Biotreatment of industrial effluents CHAPTER 26 – treatment of solid waste CHAPTER 27 – treatment of municipal waste

Biotreatment of industrial effluents CHAPTER 26 – treatment of solid waste CHAPTER 27 – treatment of municipal waste Biotreatment of industrial effluents CHAPTER 26 – treatment of solid waste CHAPTER 27 – treatment of municipal waste Biotreatment of industrial effluents CHAPTER 26 – treatment of solid waste CHAPTER 27 – treatment of municipal waste Biotreatment of industrial effluents CHAPTER 26 – treatment of solid waste CHAPTER 27 – treatment of municipal waste Biotreatment of industrial effluents CHAPTER 26 – treatment of solid waste CHAPTER 27 – treatment of municipal waste Biotreatment of industrial effluents CHAPTER 26 – treatment of solid waste CHAPTER 27 – treatment of municipal waste Biotreatment of industrial effluents CHAPTER 26 – treatment of solid waste CHAPTER 27 – treatment of municipal waste

C H A P T E R 26

Treatment of Solid

W a s t e

Introduction

Solid waste is defined as waste that is collected and transported by a means other than water Solid waste can be classified into different types depending

on the source:

9 Household waste, also called municipal waste

9 Industrial waste

9 Hospital or biomedical waste

Municipal solid waste consists of household waste, construction and demo- lition debris, sanitation residue, and waste from streets This garbage is generated mainly from residential and commercial complexes Garbage itself can be classified into four categories:

9 Organic waste: kitchen waste, vegetables, flowers, leaves, fruits

9 Toxic waste: old medicines, paints, chemicals, bulbs, spray cans, fertilizer and pesticide containers, batteries

9 Recyclable: paper, glass, metals, plastics

9 Soiled: waste from first aid, cleaning vehicles and other machine parts Over the last few years, the consumer market has grown rapidly, leading

to products being packed in cans, aluminum foil, plastics, and other such nonbiodegradable items Industrial solid waste includes metals, chemicals, paper, pesticides, dyes, rubber, and plastics Hospital waste is generated during the diagnosis, treatment, or immunization of human beings or ani- mals, in research activities in these fields, and in the production or testing

of biologicals These are in the form of disposables, swabs, bandages, etc This waste is highly infectious and can be a serious threat to human health

267

268 Biotreatment of Industrial Effluents

TABLE 26-1

The Type of Litter We Generate and Approximate Time It Takes to Degenerate (Untreated)

Type of litter Approximate time it takes to degenerate

Organic waste (vegetable, fruit

peels, leftover foodstuff, etc.)

Paper

Cotton cloth

Wood

Woolen items

Plastic bags

Glass bottles

A week or two 10-30 days 2-5 months

10 to 15 years

1 year Undetermined (many years) Undetermined

if not managed in a scientific and discriminate manner These different categories of waste each take their own time to degenerate if left untreated (as illustrated in the Table 26-1)

Bioremediation

Solid waste m a n a g e m e n t and t r e a t m e n t calls for a multipronged approach; ideally it should involve all the four Rs of waste management, alongside judiciously planned biotreatment Biotreatment, if planned, is the most suit- able because it would generate m e t h a n e gas, which can be used for energy purposes (biogas), while ensuring that detoxification is achieved

The need for a biological approach to improve environmental condi- tions directly relates to the increasing size of the h u m a n population on

a planet of finite dimensions In 1996 earth's estimated population was

6 billion people, but by the year 2100 that number is expected to almost double (Ashford and Noble, 1996) As populations grow in size, increases

in a variety of adverse h u m a n health and ecological effects (and associated costs such as healthcare expenses) are also expected The U.S EPA's Toxic Substances Control Act Chemical Inventory includes more than 72,000 chemicals, with approximately 2,300 new chemicals submitted to the U.S Environmental Protection Agency every year (Hoffmann, 1982) Along with population increases, the n u m b e r of different chemicals and the total a m o u n t

of chemicals produced are also bound to increase in the future In 1990, the total release of toxicants into the environment by U.S manufacturers was approximately 4.8 billion pounds (Ember, 2000) In addition, large quanti- ties of a n u m b e r of toxic products are released into the environment by end users in more or less unaltered form These products include those designed

