Wastewater Reuse and Watershed Management

Engineering Implications for Agriculture, Industry, and the Environment

Ajai Singh, Ajai Singh

• Publisher: Apple Academic Press
• Year: 2019
• ISBN:
  9780429783623
• Edition: 1
• Topic: Biological Sciences
• Subtopic: Science General
• Index: Biological Sciences

Water is a finite resource, and the demand for clean water is constantly growing. Clean freshwater is needed to meet irrigation demands for agriculture, for consumption, and for industrial uses. The world produces billions of tons of wastewater every year. This volume looks at a multitude of ways to capture, treat, and reuse wastewater and how to effectively manage watersheds. It presents a selection of new technologies and methods to recycle, reclaim, and reuse water for agricultural, industrial, and environmental purposes.

The editor states that more than 75–80% of the wastewater we produce goes back to nature without being properly treated, leading to pollution and all sorts of negative health and productivity consequences. Topics cover a wide selection of research, including molluscs as a tool for river health assessment, flood risk modeling, biological removal of toxins from groundwater, saline water intrusion into coastal areas, urban drainage simulations, rainwater harvesting, irrigation topics, and more.

Key features:
• explores the existing methodologies in the field of reuse of wastewater
• looks at different approaches in integrated water resources management
• examines the issues of groundwater management and development
• discusses saline water intrusion in coastal areas
• presents various watershed management approaches
• includes case studies and analyses of various water management efforts

PART I
Wastewater Management

CHAPTER 1

Vermifiltration of Arsenic Contaminated Water Using Vermifiltration Technology: A Novel Bio-Filter Model

CHANDRAJEET KUMAR¹, SUSHMITA², NUPUR BOSE³, and ASHOK GHOSH⁴

¹PhD Scholar, UGC-RGNF-SRF, Department of EWM, A.N. College, Patna 23, Bihar, India, E-mail: [email protected]

²PhD Scholar, Department of EWM, A.N. College, Patna 23, Bihar, India

³Associate Professor, Department of Geography, A.N. College, Patna–23, Bihar, India

⁴Professor and Head, Research Section, Mahavir Cancer Sansthan and Research Centre, Patna 801505, Bihar, India

ABSTRACT

Arsenic toxicity has become a global concern owing to the increasing contamination of soil, groundwater, and crops in many regions of the world, and Bihar is one of the worst affected states of India where Arsenic concentration has been found up to 1861 ppb in groundwater. As Arsenic has a high magnitude of solubility, its removal from contaminated water and soil is very difficult. Vermifiltration of Chemically contaminated and sewage water using earthworms is a newly conceived novel technology with several advantages over the conventional water filtration systems. Certain species of earthworms (Eisenia fetida and Eudrillus euginae) have been found to purify the contaminated wastewater. Their bodywork as a ‘bio-filter’ having the capacity to bio-accumulate high concentrations of toxic chemicals in their tissues and the resulting purified water (termed as Vermiaqua) becomes almost chemical and pathogen-free. To make vermifiltration unit, a vermifilter bed was prepared using plastic drum which was in depth filled with a large, medium, small size stone chips followed by sand and humid soil at the top layer and 5000 earthworms were released in the moist soil top layer. Water controller knob was attached with a sample container which allows 50–60 drops per minute water input into the top layer of vermifilter bed which was also attached with Filtrate collector container through pipe for filtrate collection. Prepared arsenic trioxide solutions of 10,000 µgl^–1 and 20,000 µgl^–1 were poured in separate sample collection container and allowed to pass through layers of vermifilter bed for continuous three days and on the fourth day purified water was collected in nitric acid washed filtrate collection container and analyzed by atomic absorption spectrophotometer (AAS). According to the AAS analysis, the arsenic concentration of 10,000 µgl^–1 and 20,000 µgl^–1 values were decreased to 7.716 µgl^–1 and 6.186 µgl^–1, respectively and accordingly in the body tissue of earthworms, 127.9 µgl^–1 and 63.81 µgl^–1 arsenic were found, respectively.

