Regional material flow behaviors of agro-food processing craft villages in Red River Delta, Vietnam

The economic reform “Đổi Mới” in 1986 has rapidly increased the number of craft villages in Vietnam, especially in the Red River Delta (RRD) leading to environmental degradation. This article presents an assessment of environmental and resource issues of agro-Food Processing Craft Villages (FPCVs) in RRD using a refined approach to material flow analysis focusing on consistent quantification of uncertainty with particular attention to secondary and empirical data that are often faced in material flow analyses in transition economies. Material flows of agro-Food Processing including eight types of production were examined and linked to activities of private Households, Rice Cultivation, and Pig Farming in a model called Red River Delta. Materials investigated were Goods (i.e., total materials), organic carbon (org.C), nitrogen (N), and phosphorus (P). The findings reveal material cycles are almost entirely open, that is, the materials used in FPCVs do not recycle within the region. From ∼10.5 million tons/year of imported Goods used for agro-Food Processing, final products and utilized materials account for minor fractions (∼5%, by weight). Conversely, the majority (88%) is directly discharged. Materials accumulated as stocks represent 1% of Goods (100,000 tons/year), 21% of org.C (∼34,000 tons/year), 42% of N (∼1,300 tons/year), and 57% of P (∼300 tons/year), whose substance concentrations vastly exceed natural resilience capacities. Although agro-Food Processing accounts for negligible material shares in Red River Delta, FPCVs pollution is severe at local levels due to the location of home-based production. Several options for closing material loops at various system scales are recommended for environmental and resource management of FPCVs. The material flow analysis results provide a database that may be used as a decision support tool for production establishments in craft villages and relevant authorities in setting priorities on environmental planning and resource management. This article met the requirements for a gold – silver JIE data openness badge described at http://jie.click/badges. © 2019 The Authors. Journal of Industrial Ecology published by Wiley Periodicals, Inc. on behalf of Yale Universit

Development of a database of Material Flow Analysis for agro‐food processing craft villages in Red River Delta of Vietnam

Vietnam is a developing country with approximately 70 % of inhabitants dependent on agricultural practice for a living. Agro-food processing craft villages, a typical feature of rural areas, appeared before 1930 as the result of the secondary activities of farmers. Over time, they have developed rapidly, and represent a huge but unstable production sector carried out by village residents. Among 5400 craft villages they account the second largest share. Agro-food processing craft villages concentrate predominantly in the region of Red River Delta of Vietnam and currently are loosely regulated. However, fast increase in quantity and the inappropriate management of solid waste, water and wastewater in these villages are triggering alarming environmental degradation and resource depletion. The presented project aims to develop a database of Material Flow Analysis (MFA) for the agro-food processing craft villages in the Red River Delta of Vietnam based on results of a previous Vietnamese - German joint project - INHAND “Integrated water concept for craft villages in Vietnam” (2011 – 2016) funded by German Ministry of Education and Research. Furthermore, this research investigates the most typical production processes of agro-food products at craft villages in Red River Delta by measuring and monitoring the production procedures, determination of the specific material and energy flows, analyzing the resource consumption and economic effects sampling and analysis in laboratory of the waste and wastewater as well as through surveying. The targeted productions are liquor, rice noodle, spring-roll rice paper, fresh rice vermicelli, glass noodle, arrowroot and cassava starch, and tofu. The material flow accounting of Total Carbon (TC), Total Nitrogen (TN), Total Phosphorus (TP), Chemical Oxygen Demand (COD) and energy for each type of production is determined or calculated and then extrapolated for the entire Red River Delta region. This MFA database describes the balance of TC, TN, TP, COD, energy and characteristics for example production customs and technologies for each type of production chain and for the whole region of Red River Delta. From this, a comprehensive account of resource and energy use of the household food production sector is created. This can be used as a reference for the development and application of more sustainable production at household level and provide solutions or promote decision-making for environmental authorities to optimize resource and energy use as well as environmental management. Preliminary results show that the region of the capital of Vietnam, Hanoi, contains the highest density of agro food production craft villages in the Red River Delta region. Most of the investigated production processes consume vast volumes of water as well as energy and consequently produce large amounts of wastewater, which is typically discharged untreated to waterbodies or rice fields at concentrations that exceed national limits for pH, TN, TP and COD. Arrowroot starch and cassava starch are main culprits, producing not only huge amounts of wastewater (up to 50l/kg product and 24l/kg product, respectively) but also significant solid residues which are readily degradable and contain high nutrient levels. Other products mainly use rice as raw material; among these, fresh rice vermicelli and rice noodle produce the most acidic wastewater and high concentrations of COD, TN, TP. However, for some productions like rice liquor and spring-roll rice paper, the arising wastewater is reduced if the wastewater for example from rice washing and soaking process is utilized for animal feeding. This presentation focus on the completed data collection, process description and mass and energy flow analysis. Next steps will be balancing of TC, TN, TP and COD and modelling with MFA software “STAN”. The mass of TC, TN, TP and COD per unit product or per inhabitant will be calculated and further information on distribution of food villages in Red River Delta will be collected and processed to extrapolate the balance of MFA for the whole Red River Delta region