Treatment of Solid Waste 269

for household use, as well as industrial materials such as fuels, deter- gents, fertilizers, dielectric fluids, preservatives, flavorings, flame retardants, heat transfer fluids, lubricants, protective coatings, propellants, pesticides, refrigerants, and many other chemicals Such materials or their breakdown products often accumulate in soil and aquifers near landfills and dumps, in surface lakes and streams, and in sediment These pollutants are present not only in concentrated waste sites but are widely distributed throughout the environment, although in many cases at levels too low to trigger regulatory action The kinds and amounts of these chemicals are also likely to increase

as human populations swell

There are a number of excellent reviews on bioremediation of solid wastes Composition-based remediation methods are covered in some way

in other chapters Hence, the scope of the present chapter will be to give an overview of newer technologies emerging in this field Innovative alternate technologies will be given attention

Landfill

The main method used to dispose of municipal solid waste (MSW)is to place it in a "landfill" also called a "garbage dump" or a "rubbish t i p " - -

85 to 90% of domestic waste and commercial waste is disposed of in this way If the landfill is suitably aerated and if it has sufficient amounts of organic waste, aerobic degradation naturally sets in Depending on the com- ponents of the landfill, i.e., if it has sufficient amounts of organic matter with no toxic chemicals, then both aerobic and anaerobic degradation set in Initially anaerobic degradation produces volatile carboxylic acids and esters, which dissolve in the water that is present In the next stage of decom- position, significant quantities of methane gas (biogas) are released as these acids and esters are degraded to methane and carbon dioxide The presence of heavy metals and polyhalogenated aromatics dampen the growth of microor- ganisms Care must be taken to ensure that these pollutants are pretreated before being dumped into the landfill Another way to overcome the presence

of these growth retardants is to inoculate the landfill with microorganisms adapted to high concentrations of these toxins One of the major problems of landfills is the l e a c h a t e - - w a t e r seepage from the landfill This leachate con- tains organic, inorganic, and microbial contaminants extracted from solid waste, which may contaminate the groundwater Aerobic degradation is the typical treatment for rapidly decreasing the biological oxygen demand (BOD) of the leachate In the past, landfills were often simply "holes in the ground" that had been created by mineral extraction Modern municipal landfills are much more highly designed and engineered Anaerobic digestion

is gaining more acceptance in the treatment of solid wastes The high solids reactor concept for anaerobic digestion can handle more than 30% dry solids

in the feed material and achieve a high conversion of organics to methane (Rivard, 1993)

270 Biotreatment of Industrial Effluents

C o m p o s t T r e a t m e n t

A new compost technology, known as compost bioremediation, is cur- rently being used to restore contaminated soils Compost bioremediation refers to the use of a biological system of microorganisms in a mature, cured compost to sequester or break down contaminants in soil Microor- ganisms digest, metabolize, and transform contaminants in soil and ground into humus and inert byproducts, such as carbon dioxide, water, and salts Compost bioremediation has proven effective in degrading or altering many types of contaminants such as chlorinated and nonchlorinated hydrocarbons, wood-preserving chemicals, solvents, heavy metals, pesticides, petroleum products, and explosives The compost used in bioremediation is referred to

as "tailored" or "designed" compost in that it is specially made to treat specific contaminants at specific sites In addition to reducing contami- nant levels, compost advances this goal by facilitating plant growth In this role, compost provides soil conditioning and also provides nutrients

to a wide variety of vegetation In 1979, at a denuded site near the Burle Palmerton zinc smelter facility in Palmerton, PA (United States), a reme- diation project was started to revitalize 4 square miles of barren soil that had been contaminated with heavy metals Researchers planted Merlin Red Fescue, a metal-tolerant grass, in lime fertilizer and compost made from a mixture of municipal wastewater treatment sludge and coal fly ash The remediation effort was successful, and the area now supports a growth of Merlin Red Fescue and Kentucky Bluegrass (Chaney, 1994) A similar success story was observed for the remediation of soil contaminated with petroleum hydrocarbons (Fordham, 1995)

U s e of E n z y m e s

There is a growing recognition that enzymes can be used in many remedia- tion processes to target specific pollutants for treatment Recent biotech- nological advances have allowed the production of cheaper and more readily available enzymes through better isolation and purification pro- cedures (Karam and Nicell, 1997) Improvement in the useful life of the enzyme, and thereby a reduction in treatment cost, has been accomplished through different methodologies, and one of the most promising was enzyme immobilization (Nicell et al., 1993) The effect of immobilized horseradish peroxidase (HRP)(on activated alumina) and hydrogen peroxide concentra- tion on the removal efficiency of phenol showed that one molecule of HRP was needed to remove approximately 1,100 molecules of phenol when the reaction was conducted at pH 8.0 and at room temperature Both tyrosi- nase and birnessite were able to catalyze the transformation of phenolic compounds through oxidative polymerization, a process that leads to humi- fication Bollag (2003) suggested that it is possible to enhance the natural process of xenobiotic binding and incorporation into the humus by adding laccase to the soil Chlorinated phenols and anilines were transformed in