1.1 Introduction

Arsenic is a known carcinogen and a mutagen. Since the arsenic contaminated groundwater is leading to a host of health problems, often culminating in diseases with high fatality rates, like cancer. Tragically, most of the worst geogenic arsenic affected areas are located in developing economies of the world, and there is an ever-increasing demand for arsenic-free water in these heavily populated areas. The fluvial plains of South Asia have borne the brunt of incidences of arsenicosis, or chronic diseases due to arsenic poisoning, across countries of Bangladesh, India, Nepal, and Pakistan. This global health issue can be best controlled by halting direct and indirect ingestion of arsenic that is taking place through contaminated drinking water and arsenic contaminated agricultural produce, and simultaneously supplying clean water for drinking and irrigation purposes. Several proven filtration technologies are now globally in place, broadly categorized in Mandal et al. (2002). Earthworms have over 600 million years of history in waste and environmental management. Charles Darwin called them as the ‘unheralded soldiers of mankind,’ and the Greek philosopher Aristotle called them as the ‘intestine of earth,’ meaning digesting a wide variety of organic materials including the waste organics from earth (Darwin and Seward, 1903). Earthworms harbor millions of ‘nitrogen-fixing’ and ‘decomposer microbes’ in their gut. The distribution of earthworms in soil depends on factors like soil moisture, availability of organic matter, and pH of the soil. They occur in diverse habitats especially those which are dark and moist. Earthworms are generally absent or rare in soil with a very coarse texture and high clay content or soil with pH 4 (Gunathilagraj, 1996). In a study made by Kerr and Stewart (2006), it was opined that fetida can tolerate soils nearly half as salty as seawater. Earthworms can also tolerate toxic chemicals in the environment. E. fetida also survived 1.5% crude oil containing several toxic organic pollutants (OECD, 2000). Some species have been found to bio-accumulate up to 7600 mg of lead (Pb) per gm of the dry weight of their tissues (Ireland, 1983). They can tolerate a temperature range of 5 to 29°C. A temperature of 20–25°C and moisture of 60–75% are optimum for good worm function (Hand, 1988).

Vermifiltration of wastewater using waste eater earthworms is a newly conceived novel; an innovative technology developed by our research collaborator. Earthworms bodywork as a ‘biofilter’ and they have been found to remove the 5 days BOD by over 90%, COD by 80–90%, total dissolved solids (TDS) by 90–92% and the total suspended solids (TSS) by 90–95% from wastewater by the general mechanism of ‘ingestion’ and biodegradation of organic wastes, heavy metals and solids from wastewater and also by their ‘absorption’ through body walls (Sinha et al., 2015). Most successful species are the Tiger Worms (Eisenia fetida). Vermifiltration system is low energy dependent and has a distinct advantage over all the conventional biological wastewater treatment systems—the ‘activated sludge process,’ ‘trickling filters,’ and ‘rotating biological contractor’ which are highly energy intensive, costly to install and operate, and do not generate any income. This is also an odor free process. The most significant advantage is that there is ‘no sludge formation’ in the process as the earthworms eat the solids simultaneously and excrete them as vermicast. This plagues most municipal council in the world as the sludge being a biohazard requires additional expenditure on safe disposal in secured landfills. In the vermifilter process, there is 100% capture of organic & inorganic materials and any pathogen, and capital and operating costs are much lesser. Earthworm’s bio-accumulate all toxic chemicals including the ‘endocrine disrupting chemicals’ (EDCs) from sewage which cannot be removed by the conventional systems. A pilot study on vermifiltration of sewage was made by Xing et al. (2005) at Shanghai Quyang Wastewater Treatment Facility in China. Taylor (2003) studied the treatment of domestic wastewater using vermifilter beds and concluded that worms could reduce BOD and COD loads as well as the TDSS (total dissolved and suspended solids) significantly by more than 70–80%. Hartenstein and Bisesi (1989) studied the use of earthworms for the management of effluents from intensively housed livestock which contains very heavy loads of BOD, TDSS, nutrients nitrogen (N) and phosphorus (P). The worms produced clean effluents and also nutrient-rich vermicompost. Bajsa et al. (2003) also studied the Vermifiltration of domestic wastewater using vermicomposting worms with significant results.

1.2 Experimental Design

1.2.1 Construction and Installation of the Vermifiltration Unit

To make vermifiltration unit, three plastic drums of 80-liter capacity were taken. Out of these three drums, two of them were prepared as vermifilter unit for arsenic filtration and remaining one was prepared as control (Figure 1.1). In the control unit, all other materials were organized in the same way as in vermifilter unit except earthworms. All three plastic drums were filled with different layers consisting of large size pebbles with 10” height, medium size pebbles (10”), small size pebbles (10”) followed by sand (6–7”), and humid soil (20”) at the top layer to prepare filter (Figure 1.2). Finally, 5000 number of earthworms (Eisenia fetida) weighing approximately 5 kg were released in the moist soil layer of two filter unit to prepare vermifiltration unit.

FIGURE 1.1 Construction and installation of the vermifiltration unit.

FIGURE 1.2 Different layers of vermifiltration unit.

A movable iron stand of approximately 150 kg was prepared to have 4 columns and 3 rows to keep 3–4 filtration unit, sample containers, and filtrate collector containers. Upper row carries the sample container, middle row carries the plastic drum (vermifilter bed), and the lower row carries the filtrate collector container. Water controller knob was attached with a sample container which allows 50–60 ...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• About The Editor
• Table of Contents
• Contributors
• Abbreviations
• Preface
• PART I: Wastewater Management
• PART II: Integrated Water Resources Management
• PART III: Groundwater Management
• PART IV: Watershed Development and Management
• Index