Environmental Management in India: Waste to Wealth

With the concept of sustainability gaining ground, conventional waste management approaches which considered waste as a necessary evil of the development process, are fast changing. Waste is now considered as an important resource and critical component of the circular economy. Implementation of an efficient and sustainable waste management system in our cities and towns is vital for sustainable development and fulfilling of the commitments made under Agenda 2030 and Sustainable Development Goals (SDGs). Although there is no specific Goal for waste in SDGs, it is well embedded either explicitly or implicitly in almost 13 of the 17 Goals. India is facing a major waste management challenge. Apart from organized waste management through the urban local bodies, informal unorganized waste management sector provides employment opportunities to around a million people in the country. Use of municipal waste to produce energy is being practiced by some local municipalities. However, many of waste to energy plants in India have been unsuccessful due to low calorific value of the waste and its non-segregation at the source. The waste generated from healthcare facilities in India is also of serious concern to community health and environment due to improper management practices and poor or non-compliance of rules. India is also implementing the extended producer responsibility (EPR) policy which sets the responsibility of the producer of a product beyond conventional sales to its post-consumer or end-of-life (EOL) stage thus leading to a circular economy. Nature Based Solutions (NBS) are also gaining momentum for environmentally sustainable, economically beneficial and socially inclusive system for waste management. Waste management is linked to many of the sustainability issues related to urban areas. It is an entry point for addressing related issues of health, sanitation, and overall environmental improvement including the achievement of SDGs. Co-benefits of sustainable waste management for climate change, health, water and sanitation, as well as responsible production and consumption need to be promoted for realizing the potential of wastes in the achievement of SDGs.

Present chapter investigated mechanical thermal, chemical and hybrid treatment methods, their advantages, disadvantages and implementation for municipal solid waste management process. An overview of the existing solid waste treatment methods and their efficiency as per volume reduction and energy recovery in terms of syngas and bio-oil is provided. Considering the volume reduction of solid waste, incineration is found to be the best treatment method with 90% volume reduction. The highest syngas and bio-oil production was reported with gasification and pyrolysis process respectively. On the other hand, stabilization, application of acid/alkali substance, oxidation at low temperature with ozone and esterification found beneficial for ethanol production and neutralization of harmful substances present in solid waste. Hybrid technology such as fluffing, microwave pyrolysis and plasma found favourable as compared to conventional treatment methods due to high-energy recovery in a shorter span of time. Thus, the selection of the appropriate treatment method should be done on the basis of solid waste characteristics and desired end goal such as volume reduction and energy recovery.

The Indian steel industry had paramount importance and complex challenges for sustainable solid waste management generated during various operations stages. One of such emerging and aggravated solid waste management problem is Steel Slag (SS). The proposed work emphasizes the physical, chemical, mechanical, morphological, and mineralogical characteristics of SS collected from Steel Plants in India. The SS waste had different characteristics and was selected to determine their appropriateness as Recycled Aggregates (RA) instead of Natural Aggregates (NA) in the concrete industry. The detailed study comprises carbon content, Loss On Ignition (LOI), moisture content, pH, chlorides, acid-insoluble residue, X-ray fluorescence (XRF), heavy metals, particle size, X-ray powder diffraction (XRD), analysis, workability, mechanical characteristics, and compressive strength. It was identified that; various chemical, physical, mechanical and mineralogical properties of SS wastes were varying in nature. The RA's mechanical characteristics were within the Indian standard (IS) limit (IS:6579–1981 and IS:383–1970). Further, as per IS:516–1959, SS's compressive strength properties for M-20 grade cubes were attained in 28 days, and the strength was higher for 90 days. Thus, the proposed work demonstrates the possibility of SS waste for its use as RA and suitable alternatives for NA, particularly for construction activities.

One of the serious concerns today is the contamination of the environment from heavy metals. Their persistent nature makes the toxicity of heavy metals area of chief concern. There are various kinds of conventional methods such as adsorption, ion exchange, sulfide precipitation, etc. are available for removal of pollutants, but due to their excessive cost and time taking factor the area of interest has now shifted to the time and cost-effective technologies. Greener approach is gaining interest these days.

In recent years, the Indian pharmaceutical industry has gradually evolved witnessing a major development in this sector. India has become the third largest API (Active pharmaceutical ingredient) merchant and is likely to be among the top three pharmaceutical markets by 2020. Though this will strengthen the economic growth of the country but subsequently it is fuelling the major environmental crisis such as waste generation. The unwanted materials produced at the time of manufacturing can turn out to be hazardous to the environment. Like the ash produced from the boiler furnace, impurities from the extraction unit and chemical waste from the processing unit. Today waste management practices become an integrated approach of waste reduction and recycling in order to enhance sustainable development. Common management practices employed by the pharmaceutical industries in India are Incineration, autoclaving, coagulation, constructed wetlands, and vermicomposting. Also, owing to the lack of proper disposal technique, some manufacturing industries often sell the hazardous/solid waste to the authorized re-processor or end user. This chapter elucidates the possible route of waste generation from pharmaceutical industries. It also shed some light on the current waste management technique used in India and also defines its shortcoming and limitations.