Treatment of Solid Waste 271

TABLE 26-2

Enzymes and Their Potential Applications in Biodegradation

Chloroperoxidase

Lignin peroxidase

Manganese peroxidase

Tyrosinase

Laccase

Catechol dioxygenases

Phenoloxidase

Artromyces ramosus

Plant material

Caldariomyces funago Phanerochaete chrysosporium Phanerochate chrysopsorium Nematolona frowardie Agaricus bisporus Trametes hispida Pyricularia oryzae Trametes versicolor

Pseudomonas pseudoalacaligenes Phanerochate chrysopsorium

Phenol, chlorophenol, aniline degradation, dewatering of slimes

Phenol, PAH, herbicide degradation, polymerization

of humic acid Water decontamination Phenol degradation Aromatic compounds, phenols degradation

Phenols, lignins, pentachlorophenol, dyes degradation

Lignin degradation Catechol degradation Dye degradation Azo-dye degradation Chlorophenol, urea derivative degradation

Polychlorinated biphenyls, chlorothanes

Chlorinated compounds

soil by oxidative and detoxified coupling reactions mediated by laccase, per- oxidase, or metal oxides such as birnessite The potential applications of enzymes in biodegradations are listed in Table 26-2 (Duran and Esposito, 2000) Oxidative enzymes play an important role in the decontamination of soils At present, however, the commercial use of enzymes is still not real- ized because of the high cost of their isolation, purification, and production Immobilization will play an extremely important role in cost reduction

Phytoremediation

Phytoremediation is also an innovative technology that is gaining recog- nition as a cost-effective and aesthetically pleasing method of remediating contaminated soils There are several categories of phytoremediation:

9 Phytoextraction: Plants are often capable of the uptake and storage of significant concentrations of some heavy metals and other compounds in

272 Biotreatment of Industrial Effluents

their roots, shoots, and leaves This method is ideally suitable for soil contaminated with heavy metals

9 Phytotransformation: Plants metabolize some compounds and render them less toxic This method is suitable for soil contaminated with organic pollutants

9 Phytostabilization: Plant root exudates (enzymes and other chemicals) chelate with some contaminants and reduce their migration through the soil This process effectively reduces the bioavailabilty of harmful contaminants

9 Phytostimulation: At the soil-root interface, known as the rhizosphere, there is a very large and active microbial population Often the plant and microbial populations provide needed organic and inorganic compounds for one another The rhizosphere environment is high in microbial abun- dance and rich in microbial metabolic activity, which has the potential

to enhance the rate of biodegradation of contaminants by the microorgan- isms Generally, the plant is not directly involved in the biodegradation process It serves as a catalyst for increasing microbial growth and activity, which subsequently increases the biodegradation potential

According to preliminary studies, enhanced degradation of pesticides (atrazine, metolachlor, and trifluralin)was observed in contaminated soils where plants of the Kochia sp have been planted Many plants and bacte- ria have evolved various means of extracting essential nutrients, including metals, from their environment In the course of prospecting for minerals, unusually tolerant species have been observed in the vicinity of metal-rich deposits In some cases, these tolerant organisms concentrate metals several thousandfold over ambient concentrations Zajic (1969), Baker and Brooks (1989), Shann (1995), and other authors point out that such organisms may provide the opportunity to return waste material to useful products rather than merely transform them to innocuous substances However, a practical phytoremedial technology remains to be developed, although progress has been made with transgenic Arabidopsis thaliana expressing merApe9 (Rugh

et al., 1996) Grown on medium containing HgCb., at concentrations of 25 to

100 M (5 to 20 ppm), these transgenic merApe9 seedlings evolved consider- able amounts of Hg ~ relative to control plants However, the transformation

of ionic mercury to the metallic elemental form, which then volatilizes to become an air pollutant, is a less than ideal remedial solution

