Intensification Method Research Articles

Physics-informed Neural Network to predict kinetics of biodiesel production in microwave reactors

Microwaves are a process intensification (PI) method to deliver energy to reactive systems. Microwaves act directly on molecules’ dipolar moment, generating volumetric heating that allows temperature to rise rapidly, which directly impacts the overall rate of a reaction. Because reaction rates adhere to non-linear rate laws, predicting them is challenging. We use a Physics-informed Neural Network (PINN), a physics-driven model, to identify the reaction kinetics of a biodiesel production process. PINNs perform a regression on very few experimental data points and try to fit the physics at hand. We use a microwave reactor with a constant power input to perform the transesterification reaction, measure the infrared temperature and analyze the concentration of glycerides using GC-FID at different reaction times. We train the PINN to predict the reaction rates with respect to the Arrhenius equation. Results show that the PINN successfully identifies the rate constants, including their temperature dependency. Furthermore, the PINN can extrapolate its predictions to other power inputs without ever seeing the concentration data, generating a digital twin of the microwave-assisted reaction.

EXPRESS METHOD FOR CHEMICAL REAGENTS SELECTION FOR INCREASING OIL RECOVERY OF LOW-PERMEABILITY RESERVOIRS

The choice of hard-to-recover reservoir (HRR) engineering technologies is one of the actual problems facing oil companies in the Russian Federation and the World. In order to increase the efficiency of the development of such fields various methods for production intensification are used to obtain an economically profitable industrial oil inflow. It is possible to use surfactant flooding to solve this problem. The surfactant efficacy results from the fact that aqueous surfactants solutions even at low concentrations dramatically decrease the oil/water/rock interfacial tension that results to changing wettability, allowing to increase the oil inflow.The purpose of this work is to study an alternative method of testing the effect of surfactant solutions on oil recovery. The method consists in mass testing using a laboratory petrophysical centrifuge to identify the most promising solutions, followed by the classical filtration method. The method of centrifugation is based on the substitution of one fluid in the pores of the core sample by another, occurring at a pressure difference at the boundary of the two phases under the action of centrifugal force. The suggested method will allow massively and in a short time to identify the most effective solutions for specific geological conditions.To carry out this work, three surfactant solutions were selected that were tested for resistance to mineral aggression and temperature, surface tensions and phase behaviors were determined. The object of the study was the core material of the formations of the AS, BS and YuS groups of one of the deposits of Western Siberia. Two series of experiments were carried out: classical filtration tests and centrifugation of core samples under conditions of initial and residual oil saturation.The results of the experiments have shown the effectiveness and prospects of using the centrifugation method for mass testing of surfactant solutions as displacing agents. The described method is express and cannot completely replace the classical filtration experiment due to non-compliance with an important criterion – the thermobaric conditions of the reservoir.

Intensification of diethyl methylphosphite synthesis based on kinetics study and CFD modeling

AbstractA “pre‐dissolving ammonia” intensification method for continuous production of diethyl methylphosphite (DEMP) was proposed based on kinetics study of methyl dichlorophosphine (MDP) substitution and DEMP acidolysis. The method was verified in a continuous synthesis system consisting of a small jet reactor. Compared with the selectivity of ~80% obtained in a stirred flask, the selectivity reached 98% by the intensification method. Eliminating the resistance of gas–liquid mass transfer and enhancement of mixing enabled rapid removal of the produced HCl, thus, the DEMP selectivity was greatly increased. The high DEMP selectivity obtained was insensitive to reaction temperature, reactor size and ammonia to chlorine ratio in the studied range. A computational fluid dynamics (CFD) model was proposed for this liquid turbulent reactive flow. Numerical simulations revealed that HCl could be removed rapidly by the neutralization reaction, which was limited by micromixing efficiency. The CFD simulation further indicates the feasibility of “pre‐dissolving ammonia” for industrial production.

