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  A glance at the world Edited by Yang Liu This column comprises notes and info not subjected to peer-review focusing on waste management issues in different corners of the world. Its aim is toopen a window onto the solid waste management situation in any given country, major city or significant geographic area that may be of interest tothe scientific and technical community. Potential environmental performance and benefits of plastic wastes recycling in Singapore Environmental issues associated with waste plastics are a world-wide concern, especially in highly industrialized nations. Singaporeis no exception to this growing concern. With a total land area of 719.7 km 2 , the small city-state is confronted with the challenge of plastic waste management. In the year of 2016, the amount of plasticreached 822,200 tons, out of which only 7.24% was recycled viamechanical recycling (National Environmental Agency, 2017). Fourlarge waste-to-energy (WtE) plants are presently positioned as themodus operandi for waste treatment in a nation that lacks territoryfor landfill. Taken altogether, the combined capacity for WtE is 7600tons per day. From the WtE, solid wastes consisting of fly ash andbottom ash are sent to Semakau landfill by barge.Life cycle assessment (LCA) has been the environmental tool of choice applied to investigate the potential benefits and drawbacksof various types of waste management strategies in Singapore(Khoo, 2009; Khoo et al., 2010). In the next LCA case, a nation-wide investigation was carried out to analyze the environmental profilesof 822,200 tons of plastic waste treatment options.Most LCA waste management studies does not consider theoperating capacities of recycling plants. In this present study, adifferent perspective of plastic waste management is proposedby considering the possible sizes and capacities of each selectedplastic recycling alternative. Based on available capacities reported,the following was considered in the LCA system: an additional28,000 tons-per-year (tpy) or tons-per-year mechanical recyclingplant (in addition to the existing ones), potential 30,000 tpy plas-tics-to-fuels plant based on pyrolysis technology, and a potential75,000 tpy gasification system. A total of 5 scenarios were selectedfor the investigation. Based on a functional unit of 822,200 tons of plastic waste, the reference flows of each scenario are compiled inTable 1.The ReCiPe environmental impact method is applied to generateresults from climate change, terrestrial acidification, particulatematter formation and marine eco-toxicity. In addition, the netenergy output (in total GJ) will be calculated for each scenario. Theresults demonstrate that the operating capacities of all four recyclingplants have a significant influence over the environmental impactson each scenario.The best combination of options for recycling is displayed in sce-nario 3: the combined effects of total 87,500 tons, 30,000 tons and75,000 tons of plastic recycling via mechanical, pyrolysis and gasifi-cation altogether resulted in an annual reduction of about 61,000tons of CO 2 -eq. In terms of plastic waste-to-resource recovery intoenergy, plastic-to-fuel pyrolysis technology exhibited an advantageover all other recycling options. With two (2  30,000 tpy) pyrolysisplants (Scenario 4), a net energy output of 3  106 GJ was derived. Itwas also observed that impacts of marine eco-toxicity – generatedby barge transportation from WtE to Singapore’s offshore landfill –dropped by 16% when a recycling rate of 29% is achieved with thecombination of two large-scale gasification plants and 9.7% mechan-ical recycling (scenario 5). However, also in the last scenario, thehighest impacts for acidification and particulate formation are theresult of the introduction of 2  75,000 tpy gasification plants. Thegraphical representation of the case study and its results are illus-trated in Fig. 1.  Table 1 LCA scenarios 1 – 5 for the functional unit of 822,200 tons of plastic waste. Scenarios Brief description Reference flow/distribution of waste (tons)MR WTE P G1 Recycling rate of 7.24% sent to MR; the rest of is sent to WTE 59,500 762,700 0 02 Recycling rate of 10.64% sent to MR; the rest of is sent to WTE 87,500 734,700 0 03 Recycling rate of 10.64% sent to MR plus potential P + G; the rest of is sent to WTE 87,500 629,700 30,000 75,0004 Recycling rate of 10.64% sent to MR plus potential 2    P; the rest of is sent to WTE 87,500 674,700 60,000 05 Recycling rate of 10.64% sent to MR plus potential 2    G; the rest of is sent to WTE 87,500 584,700 0 150,000G = Gasification; MR = Mechanical Recycling; P = Pyrolysis; WtE = Waste-to-Energy Management 80 (2018) I–VII Contents lists available at ScienceDirect Waste Management journal homepage:  LCA was applied to highlighted environmental hotspots and ben-efits associated with various plastic recycling technologies. Eachtechnology employed demands other resource input (e.g., energyfor start-up)and emit various types of emissions,as well as, generateleftover un-recycled wastes or residues that have to be disposed.Further to the environmental assessments of the recycling options,it will be necessary to identify ideal locations to set up large thermo-chemical recycling plants for a highly industrialized city-state likeSingapore. References Khoo, H.H., 2009. Life cycle impact assessment of various waste conversiontechnologies. Waste Manage. 