V e r m i c o m p o s t i n g

Municipal solid waste (MSW) is highly organic in nature, so vermicompo- sting has become an appropriate alternative for safe, hygienic, and cost effective disposal Earthworms feed on the organics and convert material into castings (ejected matter) rich in plant nutrients The chemical analyses

of cast show 2 times the available magnesium, 15 times the available nitro- gen, and 7 times the available potassium compared with the surrounding soil

Treatment of Solid Waste 273

The action of earthworms in the process of vermicomposting of waste is physical and biochemical The physical process includes substrate aera- tion, mixing as well as actual grinding, while the biochemical process

is influenced by microbial decomposition of substrate in the intestine of earthworms (Hand et al., 1988) Various studies have shown that vermicom- posting of organic waste accelerates organic matter stabilization (Neuhauser

et al., 1998) and provides chelating and phytohormonal elements that have a high microbial matter content and stabilized humic substances A number of references are available on the potential of earthworms in the vermicompost- ing of solid waste, particularly household waste (Edwards, 1980) Advanced systems for vermicomposting are based on top feeding and bottom discharge

of a raised reactor, thus providing stability and control over key areas of tem- perature, moisture, and aeration Price and Phillips (1990) have developed an improved mechanical separator, having a novel combining action, for remov- ing live earthworms from vermicomposts Vermicomposting provides other advantages, too; some earthworms (Lempito mauritii) can also be used for specific wastes such as those from medical facilities (Hori et al., 1974) and those with high concentrations of protein or pig feed (Mekada et al., 1979),

as well as in nematode control (Dash et al., 1980)

Conclusion

Solid waste management is a necessary prerequisite for healthy living Given the growth in population and industry, solid waste is increasing geometri- cally year after year Unless there is a concerted, focused effort in dealing with this waste, both at the level of the individual and the community, waste will become a major health hazard Bioremediation is the most suitable and economical method for degrading this waste Many newer processes are being developed; of these, the most promising are (as discussed previously):

9 Landfill

9 Use of enzymes

9 Composting

9 Phytoremediation

9 Vermicomposting

Rather than adopting any single method of remediation, it is advisable that a combination of two or more of these methods be adopted This would ensure faster degradation of the waste while producing biomass (sludge) that can be used for a variety of commercial purposes

References

Ashford, L S., and J A Noble 1996 Population policy: consensus and challenges Conse- quences 2(2):25-36

274 B i o t r e a t m e n t of Industrial Effluents

Baker, A J M., and R R Brooks 1989 Terrestrial higher plants which hyperaccumulate metallic elements-a review of their distribution, ecology, and phytochemistry Biorecovery

1:81-126

Bollag, J M., H.-L Chu, M A Rao, and L Gianfreda (2003) Enzymatic oxidative transformation

of chlorophenol mixtures J Environ Qual 32:63-69

Chaney, R L 1994 Phytoremediation potential of Thlaspi caerulescens and Bladder campion

for zinc J Environ Qual 23:1151-1157

Dash, M C., B K Senapati, and C C Mishra 1980 Nematode feeding by tropical earthworms

Trop Ecol 20:10-12

Duran, N., and E Esposito 2000 Potential applications of oxidative enzymes and phenoloxidase-like compounds in wastewater and soil treatment: a review Appl Catalysis B: Environ 28:83-99

Edwards, C A 1981 Earthworms, soil fertility, and plant growth In: Workshop on the Role

of Earthworms in Stabilization of Organic Residues, vol 1, M Appelhof (ed.), pp 61-86 Kalamazoo, Michigan: Beech Leaf Press

Ember, L 2000 Reclassifying chemical relics of the Cold War Chem Eng News 78(3):44 Fordham, W 1995 Yard trimmings composting in the Air Force Biocycle 36:44

Hand, P., W A Hayes, J C Frankland, and J E Satchell 1998 The vermicomposting of cow slurry Pedobiologia, 31:199-209

Hoffmann, G R 1982 Mutagenicity testing in environmental toxicology Environ Sci Technol 16:560-573

Hori, M., K Kondo, T Yosita, E Konsihi, and S Minami 1974 Studies of antipyretic components in the Japanese earthworm Biochem Pharmacol 23(11):1583-1590

Karam, J., and J A Nicell.1997 Potential applications of enzymes in waste treatment J Chem Technol Biotechnol 69:141-153

