eChapters

Proximate Analysis of Biomass
Objective
To determine the key compositional parameters of biomass, including moisture content, volatile matter, ash content, and fixed carbon, using standardized analytical procedures.
Principle
Proximate analysis of biomass is a standardized method used to determine the basic compositional components of biomass materials. It provides essential information about fuel quality and conversion characteristics. Biomass can serve as an energy source either directly through combustion or indirectly through conversion into gaseous, liquid, or solid fuels for more efficient utilization. These transformations occur through thermochemical processes (combustion, gasification, and pyrolysis) and biochemical processes (anaerobic digestion and fermentation).
Common biomass materials such as agricultural residues, cattle dung, poultry litter, and paddy straw are analyzed for parameters including total solids (TS), volatile solids (VS), ash content, total organic carbon (TOC), moisture content, and total sugars. These parameters are typically estimated using AOAC (2000) and other standard protocol.
Requirements
Biomass samples (such as agricultural residues, cattle dung, poultry litter, paddy straw and others materials from living organisms but now dead), silica crucible, hot air oven, desiccator, muffle furnace, weighing balance, 5% Phenol, concentrated H2SO4, UV-VIS spectrophotometer, vortex mixer, glassware like beaker and test tubes

Objective
To determine the chemical composition of biomass in terms of cellulose, hemicellulose, lignin, and silica content using standard detergent fiber analysis and acid digestion techniques.
Principle
Chemical analysis of biomass helps in evaluating its structural and compositional characteristics, which influence its thermal behavior, degradation properties, and suitability for bioenergy applications. Biomass primarily consists of cellulose, hemicellulose, lignin, and pentosans, each playing a distinct role in the structure and energy potential of plant material:
Cellulose – A linear polymer of ß-D-glucose units linked by ß-(1?4) glycosidic bonds. It provides tensile strength and rigidity to plant cell walls and serves as the main carbohydrate source in biomass.
Hemicellulose – A heterogeneous branched polymer composed of pentoses (xylose, arabinose) and hexoses (mannose, glucose, galactose). It acts as a matrix surrounding cellulose microfibrils, providing flexibility and binding lignin and cellulose together.
Lignin – A complex three-dimensional polymer made up of phenylpropane units. It is highly resistant to microbial degradation, provides compressive strength, and acts as a natural binder in plant tissues.
Pentosans – Polymers of five-carbon sugars that contribute to carbohydrate storage and structural integrity.

Key facts

    
•    Arsenic (As) is a metalloid, with properties intermediate between those of a metal and a non-metal. Arsenic can exit in the environment and biological systems in various inorganic and organic forms (species). These are arsenite - AsIII, arsenate - AsV, monomethyl arsonic acid (MMAA), dimethyl arsinic acid (DMAA), arsenocholine, arsenobetaine and arsenosugars. 
    
•    Arsenicals have a wide range of toxicity. In general, inorganic arsenicals are more toxic than oragnoarsenicals to biota and trivalent arsenic (arsenite) is more acutely toxic than pentavalent (arsenate) form in the following orders:
    
    Arsenous acid (AsIII) ®  arsenic acid (AsV) ® MMAA ®DMAA ® arsenocholine ® arsenobetaine.
    
•    Under oxidizing and aerobic conditions, the predominant form of arsenic (As) in soil and water is arsenate (AsV), whereas under anaerobic and reducing/or waterlogged conditions, arsenite (AsIII) predominates.
    
•    Inorganic AsIII and AsV are the major As species in groundwater, soils, terrestrial plants, whereas the main species found in marine animals is Arsenobetaine (AsB), which is considered to be non-toxic.
    
•    The LD50 values of different arsenicals show that arsenite (AsIII) is most toxic (LD50 range 15-42 mg/kg) and arsenobetaine is least toxic (LD50 > 10,000 mg/kg).

Key facts

Freshwater biotoxins

    
•    Biotoxins are naturally occurring toxic compounds produced by some freshwater cyanobacteria (blue-green algae) and marine algal species (dinoflagellates, diatoms).
    
•    Cyanobacteria are now recognised as a serious water quality problem with regard to drinking water supply and recreational use.
    
