Closed system for local reuse of blackwater and food waste, integrated with agriculture

1999 ◽  
Vol 39 (5) ◽  
pp. 161-168 ◽  
Author(s):  
O. J. Skjelhaugen

To increase the recycling rate of blackwater and food waste to farm land, a small scale system, independent of sewer pipelines and sewage works, has been developed. It reduces water and air pollution, allows for source control of the recycled material, integrates farmers into the waste handling business, and reduces domestic water consumption. Parts of the system have been implemented in four Norwegian communities. Greywater is treated in local nature-based systems or in a new compact filter unit. Food waste and blackwater from new water saving toilets is stored in sub-surface tanks close to the house for one to two years, and then treated in a closed system. By combining the separate blackwater and food waste streams into one, logistics are greatly simplified. After collection by a tanker, the material is sanitised and stabilised in a thermophilic aerobic reactor, especially suited for decentralised solutions. No ammonia is lost, and the product has the highest possible agronomic value, with respect to nutrient content and organic matter. The treated material is spread onto farm land during the growing season. The different parts of the system can be implemented step by step over a longer time period.

Facilities ◽  
2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kwok Wai Mui ◽  
Ling Tim Wong ◽  
Tsz-Wun Tsang ◽  
Yin Hei Chiu ◽  
Kai-Wing Lai

Purpose This study aims to evaluate the generation of food waste in a university and the handling efficiency of an automatic waste collection system. Design/methodology/approach The quantity of food waste generated and collected from a university canteen was surveyed. The food waste handling efficiencies using manual collection strategy and automated food waste collection system were determined by the density of food waste. Life-cycle costing analysis was done to evaluate the economic impacts of various food waste collection methods. Findings As compared with the manual collection approach, the automatic system can improve the food waste handling efficiency by 30% (from 0.01 to 0.007 bin kg−1) and reduce the water use by 20% (from 0.512 to 0.406 L kg−1); however, it also consumes 4.4 times more energy (from 0.005 to 0.027 kWh kg−1). Under ideal system operation, the 10-year cost of food waste collection was significantly reduced from $3.45 kg−1 in the manual collection to $1.79 kg−1, and the payback period of the system collection was 1.9 years without discount. Practical implications The outcomes of this study show that an automatic food waste collection system is feasible, and it is recommended for small- and medium-sized catering facilities (e.g. canteens and food courts) to improve food waste handling efficiency. This study also provides useful reference data of automatic food waste collection systems for planning food waste management programs for catering facilities. Originality/value To the best of the authors’ knowledge, this is the first study to evaluate the waste handling efficiency, operational expenditure and life-cycle cost of a small-scale automatic food waste collection system.


2020 ◽  
pp. 140-148
Author(s):  
Md. Kumail Naqvi ◽  
Mrinal Anthwal ◽  
Ravindra Kumar

Biogas is the product of anaerobic vitiation of biodegradable matter. This paper focuses on the need of alternative and green sources of energy at a household level and how biogas produced from the everyday organic waste has the potential and possibility to replace LPG cylinders at houses, shops etc. and empower us to step towards an eco-friendly future. The purpose this small-scale experiment has been to find the perfect input matter that is easy to acquire and which produces the maximum amount of gas from minimum input and within small period of waste retention. Four different types of input waste material containing different quantities of cow dung and kitchen food waste were studied through individual experimental setups. Waste was mixed and kept at room temperature and the pH and total solid concentration of the samples were recorded on regular intervals. From the experiment it was found that the optimum yield of biogas at a small scale, based on the parameters such as retention period, pH and total solid con-centration can be obtained by the use of food waste form households and kitchens. The exact composition has been discussed in this paper. The energy generated by the small-scale generator has also been compared to that of an LPG cylinder and an LPG replacement model has also been presented.


