Cassava Waste Research Articles

Economic and environmental analysis of waste-based bioenergy integration into industrial cassava starch processes in Africa

This study assessed the economic and environmental performances of cassava waste bioenergy (CWB) [bioelectricity, thermal energy for starch drying (TESD)] generation in cassava starch facilities (CSF) using cassava stems (CS) and cassava starch wastewater (CWW) in the contexts of seven leading cassava growing countries in Africa (Angola, Cameroon, DR Congo, Ghana, Malawi, Nigeria, Tanzania). The CWB scheme consists of Aspen Plus® simulated process for converting the CS and biogas obtained from anaerobic digestion of CWW from a 200 t starch/d CSF using a steam boiler/steam turbo-generator technology that resulted in energy self-sufficient CSF plus surplus power of 26.36 MW. The economic assessment included profitability analysis for alternate scenarios of bioelectricity prices [grid price (0.018–0.163 US$/kWh) vs bioenergy price higher than the grid's by 20%] and CS prices [diesel (5.5–29.4 US$/GJ) vs wood fuel (7.7 US$/GJ) equivalents]. The environmental assessment involved SimaPro® based gate-to-gate life cycle analysis for the CWB vs fossil energy scenarios (FES) [fuel-oil based heat & diesel-oil based electricity]. Grid prices were low for viability of the CWBs for all countries. Only Cameroon and Malawi displayed profitability under the low-cost CS plus bioenergy price scenario. Compared to the FES, except for freshwater eutrophication & ecotoxicity and water consumption, the CWB could mitigate various environmental impacts by ≈42–99%. Grid tariffs designed to recover fixed and variable costs, and feed-in-tariffs that reflect the environmental savings vs the fossils, are essential for viability of the CWBs. Considering the erratic supplies of grid power and fossil fuels in SSA due to unsustainable government policies (e.g. subsidies on grid power or fossil fuels), the CWBs could be promising alternative for energy security for stable CSF operations. At the global level, the CWBs could enhance the net environmental profiles of CSFs via the incorporated circular economy strategy of recovering waste resources (CS energy, liquid digestate and boiler ash) for reuse in the cassava cultivation and processing industries vs the current waste management scheme (i.e. anaerobic digestion of CWW for biogas for TESD generation while the liquid digestate is disposed into watercourses and CS is burnt on farms). Thus, implementation of the CWBs and austere sustainable energy policies could be promising for sustainability enhancement in cassava industries.

Microbial conversion and biovalorization of fermented cassava waste biomass into livestock-based diets

Microbial conversion and biovalorization of fermented cassava waste biomass into livestock-based diets

Chemical Composition of Palm Oil Mill Sludge-Biodegraded Sweet Orange Peel Meal Mixture and Its Effect as Dietary Energy Source on Nutrient Digestibility by Broiler Chickens

A feeding trial, which lasted for seventy days, was conducted in which palm oil mill sludge and biodegraded sweet orange peel mixture was fed to substitute maize in broiler chicken diet at 0%, 5%, 10%, 15%, 20% and 25%. Sweet orange (Citrus sinensis) fruit peel was fermented by soaking for 48 h in retted cassava waste water (CWW) and sundried, to obtain biodegraded sweet orange peel (BSOP). Palm oil mill effluent was filtered with a 0.30 mm pore plastic mesh sieve, poured into a 0.75 μm pore fine cheesecloth bag and allowed to stand for five hours to produce a paste of palm oil mill sludge (POMS). The POMS was mixed with BSOP in ratio 1:1, sundried, milled to produce a POMS-BSOP mixture. One hundred and eighty day-old Cobb 700 broilers divided into six equal parts, and three replicates of 10 birds each were used. Each part was assigned to one of 6 diets compounded with 0% (T1), 5% (T2), 10% (T3), 15% (T4), 20% (T5) and 25% (T6) of POMS-BSOP mixture. The microbial composition of retted CWW, chemical composition of the POMS-BSOP mixture, and the digestibility of nutrients by the broiler chickens were determined. Isolated from CWW were; Staphylococcus aureus, Streptococcus spp., Salmonella spp., Escherichia coli (bacteria), Aspergillus spp. (fungus) and Candidia spp. (yeast). POMS-BSOP was high in energy (4415.69 kcalME/kg), ether extract (41.50%), crude fibre (25.63%) and dry matter (92.28%), moderate in crude protein (6.83%), low in indigestible lignin (4.90% ADL), alkaloid (0.01%), tannin (0.02%), saponin (0.03%), phytate (0.05%), oxalate (0.15%) and flavonoid (0.17%). Dietary treatments significantly (P<0.05) affected digestibility of ether extract and metabolisable energy and crude protein digestibility by broiler chickens. Dietary maize can be replaced at up to 25% with a POMS-BSOP mixture to improve energy digestibility by broiler chickens.

