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Use of some natural and waste materials for waste water treatment
PII: S0043-1354(01)00047-1
Wat. Res. Vol. 35, No. 15, pp. 3738–3742, 2001 # 2001 Elsevier Science Ltd. All rights reserved Printed in Great Britain 0043-1354/01/$ - see front matter
RESEARCH NOTE USE OF SOME NATURAL AND WASTE MATERIALS FOR WASTE WATER TREATMENT SHAMIM AHSAN1*, SATOSHI KANECO1, KIYOHISA OHTA1, TAKAYUKI MIZUNO1 and KEIKO KANI2 1 Department of Chemistry for Materials, Faculty of Engineering, Mie University, Tsu, Mie 514-8507, Japan and 2 International Center for Environmental Technology Transfer, Japan
(First received 24 July 2000; accepted in revised form 15 January 2001) Abstract}A fundamental study was conducted to assess removal and filtration capacity of waste and natural indigenous materials as treatment mediums e.g., shell, limestone, waste paper mixed with refuse concrete, refuse cement, also processed nitrolite, charcoal-bio and charcoal. Under room temperature condition removal of phosphoric, nitric and ammonium-ions, filtration of suspended substance (SS) together with removal of COD in waste water was investigated. Influence of particle size effect for all treatment mediums except for waste paper was pursued. Significant improvement of waste water quality with respect to SS, phosphoric ions and decrease in COD is possible by treating with these filtration mediums. With specific reference to some treatment mediums NO3–N and NH4–N showed reasonable improvement in quality, although generally removal effect was not very significant. Efficacy of treatment was dependent on the particle size of treatment mediums in general, however, nitrolite for NH4–N, charcoal-A for SS and COD, refuse cement mixed with waste paper for PO4 ion removal showed insignificant variability on the particle size effect. Results of this fundamental study demonstrate effectiveness and feasibility for applied application of these proposed waste and naturally available treatment ingredients at lower cost. # 2001 Elsevier Science Ltd. All rights reserved Key words}waste treatment, removal, filtration, indigenous materials
INTRODUCTION
Suspended substances, nutrients and organic load as COD contribute major pollutants in the rivers, lakes and ponds. Removal of these contaminants in waste water is one of the fundamental goal in waste treatment. A range of technologies are available to treat various types of wastes to adequate levels. However, conventional waste treatment technologies as adopted in the industrialized nations are expensive to build, operate and also maintenance. Therefore, intensive research efforts are continuing to develop less costly treatment technologies appropriate in rural, semi-urban, isolated communities and a variety of industrial simulations. Moreover during recent years stringent regulation of nutrients discharge into waterways is receiving wider consensus. To comply with stringent regulations and restore safe environment, it has become imperative to find some less costly-adaptable treatment technology.
*Author to whom all correspondence should be addressed. Tel.: +81-59-231-9427; fax: +81-59-231-9442/9471/ 9427; e-mail: [email protected]
In order to achieve efficient cost effective technology, natural materials e.g., sands, red mud (residues from bauxite refining), soils, gravel, biomass char, activated carbons and water hyacinth etc., are generally been applied in waste water treatment facilities to remove pollutants. A recent review reported one such successful attributes designated as ‘Simanto–gawa system’ in Japan (Matsumoto, 1997, 1999), which used plastic filter, nitrolite, organic matters with high carbon–organic ratio, charcoal-bio, charcoal, processed limestone as treatment mediums. Nevertheless, promotion of integrated small scale treatment using cheaper treatment medium is still warranted. In a previous study (Ohta et al., 1998), it has been found that the rocks as andesite, granite, marble, refuse concrete and refuse cement is very effective as treatment mediums for simple waste treatment process. In the present study, the effect and behavior of the various refuse and naturally available materials (Shells, limestone, nitrolite, charcoal-bio, charcoal and waste paper-mixed refuse cement and concrete) was investigated for more efficient waste water treatment technologies.
3738
Waste water treatment by natural and waste materials MATERIALS AND METHODS
Instrumentations + For the determinations of SS, PO3 4 , NO3 , NH4 UVDouble Beam Spectrometer (UVIDEC 610. 650, Japan Spectroscopic company Limited) was used with a resonance line of 660, 880, 540 and 630 nm, respectively. Sample mass of the chemicals and samples was determined by using a semimicro analytical balance H20 (Mettler) providing a resolution of 0.01 mg. Samples were grounded by an iron mortar and sieved to different particle sizes with stainless sieves (NIPPON RIKAGAKU KIKAI). Ultrapure water was prepared using ADVENTEC ultrapure water system CW-102.