Open cast coal mining operations degrade the natural landscape and generate large quantity of mine refuse accumulated as over burden dump (OB dump), which is a serious environmental concern along with occupying the usable land area. Its proper restoration is required as a part of overall mining management plan. Taking into consideration, the R&D work was carried out aiming to identify and grow the efficient photosynthetic and soil conserver native plant species on selected OB dump in Eastern Jharia Coalfield (BCCL), Dhanbad. The selection of species is based on the ability to grow on the poor and dry mine soils, develop the vegetal cover in a short time, bind soil efficiently and improve the soil organic matter status. The mine refuse characteristics was determined before and after successive stages of the plantation together with growth performance of the planted species. After plantation of selected species, the physicochemical and biological parameters of mine soils were successively improved together with > 90% survival rate of the planted species. Among the species, i.e., Albizia lebbeck, Dalbergia sissoo and Acacia auriculaeformis (trees) and Vetiveria zizanioides and Cymbopogon flexuosus (herbs) were observed higher photosynthetic rate (8.9–26.5 μmol/m²/sec) and soil conserving efficiency (62.0–92.0%). SPM, SOx, NOx, and ambient CO₂ concentrations were significantly (p < 0.05) reduced after selective plantation. The riparian habitat, an extremely fragile and delicately balanced ecosystem is severely degraded due to recurrent soil and water erosion leading to the deposition of silt in nearby water bodies. Herbaceous plant species on the riparian slopes play a major role in reducing the soil erosion, water runoff and nutrient loss. The role of some selected native riparian herbs dominant on the bank of nearby River Damodar was assessed in conserving the soil erosion and water loss. The soil and water conservation values (CV) of each of the species were computed. Among the vegetated plots, soil CV ranged from 30 to 85% and water CV from 20 to 48%. The losses through runoff water and eroded soil were found to be minimized from vegetated plots to a great extent as compared to the bare plots.

Management of solid waste poses a great challenge and is a global problem being faced by all the developed as well as developing countries. The population living in cities is rising worldwide, which has led to the accelerated solid waste generation. In major Indian cities, an enormous amount of organic waste is generated from day to day activities which remain unutilized and is either burnt or dumped in open sites creating health and environmental hazards. In the present paper, the aspects of solid waste management pertaining to the agricultural application in India are reviewed. Total waste generation in India is around 62 million tons every year, of which less than 60% is collected and around 15% is processed. More than 50% of this waste generated consists of biodegradable matter. Instead of disposing this organic waste, it can be effectively recycled and used as compost to meet the nutritional requirements of the crops. Many studies have shown that the effect of using the chemical and synthetic fertilizers have led to decreasing in the nutritional value of the crops. Excessive use of chemical fertilizers has not only proven to become expensive, but also they get accumulated in the soil and causes bio-magnification leading to various health and environmental menaces. The application of the treated organic waste as a nutrient supplier, fertilizer, compost, etc. will help promote its effective use in agricultural enhancement but will also be useful in solving the problem of disposal. Still, the effects of the waste materials in terms of the presence of heavy metals, organic pollution, etc. must be taken into account.

India generates 2.07 billion cubic meters of biogas per annum. This is equivalent to 5% of the total liquefied petroleum gas (LPG) consumption in the country. Biogas production (e.g., Methane) often requires anaerobic digestion of food waste in an optimum temperature to get maximum biogas yield. The gas produced after anaerobic digestion can be dewatered and cleaned to be utilised through a biogas based fuel generation system. In addition, the by-product (slurry) formed in the process provides additional organic manure for farming and maintaining the soil fertility. The present work discusses about a fabricated simple, convenient and cost-effective Organic Processing Digester (OPD) system that can produce biogas in an eco-friendly way. This proof of concept establishes that there is potential of using food waste/municipal solid waste (MSW) in a sustainable way to divert the waste from landfilling, whilst also reducing the carbon dioxide and methane emissions to the atmosphere. In this study, food waste collected from three selected sites of Dhanbad district of India was subjected to anaerobic digestion in the above-mentioned digester. The methane yield obtained in this process was about 43%, 33% and 24% in summer, rainy and winter seasons respectively. The results of this study indicated that the food wastes are highly desirable substrate for anaerobic digesters with regards to their high biodegradability, methane yield and as a potential source of sustainable renewable energy.