Production of α-amylase from Aspergillus flavus S2-OY using solid substrate fermentation of potato (Solanum tuberosum L.) peel

Amylases find commercial applications in diverse industries. This study investigated the production of α-amylase from a fungus, using potato peel as an alternative substrate. Six fungal isolates from the soil of cassava waste dumpsite were tentatively identified as two Aspergillus species and one species each of Rhizopus, Trichocladium, Neosartorya and Ascodermis. They were screened for their relative amylolytic activities using the starch agar hydrolysis test. Molecular characterization, using the ITS rRNA gene sequencing, was used to confirm the identity of the selected fungus as Aspergillus flavus S2-OY. Amylase production from the fungus via solid substrate fermentation of potato peel was carried out and the effect of production parameters investigated. Maximum α-amylase production was at an incubation period of 72 h, pH of 5.0 and temperature of 25 °C. Casein and maltose were the best nitrogen and carbon sources, respectively while the optima inoculum and moisture volumes for enzyme production were 1.5 mL and 5.0 mL, respectively. Aspergillus flavus S2-OY has great potential for α-amylase production using potato peel as an alternative and cheap substrate, under solid substrate fermentation condition. This has implications for the cost-effective production of an industrial enzyme and reduction of environmental pollution problems through effectual management of agro-industrial wastes.

Utilisation of cassava waste among processors in Akoko Southwest, Ondo State, Nigeria

Abstract There is a considerable gap in knowledge about cassava waste management among small-scale processors in Nigeria. This study investigated the utilisation of cassava wastes among processors in Akoko southwest, Ondo State, Nigeria. Two hundred processors were sampled in four communities, using a multistage sampling procedure. Data were analysed using frequency counts, and percentages and Pearson Product Moment Correlation (at α 0.05). The majority of the processors were males (53.5 %), married (49.0 %), Christians (49.0 %), and with secondary education (22.0 %). Most respondents had knowledge that cassava waste could be sold to generate income (81.0 %), used to produce chemicals (78.5 %) and utilised as a source of energy (78.5 %). The major constraints to cassava waste utilisation included high cost of cassava waste processing (82.0 %) and the lack of processing equipment (82.0 %). The correlation analysis shows a significant correlation between the ages of respondents and cassava waste utilisation (r = −0.538 p < 0.05), years of education, and cassava waste utilisation (r = −0.073, p < 0.05). However, marital status (r = −0.087, p < 0.05) and income (r = −0.048, p < 0.05) had hypothesised a positive relationship with cassava waste utilisation, but not significant. The study concluded that the majority of the respondents had a positive attitude towards cassava waste utilisation, but were constrained by inadequate finance, lack of processing equipment, high cost of hired labour, and high cost of processing. The biogas properties of cassava waste have transformational potential in addressing energy poverty in developing economies like Nigeria.

Interaction of Lead and Calcium with Biochar Produced from Cassava Waste: Perspectives for Agricultural and Environmental Application

The biochar from slow pyrolysis under controlled conditions is favorable in the transformation of waste into materials that serve as soil conditioners, and/or environmental remediation. Thus, this work aimed to produce and characterize biochar from cassava waste under different temperature conditions and evaluate interactions with Ca2+ and Pb2+ for agricultural and environmental applications. To investigate the efficiency of the interaction of biochar with nutrients (Ca) and contaminants (Pb), the influence of pH and contact time were evaluated. There was an increase in pH, pHzpc (zero point charge), and condensed aromatic structures in BC, due to the increase in pyrolysis temperature. Also, biochar demonstrated a Pb2+ adsorbed amount of 2.03 to 2.37 mg g–1 and a Ca2+ release capacity of 0.655 to 0.765 mg g–1. In this way, biochar produced from residues of cassava waste can be a viable strategy to enhance agricultural production and reduce environmental contaminants.

