Wastewater Treatment Using Microalgae

Six different concentrations of Chlorella vulgaris microalgae culture are incorporated with raw wastewater to improve treatment efficiency in three phases. In phase one of study, 30% and 40% microalgae were incorporated with raw wastewater with 24 hrs retention period for 18 days in a batch mode and these conditions are made same for all phases. During phase two and phase three of study, 20%, 25% and 35%, 45% micro-algae concentrations used to treat raw wastewater respectively. Amongst all the six concentrations, 30% microalgae behaves most efficiently and is able to reduce 34 to 81% COD, 43 to 75% nitrate, and 36 to 99% of phosphorous. Overall ammonia nitrogen reduction varies from 80% to 99%. No attempt was made to control temperature or evaporation losses. These attempts can definitely increase the growth process of microalgae and increase the removal efficiency of nutrients in wastewater.

Sustainable Solid Waste Management via Biological Treatment

The solid wastes generated as a result of human activity have become very complex. Unscientific management of such wastes has resulted in environmental pollution, thereby putting a serious risk to the ecosystem and human health. A sustainable waste management is required for reduced pollution levels as well as for safeguarding the environment for future generation. Biological methods have gained in importance mainly because of its environmentally friendly option for recovering materials and energy. This is true as per the guidelines of “Hierarchy of Sustainable Waste Management.” Composting and anaerobic digestion are two treatment options that is commonly followed in both developing as well as developed countries. The aim of this chapter is thus to address the technical background, advantages, as well as shortfalls related to the waste treatment via biological methods. An up-to-date literature thus presented may be beneficial to the scientists and researchers for working towards further improvement of the present system of waste management.

Wood Waste Characterization and Reuse Possibilities

Wood is the most versatile natural material. It can be used to obtain sawn wood, wood for civil construction, naval purpose, packaging, furniture, wood flooring, composites, bioenergy, pulp and paper. More recently, nanotechnology and the biorefinery processes create new possibilities for wood use; however, wood processing still generates a large amount of waste. Wood can be processed mechanically or chemically. The mechanical processing of wood has residues like sawdust, cuttings, and wood chips. From the chemical processing of wood, the main residue is black liquor.

Safe Use of Wastewater in Agriculture Through Bioremediation Processes

Population growth, industrialisation, urbanisation, and climate change have created huge pressure on freshwater resources to fulfil the demand. Approx. 70-80% of the freshwater supply returns as wastewater, which is difficult to tackle and manage. We need to tackle the freshwater demand from different sectors like domestic, industrial, and agriculture. Most important is how to use the wastewater safely in agriculture. Therefore, it is an apt time to refocus on ways to recycle water especially in sectors like agriculture and for ecosystem services. The major concern in using wastewater in agriculture is its quality as the wastewater may carry pathogens, heavy metals, and many other pollutants, which might reach to human beings and animals via food chain. A solution to wastewater reuse is through bioremediation techniques. Bioremediation should be considered as a feasible and futuristic technology for safe use of wastewater in agriculture as it will reduce the burden on centralised water treatment system as well as it being economic and eco-friendly.

Use of Wastage Biomaterial/Biomass for Wastewater Treatment and Modeling

Recently, the existence of toxic materials in our environment has caused severe concern to the living organism. The main causes for the contamination of such toxic materials in the environment are rapid industrialization and agricultural activities. The different toxic entities present in the environment mainly depend on the nature of the industry. However, some of the common generated toxic pollutants present in the water bodies are heavy metal ions, phenol, dyes, pesticides, insecticides, detergents, and a wide spectrum of aromatic compounds. Among those substance, heavy metals have been reported the major one for the last few decades. So, these heavy metals must be removed from the environment by proper techniques to save the society. The chapter deals with the different toxic material removal technologies and mathematical modeling.