•    Environmental conditions that can promote cyanobacterial/blue-green algal blooms are: excessive nutrients (phosphorus and nitrogen); warm water temperatures (15-30OC); sunlight for photosynthesis; and quiescent or stagnant water.
    
•    Outbreak of human poisoning attributed to cyanobacteria are neurotoxins (e.g. anatoxin-a, anatoxin-a(s), saxitoxins) and hepatotoxins (e.g. microcystins, nodularin) produced by some strains of the cyanobacteria including Microcystis, Anabaena, Aphanizomenon spp.

Key facts
    
•    Dioxins are the most dangerous and ‘super toxic’ chemicals so far known on the earth and three closely related families are collectively known as dioxins. These are Polychlorinated dibenzo-p-dioxin or dioxins (PCDDs), Polychlorinated dibenzofurans or furans (PCDFs) and polychlorinated biphenyls (PCBs).
    
•    2, 3, 7, 8-TCDD (or called TCDD) is the most potent of all the congeners. The toxicity equivalency factor or TEF of TCDD has been assigned as 1, while all other congeners assigned in order of toxicity ranking magnitude relative to TCDD.
    
•    There are 75 compounds/congeners in the dioxin family (PCDD), 135 compounds in the furan family (PCDF) and 209 possible compounds in the PCBs based on the possible number of chlorine atoms.
    
•    The toxicity of dioxins and dioxin-like compounds vary substantially among the different PCDDs, PCDFs and PCBs. It is generally accepted that only 29 out of the 419 congeners of dibenzo-p-dioxins, dibenzofurans and polychlorinated biphenyls are toxic to humans and other organisms. The TCDD is most toxic and registered by the WHO as carcinogenic for humans.

Key facts

    
•    Endocrine disrupting chemicals (EDCs) are micropollutants with estrogenic or androgenic activities at very low concentrations and are emerging as a major concern for water quality.
    
•    EDCs include natural and synthetic hormones (Estrone or E1, 17b-estradiol or E2, Estriol or E3, 17a-ethynylestradiol or EE2); alkylphenols (nonylphenol or NP; octyphenol or OP), phenols (bisphenol-A or BPA), phthalates (Di-n-butyl phthalate or DBP, Di-2-(ethylhexyl)-phthalate or DEHP); organotins (tributyltin or TBT); and phytoestrogens (b-sitosterol, coumestrols, genistein). 
    
•    Wastewater treatment plants, intensive livestock effluents, industrial wastewaters, landfill, paper and pulp mill effluents and antifouling paints are important sources of EDCs in the environment.

Key facts
    
•    Pesticides are chemicals that are broadly used to protect crops, livestock and other animals and plants from pests and diseases. They are classified according to the type of pest to be controlled (algicides, herbicides, fungicides and insecticides).
    
•    Commercial production of DDT began in 1943. At that time, DDT was considered to be a wonderful invention. It was cheap to produce, very toxic to insects and much less toxic to mammals and its usage resulted in a sharp decline of mosquito borne diseases. In 1962, it was discovered that DDT was causing egg-shell thinning in bird eggs and thus was leading to the near extinction of bird species such as peregrine falcons and bald eagles.
    
•    Pesticides use has greatly helped to increase and improve the world food production. Use of pesticides also increases farmer’s profits by preventing crop losses due to pest attacks and weed infestation.

Key facts
    
•    Biotoxins are naturally occurring toxic compounds produced by some freshwater cyanobacteria (blue-green algae) and marine algal species (dinoflagellates, diatoms).
    
•    Tonnes of pharmacologically active substances are used annually in human and veterinary medicines, some of these substances are excreted (human and animal) non-metabolised or an active metabolites and enter into the environment since waste water treatment plant (WWTP) cannot degrade them.
    
•    In Europe, around 4,000 different pharmaceutically active compounds are used as human and veterinary drugs and the annual consumption is about several hundred tonnes.
    
•    European Union and the United States laws require an assessment of potential risks to the environment as part of license application processes for new medicinal products.

•    Pharmaceutical products are generally polar, water soluble and low volatile molecules, it means that they have high mobility in the environment.

