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The recovery of date palm leaflet waste (DPLW), generated by palms through anaerobic digestion (AD) technology, attracts more attention because of its many economic, social, and environmental benefits. In this study, a laboratory-scale experiment using a continuous stirring tank reactor digester (CSTR) operating in mesophilic semi-batch mode was conducted to evaluate experimental methane production, biodegradability, and organic loading rate (OLR). Besides, a theoretical estimate of methane was assessed using a Buswell–Neave equation. Moreover, three modified kinetic models (Logistic, Gompertz, and Richards) were applied to adjust the experimental methane production from the AD of DPLW. This study showed that the experimental methane yield and biodegradability of DPLW were 133 NmL CH4/g VS and 33%, respectively, while the OLR was 2.76 kg VS/m3.d. The kinetic results showed that all three modified models (Gompertz, Richards, and Logistic) were useful for predicting methane production as a function of the added loads. However, the modified Gompertz model was the most suitable for experimental data, even under critical conditions. Indeed, the modified Gompertz model fitted the experimental methane production with an optimal correlation coefficient R2 = 0.998.

Environmental pollution is a serious concern within the Mediterranean area, this situation results mainly from olive mill wastewaters (OMW), the liquid effluents generated during olive oil extraction. Anaerobic digestion of olive mill wastewaters is negatively affected by nitrogen deficiency, low pH, and the presence of phenolic compounds. This study examines the feasibility of OMW co-digestion with rich nitrogen substrates in batch and continuous mode under mesophilic conditions. Four substrates were tested at different ratios (substrate/OMW) in batch mode. Optimal ratio (substrate/OMW) was 80:20 for poultry manure (PM), 20:80 for both cheese whey (CW) and grass, and 50:50 for slaughterhouse wastewater (SWW). Furthermore, the effect of organic loading rate was assessed in continuous mode, using an anaerobic sequencing batch reactor for the mix (SWW/OMW) at 50:50. The reactor was able to degrade 10 g COD/L/day, as the maximal limit for biogas production and process stability. The results proved that co-digestion of SWW with OMW at 50:50 produced the higher biogas volume in batch mode and ensure good process stability, expressed by high alkalinity (2150 eq mg CaCo3/L) and low rate of volatile fatty acids (VFA) (150 eq mg acetic acid/L). Co-digestion of OMW with SWW is an efficient solution, to solve environmental pollution and recover renewable energy from these two organic wastes.

The main objective of this study is the evaluation of RPPW anaerobic digestion feasibility at laboratory scale under Mesophilic condition. The experiment is conducted using a two-stage biofilm digester of 5 L capacity with mobile support material. Anaerobic treatment of wastewater from recycled pulp and paper industry in Morocco was tested using a laboratory-scale anaerobic biofilm digester that operated under mesophilic conditions over a 70-day. Chemical oxygen demand (COD) efficiency, volatile and total solid (VS, TS) elimination of the substrate during the process were: 78%, 52% and 48% respectively. The system was stable throughout its operating cycle with an optimum pH (7.24), alkalinity (1750 mg CaCO3/L) and a volatile fatty acid value (760 mg/L). The experimental daily biogas production measured reaches a value of 5 L/day with a composition of 71% methane, 27.6% carbon dioxide, 0.2 oxygen and 7713 ppm of the H2S. The study results show that the anaerobic biofilm reactor is a suitable technique for recycled pulp and paper wastewater (RPPW) treatment. The reactor shows high performances in terms of process stability, removal efficiency (> 70%) and biogas production. Anaerobic digestion is an efficient waste treatment technology that uses natural anaerobic decomposition to reduce the volume of waste while producing biogas. However, research is needed to strengthen microbial metabolism, biochemistry and the functioning of the rector to improve biogas production. The RPPW AD experiment with biofilm digester technology was stable throughout the operation period. The digester knows an overloaded in the last phase of the experiment which leads to an inhibition of biogas production.