Municipal solid waste collection evaluation tool as basis for LCA of MSW Management

The City of Bangalore, India, with 11 million inhabitants is currently investigating the improvement of the municipal solid waste collection system due to low efficiency and significant environmental impacts of the prevalent collection system. The present door-to-door collection covers only 50 % of the generated MSW whereas the rest is discharged at Litter Spots (30 %) and complemented by street sweeping waste (20 %). This presentation describes the conceptual design of an appropriate and innovative MSW collection system for Bangalore on the basis of a MSW collection evaluation tool. This collection tool is developed to project and simulate different scenarios and options for the collection system, considering temporary and spatial fluctuations of specific key parameters. The approach analyses three different scenarios – only door-to-door collection, only community bin collection, mixed systems – and three different options for waste segregation – separate collection of mixed, dry and wet waste, separate collection of wet waste as well as dry and mixed waste together, separate collection of dry waste as well as wet and mixed waste together. The evaluation tool calculates the capital and operational expenses per time unit to enable a scientific comparison of all systems. Additionally, CO2 emissions, number of community bins and collection vehicles as well as the number of employees were simulated for temporal and spatial variations. For the design of the evaluation tool, multiple key parameters are applied in order to investigate the variation of the entire system when one parameter is changed. The development of the investigated parameters is projected for three different strata in Bangalore. Key parameters are among others the ratio of door-to-door collection in the entire system, the rate of waste segregation at source and the collection frequency for community bins per week, as well as salary and number of employees per vehicle. The evaluation tool uses the results of the previous Municipal Solid Waste (MSW) characterization study and analysis of Bangalore (Weichgrebe et al., 2015), including waste densities, population and waste generation data as well as physical and chemical compositions. While varying the input parameters, the optimal value can be identified with respect to capital and operational expenses, feasibility and CO2 emissions. Moreover, the development of an increasing segregation at source rate can be investigated regarding impacts on the systems. The evaluation tool also calculates the specific waste volumes per community bin point in order to verify the space requirements and availability of land on ground. As a result, the collection evaluation tool shows that a decrease in collection frequency for Community Bins is not seen as a feasible method to reduce costs. A frequency of 7 times a week is recommended considering all interdependencies. If a combination of both systems is desired, it is recommended to remain within a share of door-to-door collection coverage of 80 % to 25 % in order to avoid efficiency losses. However, a system with only community bin system shows significantly lower costs compared to a door-to-door collection system. In order to optimize community bin sizes and maximum walking distance, a radius of 200 m around each community bin is recommended for low density areas. For medium density areas, a radius of 135 m balances cost and bin volume in an optimal way, while for high density areas 100 m are recommended. Following the results, a community bin collection system with one separate wet waste bin and one dry & mixed waste bin can be recommended. Moreover, the results are used as part of a multi-criteria analysis to facilitate the decision process for the systems. In conclusion, the evaluation tool for waste collection can be adapted and applied for urban areas in emerging countries. It offers great advantages to optimize the system parameters of existing and future waste management systems