Recent Advances in the Selective Transport and Recovery of Metal Ions using Polymer Inclusion Membranes

AbstractPolymer inclusion membranes (PIMs) have gained significant attention in the field of metal separation and recovery due to their high selectivity, long service life, high stability, flexible design and low cost. Over the past 10 years, interest around PIMs has increased considerably; hence, the number of research papers has grown exponentially. This review provides the preparation methods and composition of PIMs, presents an overview of studies on PIMs reported since 2012, and discusses the relationship between the physicochemical properties of different types of membrane components and the microstructure, selectivity, transport performance and stability of prepared PIMs. This review also elucidates the metal transport mechanism at the interface and interior of PIMs and summarizes the modification and separation intensification methods of PIMs. Additionally, the structure and stability of PIM relative to other liquid membranes are also discussed. Finally, the existing challenges and perspectives of PIMs in the field of metal separation and recovery are proposed and highlighted. Notably, the need for highly selective and low‐cost carriers, a deeper understanding of membrane microstructure and separation mechanisms, and strategies for promoting widespread adoption of polymer inclusion membrane‐electrodialysis technology deserve particular consideration, which are of guiding significance for accelerating the industrialization process of PIMs.

EFISIENSI TEKNIS USAHATANI PADI KALIMANTAN TENGAH: PENDEKATAN STOCHASTIC FRONTIER ANALYSIS

<p>The strategy to increase rice production is crucial to maintain food availability. The agricultural land expansion program in Central Kalimantan through the food estate program is considered an inappropriate solution considering social, environmental, and land conditions. The agricultural intensification method in Central Kalimantan is the answer to increasing the productivity of existing agricultural businesses by increasing production efficiency. This research aims to analyze the technical efficiency of lowland rice farming and the factors that influence it in Central Kalimantan province. This research used secondary data from the 2014 Rice Plantation Household Survey from the Central Statistics Agency. The data was analyzed using the stochastic frontier production function with Maximum Likelihood Estimation (MLE). The research results show that rice farming in Central Kalimantan is technically inefficient. Factors influencing the technical efficiency of rice farming are farmer age, land type, planting system, agricultural facilities, extension, farmer groups, and SLPTT participation. The low level of technical efficiency of rice farming in Central Kalimantan is an indicator that must be utilized to increase rice production so that food availability can be well-maintained.</p>

Penerapan Metode System of Rice Intensification (SRI) dalam Upaya Peningkatan Produksi dan Peningkatan Kesejahteraan Petani Kecamatan Sakti

The System of Rice Intensification (SRI) method has become a popular approach in rice cultivation aimed at increasing rice crop productivity and farmers' welfare. This study aims to analyse the implementation of the SRI method in efforts to increase rice production and improve the welfare of the farmer in Subdistrict Sakti. The study employs a qualitative method. Data collection is conducted through in-depth interviews with rice farmers who apply the SRI method in Subdistrict Sakti. The results of the study show that the implementation of the SRI method in Subdistrict Sakti has a positive impact on rice production. The average rice production of farmers who apply the SRI method significantly increased compared to those using conventional methods. The SRI method is able to enhance crop productivity by utilizing efficient management related to the use of quality seeds, appropriate fertilization, effective water management, and good weed control. The income of farmers applying the SRI method has increased, directly contributing to their improved welfare. Furthermore, the SRI method also helps reduce farmers' dependency on external inputs such as chemical fertilizers, reducing production costs and positively impacting environmental sustainability. Therefore, it is recommended that local governments and relevant institutions provide policy support and technical assistance to farmers in widely implementing the SRI method.