The aims of this study were to perform the anaerobic digestion of recycled pulp and paper sludge (RPPS) at laboratory scale, using a continuously stirred tank reactor (CSTR) digester, to determine the methane yield of this type of waste, and to control the physico-chemical parameters to maintain its stability during the experiment. Recycled pulp and paper sludge has an important organic matter with a COD/BOD5 ratio of 1.94, which is easily degradable. The result of anaerobic digestion experiment has given a methane yield coefficient of 159 N mL CH4/g VS, while biodegradability was found around 77% (in VS). The results obtained from the kinetic models studied in this work, mainly the modified Gompertz, first-order, Richards, and Logistic kinetic models show that the difference between the predicted and measured methanogenic potentials was higher in the modified Gompertz kinetic model (0.25–12.94%) than in the Logistic model (0.18–2.69%). The Logistic model showed the best fit for the substrates used. The Logistic, the modified Gompertz, Richards models fitted adequately to cumulative methane production (R2 was 0.9744; 0.9597 and 0.9655, respectively). Specifically, the Logistic model predicted the methane production volume like the experimental within loads added of 2.5 g VS/L.

Palm waste is generated in the oasis and poorly valued by burning in random way. This waste can be recovered in many methods according to their physicochemical characterization. The organic values of EFB could allow us to use anaerobic digestion (AD). The elementary compositions are used to estimate the heating value for thermochemical conversion (TC). The study aim is to explore the energetic potential (Ep) of EFB using the AD and TC. The Ep results are 10.87 and 39.1 GWh/y, respectively.

Kinetics modeling is a necessary step to understand the anaerobic digestion (AD) process. This kinetics depends essentially on the nature of the substrate and the operating conditions. There are several studies on kinetic models of AD related to inhibition phenomena, product formation kinetics, hydrolysis phase, biogas production, and biodegradability. AD technologies are known to be quite complex processes. AD can sometimes suffer from instabilities that are mainly due to the significant fluctuations of some parameters. The aim of this chapter is to show the important role of the kinetic study on the performance of AD. The main kinetics models used to characterize the AD process are discussed.

This study focuses on evaluating the effect of combined alkali-thermal pretreatment on the methane potential of the date palm empty fruit bunch (EFB). For this purpose, the Biochemical Methane Potential (BMP) tests were conducted with substrate:inoculum ratio of 2, the alkali pretreatment was tested with 6% (w/w) (ratio weight of NaOH/weight of VS) and with the thermal condition at 50 °C for 10 min. The anaerobic digestion experiments were conducted at mesophilic conditions (37 °C). The combined alkali-thermal pretreatment result (144 NmL/gVS) was better than the alkali pretreatment one (132 NmL/gVS), knowing that the methane potential for the control test was only 118.5 NmL/gVS. Furthermore, the kinetic study was applied for all experimental results to explore the best fitting and process parameters (Modified Gompertz, Logistic function Transference function and First-order function). The Transference function corresponds to the higher µ and R2, which allows concluding that this model is the more adequate to the kinetic modeling fitting.

Anaerobic co-digestion of residual cabbage and cauliflower mixed at a ratio 1:1 (w/w) was investigated in two continuously stirred tank reactors under mesophilic conditions to ensure stability and enhanced methane generation. The experiments, including start-up, inoculum acclimatisation and treatment of the waste mixture, were carried out over a 65-day period. The characterisation results showed that the residual mixture contained a high proportion of total Kjeldahl nitrogen (around 37 g N/kg dry weight). The maximum value of methanogenic yield potential was found to be 250 L

Highlights • UASB was proposed for RPMW anaerobic treatement under mesophilic conditions. • Start-up up of the UASB reactor was completed in the 24 days. • 80,76 % COD and 90 % TS were removed at an OLR of 7,27 g COD/L d. • At optimal OLR of 8.31 g COD/L d was required to produce 62.51 L/d biogas. • For HRT 15.14 h, after reactor start-up 80.63 % of COD was removed. • The average biogas composition was 72.98 % CH4, 19.76 % CO2, 0.9 % O2., The anaerobic digestion (AD) has become an alternative source and an attractive treatment method. Up-flow Anaerobic Sludge Blanket (UASB) digester has been designed to treat the Recycled paper mill wastewater (RPMW) in Morocco. This paper provides a research on anaerobic digestion of RPMW using UASB technology. The UASB digester was designed following the characterization of wastewater and the feed rate, with the volume of 70 liters. The UASB reactor treating the RPMW was operated for 130 days with minimal overload problems. The experiments were carried out in the mesophilic temperature (37 °C) at different organic loading rates (OLR). A daily analysis was performed to ensure the efficiency of the digester. In this study, the AD experiment was performed in continuous mode with an effluent inlet flow rate equal to 1 L/h. Using the optimal OLR value 5.18 g COD/Ld and with an effluent 5,7 g COD/L, a biogas yield of 92 N mL/g COD removed (at normal temperature and pressure) was obtained during the RPMW anaerobic treatment. The reactor was operated at an optimal hydraulic retention time (HRT) of 15.14 h with a biogas production volume of the optimal value 62.5 L/d. These results indicate that RPMW can be effectively treated in a UASB reactor with the advantage of producing biogas. We tested our system with RPMW, to see the production capacity of the UASB system, which the objective is to develop the system for the industrial scale.