2020 ◽  
Vol 13 (1) ◽  
pp. 259
Author(s):  
Ioanna Ntaikou ◽  
Georgia Antonopoulou ◽  
Gerasimos Lyberatos

In the current study, a domestic food waste containing more than 50% of carbohydrates was assessed as feedstock to produce second-generation bioethanol. Aiming to the maximum exploitation of the carbohydrate fraction of the waste, its hydrolysis via cellulolytic and amylolytic enzymatic blends was investigated and the saccharification efficiency was assessed in each case. Fermentation experiments were performed using the non-conventional yeast Pichia anomala (Wickerhamomyces anomalus) under both separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) modes to evaluate the conversion efficiencies and ethanol yields for different enzymatic loadings. It was shown that the fermentation efficiency of the yeast was not affected by the fermentation mode and was high for all handlings, reaching 83%, whereas the enzymatic blend containing the highest amount of both cellulolytic and amylolytic enzymes led to almost complete liquefaction of the waste, resulting also in ethanol yields reaching 141.06 ± 6.81 g ethanol/kg waste (0.40 ± 0.03 g ethanol/g consumed carbohydrates). In the sequel, a scale-up fermentation experiment was performed with the highest loading of enzymes in SHF mode, from which the maximum specific growth rate, μmax, and the biomass yield, Yx/s, of the yeast from the hydrolyzed waste were estimated. The ethanol yields that were achieved were similar to those of the respective small scale experiments reaching 138.67 ± 5.69 g ethanol/kg waste (0.40 ± 0.01 g ethanol/g consumed carbohydrates).


2021 ◽  
pp. 0734242X2110291
Author(s):  
Gabriel Andari Kristanto ◽  
Dini Kemala ◽  
Paras AC Nandhita

This article presents the informal recycling sector’s (IRS) social, economic driving factors in five cities in Indonesia and their contribution to waste management in the cities. An on-field analysis was conducted by random and incidental sampling method of questionnaire administration followed by observation. Among the respondents ( n = 178), 79% of individuals were waste pickers, 15% were small-scale waste collectors, and 6% were medium-scale waste collectors. The majority of the waste pickers sampled are male (79%). The amount of waste collected by individual waste pickers is 43.87 kg person−1 day−1, a corresponding recycling rate of approximately 12%, and an average monthly income of US$91.7. Gender differences are apparent as the male waste pickers generated higher incomes than those earned by their female counterparts (US$128.3 for men and US$69.7 for women) even as their average work hours are similar to that of the men (7.8 and 7.6 hours day−1, respectively). Economic motives are the respondents’ primary driving factors as moving to large cities accompanied by their family members. The study concluded that the IRS plays substantial contribution to waste management; further integrating them into the waste management system via IRS association, additional investment, formulation of law and policies and efforts by municipalities can give various benefits for involved stakeholders, the community and the environment. The results can serve as a significant reference for improving the solid waste recycling system and informal sector management in Indonesian cities and other developing countries.


2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Rochelle Werner ◽  
Bess Caswell ◽  
Kenneth Maleta ◽  
Christine Stewart