Mekada, H., N Hayashi, H Yokota, and J Okumura 1979 Performance of growing and laying chickens fed diets containing earthworms(Eisenia foetida) Jpn Poult Sci., 16:293-297 Neuhauser, E F., R C Loehr, and M R Malecki 1998 Earthworms in waste and environmental management, The Hague: SPB, Academic Publishing

Price, J S., and V R Phillips 1990 An improved mechanical separator for removing live worms from worm-worked organic wastes Biol Waste 33(1 ):25-3 7

Rivard, C J and N J Nagle 1993 Anaerobic biodegradation of sewage-derived fat, oil, and grease (FOG) at mesophilic and thermophilic temperatures In: Proceedings of the 1994 food

industry environmental conference, p.71, Atlanta, GA: Georgia Tech Research Institute

Rugh, C L., H D Wilde, N M Stack, D M Thompson, A O Summers, and R B Meagher

1996 Mercuric ion reduction and resistance in transgenic Arabidopsis thaliana plants expressing a modified bacterial merA gene Proc Natl Acad Sci USA 93:3182-3187 Shann, J R 1995 The role of plants and plant/microbial systems in the reduction of exposure

Environ Health Perspect 103(5):13-15

Zajic, J E 1969 Microbial biogeochemistry New York: Academic Press

C H A P T E R 27

Treatment of Municipal

W a s t e

Introduction

The term "sewage" refers to the wastewater produced by a c o m m u n i t y ,

w h i c h m a y originate from three different sources:

9 Domestic wastewater

~ Industrial wastewater

9 Rainwater

Domestic wastewater is usually the m a i n component of sewage and is often used as a synonym The sewage flow rate and composition vary consider- ably from place to place, basically depending on economic aspects, social behavior, climatic conditions, water consumption, type and conditions of the sewer systems, and so forth It is not u n c o m m o n for water polluted by organic substances associated w i t h animal or food waste or sewage to have

an oxygen demand that exceeds the m a x i m u m equilibrium solubility of dis- solved oxygen Under such circumstances, unless the water is continuously aerated, it will soon be depleted of its oxygen, and fish living in the water will die The average composition of sewage is given in Table 27-1

Improved bioremediation of biological wastes is envisioned as a nec- essary first step in breaking the chain of events associated w i t h micro- bial pathogenesis In England, the recent outbreak of bovine spongiform encephalopathy (mad cow disease}, w h i c h is believed to be associated

w i t h Creutzfeldt-Jakob disease in humans, has increased concern over disease transmission from food animals to h u m a n s (Narang, 1996) In fact, a great m a n y microbial diseases (zoonotic diseases) can and often

do cross over to affect humans Diseases that can pass to h u m a n s from swine, for example, include bacterial infections, such as anthrax (Bacillus antracis), brucellosis (Brucellosis suis), ampylobacteriosis (Campsylobac- ter jejuni), erysipeloid (Erysipelothrix rhusiopathiae); viral infections, such

as encephalomyocarditis (Cardiovirus), influenza (Influenzavirus), Japanese

275

276 Biotreatment of Industrial Effluents

TABLE 27-1

Average Composition of Sewage

Microorganisms

E coli 4 x 107 (no in 100 mL) Viruses

Emerging contaminants

Acidic pesticides

Surfactant metabolites

B encephalitis [Flavivirus (gp A)], and vesicular stomatitis (Vesiculovirus);

nematode infections, such as ascariasis (Ascaris s u u m ) a n d trichinosis

(Trichinella spp.); protozoan infections, such as balantidiasis (Balantid- ium coli), toxoplasmosis ( Toxoplasma gondii), amoebic dysentary/amebiasis

(Entamoeba polecki) and sarcocystosis (Sarcocystis suihominis); and spiro- chetal infections, such as leptospirosis (Leptospira interrogans)(Beran, 1994) Although the advent and continued development of antibiotics have kept infectious disease in developed countries under control for m a n y years, there is growing evidence that this may not be effective indefinitely because increasingly virulent and antibiotic-resistant strains continue to evolve (Tenover, 1995) Hence, proper treatment of the sewage becomes essential for maintaining a healthy environment

Treatment

Wastewater purification is the clearest paradigm of environmentally friendly technologies Some negative aspects of development and urbanization can

be diminished, or even eliminated, through a comprehensive t r e a t m e n t of domestic and industrial wastewater, directly and immediately enhancing the quality of the environment

Bioremediation is not new to the h u m a n race, although new approaches that stem from advances in molecular biology and process engineering are