Food chains in general and dairy industries in particular increase from one year to the other; which generates enormous waste, the management of these waste concerned producers. The aim of this study is the energy estimation of the dairy industry sludge. Anaerobic digestion of the dairy sludge (DS) is conducted in a CSTR digester (continuous stirred tank reactor) at mesophilic temperature conditions (37C°) with a retention time of 45 days. The results obtained show that this dairy sludge(DS) has an encouraging proportion of volatile solids around 88 %, the maximum methanogenic yield potential reached 434 (NmL / g VS added) and the biodegradability recorded was 96 % at these conditions. In this context, one tone of dairy sludge could generate approximately 57kwh/year of electric power through the anaerobic digestion process. This will reduce considerably the industries of electrical energy consumption.

Anaerobic digestion (AD) of organic waste requires pretreatment to improve its performance. The substrate chosen for this study is easily degradable it's from a University canteen in Morocco. This process was studied at the laboratory scale, under mesophilic conditions, using a mixed stirred reactor (CSTR: Continuous Stirred-Tank Reactor). The main objective of this research is to study the effect of ultrasonic pre-treatment on methane production. After ultrasonic pretreatment, the waste showed a decrease in VS from 156.2 g/Kg (93.75%) to 134.03 g/Kg (92.95%) and the recorded methanogenic potential was in the order of 461 (NmL CH4/g VS added), which is a 31% improvement compared to the methanogenic potential recorded by an experiment without ultrasonic pretreatment. Thus the process operated under good pH and alkalinity conditions.

Anaerobic co-digestion of cow manure (CM) and banana waste (BW) was investigated. The experiments have been carried out and were tested for different mixture ratios of CM:BW in terms of volatile solids : 100:0, 80:20, 60:40, 50:50, 40:60, 20:80 and 0:100 with the aim to maximize methane yield and methane production from the anaerobic co-digestion of cow manure and banana waste. The results obtained show that a maximum methane yield of 229 mLSTP/g VS added was obtained at a (CM): (BW) ratio of was 40:60 with a biodegradability of 86% for an organic loading rate in the range of 1.49- 3.57 kg waste mixture/(m 3

The aim of this research it is to show how the biogas anaerobic digestion from treatment of recycled pulp and paper wastewater industry (RPPW) can be a renewable energy. Furthermore, a kinetic study of hydrolyzed COD and productions of methane from UASB digester treating RPPW for the continuous test is established. This will allow to reduce the organic matter deposited in landfills and CO2 emissions and to find viable solutions to minimize the environmental impact of RPPW. This study analyses the biogas products and energy recovery processes from a thermic and electric point of view from the theoretical equations. Thus, this study evaluated the performance of mesophilic methanogenic up-flow sludge blanket reactors (UASB) operating continuously in single-stage (UASB I). The maximum methane yields were 250.9 mLCH4/gCOD removed for UASB I, corresponding to 82.7% of the maximum theoretical energy 6.336 kJ/gCOD removed, Methanogenic potential were 4 137 928 m3CH4/year and electrical energy potential were 510 703 MWh/year. The kinetic study allowed us a hydrolysis rate kh = 0.04 indicates a correct simulation for the UASB digester treatment system for RPPW with an R = 99.668%.