Cassava pulp added to fermented total mixed rations increased tropical sheep's nutrient utilization, rumen ecology, and microbial protein synthesis.

The price of animal production will be affected by the significant increase in feed costs. The objective of this research was to investigate the impact of adding waste cassava pulp to fermented total mixed ration (FTMR) on nutrient utilization, rumen ecology, and microbial protein synthesis in tropical sheep. A 3 × 3 replicated Latin square design was used to randomly arrange nine crossbreed lambs (Santa Inês × Dorper) with an initial body weight (BW) of 18.7 ± 1.6 kg (mean ± SD). During a 21-day trial, the animal was offered a random selection of concentrate diets and rice straw (control), total mixed ration (TMR), or FTMR. During the investigation, data on nutrition utilization, rumen ecology, and microbial protein synthesis were analyzed using analysis of variance. The finding shows that FTMR had significantly higher dry matter (DM) intake and DM intake per BW than either TMR or control (p < 0.05). Lamb fed on FTMR had significantly higher DM, organic matter protein, crude protein, and neutral detergent fiber digestion than those on control or TMR (p < 0.05). Rumen pH values for all treatments ranged from 6.68 to 6.73, with no significant differences. Growing lambs fed FTMR had greater rumen total volatile fatty acid and propionic acid concentrations than those given TMR and the control (p < 0.05). Protozoa were not different across the FTMR groups, although total bacterial and fungal zoospores were increased. In addition, when lambs were fed FTMR containing cassava pulp, ruminal microbial protein synthesis was significantly increased. It could indicate that feeding growing lambs with FTMR could improve nutrient utilization, ruminal fermentation, and microbial protein synthesis. However, studies on the effects of FTMR on sheep performance, meat quality, and milk quality are necessary.

Analysis of the optimum pH and salinity conditions for the cultivation and biomass production of Chlorella vulgaris from cassava waste

Biofuel serves as an alternative energy to the common fossil fuels currently in use globally and are drawing increasing attention worldwide as substitutes for petroleum-derived transportation fuels to help address challenges associated with petroleum derived fuels. Third generation biofuels, also termed advanced biofuels, are produced from fast growing microalgae and are potential replacements for conventional fuels. The growth and biomass production of these microalgae is dependent on the conditions they are cultivated such as pH and Salinity. Cassava waste mixtures were cultivated on Chlorella vulgaris stock culture at different concentration ratio at ambient temperature, natural light and dark conditions at 670nm absorbance for 14 days. Optimum growth was obtained at 160:40 for cassava peel water to cassava waste water CP:CW. pH variations 6.0, 6.5, 7.0, 7.5, 8.0, 8.5 and 9.0 were checked to determine the optimum pH for the growth and biomass production of Chlorella vulgaris on the optimum cassava waste mixture concentration. It revealed that at pH 6.5, optimal growth and biomass production was achieved, minimal growth was observed at pH 8.0 while minimal biomass was produced at pH 9.0. Salinity variations of 5, 10, 15, 20, 25, 30, 35 and 40 mg/l were used to determine the growth response and biomass production of Chlorella vulgaris. It revealed that salinity variation at 10ppm will be necessary for highest growth on the cassava waste as well as in biomass production. The use of optimal pH and salinity can significantly increase biomass production thus enhancing biofuel production.

Pectinase Production from Banana Peel Biomass via the Optimization of the Solid-state Fermentation Conditions of Aspergillus niger Strain