Key Facts

    •    The heavy metals (HM) or trace metals in an aquatic environment can come from natural (e.g. geological minerals, wind blown silicate dust, volcanic emissions, sea spray and combustion) and anthropogenic sources (e.g. mining, industry and sewage treatment discharges as well as electronic waste and agriculture fertilisers). In aquatic systems, the heavy metals of greatest concerns are cadmium, copper, lead, mercury and zinc.
    •    Metals may exist in a number of physico-chemical states in aqueous systems such as particulate matter and dissolved forms. Metal speciation in freshwater is strongly influenced by hardness, alkalinity, pH, natural dissolved organic matter (DOM) and redox potential. 
    •    Water hardness is quantitatively related to metal toxicity in freshwater (i.e. toxicity of heavy metals decrease with increasing hardness and alkalinity; on the other hand, toxicity increases with decreasing salinity, dissolved organic matter and chelators). The uptake and toxicity of heavy metals of most metals in marine waters is low as compared to freshwater because metals are easily complexed with chloride ions.
    •    The toxicity of HMs is related to the dissolved ionic form of the metal rather than total concentration of the metal. Each different physico-chemical forms of an element has a different toxicity, for example, if the element (e.g. Cu) is absorbed on a colloidal particles it is expected to be of little or no effect on aquatic organisms, however,  if the copper is available as free Cu (II) ion, few aquatic organisms may survive.

Key facts

    
•    The use of chemicals has many benefits, however, there are potential risks that some of these chemicals may cause harm to organisms and human health if they enter into the environment.
    
•    Harmful chemicals are those chemicals which are persistent, bio-accumulative, as well as toxic (PBT). 
    
•    Environmental or ecological risk assessment (ERA) consists of hazard identification, effect assessment, exposure assessment, risk characterization, risk classification, risk-benefit analysis, risk reduction and monitoring.
    
•    The five types of environmental monitoring are: chemical monitoring, bio-accumulation monitoring, biological effect monitoring, health monitoring and ecosystem monitoring. 
    
•    An integrated monitoring program is a coordinated monitoring activity comprising of both chemical and biological measurements in a variety of environmental compartments. There are four different monitoring levels in an integrated ERA, these are: suborganismals (biomarkers), organisms (bioassays), populations (bio-indicators) and ecosystems (ecological indicators).

Hybridization is a potent technique to create variability for selection and breaking yield barriers, evolve varieties having built in high potential. The selection of suitable parents for hybridization is one of the most important step in hybridization program. Selection of parents on the basis of phenotypic performance alone is not a sound procedure since phenotypically superior lines may yield poor recombinations in the segregating generations. It is therefore essential that parents are chosen on the basis of their genetic value. Some of the commonly utilized techniques for assessing the genetic value of a genotype are:

Introduction
A biogas plant is an engineered system designed to generate biogas through the anaerobic digestion of organic materials rich in cellulose, such as cow dung, agricultural residues, poultry waste, and other biodegradable biomass. In the absence of oxygen, microorganisms decompose these materials, producing a mixture of methane (CH4), carbon dioxide (CO2), and traces of hydrogen sulfide (H2S). This biogas can be utilized as a renewable energy source for cooking, heating, and power generation.
In India, cow dung has traditionally served as the primary substrate, and such systems were popularly known as Gobar Gas Plants. The early designs were promoted by the Khadi and Village Industries Commission (KVIC)
Components of a Biogas Plants
A typical biogas plant consists of the following major components:
• Foundation: Provides structural support to the digester and gas holder.
• Digester (Fermentation Tank): The main chamber where anaerobic digestion occurs.
• Gas Holder (Masonry Dome or Drum): Collects and stores the biogas produced.
• Mixing Tank: Used to prepare the slurry by mixing feedstock with water (commonly 1:1 ratio).
• Inlet Chamber/Pipe: Feeds the prepared slurry into the digester

Indian Government has several developmental programmes to promote agriculture and rural sector. It includes Drought Prone Area Program, Antodaya Programme, Integrated Rural Development Programme, Hill Area Development Programme, Desert Development Programme, Intensive Jawahar Rojgar Yojna and Employment Assurance Scheme, Indira AwaasYojna, Integrated Waste Land Development Programme, National Food Security Mission, National Horticulture Mission, etc. Mahatma Gandhi National Rural Employment Guarantee Scheme (MGNREGS) has the main focus to provide guaranteed employment for 100 days in a year to every rural household. Since 2014, the Swachh Bharat Abhiyan has been a major initiative by the Government of India.