Effect of co-digestion and hydrodynamic disintegration on the methane potential of sewage sludge and organic fraction of municipal solid waste with consideration of the carbon footprint

The study objective was to investigate the applicability of co-digestion and/or hydrodynamic disintegration as potential methods of methane production intensification from sewage sludge (SS) and the organic fraction of municipal solid waste (OFMSW) with consideration of carbon footprint (CF) assessment. Methane production was determined by means of biochemical methane potential tests. For co-digestion, the highest increase in methane production (53.8 %) was observed for the SS:OFMSW mixing ratio 40:60. Hydrodynamic disintegration at all tested energy densities (10, 30 and 60 kJ/L) caused release of soluble organic compounds from both substrates, although accelerated methane production was only observed at 10 kJ/L. An increase in methane potential for substrates disintegrated separately did not imply analogical results for the disintegration of their mixture. Within the assumed limits, CF per 1 Nm3 of produced methane, CF per 1 t of wet feedstock for the digester, and estimated CF per 1 kWh produced were also calculated. Comparable values of all indicators were obtained for monodigestion and co-digestion. The highest CF indices were achieved for monodigestion of disintegrated SS and increased significantly with applied energy density. The obtained results can serve as valuable material for operators of wastewater treatment plants facilitating the selection of sustainable methods of increasing renewable energy production.

COMMUNITY EMPOWERMENT THROUGH ORGANIC RICE CULTIVATION: CREATING A SUSTAINABLE AGRICULTURAL ENVIRONMENT

The PSRLB Program in Talang Ubi Utara Village represents a commendable initiative aimed at promoting sustainable and environmentally friendly agriculture practices. This program actively engages local farmers and the community in the pursuit of organic rice cultivation. It achieves this by providing farmers with essential training and guidance in adopting the Sustainable System of Rice Intensification (SRI) method, a sustainable approach that eliminates the need for chemical fertilizers. The results of the PSRLB program's implementation have been promising. It has not only significantly increased the productivity and quality of organic rice harvests but has also mitigated negative environmental impacts associated with conventional farming practices. As such, the PSRLB program stands as a shining example, offering inspiration to other farming communities seeking to embrace sustainable and eco-friendly agricultural methods. Its success underscores the potential for agriculture to harmoniously coexist with nature while fostering healthier, more prosperous farming communities.

An Assessment of Net Returns from Rice Production Practiced through Conventional and System of Rice Intensification (SRI) Methods in the Light of Climate Change in Bhandara District of Maharashtra, India

Indian farming witnessed surplus production of cereals along with other food commodities. The production of rice across the Indian subcontinent has a subsistent impact on achieving food security and attaining judicious socio-economic growth for the farming community. However, it also faces certain challenges and difficulties. The phenomenon of climate change has been creating a menace against the sustainable growth of food crops. Due to this, it has become necessary to assess the economic impact of farmers practicing rice crops in terms of net returns from rice. By applying ex post facto research design, this study aimed to estimate the inter and intra-level of interaction between sets of predicted variables, Net returns from rice (both conventional and SRI methods), and predictor variables (x1-x35) and to generate policy at the micro-level. To conduct the study, the State, District, Blocks, and Villages were selected using purposive sampling techniques. Two hundred (200) respondents were selected from two talukas of the Bhandara district of Maharashtra using a simple random sampling method. For the purpose of data analysis, following statistical tools were used: Coefficient of Correlation, Stepwise regression analysis and Path analysis. The correlation coefficients found that farmers having a higher level of education have been showcasing higher net returns from rice produced by conventional methods. Regression results implied that 35 causal variables together have contributed 32 percent and 83.8 percent of the variance in the consequent variable, net returns from rice (y) practiced by conventional and SRI methods respectively. The results of a path analysis revealed that the variable farm size has got the highest indirect individual effect on net returns from rice practiced by both the conventional and SRI methods.