In this study, the biomass of banana peel was used to produce pectinase via optimization of solid-state fermentation conditions of the filamentous fungi Aspergillus nigeA. niger). The operating conditions of solid-state fermentation were optimized using the method of full factorial design with incubation temperature ranging between 25 °C and 35 °C, moisture content between 40% and 60%, and inoculum size between 1.6 x 106 spores/mL and 1.4 x 107 spores/mL. Optimizing the solid-state fermentation conditions appeared crucial to minimize the sample used in this experimental design and determine the significant correlation between the operating conditions. A relatively high maximal pectinase production of 27 UmL-1 was attained at 35° C of incubation, 60% of moisture content, and 1.6 x 106 spores/mL of inoculum size with a relatively low amount of substrate (5 g). Given that the production of pectinase with other substrates (e.g., pineapple waste, lemon peel, cassava waste, and wheat bran) generally ranges between 3 U/mL and 16 U/mL (Abdullah et al., 2018; Handa et al., 2016; Melnichuk et al., 2020; Thangaratham and Manimegalai, 2014; Salim et al., 2017), thus the yield of pectinase derived from the banana peel in this study (27 U/mL) was considered moderately high. The findings of this study indicated that the biomass of banana peel would be a potential substrate for pectinase production via the solid-state fermentation of A. niger.

Physical characterization of biopolymers with starch from potato and cassava organic wastes polymerized in water

During the last decades, the use of plastic has become indispensable for the daily life of people; the global production of these materials reaches approximately more than 200 million tons per year. For this reason, research has been carried out to manufacture substitute materials that have similar physical properties, such as starch-based biopolymers; in this research we initially characterized the physical properties of a biopolymer based on starch polymerized in water, without plasticizers, and also to find an optimal proportion between starch and water; in this way an experimental design is generated where the proportion of these two varies, in which starch extracted from potato and cassava wastes was used. These biopolymers were characterized for linear shrinkage, density, and hardness properties. The results of the characterizations showed that the proportions lower than 1:5 starch-water present difficulty to process and deficiency in the homogeneity of the mixture, while the proportions higher than 1:5 presented a linear shrinkage higher than 82. 69% and a loss in weight higher than 74.45%; on the other hand, the hardness analysis showed an average of 79 points on the shore A scale and density with an average of 1.055 g/cm3, the results determined that the most adequate proportion is 1:6.5 starch-water.

Molecular identification and technological properties of yeasts isolated from spontaneously fermented cassava waste pulp

The aim of this work was to report on molecular identification and technological properties of the yeast flora isolated from spontaneously fermented cassava waste pulp. This was done with a view of obtaining yeast strains that could be used as a starter culture for the fermentation of cassava waste pulp. Molecular identification was based on the nucleotide sequence of the ITS region of the genomic DNA of the yeast isolates while the technological properties evaluated include linamarase (U/mL), gelatinase, and haemolytic activity; growth at pH 2.5 and tolerance to 2 % bile salt. All the representative five isolated yeasts were identified as Geotrichum silvicola KLP04 – KLP08. The isolates exhibited linamarase activity ranging between 3.3 and 4.2 with strain KLP04 having the highest value and strain KLP05 the least. None of the isolates demonstrated gelatinase and haemolytic activity except strain KLP08 which was partially haemolytic. All the examined yeasts exhibited good growth at pH 2.5, with strain KLP08 having the highest viable counts of 4.1 log10cfu/ml and strain KLP04 the least value of 3.5 log10cfu/ml after 72 h of growth. All the identified yeasts showed strain-specific tolerance to 2% bile salt with strain KLP04 having the highest viable count of 4.3 log10cfu/ml and strain KLP08 the least value of 2.2 log10cfu/ml at the end of 72 h of incubation. Based on all the examined technological properties, Candida silvicola KLP04 strain had the highest potential to be considered for starter culture for the fermentation of cassava waste pulp.

Preparation of Nano-Iron Loaded Cassava Fibre Composite Material for Hexavalent Chromium Removal

Waste cassava fiber and tea polyphenols were used as carrier materials and reducing agents, respectively, to prepare nano-iron loaded cassava fiber composite (CF-FeNPs). This work investigated the factors affecting the removal of Cr(Ⅵ) by CF-FeNPs under different environmental conditions and the removal mechanism. The SEM characterization results show that as the initial Fe2+ concentration increases, the amount of nano-iron on the surface of the composite material increases. The results show that the increases of the initial Fe2+ content and dosage of CF-FeNPs can enhance the removal rate. Meanwhile, the decrease of the initial concentration of Cr(Ⅵ) solution and pH also beneficial for the removal performance. When pH=2.0 and the initial concentration of Cr(Ⅵ) is 10 mg/L, the removal rate of hexavalent chromium by CF-FeNPs can reach 81.4% within 2 h. The reaction conforms to the pseudo first-order kinetic model. The results of this study can provide technical reference for the remediation and treatment of Cr(VI)-containing wastewater.