One ofthe biggest issues the world is facing today is the lack of clean and pure water. Due to rising water demands, rigid health regulations, and xenobiotic pollutants, traditional wastewater treatment technologies cannot provide safe water. The present era necessitates innovative approaches to wastewater treatment technologies and improved water resource conservation and management materials. By utilizing innovative nanomaterial, nanotechnology guarantees a continuous provision of potable water and contributes to the preservation of water sources. Nanomaterials expedite rapid processes for the purification, conservation, and reuse of wastewater, complementing other enduring industrial methods. 

Introduction

We have now started to feel the impacts of climate change, as a threat to our health, directly as heat stress on our bodies, and indirectly as it damages crops, and causes storms, floods and wildfires (IPCC, 2022). People working in fields or factories, or in the open, suffer the most. Buildings are our first defense as we learn to adapt to these changes. Resilient buildings that provide passive cooling can protect us better from heat waves, buildings designed to withstand storms and f loods can provide better shelter, and net-zero buildings that produce and store their own energy can enable critical operations when the electric grid is down.

Introduction

Drylands account for over 40% of the global land surface, or approximately 5.2 billion hectares (de Sherbinin, 2002). They provide home for more than 2 billion people or nearly 40% of the population of the world (White and Nackoney, 2003). Asia alone accounts for about 32% of the World’s drylands. Broadly defined by their modest water supply drylands have many regional names, such as semideserts, grasslands, savannas, steppes, and pampas. Dryland ecosystems are a vital part of the earth’s human and physical environments and play a major role in global biophysical processes. They provide much of the world’s grain and livestock, forming the habitat that supports many vegetable species, fruit trees and micro-organisms. With an exception of Australia and the United States, almost all drylands are situated in developing countries with populations living in extreme poverty. Populations of drylands are frequently some of the poorest in the world. Food security and water availability of these areas has always been unstable due to high variability in both rainfall amounts and intensities and the occurrence of prolonged periods of drought. The increasing pressures caused by the global climate change and massive land-use changes further increase human vulnerability in dry regions. The impacts of climate change in drylands are likely to lead to still larger populations being affected by water scarcity and the risk of declining food security and increase the risk of environmental migrations and violent conflicts caused by the decline of resources, which are important to sustain livelihoods (Barnett and Adger, 2007).

Summary

Water security can be defined as reliable availability of water in sufficient quantity and quality to sustain human health, livelihoods, food (agriculture, fisheries and aquaculture) and the environment (biodiversity and ecosystems). Discharge of chemical and biological pollutants (from agriculture, industry and domestic uses) into rivers and development of engineering infrastructure such as dams and weirs over rivers have modified river ecosystems threatening the global water security, water quality and water dependent biodiversity. Climate change (increase in the intensity and frequency of floods, droughts, bushfire and sea-level rise, ocean acidification, etc.) is an additional stress on water security. There is a need to reduce climate change impacts on water security which can be done via adaptations to climate change. Adaptation is adjustment in natural or human systems in response to actual or expected climatic stimuli or their effects, which moderates harm or exploits beneficial opportunities. In other words, the adaptation can be considered as, tackling the effects of climate change. Adaptation to climate change in terms of sustainable use of water may include increasing water availability by developing hydro-basins and transferring water from areas in which it is abundant to areas in which there is scarcity, the reduction of water losses, increasing storage capacity by building reservoirs and dams, rainwater harvesting, improvement of water use efficiency, desalination of seawater, water savings (leakage management, metering, retrofitting existing homes with water efficient products in toilets, showers, baths, using energy efficient dishwashers and washing machines), mandatory rainwater tanks in new and old buildings (for toilet flushing, washing clothes, gardens, car washing), use of recycled or reclaimed water for landscape irrigation or to recharge groundwater aquifers, and to meet commercial and industrial water needs.