Biochar from co-pyrolysis of urban organic wastes : Investigation of carbon sink potential using ATR-FTIR and TGA

Urban organic wastes (UOW) strain the infrastructures for solid waste treatment (SWT) in emerging economies. This study investigated biochar gained from three major UOW sources in India—banana peduncles (BP), a fibrous waste, from fruit markets; sewage sludge (SS) from wastewater treatment plants; and anaerobic digestate (AD) from food and market waste processing facilities—in terms of its potential to sequester and become long-term carbon sink in soils. Herein, the chemical properties (using ATR-FTIR) and thermal oxidative stability (using TGA) of biochars derived from these UOW and their three blends were examined. Biochar from SS and AD and the blends were found to possess more ash content, Cl, and alkali and alkaline earth metals (AAEM) than that from BP. The conventional recalcitrance index (R50) could not quantify and compare the stability of these mineral- and ash-rich biochars. Hence, a modified thermal oxidative recalcitrance index (TORi) is proposed. All the biochar from blends prepared at highest treatment temperature of 650 °C shows similar aromaticity. However, biochar from blend of 50% SS, 30%BP, and 20% AD exhibits the highest recalcitrance (TORi = 0.193) to become a long-term carbon sink in soil. More than aromaticity, the influence of Si, Fe, and AAEM on the biochar matrix affects its recalcitrance. Variations in the structural properties and recalcitrance of biochars from blends are attributable to the synergy among their constituents SS, AD, and BP. The determined TORi confirms the potential of biochar from the blends of UOW as a long-term carbon sink. © 2020, The Author(s)

Biogas potential of organic waste onboard cruise ships : A yet untapped energy source

To tap the organic waste generated onboard cruise ships is a very promising approach to reduce their adverse impact on the maritime environment. Biogas produced by means of onboard anaerobic digestion offers a complementary energy source for ships’ operation. This report comprises a detailed presentation of the results gained from comprehensive investigations on the gas yield from onboard substrates such as food waste, sewage sludge and screening solids. Each person onboard generates a total average of about 9 kg of organic waste per day. The performed analyses of substrates and anaerobic digestion tests revealed an accumulated methane yield of around 159 L per person per day. The anaerobic co-digestion of sewage sludge and food waste (50:50 VS) emerged as particularly effective and led to an increased biogas yield by 24%, compared to the mono-fermentation. In the best case, onboard biogas production can provide an energetic output of 82 W/P, on average covering 3.3 to 4.1% of the total energy demand of a cruise ship. © 2021, The Author(s)

Biochar production though combined solar drying & single chamber pyrolysis

In this study, the challenging management of fibrous organic wastes (FOW) and dewatered municipal sewage sludge (MSS) in urban areas of Asia’s newly industrialised countries is presented with high energy efficiency, negative CO2 balance and biochar generation. This study investigates the feasibility and benefits of a combined treatment approach for both of the substrates, comprising solar drying (SD) and pyrolysis process (PYR). Based on material investigations, a calculation model is developed to project the material and energy flows of this process combination on the example of Chennai, India. Please click Additional Files below to see the full abstract

Biochar Synthesis from Mineral- and Ash-Rich Waste Biomass, Part 1: Investigation of Thermal Decomposition Mechanism during Slow Pyrolysis