Acoustic cavitation for the process intensification of biological oxidation of CETP effluent containing mainly pharmaceutical compounds: Understanding into effect of parameters and toxicity analysis

The current work investigates the efficacy of acoustic cavitation (AC) based pretreatment as a process intensification method for improving the conventional biological oxidation (BO) treatment of the effluent from common effluent treatment plant (CETP) mainly containing pharmaceutical compounds. The effluent acclimatized with cow dung-based sludge was utilized for the aerobic oxidation with an optimum condition of 1:3 ratio of sludge to effluent and 6 h as duration. COD reduction of 19.58% was achieved with the conventional biological oxidation, which was demonstrated to be improved by incorporating acoustic cavitation-based pretreatment approaches under optimized conditions of 125 W and 70% duty cycle for only AC as well as oxidant loadings as 1000 mg/L for H2O2, 250 mg/L Fe(II) with 1000 mg/L H2O2 for Fenton, 1000 mg/L for KPS and 0.5 L/min for the O3 during the combination approaches. The improved COD reduction after the use of pretreatment approaches followed by the BO of 6 h duration was 29.26%, 72.42%, 85.47%, 45.68% and 69.26% for the AC, AC + H2O2, AC + Fenton, AC + KPS and AC + O3 based approaches respectively. The toxicity assay of the effluent before and after every pretreatment approach using bacterial strains ofStaphylococcus aureusandPseudomonas aeruginosaensured the biodegradability of the treated effluent as no toxic intermediates could be seen. Overall, the present work elucidated the effectiveness of acoustic cavitation-based pretreatment approaches for the improvement of conventional BO of CETP effluent.

Review of Developments in Plate Heat Exchanger Heat Transfer Enhancement for Single-Phase Applications in Process Industries

A plate heat exchanger (PHE) is a modern, effective type of heat transfer equipment capable of increasing heat recuperation and energy efficiency. For PHEs, enhanced methods of heat transfer intensification can be further applied using the analysis and knowledge already available in the literature. A review of the main developments in the construction and exploration of PHEs and in the methods of heat transfer intensification is presented in this paper with an analysis of the main construction modifications, such as plate-and-frame, brazed and welded PHEs. The differences between these construction modifications and their influences on the thermal and hydraulic performance of PHEs are discussed. Most modern PHEs have plates with inclined corrugations on their surface that create a strong, rigid construction with multiple contact points between the plates. The methods of PHE exploration are mostly experimental studies and/or CFD modelling. The main corrugation parameters influencing PHE performance are the corrugation inclination angle in relation to the main flow direction and the corrugation aspect ratio. Optimisation of these parameters is one way to enhance PHE performance. Other methods of heat transfer enhancement, including improving the form of the plate corrugations, use of nanofluids and active methods, are considered. Future research directions are proposed, such as improving fundamental understanding, developing new corrugation shapes and optimisation methods and area and cost estimations.

Process intensification in the extraction of Mn from spent Li-ion battery simulated leachate via (G1/W+G2)/O microdispersion system with phase inversion

Recycling valuable metals from spent Li-ion batteries effectively alleviates the shortage of metal resources as well as avoids harm to human health and ecological environment. In this study, D2EHPA/TBP/sulfonated kerosene was selected as the extractant to conduct the process intensification in the reactive extraction of Mn. Five different methods with stepwise intensified mass transfer were designed to prepare liquid/liquid, gas/liquid/liquid and gas/liquid/gas/liquid systems, respectively. Effects of the dispersion method, fluid flow rates and residence time on the mass transfer performance were systematically investigated. The optimal structure and its efficient operating interval for process intensification were recommended, in which the Murphree efficiency of Mn reached 95.3% at the outlet of the dispersion module and reached 99.2% within a contacting volume of 2.12 mL, while was only 35–45% within 21.36 mL in the millimeter-dispersed emulsion system. The intensification fundamentals were discussed, via calculating the mass transfer coefficients and establishing corresponding mathematical models. This study provided simple and effective methods for process intensification of reactive extraction with viscous extractants in recycling valuable metals from spent Li-ion batteries.