29 (6), 1892–1900.Khoo, H.H., Lim, T.Z., Tan, R.B.H., 2010. Food waste conversion options in Singapore:environmental impacts based on an LCA perspective. Sci. Tot. Environ. 408 (6),1367–1373.National Environmental Agency, 2017. Waste Statistics and Overall Recycling,<>. Hsien H. Khoo Institute of Chemical and Engineering Sciences, 1 Pesek Road, Jurong Island Singapore 627833,SingaporeE-mail address:  Waste management practices among private operators in Josmetropolis, Plateau state, NigeriaIntroduction Data for this study was gathered from fourteen private wasteoperators in Jos metropolis, Plateau state Nigeria, in year 2008.Structured questionnaires were used to gather data and interviewswere also carried out with the private waste operators. To ensurerepresentativeness, a simple random sampling method was used toselect the sample for this study. The list of all registered twenty-fiveprivate waste operators within the metropolis were obtained fromMinistry of Environment, and a random selection of the privatewaste operators were drawn from them. A 30 item structured ques-tionnaire was administered to respondents to understand the wastemanagement practices by private waste operators. The question-naire comprised of four sections; Background information, patternsof solid waste evacuation, methods of treatment of waste, methodsof final disposal, Reuse and recycling of waste and challengesencountered by the private waste operators. Data gathered in thecourse of the study was processed using Microsoft excel. Descriptivestatistics were used to analyze and present the data. Patterns of solid waste evacuation Two indicators were used to understand the patterns of solidwaste evacuation involved; the ‘‘site of evacuation” and ‘‘frequencyof evacuation”. More than half (64.29%) of the respondents evacu-ated waste from house to house, while 35.71% evacuated waste fromboth house to house and from designated communal dump sites.Personal interviews revealed that designated dumpsites were usedin locations with high density and poorly planned areas which hin-dered access to the individual residences. The frequency of wasteevacuation was less in office areas as compared to residential areas.However, in densely populated residential areas the visits by thewaste collectors were less than the visits in sparsely planned resi-dential areas. Inquiries were further made as to quantities of wasteevacuated based on their types, however the respondents reportednot having any data on the types of waste disposed - as waste wasnot sorted before disposal and thus no measurements were taken.The poor practice of not sorting of waste at household level andthe lack of information on the quantities of waste disposed basedon the various types as observed in the study area, may further ham-per the choice and development of industries to recycle and reusedominant waste materials. Methods of treatment and disposal of waste Findings show that half of the respondents treated their waste byburning and the other half indicated that they did not treat theirwaste before final disposal. Nearly half (42.86%) of the respondentsused waste to reclaim tin mining ponds. More than one quarter(28.57%) engaged in open dumping of waste on sites at the outskirtsof town, while 14.29% of the respondents disposed their wastes inlandfills, and 14.29% engaged in composting of wastes and eitherlandfilled the non-biodegradable materials or openly dumped themat the outskirts of town.The methods of treatment of waste before final disposal showsthat half of the respondents have been able to treat and reduce the Fig. 1.  Graphical representation of the case study and its associated results.II  A glance at the world/Waste Management 80 (2018) I–VII   volume of waste before final disposal by burning. However, thepractice of uncontrolled burning which is a dominant practice inthe study area can result in air pollution, the release of CO 2  andother environmental problems such as smoke and reduction of vis-ibility, wildfires, and the release of soot which can also reduce theaesthetic value of buildings in surrounding areas. Thus a method of incineration which involves disposing of wastes by controlled com-bustion at a very high temperature is more environmentallyfriendly. More than half of the respondents used wastes to reclaimmining ponds, this practice was reportedly directed by the govern-ment supervisory agency. This practice sought to reclaim landsaffected by Tin mining activities which started in Jos metropolisin 1902. Tin exploration and mining left a grotesque legacy of over4,000 abandoned mining ponds, which has continued to pose aserious threat to the environment and the inhabitants (Faden,2015). However, the use of waste to reclaim mining ponds intro-duces the risk of pollution of ground water sources. Open dumpingwhich has the second highest frequency is a system used morecommonly in developing countries. It is the cheapest form of wastedisposal, but it has been identified as the underlying cause of sev-eral public health problems in terms of disease spread such asmalaria, cholera and respiratory infections among others. Otherenvironmental problems that have also been associated with thismethod are air & water pollution and wild fires. Open dumpingcan