Synthesizing biochar from mineral- and ash-rich waste biomass (MWB), a by-product of human activities in urban areas, can result in renewable and versatile multi-functional materials, which can also cater to the need of solid waste management. Hybridizing biochar with minerals, silicates, and metals is widely investigated to improve parent functionalities. MWB intrinsically possesses such foreign materials. The pyrolysis of such MWB is kinetically complex and requires detailed investigation. Using TGA-FTIR, this study investigates and compares the kinetics and decomposition mechanism during pyrolysis of three types of MWB: (i) mineral-rich banana peduncle (BP), (ii) ash-rich sewage sludge (SS), and (iii) mineral and ash-rich anaerobic digestate (AD). The results show that the pyrolysis of BP, SS, and AD is exothermic, catalyzed by its mineral content, with heat of pyrolysis 5480, 4066, and 1286 kJ/kg, respectively. The pyrolysis favors char formation kinetics mainly releasing CO2 and H2O. The secondary tar reactions initiate from ≈318 °C (BP), 481 °C (SS), and 376 °C (AD). Moreover, negative apparent activation energies are intrinsic to their kinetics after 313 °C (BP), 448 °C (SS), and 339 °C (AD). The results can support in tailoring and controlling sustainable biochar synthesis from slow pyrolysis of MWB

Anaerobic Digestion of Hemp and Flax Straw and Shives and Rapeseed Straw by the Ruminal Microbiota

To mitigate greenhouse gas emissions and improve energy supply security, there is an increasing effort toward the use of non-fossil energy sources. Crop residues have a great potential to be exploited as biomass for biogas production. However, due to their lignocellulosic structures they are difficult to degrade and do not reach competitive performance. A feasible option to mine these substrates is present in the forestomach of ruminants. Therefore, the aim of the present study was to use rumen microorganisms to improve anaerobic digestion (AD) of crop residues. For this purpose, hemp straw, mechanically pre-treated hemp fibers and shives, flax straw, flax shives, and aged and fresh rapeseed straw were evaluated using the rumen simulation technique. The AD of the substrates was divided into three batches. In two batches, hay was added as a control substrate. In summary, none of the analyzed substrates had an equivalent performance as the control hay, but pre-treated hemp fibers and shives had better AD parameters compared to all other alternative substrates, with the lowest pH (mean: 6.81), highest short chain fatty acid (20.0 mmol/day) and H2 production (25.6 mM) and highest degradability (25.2%). Flax straw had the second-best performance (6.81, 17.4 mmol/day, 20.6 mM and 22.2%, respectively), followed by fresh rapeseed straw, hemp straw, aged rapeseed straw and flax shives. Therefore, hemp fibers and shives demonstrated to be the most suitable substrates for AD. However, since pre-treatment can represent significant additional costs for biogas production, flax straw also demonstrated to be a good alternative

Physico-chemical characterization of walnut shell biochar from uncontrolled pyrolysis in a garden oven and surface modification by ex-situ chemical magnetization

The shells of walnuts (WS) are major refuse in the global fruits and nuts trade. This, otherwise discarded, lignin-rich material can be carbonized to biochar—a value-added product with environmental applications such as carbon sequestration, soil amelioration, and pollutant adsorption. These applications are dictated by structural and chemical characteristics of the biochar carbon. Conventional controlled pyrolysis (CPy) of biomass is cost-intensive and technically too complex for widespread adoption, especially in emerging economies. Here, walnut shell biochar (BWS0) is derived through uncontrolled pyrolysis (UCPy) in a pyrolysis oven and further hybridized as magnetic biochar through ex-situ chemical co-precipitation. The physico-chemical characteristics of biochar and its water-extractable fractions are comprehensively investigated to understand their carbon structure and environmental applicability. The sp2 amorphous carbon sequestered in BWS0 is 0.84 kgCO2/kgbiomass with a BET (N2) surface area of 292 m2/g and is comparable to biochar from CPy in terms of carbon structure. The polyaromatic hydrocarbons present are only trace amounts of naphthalene, biphenyl, and phenanthrene. The magnetization decreases porosity of BWS0 while greatly facilitating its separation from aqueous media. BWS0 is suitable for adsorption of cations (between pH 2.8 and 9.45) and hydrophobic pollutants with only 19 mg L−1 fouling from their intrinsic dissolved organic carbon. In combination with fast-release N, P fertilizers, BWS0 (C/N of 24.8) is suitable for application in hydrophilic soils at higher loading rates. The results suggest an avenue where WS biochar can also be prepared via UCPy for direct environmental applications. Future investigations into soil incubation and adsorption tests are recommended. Graphical abstract: [Figure not available: see fulltext.