Samples, reagents and standards Waste samples collected from waste water treatment plant of Mie university, constitute a mixture of domestic and chemical wastes from the university campus. Reagents and standards were prepared to desired concentration periodically, as and when required. Chemicals for the + analysis of PO3 4 , NO3 , NH4 and COD and standards 3 + for PO4 , NO3 , NH4 were obtained from Nacalai Tesque Inc, Kyoto, Japan. All reagents and chemicals used were of analytical grade or spectroscopic purity. Medium preparations and analytical procedures Treatment mediums were picked up from in and around university campus except for shell(oyster) from the sea side. Processed nitrolite (a partially processed mineral zeolite), charcoal (made from coconut) and charcoal-bio (charcoal embedded with microorganisms) were supplied from Toyo Denko, Japan. Used newspapers were cut to an averages sizes of 1–2 mm before use. After grinding all mediums were made to different particle sizes using 25.6, 35.5, 42, and 50 mesh-stainless sieve and then washed with pure distilled water until visible dirts are removed and dried at room temperature. An accurately weighed dried 5.0 g of shell, nitrolite, limestone, charcoal and charcoal-bio were poured and packed into 50 ml size burette. Alternatively, for mixed mediums 2.5 g of dried refuse concrete and cement powders together with 1.0 g (1–2 mm size) of waste paper were transferred and packed into the burette. Continuous filtration of 100 ml of waste samples was performed with different mediums under room temperature at a flow rate of 0.33 ml min1.
3739
one of the detrimental criteria in waste water treatment. In this study filtration of SS with the aforementioned mediums were conducted and treatment efficiencies are presented in Table 1. The reproducibility (R.S.D.) of this method was better than 15% for 3 repeated measurements. Filtration of SS with single medium varied within 42–100%, and with mixed mediums 55–91%. As in Fig. 1 with smaller particle diameter mediums filtration of SS increased in general, while in Fig. 2 filtration was lower with smaller and larger particle size mediums of refuse cement and refuse concrete, respectively, mixed with waste papers. The reason of this phenomenon is not clear. Presumably it may be due to the presence of dirt which arose from refuse cement. Consequently, best filtration of SS 99–100% was observed with charcoal, independent of particle size effect, as shown in Fig. 1. Phosphoric ions removal To remove phosphate from contaminated waste water both biological and physico–chemical processes have been extensively studied. In European Union using different biological or physico–chemical processes allowed to cope with discharge content of 1–2 mg l1 (Copper et al., 1994). Nevertheless, in
RESULTS AND DISCUSSION
Suspended substances (SS) Suspended substances play an important (and often underestimated) role in characterizing the treatability and hence the degree of contaminant removal in waste water. Therefore, removal of SS is
Fig. 1. SS removal in the waste water treatment with shell, nitrolite, limestone, charcoal and charcoal-bio at different particle sizes: (*), Shell, (4), Nitrolite, (*), Limestone, (&), Charcoal, (m), Charcoal-bio.
Table 1. Summary of treatment efficiency of different mediumsa Mediums Refuse cement and waste paper Refuse concrete and waste paper Shells Limestone Nitrolite Charcoal-bio Charcoal a
n ¼ 3.
SS
COD
PO4
NO3
NH4
62–91% 55–78% 42–88% 76–87% 72–91% 54–95% 99–100%
No removal 8–14% 42–65% 42–58% 30–61% 61–71% 85–88%
79–80% 33–54% 20–32% 13–27% 36–66% 18–32% 11–17%
14–23% 11–17% 17–37% 12–25% 7–22% 29–38% 15–19%
0–13% No removal 6–16% 7–12% 65–75% 31–62% 11–32%
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Shamim Ahsan et al.
Fig. 2. SS removal in the waste water treatment with waste paper-mixed refuse cement and refuse cement at different particle sizes: (*), Refuse cement mixed with waste paper, (*), Refuse concrete mixed with waste paper.