Abstract Objectives To characterize the nutritional composition of chicken eggs from a large-scale commercial producer and a small-scale household producer in rural Malawi. Methods A convenience sample of 28 large commercial and 32 village eggs from Malawi were hardboiled and measured for the weight in grams of the whole egg, peeled egg, egg white, and egg yolk. A separate convenience sample of 11 commercial and 17 village eggs were selected for nutrient analysis. Eggs were hardboiled for 4 minutes, refrigerated, and shipped to a nutrient analysis lab in the United States. Eggs from each source were pooled and analyzed for macronutrients, amino acids, fatty acids, vitamins, and minerals. Analytes were reported per 100 g sample and converted to nutrients per egg using the mean peeled egg weight. Results The mean weight in grams of whole commercial eggs (59.4 ± 5.3) was 19 g greater than whole village eggs (40.4 ± 3.0). Commercial eggs had a 15 g greater mass of egg whites (37.0 ± 4.2) than village eggs (21.8 ± 2.5), but the mass of egg yolks only differed by one gram (commercial: 15.3 ± 1.0 and village: 14.1 ± 1.4). Per 100 g sample, commercial and village eggs had similar calories (143 kcals vs. 162kcals), protein (12.5 g vs. 12.5 g), water-soluble vitamins (1.61 µg vs. 1.92 µg Vitamin B-12; 63.5 µg vs. 59.9 µg folate, DFE) and minerals (1.7 mg vs. 2.1 mg iron; 21 µg vs. 24 µg selenium; 1.1 mg vs. 1.4 mg zinc). For fat-soluble nutrients, the 100 g sample of commercial eggs had a higher concentration of Vitamin A than the village eggs (150 µg vs. 102 µg RAE) but lower concentrations of Vitamin D3, α-tocopherol, and choline than the village eggs (0.8 µg vs. 2.9 µg Vitamin D3; 2.25 mg vs. 4.08 mg α-tocopherol; and 238 mg vs. 314 mg choline). However, when compared on a per egg basis, the fat-soluble nutrient content of the whole eggs was similar due to the smaller size of the village eggs. Conclusions On a per egg basis, eggs from small-scale households may deliver comparable amounts of fat-soluble nutrients but fewer calories, protein, and minerals compared to eggs from commercial producers; however, on a per 100 g basis, village eggs were a more nutrient-dense option. Funding Sources The Bill and Melinda Gates Foundation, BLUM Center of UC Davis.


PLoS ONE ◽  
2014 ◽  
Vol 9 (3) ◽  
pp. e91998 ◽  
Author(s):  
Kadri Koorem ◽  
Antonio Gazol ◽  
Maarja Öpik ◽  
Mari Moora ◽  
Ülle Saks ◽  
...  

Water Policy ◽  
2009 ◽  
Vol 12 (2) ◽  
pp. 237-247 ◽  
Author(s):  
Stacey Noel ◽  
Hoang Thi Phuong ◽  
John Soussan ◽  
Jon C. Lovett

A number of rural household-based productive activities, such as kitchen gardens, livestock rearing and micro enterprises, are dependent on adequate supplies of domestic water to operate. This paper examines whether improved access to piped water can facilitate these types of activities, particularly for poor households. Using data from rural Vietnam, we find that most household enterprises use non-metered water and have very small profit margins. Thus, the evidence suggests that these enterprises may be better supported by a household-level water supply infrastructure, such as well pumps and rainwater catchment tanks, rather than by piped systems in rural areas. We also found an unanticipated link between operating small-scale food production businesses and raising livestock: for many households, waste products from food-based micro enterprises were used for rearing pigs, and this enabled business owners to expand their pork production, a significant source of income and prosperity in rural Vietnam.


2011 ◽  
Vol 133 (2) ◽  
Author(s):  
S. Gowreesh ◽  
J. Estrada ◽  
C. K. Ong ◽  
T. K. Xiao

A boiler or steam generator is a device used to create steam by applying heat energy to water. Compact boilers are specially designed to generate unlimited amount of steam in short time span for home appliance applications. The main objective of the present work is to analyze pressure behavior of a compact boiler when heat energy is applied under closed-open-closed system conditions (saturation pressure condition) and to study the characteristic behavior of water during the transition between liquid and vapor phases. This experiment investigates the pressure-temperature relationship at constant volume when the system reaches saturation point. This experiment also investigates the effect of suction pressure (saturation pressure at room temperature) on the system during the cold start condition and possible solutions to overcome the undesired final effect. Also, experiments are conducted on a small scale of the equipment and used as a base line values for the current experiments.


2020 ◽  
Author(s):  
Rejani Nair

<p><i>Food waste and its accumulation are becoming a critical problem. </i><i>In this context, this paper takes a look at the general view with the aim of achieving a better understanding of the different types of food waste, and tries to ponder on</i><i> the required steps or standard management practices should be taken to reduce the impact of food waste burden. The study has tried to analyse the waste management practices, cost of waste management practices etc. in small scale food processing units.</i><i></i></p>


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