Integrated water management concept for craft villages - example from the food processing craft village Dai Lam: Short communication

Craft villages played a significant role in the development of Vietnam’s rural economy for a long time. The range of products and production methods, including the processing of materials and chemicals, are now adapted to modern market requirements but environmental and labour protection issues are not adequately considered in the management of the craft villages. The reasons are various: poor education of responsible operators, deficient technical equipment or missing regulatory framework and implementation of existing regulations. The INHAND project (Integrated Water Management Concept for Craft Villages) started in 2011 and is studying the food processing village of Dai Lam located on the banks of the Cau River in the Bac Ninh province (about 40 km NE of the capital Hanoi). The household-scale business focus mainly on rice and cassava processing with 200 out of 1000 households producing alcohol from cassava and rice, 10 households producing tofu, and 30 households recycling aluminium. In addition, most households also raise pigs. The wastewater is released mostly untreated into the receiving stream. Within the framework of the INHAND project, four German und two Vietnamese partners will conduct a basic analysis inventory in the village with identification of suitable measure for an integrated, environmentally sound concept for the removal and reuse of all output streams. The second major task of the 3.5 years research project is the conceptualisation, development and implementation of pilot-scale treatment facilities in the village and the scientific monitoring of their planning and operation.Đã từ lâu, làng nghề đóng vai trò quan trọng trong quá trình phát triển kinh tế nông nghiệp tại Việt Nam. Các sản phẩm và phương thức sản xuất, bao gồm cả giai đoạn xử lý vật liệu và hóa chất, đã từng bước được cải tiến cho phù hợp với yêu cầu của thị trường hiện đại. Tuy nhiên, những yếu tố về môi trường và an toàn lao động vẫn chưa được quan tâm đúng mức tại các làng nghề do nhiều nguyên nhân như: trình độ của nhà sản xuất, vận hành còn hạn hẹp, thiếu trang thiết bị kỹ thuật, các quy chuẩn còn thiếu hoặc chưa được thi hành triệt để. Dự án INHAND (đề án xử lý nước tổng thể cho làng nghề) được khởi động từ năm 2011 và hiện đang tiến hành nghiên cứu làng nghề chế biến thực phẩm Đại Lâm ,nằm bên bờ song Cầu, thuộc tỉnh Bắc Ninh, cách Hà Nội 40 km. Mô hình kinh tế hộ gia đình tại làng chủ yếu tập trung vào chế biến gạo và sắn: 200 trong số 1000 hộ gia đình nấu rượu gạo và sắn, 10 hộ sản xuất đậu phụ, 30 hộ tái chế nhôm. Ngoài ra, gần như tất cả các hộ đều có nuôi lợn. Nước thải của làng được dẫn trực tiếp ra các khối nước mở, gần như không qua xử lý. Trong khuôn khổ dự án INHAND, bốn đối tác Đức và hai đối tác Việt Nam sẽ tiến hành phân tích hiện trạng môi trường của làng để tìm ra những biện pháp thích hợp nhằm xử lý và tái sử dụng các dòng thải. Nhiệm vụ thứ hai trong thời gian 3,5 năm của dự án là lập ra đề án, phát triển và triển khai các trạm xử lý ở quy mô thử nghiệm, đồng thời quan trắc khoa học các quá trình thiết kế và vận hành