Environmental issues and management in primary coffee processing

The paper examines the broader environmental issues and environmental management aspects of primary coffee processing in general and more specifically how it is addressed in India. Primary processing, the production of green beans from the coffee fruits, is practised to bring out more flavour. Coffee is an important global commodity, yet seen from a systemic view the producers and consumers of such an important commercial commodity are far apart. Primary coffee processing, with all its attendant environment impact, takes place at the producer end. The consumers in general are unaware of these impacts. The various methods of processing, the processing steps and the waste discharge associated with them are reviewed. A review of pollution and associated management methods is presented. An anaerobic bioreactor design developed and tested in a few Indian coffee plantations as a simple solution is also described

Nitrogen pool, flows, impact and sustainability issues of human waste management in the city of Bangalore

Cities in the developing countries have multiple modes of human and animal waste treatment and disposal that finally decide the overall impact on the urban ecosystem, and these have been studied for the city of Bangalore. Four modes are found, namely underground sewage systems, decentralized soak pits and septic tanks, open defecation and a miniscule effort at composting. The extent of N released per unit area is high, ranging between 0.44 and 1.4 t $ha^{-1}$ of the urban landscape.In this study the N release and outflow have been estimated. The N entering or flowing in the lithosphere,hydrosphere and in wastewater streams forms the major component. The pool size has first been determined. The size and movement through these pools were estimated with a view to determine the state of the N cycle and if there is a cause for alarm in similar cities in other developing countries. N contribution from human waste (excreta and urine) forms the singlelargest influx and sewage flowing out of the city forms the single largest efflux of N pool. Owing to a seemingly large use of soak pits and open conveyance of sewage in some parts of the city, coliforms and $NO_3$–N have seeped into shallow and deep-ground aquifers and show up in ground- and sub-soil waters in the city.The level of N in these waters at a few places is slightly higher than the permissible limits. This suggests that there is a need to find alternatives to modes like the ubiquitous soak pit, such that pollution of shallow and deep aquifers is avoided in the future. Currently,there is little effort in stripping the waste water off N.Also, there is no significant effort in recovery and reuse of nutrients, and this is required to increase the sustainability levels

Environmental Issues and Management in Primary Coffee Processing

The paper examines the broader environmental issues and environmental management aspects of primary coffee processing in general and more specifically how it is addressed in India. Primary processing, the production of green beans from the coffee fruits, is practised to bring out more flavour. Coffee is an important global commodity, yet seen from a systemic view the producers and consumers of such all important commercial commodity are far apart. Primary coffee processing, with all its attendant environment impact, takes place at the producer end. The consumers in general are unaware of these impacts. The various methods of processing, the processing steps and the waste discharge associated with them are reviewed. A review of pollution and associated management methods is presented. An anaerobic bioreactor design developed and tested in a few Indian coffee plantations as a simple solution is also described

Evolving biomass-based biogas plants: The ASTRA experience

Anaerobic digestion of animal waste in biogas plants for energy, manure and sanitation has made a significant impact in quality of rural life wherever it has been deployed. Insufficiency of animal dung resources limits the use of this technology to only an eighth of the overall Indian rural population. Yet the convenience of a biogas plant in rural households has led R&D efforts to extend the use of biogas plants to other nonanimal dung biomass feedstock and rural residues.Fermenting typical biomass residues in conventional slurry-based biogas plants has been far from successful. Most attempts to convert rural biomass residues into ‘flowable’ slurries like animal dung have rarely been successful. Alternative concepts were required. Achieving successful quasi-continuous fermentation of biomass residues has come through a break away from the ‘slurry’ fixation and animal dung digester designs of the past. A better understanding of the underlying processes has greatly helped evolve new fermentation concepts. Success has emerged only through use of multi-stage processes, where key fermentation properties of biomass feedstock have been acknowledged and digesters designed accordingly. Here, a 25-year effort in understanding the processes of biogas and biomass fermentation, developing new techniques and technologies to ferment biomass feedstock and efforts at simplifying the technology to enable sustainability carried out at the Centre for Sustainable Technologies, IISc, Bangalore is described. Finally, integration of the two or three fermentation steps into a single reactor configuration has enabled evolving simple-to-use digester designs for biomass feedstock, namely the plugflow and the solid-state stratified bed digesters