Bioremediation and Biodegradation Technologies for Removal of Pollutants and Wastes from the Environment

Bioremediation is defined as the process whereby organic wastes are biologically degraded under controlled conditions to an innocuous state, or to levels below concentration limits established by regulatory authorities. For bioremediation to be effective, microorganisms must enzymatically attack the pollutants and convert them to harmless products. As bioremediation can be effective only where environmental conditions permit microbial growth and activity, its application often involves the manipulation of environmental parameters to allow microbial growth and degradation to proceed at a faster rate. Bioremediation techniques are typically more economic than traditional methods such as incineration, and some pollutants can be treated on site, thus reducing exposure risks for clean-up personnel, or potentially wider exposure as a result of transportation accidents. Bioremediation is based on natural attenuation. The public considers it more acceptable than other technologies.

Performance of Chitosan and Polyglutamic Acid in Palm Oil Mill Effluent Treatment

This chapter presents the study on pollutant removal efficiency in palm oil mill effluent using chitosan and polyglutamic acid (PGA). Up until today, palm oil mill effluent (POME) has been considered one of the significant sources of environmental pollution. The characteristics of POME include contaminating the source of drinking water, which is also harmful to the aquatic ecosystem by creating a highly acidic environment or causing eutrophication. With increasing public awareness of environmental pollution, it creates the need to address this issue. Both chitosan and PGA are non-polluting food-based anionic and biodegradable biopolymers that are environmentally friendly in wastewater treatment. The critical parameter to determine the effectiveness of pollutants removal is chemical oxygen demand, colour, and total suspended solids. In this aspect, this chapter also discussed some of the significant findings done in previous studies to provide proper understandings and implications on this topic.

A Review on Solid Waste Management Using the DPSIR Framework in a Southern Africa Case Study

This chapter uses the DPSIR framework to examine logistical, infrastructural, and operational challenges in SA's SWM system using Buffalo City Municipality as case study. Findings suggest that SWM is an endemic problem in the municipality characterised by a preference to landfill disposal, minimal recycling tendencies, poor waste services, non-enforcement of existent waste regulation, inadequate funding, and non-involvement of urbanites and informal sector in the process. To counter these challenges, BCM has enhanced its financial resources to facilitate scientific landfilling and transit to perceptions of solid waste as a useful good. The municipality has collaborated with local industries and international organizations to synergize efforts to implement state and local waste management plans. For an integrated model of SWM, this review suggests SA and BCM's need to plan innovatively, adopt landfill-mining, plan strategically on all waste cycle aspects, and modify existing regulations to accommodate urbanites and informal waste pickers in the process.

A Review on Isolation of Acetobacter and Production of Vinegar From Pineapple and Papaya Waste (Peels) Using Acetobacter aceti

India is the second-largest producer of contemporary fruits and vegetables. This leads to generation of a large amount of waste, both solid and liquid. This waste is incautiously or carelessly being thrown without any treatment promoting environmental deterioration. The chapter deals with how these fruit wastes, especially pineapple and papaya peels, which are usually discarded during the processing or consumption of the fruit, are useful in preparation of vinegar, which is termed as a useful product from waste. It also discussed the general characteristics of Acetic acid bacteria, importance of the bacteria, and how it can be isolated by natural sources, which is cost effective. So, the waste peels generated after consuming the fruits and vegetables need not be discarded as waste; instead, it can be used in so many ways to produce useful products.

Microalgal Photobioreactors as an Integrated Approach for Simultaneous Wastewater Treatment, Carbon Sequestration, and Recovery of Valuable Resources

Unplanned and unmonitored growth of civilization and industries recorded in the previous decades have resulted in the introduction of several pollutants of emerging concern like pharmaceuticals and antibiotic drugs, endocrine disrupters, personal care products, etc. in adjacent aquatic environments. Moreover, the primary considerations of recent wastewater treatment strategies include energy neutrality and efficient recovery of valuable products as end/byproducts of the concerned process. The present study reviews such recent advances in designs, development, and implementation of algae based photobioreactors for simultaneous CO2 capture and treatment of effluents containing various types of emerging contaminants with negligible energy input. It also discusses the subsequent usage of algal biomass for production of value-added products like bioethanol, alginate, etc. This study has primarily addressed the potential and limitations of such photobioreactors for simultaneous achievement of wastewater remediation, CO2 sequestration, and bioenergy production with a zero-discharge concept.