Enhancing and upgrading biogas and biomethane production in anaerobic digestion: a comprehensive review

Anaerobic digestion (AD) processes can face operational challenges or flaws such as substrate structure and characteristics complexity, process complexity, low productivity, inefficient biodegradability, and poor stability, which suppresses or reduces biogas and biomethane production. As a result of the need to overcome these challenges/shortcomings and improve or enhance biogas and biomethane yield, process intensification methods have gained attention. There is some literature review on pretreatment and co-digestion as a means of improving AD performance; however, there is no systematic information on the various strategies required for improving AD performance and, in turn, increasing biogas/biomethane yield. The AD process produces biogas, a valuable renewable biofuel. Biogas is composed primarily of biomethane and other undesirable components such as carbon dioxide, oxygen, hydrogen sulphide, water vapour, ammonia, siloxanes, nitrogen, hydrocarbons, and carbon monoxide, which act as impurities or contaminants and tend to reduce the biogas specific calorific value while also causing various problems with machine operation. As a result, various technologies are used to improve raw biogas quality by removing contaminants during biogas transformation to biomethane. As a result, this paper provides a comprehensive review of the various systematic process intensification strategies used to overcome AD process challenges/shortfalls, improve or enhance biogas and biomethane production, and conventional and emerging or advanced technologies for biogas purification, cleaning, and upgrading.

Effect of Crop Establishment Methods and Fertility Management on Growth Parameters of Rice (Oryza sativa L.)

An experiment was conducted at Agronomy Research Farm of Narendra Deva University of Agriculture and Technology, Kumarganj, Ayodhya (Uttar Pradesh) during Kharif season 2021 -22 in order to study the effect of crop establishment methods under fertility management on growth parameters of rice. The experiment was laid out in split plot design with three replications. The treatment consisted of four crop establishment methods i.e., (M1) Transplanting rice (Conventional) (M2) Direct seeded rice by line sowing (Conventional) (M3) Drum seeded method under puddled condition (M4) System of Rice Intensification (SRI) method kept in main plots .However, four nitrogen levels viz, (N1) 100% RDF (150: 60:40 kg N:P:K ha -1), (N2) 75% RDF +25% RDN through FYM, (N3) 75 % RDF + 25% RDN through Vermi-compost, (N4) 50 % RDF + 25 % RDN through V.C. + 25% RDN through FYM allotted the in sub plots. This way there was made 16treatment combinations. As per the results the values of growth parameters viz. plant height (cm), number of tillers m-2, dry matter accumulation (m-2) and leaf area index of rice were increased significantly with system of rice intensification (SRI) method followed by transplanting method. However, in fertility management the application of 100% RDF (150: 60:40 N: P: K kg ha -1)) recorded the maximum plant height, dry matter accumulation, no of tillers, leaf area index, CGR, RGR, NAR, AGR and LAR, which was at par with the application of 75 % RDF + 25% RDN through Vermi- compost and significantly superior over rest of the treatments.