A thermostable extracellular α-amylase from Aspergillus flavus S2-OY: Purification, characterisation and application in raw starch hydrolysis

An amylolytic fungus was isolated locally from the soil of a cassava waste dumpsite. It was identified as Aspergillus flavus S2-OY using 18S rRNA gene sequencing with gene bank accession number MZ267053.1. α-Amylase was produced from the fungus through solid substrate fermentation of potato (Solanum tuberosum L.) peel, a cheap and renewable substrate. The fungal enzyme was purified 13.41-fold by ammonium sulphate and ion exchange chromatography (CM Sephadex C-50), with final yield of 13.41%. Apparent molecular weight of 55.0 kDa was obtained for the purified enzyme, using SDS-PAGE. Optima pH (6.0) and temperature (70 °C) of α-amylase activity were determined for the enzyme which also showed thermal stability up to 70 °C, with 80% residual activity after 120 min. The enzyme exhibited a wide range of pH stability (4.0 to 7.0). Kinetic parameters Km and Vmax values obtained with soluble starch were 158 µg/ml/min and 1.51 mg/ml, respectively. The enzyme was slightly inhibited by Mg2+. Mn2+, Zn2+, Na+, K+, Hg2+ and the chelating agent, EDTA, at 5.0 mM concentration. However, it was activated by Sn2+. The enzyme hydrolysed gelatinised and ungelatinized raw yam, corn, rice and millet starches strongly but cassava starch moderately. These results revealed that cost-effective α-amylase production from Aspergillus flavus S2-OY could be realised with the use of potato peel as a cheap substrate, under solid substrate fermentation condition. Also, the fungal α-amylase is a raw starch-hydrolysing, acid to neutral and thermostable enzyme with potential for broad biotechnological applications.

Potentials of multi-stress tolerant yeasts, Saccharomyces cerevisiae and Pichia kudriavzevii for fuel ethanol production from industrial cassava wastes

Cassava processing wastes are suitable substrates for bioethanol production due to their high starch contents. However, these cassava wastes often contain various substances that inhibit cell growth and ethanol production. The abilities of multi-stress tolerant Saccharomyces cerevisiae LC269108 and Pichia kudriavzevii LC375240 to produce ethanol from cassava industrial wastes were evaluated. Analysis of cassava peels and pulps from two cassava starch factories showed that the cassava peels contained high cyanide (KCN) concentrations while cassava pulps contained high concentrations of sodium dodecyl benzene sulfonate (SDBS) used to improve starch extraction in the factory. Although S. cerevisiae LC269108 produced ethanol efficiently from the cassava peel, its growth and ethanol production were inhibited in the cassava pulp. On the other hand, the growth and ethanol production by P. kudriavzevii LC375240 were inhibited slightly in the cassava peel but not in the cassava pulp. Based on the intracellular pyruvate concentrations in the presence of KCN and SDBS, it was inferred that their inhibition site is on the pyruvate synthetic pathways. With a co-culture of the two strains, ethanol production from the cassava peel increased significantly but there was no significant improvement in ethanol production from the cassava pulp.

SYNTHESIS L-LACTIC ACID FROM FERMENTATION OF CASSAVA PULP BY USING TEMPEH INOCULUM

SYNTHESIS L-LACTIC ACID FROM FERMENTATION OF CASSAVA PULP BY USING TEMPEH INOCULUM. This study used cassava waste pulp as a fermentation substrate to produce lactic acid using a tempeh inoculum. Tempeh inoculum is a mixed culture of Rhizopus with Rhizopus oligosporus as the primary fungus. Lactic acid is an organic acid most widely used in the food, pharmaceutical, cosmetic and chemical industries. One of the important uses of lactic acid is as a raw material for producing Polylactic Acid (PLA) biopolymers, namely polymers that can decompose naturally in a relatively fast time. The analysis was performed using the Response Surface Methodology (RSM) method and the Box Behnken Design (BBD) experimental design with substrate concentration parameters, inoculum concentration, and incubation time on lactic acid. The fermentation process is carried out using a flask shaker at a temperature of 30 ºC, pH 6.0, and a rotational speed of 150 rpm. The optimum yield for lactic acid is 6.65 g/L. It was acquired at substrate 20 g/L, inoculum concentration 0.30 % (w/v) at an incubation time of 72 hours.

