Effect of cod loading rate on an upflow anaerobic sludge blanket reactor during anaerobic digestion of palm oil mill effluent with butyrate /

Palm oil Mill Effluent (POME) with concentrated butyrate was treated in a 4.5 l upflow anaerobic sludge blanket reactor (UASBR), run over a range of influent concentrations (16.5–46.0 g-COD l−1), chemical oxygen demand (COD) loading rates (1.5–11.5 g-CODl−1d−1) and 11–4 days hydraulic retention time (HRT) at 37 °C by maintaining pH between 6.5–7.5. The process consistently removed 97–99% of COD at loading rates up to 1.5–4.8 g-COD l−1d−1 by varying HRT (11–7.2 days). Butyrate is an important intermediate in the anaerobic degradation of organic matter. In sulphate-depleted environment, butyrate in POME (BOD/COD ratio of 0.5) is β-oxidised to acetate and hydrogen, by obligate proton reducers in syntrophic association with hydrogen utilizing methanogens. The conversion of acetate to methane appeared to be rate limiting step. Maximum biogas (20.17 ll−1d−1) and methane production (16.2 ll−1d−1) were obtained at COD loading rate of 4.80 gl−1d−1and HRT of 7.2 days. The biogas and methane production were higher in the presence of butyrate compared to control. The methane content of the biogas was in the range of 70–80% throughout the study while in control it was 60–65%. Finding of this study clearly indicates the successful treatment of POME with butyrate in UASBR. Santrauka Palmių aliejaus gamybinės nuotekos (POME) su koncentruotu butiratu buvo apdorotos 4,5 l talpos aukštyn tekančio aerobinio dumblo plokšteliniame reaktoriuje (UASBR). Nuotekos tekėjo įvairių koncentracijų (16,5–46,0 g – ChDS 1−1), cheminio deguonies suvartojimo (ChDS) normos (1,5–11,5 g – ChDS 1−1d.−1). Hidraulinio sulaikymo trukmė (HRT) nuo 11 iki 4 dienų, kai temperatūra 37 °C, pH palaikant 6,5–7,5. Vykstant procesui nuolat buvo pašalinama 97–99% ChD, kai tiekimo ir pakrovimo sparta 1,5–4,8 g – ChDS 1−1d.−1 kintant HRT(11–7,2 d.). Butiratas yra svarbus tarpininkas organinių medžiagų anaerobinio skilimo procese. Sulfatas iš aplinkos, butiratas iš POME (BDS/ChDS santykis 0,5) yra acetato ir vandenilio β oksidatoriai, priverčiantys protonų reducentus sintrofinės sąveikos su vandeniliu metu utilizuoti metanogenus. Acetato virtimas metanu pasirodė esąs greitį ribojantis veiksnys. Daugiausia biodujų (20,17 l 1−1 d.−1) ir metano (16,2 l 1−1 d.−1) susidarė tada, kai suvartojamo ChD tiekimo greitis buvo 4,80 g 1−1d.−1, o HRT – 7,2 dienos. Daugiau biodujų ir metano susidarė dalyvaujant butiratui, palyginti su kontroliniu pavyzdžiu. Biodujose metano kiekis tyrimo metu svyravo 70–80%, o kontroliniame buvo 60–65%. Šis tyrimas aiškiai parodė, kad POME su butiratu UASBreaktoriuje apdorojamas sėkmingai. Reikšminiai žodžiai: anaerobinis skilimas, palmių aliejaus gamybinės nuotekos, butiratas, acetatas,  UASB reaktoriu

The effects of chemical modification on adsorbent performance on water and wastewater treatment - A review

Current strategies for removing inorganic pollutants from wastewater are expensive, energy-intensive, and necessitate the disposal of producing toxic waste. Hence, there is a need for an effective, selective, and cost-effective adsorbent material. Adsorption has become one of the oldest and most recognized approaches for treating water and wastewater. As an indirect observation, adsorption performance is highly influenced by the surface phenomenon (physical and chemical) of the unmodified and modified precursor. The surface chemistry with the modification method and the material's composition substantially affects the surface's functions. The chemical approach of surface activation is a process that modifies the surface properties and structure of the material to increase the adsorption efficiency. The adsorbent modification could provide a versatile, low-cost, and sustainable solution to pollution of freshwater's inorganic point source. This paper focuses on presenting a comprehensive assessment of the selection and influences of chemical modification on various well-known adsorptive feedstocks

Dyes removal from textile wastewater by agricultural waste as an absorbent – A review