КОМПЕТЕНТНІСНИЙ ПІДХІД У ПІДГОТОВЦІ ФАХІВЦІВ ТУРИСТИЧНОЇ СФЕРИ ДО РОБОТИ В УМОВАХ КРИЗОВИХ СТАНІВ

Tourism as one of the promising branches of economy demands competent, active and highly qualified specialists who are capable of professional self-determination generating and implementing their own plans in the relevant market conditions as well as in the state of crisis. The training of future tourism specialists is associated with the need to form professional and personal competence, which involves the development of theoretical knowledge and practical skills, a vision of their professional behaviour in various situations of interpersonal interaction. The purpose of the article is to substantiate the essence of a competent approach in preparing tourism specialists to work in crisis conditions. The tasks of this work were to study scientific views on the issue of training tourism specialists to work in crisis conditions, to determine the main requirements for specialists in the tourism sector. To solve the problems of research, a set of methods was used: theoretical analysis and synthesis of ideas, results, theoretical statements disclosed in the scientific and pedagogical literature; summarizing and systematizing the results of existing studies on this issue. At the stage of development of the socio-cultural sphere, the tourism business needs personnel who are ready to organize activities in the conditions of crisis camps. Stakeholders and applicants seeking to expand the range of competitive opportunities in acquiring knowledge and skills are interested in implementing an educational program for training tourism specialists who are able to work in new socio-cultural conditions. The article generalizes views of scientists with respect to the interpretation of “competence approach” notion. Basic information on future tourism specialists training (taking into consideration all the directions of strategic development and global changes in the tourism market) is presented. The training issues are connected with the key problems of improving the tourism development management system, ensuring the competitiveness of tourism products and service in the implementation of national projects. It is determined that the main methodological requirement to future tourism specialists’ professional training is the updating of forms and content of practical components. Some of the methods of the educational process intensification that guarantee the effectiveness of theoretical and practical training are disclosed. Based on a thorough analysis of researches on this problem, a comprehensive definition of future tourism specialists’ professional training was defined, taking into account their readiness to operate in crisis situations. Professional competence in the context of the study is defined as an integrative quality, property, or dynamic state of a future specialist that ensures physical, psychological, professional, and personal compliance with needs, qualification standards, and requirements for work in the state of crisis. The set of competences such as general scientific, professionally qualified, social, individual and instrumental competence are relevant components of the professional competence of a tourism specialist, who is ready to operate in state of crisis. The introduction of academic discipline “Principles of anti-crisis management in tourism industry” that is aimed at the development and improvement of professional and personal tourism specialists’ qualities that are necessary to be effective in crisis situations was proposed.

Impact of crop establishment techniques and weed management practices on Oryza sativa L. growth and yield

AbstractDue to increased demand, labor costs, and water scarcity, farmers look for an alternative way of rice cultivation under prevailing conventional transplanting. Direct‐seeded Oryza sativa and system of rice intensification (SRI) have been developed as superior substitutes to transplanting. However, if weeds are not controlled properly, the direct seeding method faces serious weed infestation and yield losses. In this context, a field study was undertaken during kharif growing seasons to evaluate the growth and yield of O. sativa under various crop establishment methods and weed management practices. The results revealed that system of rice intensification (SRI) method of crop establishment significantly produced taller plants, higher dry matter accumulation, a greater number of tillers per meter square, highest leaf area index, yield attributes, namely, panicle density, panicle length, and grains per panicle, and higher grain and straw yield over direct seeded rice (DSR) and transplanted O. sativa. Among the various weed management practices, penoxsulam produced significantly higher grain and straw yield. The results demonstrated that average grain yield increase with SRI was reported to be 24.11% and 23.62% over DSR and 10.47% and 12.23% over transplanted O. sativa. Among various establishment techniques, lower weed density and dry weed biomass were achieved by transplanting O. sativa. Penoxsulam herbicides significantly reduced the weed density and dry weed biomass but penoxsulam herbicide demonstrated significantly the maximum reduction in number of weeds per meter square and dry weed biomass and proved superior against complex weed flora.

Magnetic Field Measurements of Low-mass Stars from High-resolution Near-infrared IGRINS Spectra

We present average magnetic field measurements derived from high-resolution near-infrared IGRINS spectra of a carefully selected sample of 28 M dwarfs. All 28 have reported magnetic field strengths in the literature. The main goal of this work is to investigate the accuracy, precision, and limitations of magnetic field measurements from IGRINS spectra. This investigation is critical to validating the robustness of our methods before we apply them to over 500 IGRINS-observed M dwarfs in the next paper of the series. We used the Zeeman broadening and Zeeman intensification methods to measure average magnetic fields. Our measurements are all consistent with the previous measurements to within ±1 kG, with an average offset of −0.17 kG for the broadening method and +0.19 kG for the intensification method. We find that the detection limit of IGRINS is ∼0.9 kG with the Zeeman broadening method, in accordance with the instrumental broadening limit of the spectrograph. With the Zeeman intensification method, we are able to detect down to ∼0.7 kG with a signal-to-noise ratio of 150 or greater. We find an advantage of using the intensification method over the broadening method, which is the ability to reliably measure the magnetic field strengths of stars that are cooler than 3100 K where the spectrum becomes dominated by molecular lines. Therefore, the intensification method is crucial to study stellar magnetism of late-M and brown dwarfs.