Phytochemicals and in vitro anti-apoptotic properties of ethanol and hot water extracts of Cassava (Manihot esculenta Crantz) peel biogas slurry following anaerobic degradation

BackgroundWastes emanating from cassava (Manihot Esculenta Crantz) processing in African countries significantly contribute to environmental pollution, besides, such toxic wastes contribute to greenhouse gas emission. Although cassava peel has been successfully used as a raw material in mushroom cultivation, feedstock for livestock, biogas production but the bio-transformed products recovered from the anaerobic digestion of cassava wastes, especially the peels have often been overlooked. Therefore, this research aimed at quantifying the secondary metabolites in the slurry recovered from ethanol and hot water extraction of cassava peel subjected to biogas production, in vitro, for anti-apoptotic properties.MethodsFresh cassava peels were allowed to ferment anaerobically to produce three states of matter; gas, solid, and liquid/slurry. The slurry was extracted using 95 % ethanol and 100 oC hot water to obtain crude extracts, which were then subjected to anti-apoptotic screening using the mitochondrial swelling assay. The qualitative phytochemical analysis of the crude extracts was done using standard methods. Further characterization of the crude extracts was done by FTIR for the chemical elucidation of the functional groups present.ResultsThe qualitative phytoconstituents revealed that the slurry extracts are naturally enriched with alkaloids, steroids, flavonoids, and saponins. The infrared spectrum of the crude extracts revealed the presence of hydroxyl, alkane, carboxyl groups in the ethanol extract, and hydroxyl, alkene, amide, carbonyl groups in the hot water extract. In the presence and absence of exogenous Ca2+, both extracts of the slurry induced liver mitochondrial permeability transition pore opening albeit at low amplitude swelling as the mean absorbance was less than one (at 540 nm).ConclusionsBased on these results obtained, the crude extracts of cassava peel biogas slurry have been proven to possess bioactive compounds that could induce liver mitochondrial permeability transition pore opening, in vitro.

Valorization of cassava residues for biogas production in Brazil based on the circular economy: An updated and comprehensive review

Biorefining is an essential component for achieving a sustainable economy. This approach makes use of zero-waste technologies and generates renewable energy. Besides converting organic waste into profit, the technology also avoids competition with biomass and different food-based feedstocks, water use, and impacts on biodiversity, making it a viable alternative to energy crops. In this context, anaerobic digestion (AD) allows proper waste management through controlling pollution/waste accumulation and converting organic matter into higher-value products: biogas and biofertilizer. Considering these points, Brazil has substantial agricultural productivity and generates a significant amount of waste residues that has enormous potential for biogas and bioenergy production. Cassava is an important staple crop for the country, particularly in northern and northeastern regions, where it is produced and processed mainly by families on a small-scale. It produces solid residues (peels, stems, and leaves) and wastewater, known as cassava wastewater, which is characterized by a high chemical oxygen demand, many mineral nutrients and cyanide. Nonetheless, all of these residues are usually disposed of in the vicinity without any treatment, rather than being used to produce higher value-added products. Hence, this review explored the potential role of anaerobic digestion for cassava residues management in association with the bio-based circular economy. Overall, the current manuscript emphasized cassava waste residue's potential for biogas generation, process intensification, scale scale-up strategies, and challenges. • In Brazil, cassava is a valuable staple crop that generates a lot of waste. • Anaerobic digestion of cassava residues is promising but has not yet been widely applied. • Co-digestion with animal manure or sewage sludge is a practical option. • The economic viability of biogas output from cassava residues is still required.