also lead to pollution of ground and surface water sources, itfurther reduces the aesthetic value of such areas and becomes abreeding ground for insects and reptiles. Reuse and recycling of waste More than three quarters (78.57%) of the respondents were notinvolved in the reuse of waste materials, while 21.43% reported thatthey were involved in the reuse of waste materials. The waste mate-rials reused include waste papers generated from office spaces andacademic institutions which were in turn sold to tissue paper man-ufacturing companies. Metals and plastics were also sold to cottage/small scale industries that in turn recycle them. Biodegradable itemsfrom markets such as food wastes/vegetables were deposited ascompost on farm lands and the farm owners’ in turn paid for suchservices.The study revealed that none of the respondents engaged in anyform of recycling. Nearly three-quarters (71.43%) reported that itwas due to the high cost and lack of technical know-how, 14.29%reported that the government had recommend that waste shouldbe used to reclaim mining dumps, and this further limited thechances of recycling. However, 14.29% of the respondents reportedthat they intended to engage in recycling in the future. Explainingthat at present their contracts are for a short periods and it willnot be cost effective to invest in recycling. Challenges encountered by private waste operators Investigations were made on the various challenges encounteredby private waste operators in the course of their operations. Findingsshowed the following; All of the respondents reported the unwilling-ness of some of their clients (especially among low income resi-dents) to pay for the waste collection service as they felt it shouldbe a social service covered by the government; Public attitudes suchas indiscriminate waste disposal in gutters/water channels and inopen spaces; overlappingroles betweenregulatorybodies pertainingto collection of fees from the clients and the short duration of theircontracts was another problem; the poor enforcement of the policyby the government; the lack of subsidies by the government limitedthe quality and the output of the services rendered and high admin-istrative charges. Conclusion The success of waste management by private operators is depen-dent not just on the service providers but equally hinged on bothenvironmental and social factors. Environmental factors such asthe terrain can facilitate or hamper access. Social factors such asacceptability of the policy by residents, favorable attitudes such assorting of waste and proper disposal at designated collection pointsand availabilities of government subsidies to augment the high costof service provision, lastly the feasibility and sustainability of con-tractual agreements must not be overlooked. Thus there is need tofurther educate residents and provide an enabling environment thatwill encourage efficient waste management from the collectionstages to the final stages of disposal in an environmentally friendlymanner. References Faden J., 2015. Jos: A Century of Tin Exploration and Environmental Neglect. TheNigerian Investigative, Reporting Project.<> posted 16 February2015. Retrieved on 16th October 2015. Sallau-Asiribo Rachel OsesienemoDangana Kudu Department of Geography, Faculty of Natural Sciences, IbrahimBadamasi Babangida University, Lapai, Niger State, NigeriaE-mail addresses: (S.-A.R Osesienemo), (D. Kudu)Dung-Gwom John Department of Urban and Regional Planning,Faculty of Environmental Sciences,University of Jos, Plateau State, Nigeria Solid waste management in Nagpur, India: The bin-free city  Nagpur is the largest city in the state of Maharashtra with a pop-ulation of about 2.4 million. It generates 900 to 1000 tons of solidwaste per day with average waste generation at 0.49 kg/day per per-son. The rising population means that waste generation in Nagpurwill increase by 50% between 2021 and 2041. The Nagpur MunicipalCorporation (NMC) is responsible for managing solid waste and thecity has made significant progress towards reducing the impact of waste on public health and the environment through the introduc-tion of the Swatchata Doot Aplyadari or ‘Sanitary worker at yourdoorstep’ scheme. However significant challenges and barriers arelimiting further progress, as discussed in this article.The ‘Sanitary worker at your doorstep’ scheme has been identi-fied as an example of good practice by the UN Habitat Program(NMC, 2014). Those employed as swachata doot previously workedunder uncontrolled and unhygienic conditions as part of the infor-mal sector but they are now part of an organised formal waste man-agement system. They complete door to door waste collection, wastesegregation atsource, wastetransportation and waste disposalat theBhandewadi landfill site. Waste management in Nagpur typicallyemploys 901 swachata doot, 182 lifting labourers, 218 drivers, 38mechanics/helpers, 46 supervisors, 11 other staffs and 14 personsin charge. Nagpur also benefits from an extensive street sweepingmanagement plan that keeps the city clean. This employs about7,500 sweepers with each one responsible for cleaning from 500 to900 meters of road.Nagpur had the aspiration of becoming a ‘Bin-Free’ city and thisresulted in the number of publicly available bins reducing from  A glance at the world/Waste Management 80 (2018) I–VII   III  700 in 2008 