Water pollution from the textile industry affects environmental conditions by generating large-scale effluent mixed with various dyes. Dyes are mostly organics with multiple compound structural and molecular weight variations; if not managed properly before release, they may harm the environment and organism. However, many dyes are categorized into distinct groups, and various adsorbents for dye adsorption have been identified. Among these dyes, methyl dyes, which come in multiple colours, are the most popular in research due to their availability and accessibility. It is imperative to use effective treatments using special adsorbents to remediate water contamination before discharging into streams. As awareness of environmental issues increases with time, the need for a wide range of adaptive alternative feedstock that satisfies ecological regulations has become a priority for researchers worldwide. Therefore, there is a need to develop other adsorbents from alternatively economic raw materials such as locally available industrial and mineral waste and by-products. Additionally, numerous materials have been used, prepared, or grafted from various agricultural peel-based adsorbents. Biomass is a significant source of renewable adsorption processes for hazardous compounds, including toxic organics and metals/elements. It is much cheaper, has abundance, effective adsorption capability, and reusability, have numerous advantages over conventional materials. This review focuses on using plant agricultural wastes to remove dyes. Different adsorption capacities, operating conditions, and application forms have been investigated. The adsorption kinetics and isotherms are demonstrated to illustrate the adsorbent's properties and adsorption mechanisms

The synthetization of activated carbon from electrocoagulated palm oil mill effluent sludge for wastewater treatment

Activated carbon (AC) as an adsorbent has been used widely to remove pollutants in wastewater. Many attempts have been made to produce economically accessible AC. This paper explores the idea of producing an AC, a value-added product from the by-product, sludge produced from the electrocoagulation process of palm oil mill effluents (POME) through chemical activation. AC has different applications after its discovery as a solid and reliable adsorbent. Its microporous structure, high surface reactivity, and surface area make it versatile and viable for removing pollutants from aqueous solutions. Electrocoagulation (EC) is a process whereby contaminants are removed by generating an electric current flow through the aqueous solution by using two electrodes made of iron and immersed into the solution. Aside from the wastewater treatment, the resulting by-product of the EC process known as sludge is recovered and converted into AC. POME sludge was utilized as a precursor of AC. The sludge is then carbonized and activated with an activating agent. The activating agents are phosphoric acid (H3PO4) and potassium hydroxide (KOH) solutions. The electrocoagulated sludge-based AC is characterized by its surface characteristics, elemental compositions, surface morphology, and available functional group. To validate the adsorption capacity of electrocoagulated sludge-based AC, textile dye wastewater treatment was carried out to test the efficiency of AC. The AC was used as an adsorbent to test the total suspended solids (TSS) and color removal of textile dye wastewater. The performance of this low-cost AC is comparable to that of many conventional adsorbents. Results indicate that TSS in textile dye wastewater decreased as the adsorbent dosage increased. The values of TSS removal by AC from H3PO4 activation decreased steadily compared to AC from KOH activation. Meanwhile, the color removal percentage decreased when the dye concentration increased. AC from H3PO4 activation has higher color removal percentage compared to AC from KOH activation. This shows that AC from H3PO4 activation has better adsorption due to its more extensive surface area. From BET analysis, AC by H3PO4 activation offers a higher surface area, 36.1017 m3/g, compared to AC by KOH activation, which is 8.9460 m3/g. A more extensive surface area has a higher tendency to adsorb contaminations. The findings of this work confirmed the potential use of electrocoagulated sludge-based AC as an alternative and economically adsorbent for effective dye pollution removal in wastewater

Comprehensive assessment of biochar integration in agricultural soil conditioning: Advantages, drawbacks, and future prospects

Agriculture nowadays faces numerous issues because of the fast growth in food demand and environmental considerations. Due to the rapid depletion of agricultural areas and soil quality caused by a continuously growing population and the excessive addition of chemical fertilizers, rehabilitated consideration is required for sustaining viable crop production methods. Biochar (BC) use in agricultural soils has garnered considerable interest. BCs offer significant agricultural and environmental advantages, including improved soil health, enhanced crop growth and production, carbon sequestration, reduced greenhouse gas (GHG) emissions, and nutrient dynamics regulation. BC application in agricultural systems is influenced by various parameters, including pyrolysis temperature, feedstock composition, dosage and procedure, nature of the soil, crop varieties, and biotic interactions that substantially impact the efficacy of BC under varying environmental conditions. BC improved nitrogen mineralization and plant absorption by modifying the rhizosphere's abiotic and microbiological activities. Thus, BC increased the plant's resistance to pathogens, decreased the availability of heavy metals (HMs), and promoted the plant's tolerance to environmental challenges. Nonetheless, BC application is hazardous in certain circumstances. This review discusses the advantages, drawbacks, and future developments of applying BC to agricultural soils. By providing an extensive assessment of the advantages and limitations of BC integration in agriculture soil conditioning, this review is highly informative regarding the development of soil and crop-specific BC with the appropriate properties. It could help increase agriculture yield, ensure food security, and enhance environmental management. In addition, this review highlights knowledge deficits and proposes future perspectives for commercializing large-scale BC applications

The synthesization of activated carbon from electrocoagulated palm oil mill effluent sludge for wastewater treatment