Fig. 3. PO4 ion removal in the waste water treatment with shell, nitrolite, limestone, charcoal and charcoal-bio at different particle sizes: (*), Shell, (4), Nitrolite, (*), Limestone, (&), Charcoal, (m), Charcoal-bio.
some regions, more stringent measures (0.8– 0.5 mg P l1) are applied to control eutrophication (Galarneau and Gehr, 1997; Matsche´, 1997). As shown in Fig. 3 that with single medium best removal was obtained with nitrolite i.e., in the range of 36–66%. Contrarily, Fig. 4 illustrates that, most significant adsorption of PO4 ion was observed with mixed medium of refuse cement and waste paper, regardless of any particle size effect. Alternatively, Figs 3 and 4 show that with other single and mixed mediums generally removal was better with smaller particle size grains. Nitric and ammonium ions removal In various treatment methods for nitrate removal, ion exchange have been found to be very efficient (Dahab and Lee, 1988). Chemical and biological
Fig. 4. PO4 ion removal in the waste water treatment with waste paper-mixed refuse cement and conerete at different particle sizes: (*), Refuse cement mixed with waste paper, (*), Refuse concrete mixed with waste paper.
Fig. 5. NH4 ion removal in the waste water treatment with shell, nitrolite, limestone, charcoal and charcoal-bio at different particle sizes: (*), Shell, (4), Nitrolite, (*), Limestone, (&), Charcoal, (m), Charcoal-bio.
treatment of NH4–N removal is widely used. In the case of high concentration of NH+ 4 –N (>3000 mg l1) in the waste, air stripping process is the most common method. However, these treatment process is relatively expensive. Therefore, waste and natural indigenous materials were applied to nitric and ammonium ions removal. Results are presented in Table 1. Removal of NO3 ion with both single and mixed medium were generally low, supposedly, due to lesser physical adsorption affinity of NO3 ion with partially charged ions. However, shell (37%) and charcoal-bio (38%) demonstrated slightly better removal than other mediums. As presented in Table 1, maximum NH4 ion removal (75%) was obtained with nitrolite. Reasonably good and moderate removal were achieved with charcoal-bio and charcoal, respectively, and other treatment mediums demonstrated poor removal. Earlier study (Ohta et al., 1998) reported 58% NH4
Waste water treatment by natural and waste materials
3741
ion removal was obtained with only refuse concrete, contrarily, in this investigation with refuse concrete mixed in waste paper no removal was recorded. Illustration in Fig. 5 shows that with smaller particle diameter size generally removal was better than larger size. However, maximum removal of NH4 ion with processed nitrolite (75%) and charcoal-bio (62%) was obtained with 0.3 and 0.4 mm particle size powders, respectively. Decrease in COD Various treatment technologies are been utilized for organic load removal in waste water expressed as COD or BOD. Nevertheless, yet there is need to ascertain alternative effective low cost treatment methods. Therefore, in this study potentials of waste and naturally available indigenous materials for COD removal was investigated. COD curve of Charcoal in Fig. 6 show that it has little effect of particle size, while with charcoal-bio there is
Fig. 6. Decrease in COD in the waste water treatment with shell, nitrolite, limestone, charcoal and charcoal-bio at different particle sizes: (*), Shell, (4), Nitrolite, (*), Limestone, (&), Charcoal, (m), Charcoal-bio.
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Shamim Ahsan et al.
depression of curve with larger size particle. Table 1 shows limestone served to remove 42–58% representing an oval shaped curve in Fig. 6, while with nitrolite and shell best removal was recorded with 0.4 mm diameter particle size powder. Most notable removal was observed with charcoal in the range of 85–88%, which is due to high organic matter adsorption capability of charcoal. In the earlier study (Ohta et al., 1998) with refuse cement and refuse concrete as independent treatment mediums COD removal of 24–30% and 36–53%, respectively. On the contrary, in this study refuse cement and refuse concrete mixed with waste paper have shown no removal and 8–14% removal, respectively, as noted in Table 1. This phenomenon presumably may have been contributed by the presence of organic matters in the waste papers or its less biomass retention capacity.