Sewage sludge is a hazardous waste, which must be managed adequately. Mesophilic anaerobic digestion is a widely employed treatment for sewage sludge involving several disadvantages such as low methane yield, poor biodegradability, and nutrient imbalance. Tomato waste was proposed as an easily biodegradable co-substrate to increase the viability of the process in a centralized system. The mixture proportion of sewage sludge and tomato waste evaluated was 95:5 (wet weight), respectively. The stability was maintained within correct parameters in an organic loading rate from 0.4 to 2.2 kg total volatile solids (VS)/m(3) day. Moreover, the methane yield coefficient was 159 l/kg VS (0 °C, 1 atm), and the studied mixture showed a high anaerobic biodegradability of 95 % (in VS). Although the ammonia concentration increased until 1,864 ± 23 mg/l, no inhibition phenomenon was determined in the stability variables, methane yield, or kinetics parameters studied.

The objective of this study is to analyze the perception of Comorian citizens facing the situation of solid waste management (SWM). For this, a qualitative and quantitative approach is conducted on a sample of 300 households. The study shows that 61.1% of households freely dispose a waste on sensitive sites, 19.7% bring waste to collection points and 18.6% benefit from door-to-door. Moreover, 63% of households prefer door-to-door as a means of waste disposal compared to 19.5% who prefer voluntary intake and 17.5% prefer free evacuation. Home sorting concerns only 19.3% of households compared with 80.7% whose dispose mixed waste. Households that are aware of the negative impact of waste on health are 87.5%, against 5%, are unconscious and 7.5% remain without opinion. The study also shows that 40% of households are aware of the negative impact of waste on the environment, against 33% of non-conscious and 27% of non-opinion. The majority of households (58%) are unsatisfied of waste collection services schedules. However, 93.3% of households approve actions carried out by NGO and association. A financial contribution for waste management system improvement of 0.54 USD and 1.08 USD per month was approved by 67% of households.

Mesophilic anaerobic digestion is a treatment that is widely applied for sewage sludge management but has several disadvantages such as low methane yield, poor biodegradability and nutrient imbalance. In this paper, we propose orange peel waste as an easily biodegradable co-substrate to improve the viability of the process. Sewage sludge and orange peel waste were mixed at a proportion of 70:30 (wet weight), respectively. The stability was maintained within correct parameters throughout the process, while the methane yield coefficient and biodegradability were 165 L/kg volatile solids (VS) (0°C, 1 atm) and 76% (VS), respectively. The organic loading rate (OLR) increased from 0.4 to 1.6 kg VS/m3 d. Nevertheless, the OLR and methane production rate decreased at the highest loads, suggesting the occurrence of an inhibition phenomenon.

The anaerobic digestion is an available treatment technique of sludge from recycled mill paper (RPMS), this method avoids environmental problems and produce methane, which is a renewable energy. The anaerobic treatment of the RPMS was studied using a 1L CSTR reactor at laboratory scale under mesophilic conditions. A kinetic study was carried out using two models in order to compare and adjust the experimental results. The experimental results show that the RPMS methane yield is 159 Nml CH4/g VS. The load of 2.5 g VS/L gives the better methanogenic potential. The organic loading rate reaches in this experiment 4.61 g VS / Ld. The first-order kinetic and the modified Gompertz model results show that the difference between the predicted and measured methanogenic potentials is higher in the first-order kinetic model (5 – 27 %) than in the modified Gompertz model (1 – 13%) following the applied load value. the modified Gompertz model showed the best fit for the substrates used., Proceedings of the 26th European Biomass Conference and Exhibition, 14-17 May 2018, Copenhagen, Denmark, pp. 849-854

Integrated Solid Waste Management claims for combine with different treatment strategies in order to minimize related environmental impacts and increase resources recovery and conservation. This is the only way to move towards a green society. However, severe changes are required from political, managerial, technical, social and economical points of view. Waste management in many cases is still performed widely without an integrated strategy, and it results in unsustainable resource consumption, in terms of raw materials, energy and useful land. Since the last decade, tools, technologies and strategies have been developed, which could lead the process to a more (if not absolutely) sustainable future. In particular, the application of Life Cycle concepts could really foster an enhanced knowledge of industrial activities and products, allowing a deeper detection of the most impacting steps, with positive consequences from environmental, economical and social perspectives. Furthermore, many tools are available to assess not only the environmental impact from a global point of view, but also to understand the possible effects on the nearby areas and to the population living in the vicinity of a pollution source. Scientific, technical and managerial knowledge which has been reached at present, could act synergistically to greatly improve the situation of many European and Developing Countries, which could benefit in a quick time of an advanced implementation of these tools.