to 170 in 2010 (NMC, 2014). To support this the NMCintroduced an extensive door to door waste collection service com-pleted by the swatchata doot aplyadari who are supplied with per-sonal protection equipment and a vehicle, normally a modifiedbicycle. Collection occurs every day, with the waste deposited incontainers in each neighbourhood for transporting to the city’smajor landfill site. There is no waste segregation at source, althoughsome informal segregation takes place to separate waste compo-nents with local value such as plastics, ferrous metals and paper.Nagpur does not have a formal system for segregation or recyclingof waste electrical and electronic equipment. Waste collection startsat 6:30 each morning and occurs across the city in residential areas,congested slum areas, markets and other commercial areas.Waste disposal in Nagpur is primarilyat Bhadewadivillage whichis an eastern suburb, approximately 10 km from the city centre. Thiswas identified in the City Development Plan as the area for solidwaste processing and disposal and has been in use since 1969. The54-acre site contains concrete linking roads with street lightingand it is enclosed by a 2-metre high wall. It is estimated that600,000 metric tons of solid waste were deposited at the sitebetween 1969 and 2008. The waste processing and disposal facilitieshave been developed through a build, own, operate, transfer (BOOT)arrangement. A MSW disposal facility was completed in 2010 andthis currently processes   800 tons/day of MSW. The contract forprocessing MSW was awarded to M/S Hanjer Bio-Tech EnergiesPvt. Ltd., who are responsible for all aspects of the site includingwaste deposition and compaction, infrastructure development onsite and collecting fees.Nagpur has an effective collection, treatment and disposal systemfor biomedical waste (BMW). The Government of Maharshtra has a30 years contract for BMW that started in 2004. NMC has allottedland at Bhandewadi to receive BMW from hospitals, dental clinicsand other BMW producers.The poor attitude of many of the public in Nagpur to waste andfailure to properly monitor and maintain the door to door solidwaste collection system has resulted in widespread littering in Nag-pur, particularly by waste plastic (Bhuyar and Shahare, 2013). Opendrains are often clogged by plastic items, causing damage to theenvironment and public health. The door to door collection systemdoes not reach every household and waste transportation routeshave not been properly optimized. The lack of waste segregationmeans that the solid waste contains wet and dry fractions, sanitaryand first-aid treatment wastes, expired medicines, electrical andelectronic wastes and sharp objects.Local communities close to the Bhandewadi landfill are very con-cerned about odour and air pollution problems associated with thesite. Waste dumped at Bhandewadi is reported to be causing signif-icant adverse impacts on the environment and public health. Thelandfill site does not have an engineered liner system, landfill gasextraction system or landfill leachate collection system and as aresult contaminants are leaching and polluting local ground water.The leachate from the Bhandewadi landfill is reported to be migrat-ing through fractures which underlie the topsoil cover to the aquifer(Pujari et al., 2007). Management at the site needs to be improvedbecause waste deposition is not properly planned and the waste isnot compacted on site. Daily cover is not used and as a result vectornuisance problems and fires are a regular problem. Workers at thelandfill exhibit increased levels of fungal infections, skin diseases,dysentery and cholera. There is a need to increase waste segregationto separate hazardous waste from MSW and dispose of thisseparately.In conclusion, the issues associated with improving solid wastemanagement in Nagpur are complex. There is a need to use the mostappropriate waste management practices, reduce the amount of waste going to landfill and introduce waste separation to aid themove towards a more circular economy. References Bhuyar, L.B., Shahare, A.S., 2013. Reverse logistics model design Nagpur railwaystation: a case study. J. Eng. Res. Stud. 4, 1–5.Nagpur Municipal Corporation (NMC) Report, 2014. Processing and Disposal of MSW of Nagpur city on BOOT Basis at Bhandewadi, Nagpur - Technical andFinancial Scrutiny of the Bid.Pujari, P.R., Pardhi, P., Muduli, P., Nanoti, M.V., 2007. Assessment of pollution nearlandfill site in Nagpur, India by resistivity imaging and GPR. Environ. Monit.Assess. 131, 489–500. Christopher Cheeseman Department of Civil and Environmental Engineering,Imperial College London, SW7 2BU, UK E-mail address: KumarShashi Arya CSIR-National Environmental Engineering Research Institute (NEERI),Nagpur, India  An integrated waste management plan using Remote Sensing and GIS for Kharagpur, West Bengal, India Based on the latest Census of India data for 2011, the total pop-ulation of India was 1.3 billion people while the urban populationwas 32.4% of the total. The urban population in India grew at anannual exponential growth rate of 2.76% in the last decade resultingin enormous stress on existing infrastructure. More resources arerequired to maintain standards resulting in inadequate waste man-agement in urban areas. More than 90% of the Municipal Solid Waste(MSW) generated in India is directly