Possible treatment mechanism Rocks and refuse materials generally occur as silicate, aluminate, and calcium substrates in different forms. Therefore, using these naturally available materials the possible basic fundamental mechanisms for treatment are: filtration/settling, adsorption(physical) and ion exchange. Suspended substances were mostly removed by mechanical straining, filtration + and settling, while the PO3 4 , NO3 and NH4 were basically removed by ion exchange or by physical adsorption (Grimshaw and Harland, 1975). NH+ 4 ions were removed by cation exchange, while other anions removals likely were attributed by physical adsorption with partially charged ions. Furthermore, the weak chelating bond between metal elements and PO3 could occur in the treatment process. Exact 4 mechanism of holding organic matter by charcoal materials are not clearly known. However, presumably efficient removal of COD by charcoal and charcoal-bio have been attributed due to effective adsorption of organic matters in the large surface area of charcoal. Removal of organic matter by other treatment mediums is the possible result of higher affinity of carbon for silicate or aluminate substrates. The following hypothetical figures presented are based on the theoretical elucidation of ion exchange, dipole interaction and filtration which represents the possible ion exchange and some physical adsorption phenomenons presumably have taken place in the treatment of waste water (Grimshaw and Harland, 1975; Ohta et al., 1998):
CONCLUSIONS
Results of this fundamental study opened a new dimension on the utilization of waste and naturally occurring indigenous materials for the treatment of waste water. This also adds manifest on the use of cheap treatment mediums for a small scale waste treatment facilitates. Though in this investigation processed nitrolite, charcoal and charcoal-bio showed slightly better removal efficiency for some specific parameters than waste and indigenous materials, nevertheless, the most viable point in utilizing these refuse and indigenous treatment ingredients are: refuse concretes are abundant and easily available as waste materials. Moreover, utilization of these materials will definitely reduce environmental burdens as well as cost of treatment, so is the utilization of other naturally available indigenous rocks. Therefore, results obtained in the laboratory study proposes for field application of mixed mediums of refuse materials and rocks in a small scale treatment system, thus, allow an avenues to reduce treatment cost. Acknowledgements}This research work was supported by the Ministry of Education, Science and Culture of Japan and the Foundation of International Center for Environmental Technology Transfer, Japan.
REFERENCES
Copper P., Day M. and Thomas V. (1994) Process option for phosphorus and nitrogen removal from waste water. J. Int. Water Environ. Manag. 8, 84–92. Dahab M. F. and Lee Y. W. (1988) Nitrate removal from water supplies using biological denitrification. J. Water Pollut. Control. Fed. 60, 1670–1678. Galarneau E. and Gehr R. (1997) Phosphorus removal form waste water: experimental and theoretical support for alternative mechanisms. Water Res. 31, 328–338. Grimshaw R. W. and Harland C. E. (1975) Ion-exchange: Introduction to Theory and Practice. The Chemical Society, London, pp. 1–137. Matsche´ N. (1997) Phosphate removal from waste water-the situation in Austria. In La De´phosphatation des Eaux Use´es. CEDEBOC, Lie´ge, pp. 145–154. Matsumoto S. (1997) The conception and execution of improved river water quality using newly developed purification method: The Simanto-gawa system. UNEPIETC Newsletter, August, 3–6. Matsumoto S. (1999) Fundamentals and Practices of Soil Bioremediation. Soil Sci. Plant Nutr. 45(1), 237–251. Ohta K., Ahsan S., Kaneco S., Suzuki T., Mizuno T. and Kani K. (1998) Treatment of waste water with rocks (andesite, granite, marble), refuse concrete and refuse cement. Proceedings of Fourth Asian Symposium on Academic Activity for Waste Management and Resources. pp. 162–168.