Utilization of Biogas Digester Liquid for Higher Mushroom Yeilds

Biomass based biogas plants play important role in the sustainable development of rural India. These biogas plants apart from providing biogas (CH4+CO2) that can be used for cooking and other purposes also provide two other byproducts such as Biogas Digester Liquid (BDL) and Biogas Digester Residue (BDR). These byproducts contain proportion of locked nitrogen in the form of ammonia, and other nutrients such as phosphorus that can be further utilized to produce valve added products like mushroom. In this study biogas digester liquid was used as a nutrient supplement in place of water for cultivation of mushroom specie like P. florida. it was observed that the mushroom bags supplemented with biogas digester liquid gave higher yield (P. florida gave 2.4kg/kg substrate) compared to bags sprayed with water (standard bags, 1.5kg/kg substrate). The time required for pin head formation, fruiting body was also reduced by spraying biogas digester liquid. Also the mushroom samples, leachate and solid substrate were analyzed for TKN, TP and TOC. Higher degradation of the substrate was seen in P. florida by spraying BDL than compared to control bags that were sprayed with water. (C) 2016 Published by Elsevier B.V

Resource recovery potential from secondary components of segregated municipal solid wastes

Fermentable components of municipal solid wastes (MSW) such as fruit and vegetable wastes (FVW), leaf litter, paddy straw, cane bagasse, cane trash and paper are generated in large quantities at various pockets of the city. These form potential feedstocks for decentralized biogas plants to be operated in the vicinity. We characterized the fermentation potential of six of the above MSW fractions for their suitability to be converted to biogas and anaerobic compost using the solid-state stratified bed (SSB) process in a laboratory study. FVW and leaf litter (papermulberry leaves) decomposed almost completely while paddy straw, sugarcane trash, sugarcane bagasse and photocopying paper decomposed to a lower extent. In the SSB process between 50-60% of the biological methane potential (BMP) could be realized. Observations revealed that the SSB process needs to be adapted differently for each of the feedstocks to obtain a higher gas recovery. Bagasse produced the largest fraction of anaerobic compost (fermentation residue) and has the potential for reuse in many ways

Nitrogen and carbon flows through Belandur lake - Role of Bellandur lake as a natural wetland treating Bangalore wastewater

Much of the Bangalore sewage is treated in three streams namely Bellandur (K&C Valley),Vrishabhavati and Hebbal-Nagavara stream systems. Among these it is estimated that out of a total of about 500MLD of partially treated sewage is let into the Bellandur tank. We estimate that a total of about 77t N non-industrial anthropogenic nitrogen efflux (mainly urine and excreta) in Bangalore city. This is distributed between that handled by the three sewage streams, soak-pits and land deposition. About 17-24.5t N enters the Bellandur tank daily. This has been happening over few decades and our observations suggest that this approximately 380ha tank is functioning as a C and N removal system with reasonable efficiency. The ammoniacal and nitrate nitrogen content of the water at the discharge points were estimated and found that over 80% of the nitrogen influx and over 75% of the C influx is removed by this tank system. We observed that there are three nitrogen sinks namely bacterial, micro-algal and macrophytes. The micro-algal fraction is dominated by Microcystis and Euglenophyceae members and they appear to constitute a significant fraction. Water hyacinth represents the single largest representative of the macrophytes. This tank has been functioning in this manner for over three decades. We attempt to study this phenomenon from a material balance approach and show that it is functioning with a reasonable degree of satisfaction as a natural wetland. As the population served and concomitant influx into this wetland increases, there is a potential for the system to be overloaded and to collapse. Therefore a better understanding of its function and the need for maintenance is discussed in the paper