disposed on land in an unsatis-factory manner.Major problems related to urban solid waste management inIndia are: 1. Production of enormous amounts of waste and its inefficientcollection and treatment;2. Lack of proper disposal systems which results in illegal dump-ing causing health problems and environmental pollution(especially groundwater and surface water bodiescontamination);3. Overfilled bins and illegal dumping are common and lead tonuisance conditions like foul smell and scattering of refuse bywind and stray animals and birds;4. Uncontrolled waste generation and its open dumping are con-tributing to the greenhouse effect due to emissions of carbondioxide and methane. Solid Waste Management (SWM) is an obligatory function of anUrban Local Body (ULB) such as a municipality. Today, ULBs in Indiaare creating new infrastructure for better SWM and are trying tochange old and unsustainable practices. Remote sensing (RS) andGeographic Information Systems (GIS) have proved to be efficientand effective tools for improved solid waste management. RS canbe used to obtain spatial and temporal data, mainly in the form of satellite images, which can then be incorporated into GIS for design-ing successful solid waste management systems. RS and GIS can beused to design optimal routes which are efficient and cost-effective.RS-GIS combination is a dynamic method for minimizing operationalcosts, updating information regularly, making the monitoring andmanagement of urban spaces more transparent, timely and realistic.An integrated solid waste management plan was developed forKharagpur city in West Bengal, India using RS-GIS combination.These tools can be used to develop a management and decision- IV  A glance at the world/Waste Management 80 (2018) I–VII   making framework for providing better and faster results while cov-ering large areas over an extended period of time. (1) Location and size of open dumping sitesOpen waste dumping sites were identified and their areasestimated using satellite images in Google Earth. Changesin the areas of these dumps over a period of 12 years werealso estimated using Google Earth. Dumping sites look dif-ferent compared to empty land (with or without vegetation)and occupied land (buildings, and roads) due to which theycan be easily identified using satellite images. A few siteswere visited to verify the identity of such sites. The advan-tage of using RS and GIS is that large areas can be coveredin a short span of time and time-series analysis of theseareas is possible with ease.(2) Bin plan for source separation and collectionProper segregation, collectionand temporary storage of solidwaste after generation are important parts of an efficientSWM plan. This requires appropriate placement of bins onthe road to make collection and transportation of wasteeasier. Data required for designing an efficient bin plan(planning + managing) include base map, road network,information regarding class or type of road, and applicableregulations and guideline.According to Indian guidelines, the distance between binlocations should be less than 500 m and the distancebetween generation and collection points, i.e., householdsand bin locations should be less than 250 m.A sample bin location plan was prepared for Ward 20,Kharagpur city, West Bengal, using Google Earth and isshown in Fig. 1. Ward-wise population data were used forsizing of bins. Bin sizes were provided on the basis of thepopulation living within a 100 m radius around the bin loca-tion. In this plan, a distance of 100 m (±25 m) was providedbetween any two bin locations. Also, different colour codeswere used in Google Earth for bins in areas like markets, res-idential areas, and offices.(3) Collection routesWaste collection is the responsibility of local authorities ormunicipalities. Waste collection and transportation com-prise approximately 80–90% of the overall SWM budgets inlow income countries (like India) while collection efficien-cies remain less than 50%. Therefore, optimization of collec-tion routes is a critical need in low-income countries. Some Fig. 1.  Waste bin location plan and routes for collecting bins from residential areas and apartments. Colour Code: (i) Yellow pin with Yellow name - Market Bin; (ii) Red Pinwith Green name: Apartment Bin (6-floor/building, 12 units/floor); (iii) Red pin with Red name: Hauled container at Public places; (iv) Brown pin with Green name:Apartment Bin (3-floor/building, 12 units/floor); (v) Green pin with Green name: Residential Bin.  Table 1 Criteria for identifying suitable land for sanitary landfill sites. Place Minimum DistanceCoastal regulation, wetland, critical habitat areas, sensitiveeco-fragile areas, and flood plains as recorded for thelast 100 yearsSanitary landfill site not permitted within these identified areasRivers 100 metres (m) away from the flood plainPond, lakes, water bodies 200 mNon-meandering water channel (canal, drainage) 30 mHighway or railway line, water supply wells 500 m from centre lineHabitation All landfill facilities: 500 mEarthquake zone 500 m from fault line fractureFlood prone area Sanitary landfill site not permittedWater table (highest level) The bottom liner of the landfill should be 2 m above the highest water tableAirport 20 km  A glance at the world/Waste Management 80 (2018) I–VII   V
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