The oil palm industry in Malaysia is certainly the one of economic and agricultural drives for the country. Nevertheless, despite the obvious benefits that it possesses, oil palm mill also significantly contributes to environmental degradation. It generates massive amounts of solid waste, wastewater, and air pollution from its production and processing processes. Activated carbon (AC) as an adsorbent has been used widely to remove pollutants in wastewater. Many attempts have been made to produce economically accessible AC. This paper explores the idea of producing an AC, a value-added product, sludge produced from the electrocoagulation process of palm oil mill effluents (POME) through chemical activation. AC has different applications after its discovery as a solid and reliable adsorbent. Its microporous structure, high surface reactivity, and surface area make it versatile and viable for removing pollutants from aqueous solutions. The electrocoagulated sludge-based AC is characterized by its surface characteristics, elemental compositions, surface morphology, and available functional group. To validate the adsorption capacity of electrocoagulated sludge-based AC, textile dye wastewater treatment was carried out to test the efficiency of AC. Results indicate that TSS in textile dye wastewater decreased as the adsorbent dosage increased. The values of TSS removal by AC from H3PO4 activation decreased steadily compared to KOH activation. Meanwhile, the color removal percentage decreased when the dye concentration increased. AC from H3PO4 activation has higher color removal percentage. This shows that AC from H3PO4 activation has better adsorption due to its more extensive surface area. From BET analysis, AC by H3PO4 activation offers a higher surface area, 36.1017 m2/g, compared than KOH activation, 8.9460 m2/g. Extensive surface area has a higher tendency to adsorb contaminations. The findings of this work confirmed the potential use of electrocoagulated sludge-based AC as an alternative and economically adsorbent for effective dye pollution removal in wastewater

Advanced techniques in the production of biochar from lignocellulosic biomass and environmental applications

Biochar is a carbon-rich product obtained from the thermochemical conversion of biomass. Utilizing biochar is essential for enhancing economic viability and maintaining the ecology effectively. This work reviews the techniques for producing biochar from various lignocellulosic biomass sources. Pyrolysis technology for converting lignocellulosic biomass into biochar has emerged as a frontier research domain for pollutants removal. The effects of biomass feedstock parameters, production techniques, reaction conditions (temperature, heating rate, etc.), activation, and functional group modification are compared on biochar's physical and chemical properties. This review also focused on environmental applications in several domains, such as agriculture and wastewater treatment. Considering the extensive availability of feedstock, excellent physical/chemical surface properties, and inexpensive cost, biochar has a remarkable potential for removing water pollutants efficiently. Studying the evolution properties of biochar by in-situ or post-modification is of great significance for improving the utilization value of lignocellulosic biomass. Biochar is a valuable resource, yet its application necessitates additional research into its properties and structure, as well as the development of techniques to modify those factors

The anti-biofouling effect of piper betle extract against pseudomonas aeruginosa and bacterial consortium

Navigating novel biological routes to mitigate biofouling is of great worth inorder to allow sustainable performance of Membrane Bioreactors (MBRs) in wastewater treatment technology. Recently, it was confirmed that a number of natural compounds in plants have an anti-biofouling effect, reducing the formation of biofilm. This study addressed the feasibility of Piper betle extract (PBE) as anti-biofouling agent against the model organism Pseudomonas aeruginosa PAO1 and bacterial consortium. The anti-biofouling effects of PBE were evaluated via a microtiter plate assay; changes in the growth rate (μ) and EPS production. Scanning Electron Microscopy (SEM) was employed to qualitatively illustrate the biofilm formation. PBE revealed ≥ 80% reduction in biofilm formation, growth rate (87%) and reduced the EPS production. These results suggest that PBE could be a potential agent for the mitigation of membrane biofouling. However, the chemical stability, potential toxicity and consistent performance of PBE in the field will have to be further investigated for optimization of its use on a field scale

Characterization of flavonoids from fern Cheilanthes tenuifolia and evaluation of antioxidant, antimicrobial and anticancer activities

The present study is designed to identify various bioactive flavonoid compounds from the methanolic fern extract (MFE) of Cheilanthes tenuifolia. Flavonoids derived from C. tenuifolia (fern) possess potent anti-cancerous, anti-bacterial, anti-oxidant activities that are responsible for their chemo-preventive potential against selected bacterial panel. A preparative column chromatography with a column Sephadex LH-20 was used to isolate and purify flavonoids from C. tenuifolia. Their structure and chemical bonds were identified by using Nuclear Magnetic Resonance (NMR) spectroscopy and Fourier Transform-Infra Red Spectroscopy (FTIR). Two flavonoids were identified as rutin (2.8. mg) and quercetin (3.34. mg) from 100. g of C. tenuifolia. The minimum inhibitory concentration (MIC) values of (2.25 and 0.45. μg/ml) were obtained in purified flavonoids against Staphylococcus aureus and Enterobacter sp., respectively. The two flavonoids (Rutin and quercetin) showed significant in vitro anti-oxidant activity; in this regard, the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) scavenging potential of quercetin (86.1%) was higher than that of rutin (73.2%). However, for human hepatoma HepG2 and human carcinoma HeLa cells, quercetin exhibited high anti-cancer activity than rutin. The purified compounds (rutin and quercetin) with having great potential of free radical inactivator in HepG2 cells. The results suggest that MFE of C. tenuifolia could potentially be employed in traditional medicine as they are rich in compounds with anti-oxidant, anti-microbial and anti-cancer properties