Since the change in perspective of waste as an unutilized resource, the focus has shifted from waste reduction to waste utilization. Microbial fuel cell (MFC) has been a pioneer in this regard due to its unique ability to directly convert organic matter present in waste to electricity. Despite the tremendous improvement in power generated from lab-scale MFCs, they can replace the conventional waste treatment technologies only when their power output and cost of fabrication is made competitive enough. The gap between the theoretical and actual voltage achieved in MFCs majorly pertains to the overpotential losses associated with the electrode, electrolyte and proton exchange membrane (PEM). Graphene and carbon nanotubes have been a rewarding revelation in regard to electrode materials; however, incorporation of catalyst can further elevate the power generation in MFCs. This review primarily explores various cost-effective contemporary materials which could replace costly catalyst and PEM without compromising on the performance of MFC. Electrode modifications with non-metal and metal oxides doping can significantly reduce the activation losses and contribute to higher power generation in MFCs. Presently, transition metal based phthalocyanines and porphyrins have demonstrated excellent electrochemical performance, which is comparable with traditionally used platinum catalyst. In addition to the electrodes, the PEM has a major role to play in the power generation in MFCs. Recently, metal oxide doped sulfonated membranes have drawn considerable attention as an alternative to commonly used Nafion membrane. Even, the low-cost polymeric membranes are suggested to replace the sulfonated membranes. Moreover, the superior physical integrity of clay membrane makes them a suitable choice for large scale applications. The lab-scale performance of MFCs using these materials is encouraging and further efforts are required to replicate the same in the field-scale MFCs.

In recent years, there has been a paradigm shift towards exploring renewable sources of energy to reduce the dependence on fast depleting fossil fuels. Anaerobic digestion (AD) is a process that has potential to manage ever-increasing municipal sewage treatment plant (STP) sludge to protect our environment and recover energy in the form of biogas. This chapter presents a comprehensive review of the basic principles, process control, reactor design, biogas purification technologies and the energy utilization systems with a special focus on recent developments in the field for improving the process performance. Among the four stages in the process, hydrolysis is recognized to limit the process rate due to the recalcitrant properties of the sludge. Various physical, chemical and biological pre-treatment technologies have recently been implemented to accelerate the digestion through enhancing the rate of hydrolysis. These process parameters and their interactions are crucial to AD because they play a vital role in biogas production and regulate the metabolic conditions for growth of microorganisms. The centre of interest in the reactor design is the optimal utilization of sludge by enhancing its attachment to biomass. Besides, various biogas refinement techniques and systems for their utilization have been discussed. In a nutshell, this chapter reveals the current research and development trends of technological advancement in the energy recovery from STP sludge via its AD.

Plastic plays a dynamic role in enhancing the ordinary lives of a human being. The petition of plastics has been amplified because of the fast evolution of the world population. The worldwide creation of plastic has stretched approximately 322 million tons in 2017 and has amplified by 4% over 2018. Plastics are generally non-biodegradable and persist in the location for hundreds of years. High durability of plastic creates a great risk to the environment system i.e. landfill, emission of toxic gases like CO, CO₂, SO₂, NO_x, global warming, acidic rain, depletion of the ozone layer, leaching of chemicals and pollution. Dangers allied through healthcare waste and its management has expanded devotion across the world in numerous procedures, local and international opportunities, and meetings. Though, the requirement for proper healthcare waste management has been gaining acknowledgment slowly because of substantial disease burdens allied through poor practices, with exposure to infectious agents and toxic substances. There is only a limited rule existing at the global level about decomposable plastics in soil. Conditions, constraints, and testing procedures aimed at classification, cataloguing, and authentication of cultivated plastic leftover torrents through probable biodegradation in soil rendering to present global values are analysed whereas appropriate disagreements are acknowledged. In this chapter, discussion about the management of healthcare waste, biodegradation of plastic in soil, household plastic, marine plastic at national and international level.

Phytomining technology refers to the process of recovery of gold and the other usable metals from the tailings and waste dumps. The process represents a paradigm shift in the context of the waste materials being converted into the valuable products [21]. Gold phytomining is the process of extraction of gold from these waste materials/dumps to yield an economic profit. The idea of gold phytomining is being worked upon by the various scientific groups throughout the world [12, 18, 20]. Many plant species are being evaluated for their potential for the gold phytomining under the field and laboratory conditions. Since it is difficult to recover 100% of gold hosted in the minerals by conventional technology, the gold lying in the tailing dumps and waste rock piles in the mining areas around the world is wasted. The recovery of this gold using plant species is considered as a viable alternative, since the extraction or removal of gold from the tailings and waste dumps is not possible with the present state of technology. These waste dumps, and tailing sites are an environmental risk to the ecosystem. The secondary dispersion of the waste generated by the mining industry, facilitated by air and water causes a concentration of heavy metals such as arsenic, copper, and mercury and hence are a potential threat to the ecosystem. The huge cost associated with the processing of tailing and waste dumps by conventional technology needs to be relooked upon for alternative innovative biological technologies to remove and intoxicate the pollutants.

This chapter casts light on the main conclusions and recommendations of the 13 chapters presented in the book titled “Environment Management: Waste to Wealth in India”. In addition, some findings from a few recently published research work related to environmental management. Therefore, this chapter contains information on waste to wealth in India, waste to energy and waste and sustainability. In addition, a set of recommendations for future research work is pointed out to direct future research towards environmental management, which is the main subject of strategic importance under Indian circumstances.