Preparation of ammonium-modified cassava waste-derived biochar and its evaluation for synergistic adsorption of ternary antibiotics from aqueous solution

Mono- and co-sorption of the three antibiotics i.e., norfloxacin (NOR), sulfamerazine (SMR) and oxytetracycline (OTC), to raw and NH4+-modified cassava waste biochar added to aqueous solutions were investigated. The NH4+-modified biochar showed higher sorption affinity for both NOR and SMR than the raw biochar, while the raw biochar showed higher sorption affinity for OTC than the modified biochar. The highest sorption to both biochars in both the mono- and competitive sorption systems was found for OTC followed by NOR and SMR. Sorption equilibrium in all systems analyzed was reached within 15 h. Electrostatic interactions among the ionic antibiotics in the multicomponent solution increased NOR and SMR sorption to both biochars. Antibiotics’ mono- and co-sorption to biochars decreased with increasing solution pH. The co-sorption of NOR and SMR to the two biochars was regulated by π-π electron-donor-acceptor (EDA) interactions; besides, electrostatic interactions and Hydrogen (H-) bonding played an important part. Cation bridging might have been a potential mechanism to contribute to SMR sorption to the raw biochar, and OTC sorption to the NH4+-modified biochar. These observations will improve our understanding of the simultaneous removal of multiple antibiotics from water or wastewater.

The Effects of Cassava Pomace and Protected Soybean Meal on Dairy Milk Production and Quality

The objective of the study was to determine the effect of cassava pomace and protected soybean meal on dairy milk production and quality of mid lactating dairy cows. This research was conducted at Turen, Malang from January to April 2020. Twelve lactating Friesian Holstein dairy cows were divided into 2 groups so that each group consisted of 6, namely the control and treatment groups. The feed were a combination of forage and concentrate with a ratio of 35:65 in dry matter (DM). The control group received wet concentrate with DM content of 30.58%, 14.87% CP, and 75.06% TDN, while the treatment groups received concentrate with supplementation of cassava pomace 15% of DM ratio and protected soybean meal 45 g/l milk production. The variables observed were nutrient consumption, milk production and quality. Data between the two groups were analyzed using the Independent Sample T-test. The results showed that the addition of waste cassava and protected soybean meal increased (P&lt;0.05) nutrient consumption (DM, OM, CP, CF, EE, and TDN). Milk production in the treatment group was higher (P&lt;0.05) than control group (9.46 vs. 6.07 Ls/head/day). Milk protein production in the treatment group was higher (P&lt;0.05) than control group (0.37 vs. 0.21 L/head/day). The content of milk protein and milk fat between the control and treatment groups was not significantly different (respectively 3.19 Vs 3.28; 4.46 vs 4.42 %). Milk protein and fat production in the treatment group was higher (P&lt;0.05) than control group (0.21 vs 0.37; and 0.50 vs. 0.30 L/head/day respectively). The composition of glucose and blood urea in control and treatment dairy cows were not significantly different. In conclusion, giving cassava pomace and protected soybean meal to dairy cows during mid lactation increased nutrient consumption, milk production, milk protein production, and milk fat production but did not increase percentage of milk protein and fat. The treatment also did not affect blood glucose and nitrogen urea contents.

Implementing circular economy concept by converting cassava pulp and wastewater to biogas for sustainable production in starch industry

Adoption of the circular economy concept to utilize wastes and by-products from the cassava starch industry for biogas production has been considered a viable option. The annual generation of wastewater and cassava pulp in Thailand is reported to be approximately 21 million m3 and 9.5 Mt, respectively. This research therefore aimed to analyze the key drivers and challenges in implementing the circular economy concept in the cassava starch industry in order to generate higher demand for biogas systems, increase the energy security and resource efficiency, and combat the environmental problems associated with cassava wastes. The following three scenarios were analyzed in this study: (1) a factory without integrated biogas system, (2) a factory with integrated biogas installation using wastewater as a raw material, and (3) a factory with biogas system using both wastewater and cassava pulp as raw materials. The assessment of economic feasibility, resource efficiency, water recovery, land use, and global warming potential was performed to compare different scenarios. This study found that Scenario 3 generated the highest net present value and the shortest payback period of 6.14 million USD and 4.37 yr, respectively, for the 10-yr operational period. Moreover, Scenario 3 had the highest resource efficiency and water recovery with the lowest land use (1.89 × 105 m2 at 5 × 105 kg of starch d− 1) and the lowest global warming potential (0.14 kg CO2eq kg− 1 of starch).