Kinetic modeling of dynamically operated heterogeneously catalyzed reactions: Microkinetic model reduction and semi-mechanistic approach on the example of the CO[formula omitted] methanation

As the production of green hydrogen from fluctuating resources and the use of Power-to-X technologies become more and more important in the energy sector and the chemical process industries, the interest in dynamically operated reactors is increasing. In order to apply model-based optimization methods for process intensification the dynamic reactor behavior needs to be predicted sufficiently accurate by the underlying model equations, in which the reaction kinetics play a key role. Microkinetic elementary step models are able to describe the dynamic behavior on the catalyst surface. However, these models are laborious to derive, parameterize and require comparably high computational effort to solve. For these reasons, simpler semi-mechanistic kinetic models based on a rate determining step at steady state conditions are much more frequently applied in numerical studies. However, the underlying assumptions of these models are questionable for dynamic operation since sorption processes and possible changes in the reaction mechanisms are not considered. We present a semi-mechanistic kinetic model approach based on so called rate-affecting steps and the dynamic change in surface coverages, which is able to describe the dynamic behavior of the catalyst surface. The applicability of our approach is demonstrated for model reduction of an elementary step mechanism developed for the COx methanation and for kinetic model development with synthetic experimental data. Both methods result in a kinetic expression that can accurately reproduce the dynamic kinetic behavior predicted by the elementary step model, with a significant reduction in computational effort for our new semi-mechanistic model, making this new class of model approach attractive for model-based optimization applications.

Effect of Enhanced Hydrolytic Acidification Process on the Treatment of Azo Dye Wastewater.

The hydrolysis acidification process is an economical and effective method, but its efficiency is still low in treating azo dye wastewater. It is therefore crucial to find more suitable and efficient means or techniques to further strengthen the process of treating azo dye wastewater by a hydrolytic acidification process. In this study, a hydrolytic acidification aerobic reactor was used to simulate the azo dye wastewater process. The change of wastewater quality during the reaction process was monitored, and the deep enhancement effect of single or composite biological intensification technology on the treatment of azo dye wastewater by the hydrolytic acidification process was also explored. Co-substrate strengthening and the addition of fructose co-substrate can significantly improve the efficiency of hydrolytic acidification. Compared with the experimental group without the addition of fructose, the decolorization ratio of wastewater was higher (93%) after adding fructose co-substrate. The immobilization technology was strengthened, and the immobilized functional bacteria DDMZ1 pellet was used to treat the simulated azo dye wastewater. The results showed that the composite technology experimental group with the additional fructose co-matrix had a better decolorization efficiency than the single immobilized bio-enhancement technology, with the highest decolorization ratio of 97%. As a composite biological intensification method, the fructose co-matrix composite with immobilized functional bacteria DDMZ1 technology can be applied to the treatment of azo dye wastewater.

Effect of land flooding in controlling weeds to several rice varieties in System of Rice Intensification (SRI)

Rice is still a main carbohydrat source for almost Asian people. The System of rice intensification (SRI) method is one effort in increasing rice production. In cultivating rice in this method, weed is the main problem. The research aimed to study the effect of land flooding to control weeds in rice field by using various rice varieties. The research was carried out in public rice field, Kuranji district, Padang, Indonesia. It was conducted from July-September 2019. A block randomized design was used as method in the study. The treatment was rice varieties: Batang Piaman, Panca Redek, PB 42, Batang Pasaman, and Saganggam Panuah. These treatments were replied to three times. The result showed 15 weed species were found in the experiment. According to Summed dominance ratio, Echinochloa crusgalli was the most dominant species in the field (28.05%). For plant height, Saganggam Panuah was the best variety (86.00 cm), and Batang Pasaman was the best one (20.50) for a number of the tiller.