerobic microbes for oxidizing organic matter in water bodies and used for analyzing the water quality. The actual BOD prediction method is cumbersome. Instead an automatic prediction model is required that is accurate, faster and less expensive. This paper presents a data-driven model for predicting BOD, in a lower-dimensional space obtained using dimensionality reduction techniques that help remove irrelevant properties of high-dimensional data. Machine learning algorithms, namely decision stump, SVM, MLP, linear regression (LR), and instance-based learner (IBK), were trained with the full dataset with 11 parameters. The training set was later transformed into a lower-dimensional space using principal component analysis (PCA) and correlation-based feature selection (CFS). The performance of the learners on the full training set and transformed dataset was analyzed using correlation coefficient, RMSE, and MAE. The algorithms are able to preserve their predictive accuracy on the lower-dimensional space.

Chapter 4 - Aggregate Organic Constituents

Production of methane as bio-fuel from palm oil mill effluent using anaerobic consortium bacteria

Organic pollution of water bodies caused by human activities poses a significant environmental challenge. A promising and sustainable solution to this issue lies in harnessing microorganisms for the bioremediation of contaminated aquatic ecosystems. The present work explores potential of biofilm forming microorganisms as a sustainable solution for pollution control, thereby offering a cost-effective and ecofriendly method to mitigate the harmful effects of organic pollutants in water bodies. In this study, wastewater samples along with sludge, was collected from kitchen sink outlet, to foster biofilm development over a 10-day period. After treatment with pond water and measurement of Biological Oxygen Demand (BOD) reduction, the most efficient biofilm was selected based on BOD values. The selected biofilm exhibited 90 % reduction in BOD. Subsequent experiments revealed substantial BOD reducing capability of one specific bacterial strain (50 % reduction in BOD) which was isolated from the most efficient biofilm. Through biochemical and molecular characterization, the organism was identified as Enterobacter cloacae, specifically designated as E. cloacae honeykp. Qualitative and quantitative assays confirmed biofilm-forming capability of the new isolate. The application of E. cloacae HoneyKP in biofilm-based reactors, biofilters, activated sludge systems, membrane bioreactors etc. holds significant potential in terms if bioremediation of polluted water bodies. By utilizing its biofilm-forming capabilities, this isolate could potentially enhance the degradation of organic pollutants and other toxic compounds, while supporting microbial community resilience. These approaches offer innovative strategies for bioremediation, enabling the efficient treatment of wastewater, restoration of polluted water bodies, and reduction of the environmental impact of anthropogenic contaminants.

Leachate, especially from the landfill, is a pollutant that can harm human health and pollute the environment including aquatic biota, because the leachate contains various chemicals both organic and inorganic substances and also pathogen bacteria. Laboratory test by Department of Health – Yogyakarta (2001) showed that leachate from landfill had Biological Oxygen Demand (BOD) of 1032 mg/liter in which this was much higher than the limit allowed (BOD = 150 mg/liter. In order to reduce BOD in leachate, a treatment is needed. In this experiment a treatment to reduce BOD in leachate was carried out by applying coagulation andanaerobic bio-filtration with the time of 1, 2, and 3 hours. Evaluation of the tests was conducted using pre-test and post-test with control design which analysis was made descriptive and analytically using T-test with the error of about 5% (á =0,05). Results of the experiment indicated that there was a tendency of BOD reduction of about 0.9% - 1.1% for the control samples, whereas the BOD reduction for leachate attained 82.3% -90.5%. Based on the T-Test, the probability result was 0.000 (p< á =0.05). This means that there is a significant difference in BOD reduction between control samples and leachate. In other words leachate treatment using coagulation – anaerobic bio-filtration can be taken as an alternative process to reduce BOD.

Abstract
 The research is aimed at gaining a description of waste rubber factory management, Perkebunan Nusantara VIII Company Kebun Cikumpay in Purwakarta Province of West Java to Reduction of Rate BOD (Biological Oxygen Demand). The research used a theoretical descriptive method. Data have been collected by observation, interview and documents. The results showed that the reduction of rate BOD caused by the factory carried out the wastewater management by applying clean production concept for example: (1) minimizing waste with lessening wastewater volume, using of the ditch through a closed pipe, rubber trap, chemicals raw materials namely New Nicola (liquid smoke) and Food Grade with lower of hazard, more efficient and more cheap. (2) reusing of waste for sale as by products and (3) wastewater treatment with using of IPAL the consisted of 2 anaerobic and 3 facultative ponds.
 Keywords: wastewater management of rubber and reduction of rate BOD

Applicability of hybrid treatment to reduce the footprint of domestic and industrial wastewater of developing countries

An integrated physical and biological model for anaerobic lagoons

BOD analysis of industrial effluents: 5 days to 5 min

A demonstration that “second‐order”; chlororganics might, in part, be responsible for the BOD reduction that is observed upon chlorination of wastewater has been hampered by the inability to devise an experiment that is not complicated by other contributing factors. The current study compares the BOD enhancement for parent organic systems (phenols, benzoic acids, and anilines) against the BOD values obtained from those chlororganics known to be produced from the parent during disinfection. The investigation supports the hypothesis that these chlorinated organic materials are not readily degraded during the test period and, therefore, will not provide an appropriate contribution to the overall BOD value that is obtained.

<div class="htmlview paragraph">This paper describes the results of a project involving an anaerobic digestion system used in treating the human and vegetative wastes from a Controlled Ecological Life Support System (CELSS). The anaerobic digester biologically breaks down the organic matter in the wastes into a mixture of methane gas and carbon dioxide, while significantly reducing the BOD(biological oxygen demand ) of the wastewater. A standard waste was formulated consisting of a mixture of swine waste (the surrogate for human feces and urine), green wastes (primarilly lettuce), and paper wastes. The equipment used for this project was a 2.7 cubic meter digester tank filled with plastic media and heated to an average temperature of 35°C. The digester was run over period of 200 days and loaded on the average of five days per week. The results over this test period showed a 94% reduction in BOD and a 98% reduction in suspended solids in the wastewater. Biogas production was approximately 1 cubic meter of biogas per kg of BOD added to the digester per day. This biogas contained an average of 62% methane. Tests were carried out at Lockheed in Sunnyvale to determine the effectiveness of the digester effluent as a growth medium for vegetables in a hydroponic growing system.</div>

The polyfilm manufacturing process involves mono-ethylene glycol (MEG) and ethyl acetate (EA) as the main constituents. The presence of such organic compounds is responsible for the higher toxicity and Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) values of the polyfilm effluent. In our previous studies, isolation and identification of efficient MEG and EA degraders was done. All the physico-chemical parameters were found to be well above the permissible limits prescribed by the Indian Standards Institute (ISI) standards, and toxicity of the effluent was confirmed by using fish assay and pot assay. About 10–20% increase in BOD and COD reduction was obtained with developed microbial consortium as compared to the individual five microbial isolates tested at flask level studies. About 8–18% increase in BOD and COD reduction was observed with developed microbial consortium as compared to the 5% (v/v) sewage and 5% (v/v) cow dung slurry in 12 days. Pilot plant studies were carried out at the 5-l level of polyfilm effluent, and about 99% reduction in BOD and COD was obtained using developed microbial consortium. Physico-chemical levels were reduced significantly in compliance with the prescribed ISI standards showing the effectivity of the microbial remediation of polyfilm effluent. Toxicity reduction of effluent was confirmed again by fish and pot assay, thus confirming that the treated effluent can be used for irrigation purposes. Finally, results indicated that the developed microbial consortium can be employed in ready-to-use form for the treatment of polyfilm industrial effluent by end users.