Summary

The main greenhouse gases (GHGs) that have caused the global climate change or global warming are carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O). CO₂ is the principal anthropogenic GHG that affects the earth’s radiative balance. It is the reference gas against which other GHGs are measured and therefore has a Global Warming Potential (GWP) of 1. CH₄ and N₂O have a GWP of 21 and 310, respectively. CO₂ is responsible for most of the enhanced greenhouse effect of more than 50%, CH₄ for about 10-15% and N₂O for about 8%. The global atmospheric concentrations of CO₂, CH₄ and N₂O have increased since 1750. While CO₂ increased from a pre-industrial value of 280 ppm to 379 ppm in 2005, CH₄ increased from 715 ppb to 1774 ppb and N₂O increased from 270 ppb to 319 ppb during the same period. Rich countries and large developing countries account for most of global CO₂ emissions (China 23.5%, USA 18.27%, India 5.83%, Russia 5.72%, Japan 4.04% and European Union 13.98%). A new climate agreement called ‘Warsaw International mechanisms (November 2013) on loss and damage’ agreed to help the poor countries to cope with loss and damage from heatwaves, droughts, floods, typhoons, desertification and rising sea levels. The Warsaw agreement also includes a set of decisions to help developing countries to reduce GHG emissions from deforestation and degradation of forests which is backed by pledges of US$280 million financing by the United States, Norway and the United Kingdom. Projections for global average temperature rise is in the range of 1.1-6.4°C; a doubling of CO₂ (from pre-industrial 280 ppm) and average sea level rise is in the range of 0.18-0.59 m (Meehel et al. 2007) and 0.5–2.4 m (Brown et al. 2013). Hot extremes, heat waves and heavy precipitation events will continue to become more frequent. Projected data show that there is an increasing global trend in the rise of average temperature in all countries, regions or sub-zones; a decreasing trend in average precipitation in most sub-tropical areas and an increasing trend of precipitation in most of the tropical and high latitudes.

Key Facts
    
•    The United Nations Framework Convention on Climate Change (UNFCCC) defines ‘climate change’ as a ‘Change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods’.
    
•    The main green house gases (GHG) that have caused the global climate change or global warming are carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (NO₂).
    
•    CO₂ is the principal anthropogenic greenhouse gas that affects the Earths radiative balance. It is the reference gas against which other GHGs are measured and therefore has a Global Warming Potential (GWP) of 1. CH₄ and N₂O have a GWP of 21 and 310 respectively.
    
•    CO₂ is responsible for most of the enhanced green house effect of more than 50%, CH4 about 10 to 15% and NO2 about 4%.
    
•    The global atmospheric concentrations of carbon-dioxide, methane and nitrous oxide have increased since 1750, CO₂ increased from a pre-industrial value of 280 ppm to 379 ppm in 2005, CH₄ increased from 715 ppb to 1774 ppb and NO₂ increased from 270 ppb to 319 ppb in 2005.

Abstract

Increased human activities such as agriculture, mining, and manufacturing have resulted in rapid increase of green house gases (GHGs) in the atmosphere. Atmospheric accumulation of the GHGs results into global warming and climate variability or change. Climate change due to enhanced greenhouse effect arising as a result of human activity is considered a major global environmental threat to mankind today. Perhaps nowhere in the globe are people more vulnerable to climate change than in Sub-Saharan Africa (SSA). Most livelihoods in SSA are climate-sensitive due to over dependency on land and other natural resources and are thus perched on the brink of disaster due to climate change.

Climate change is now undoubtedly affecting millions of people across Africa and it actually threatens to wipe-out the past and current global efforts made to tackle poverty unless urgent and robust decisions and actions are taken. This is also a wake-up call for the world to adopt alternative development models that would ensure massive cuts in GHG emissions to avoid a potentially irreversible change. Scientists have warned that unless the global community, especially the developed countries, take genuine steps now to reduce their emissions; many more millions of people in the developing world will be negatively impacted by climate change.