Wat. Res. Vol. 35, No. 15, pp. 3738–3742, 2001 # 2001 Elsevier Science Ltd. All rights reserved Printed in Great Britain 0043-1354/01/$ - see front matter
RESEARCH NOTE USE OF SOME NATURAL AND WASTE MATERIALS FOR WASTE WATER TREATMENT SHAMIM AHSAN1*, SATOSHI KANECO1, KIYOHISA OHTA1, TAKAYUKI MIZUNO1 and KEIKO KANI2 1 Department of Chemistry for Materials, Faculty of Engineering, Mie University, Tsu, Mie 514-8507, Japan and 2 International Center for Environmental Technology Transfer, Japan
(First received 24 July 2000; accepted in revised form 15 January 2001) Abstract}A fundamental study was conducted to assess removal and filtration capacity of waste and natural indigenous materials as treatment mediums e.g., shell, limestone, waste paper mixed with refuse concrete, refuse cement, also processed nitrolite, charcoal-bio and charcoal. Under room temperature condition removal of phosphoric, nitric and ammonium-ions, filtration of suspended substance (SS) together with removal of COD in waste water was investigated. Influence of particle size effect for all treatment mediums except for waste paper was pursued. Significant improvement of waste water quality with respect to SS, phosphoric ions and decrease in COD is possible by treating with these filtration mediums. With specific reference to some treatment mediums NO3–N and NH4–N showed reasonable improvement in quality, although generally removal effect was not very significant. Efficacy of treatment was dependent on the particle size of treatment mediums in general, however, nitrolite for NH4–N, charcoal-A for SS and COD, refuse cement mixed with waste paper for PO4 ion removal showed insignificant variability on the particle size effect. Results of this fundamental study demonstrate effectiveness and feasibility for applied application of these proposed waste and naturally available treatment ingredients at lower cost. # 2001 Elsevier Science Ltd. All rights reserved Key words}waste treatment, removal, filtration, indigenous materials
INTRODUCTION
Suspended substances, nutrients and organic load as COD contribute major pollutants in the rivers, lakes and ponds. Removal of these contaminants in waste water is one of the fundamental goal in waste treatment. A range of technologies are available to treat various types of wastes to adequate levels. However, conventional waste treatment technologies as adopted in the industrialized nations are expensive to build, operate and also maintenance. Therefore, intensive research efforts are continuing to develop less costly treatment technologies appropriate in rural, semi-urban, isolated communities and a variety of industrial simulations. Moreover during recent years stringent regulation of nutrients discharge into waterways is receiving wider consensus. To comply with stringent regulations and restore safe environment, it has become imperative to find some less costly-adaptable treatment technology.
*Author to whom all correspondence should be addressed. Tel.: +81-59-231-9427; fax: +81-59-231-9442/9471/ 9427; e-mail: [email protected]
In order to achieve efficient cost effective technology, natural materials e.g., sands, red mud (residues from bauxite refining), soils, gravel, biomass char, activated carbons and water hyacinth etc., are generally been applied in waste water treatment facilities to remove pollutants. A recent review reported one such successful attributes designated as ‘Simanto–gawa system’ in Japan (Matsumoto, 1997, 1999), which used plastic filter, nitrolite, organic matters with high carbon–organic ratio, charcoal-bio, charcoal, processed limestone as treatment mediums. Nevertheless, promotion of integrated small scale treatment using cheaper treatment medium is still warranted. In a previous study (Ohta et al., 1998), it has been found that the rocks as andesite, granite, marble, refuse concrete and refuse cement is very effective as treatment mediums for simple waste treatment process. In the present study, the effect and behavior of the various refuse and naturally available materials (Shells, limestone, nitrolite, charcoal-bio, charcoal and waste paper-mixed refuse cement and concrete) was investigated for more efficient waste water treatment technologies.
3738
Waste water treatment by natural and waste materials MATERIALS AND METHODS
Instrumentations + For the determinations of SS, PO3 4 , NO3 , NH4 UVDouble Beam Spectrometer (UVIDEC 610. 650, Japan Spectroscopic company Limited) was used with a resonance line of 660, 880, 540 and 630 nm, respectively. Sample mass of the chemicals and samples was determined by using a semimicro analytical balance H20 (Mettler) providing a resolution of 0.01 mg. Samples were grounded by an iron mortar and sieved to different particle sizes with stainless sieves (NIPPON RIKAGAKU KIKAI). Ultrapure water was prepared using ADVENTEC ultrapure water system CW-102.
Samples, reagents and standards Waste samples collected from waste water treatment plant of Mie university, constitute a mixture of domestic and chemical wastes from the university campus. Reagents and standards were prepared to desired concentration periodically, as and when required. Chemicals for the + analysis of PO3 4 , NO3 , NH4 and COD and standards 3 + for PO4 , NO3 , NH4 were obtained from Nacalai Tesque Inc, Kyoto, Japan. All reagents and chemicals used were of analytical grade or spectroscopic purity. Medium preparations and analytical procedures Treatment mediums were picked up from in and around university campus except for shell(oyster) from the sea side. Processed nitrolite (a partially processed mineral zeolite), charcoal (made from coconut) and charcoal-bio (charcoal embedded with microorganisms) were supplied from Toyo Denko, Japan. Used newspapers were cut to an averages sizes of 1–2 mm before use. After grinding all mediums were made to different particle sizes using 25.6, 35.5, 42, and 50 mesh-stainless sieve and then washed with pure distilled water until visible dirts are removed and dried at room temperature. An accurately weighed dried 5.0 g of shell, nitrolite, limestone, charcoal and charcoal-bio were poured and packed into 50 ml size burette. Alternatively, for mixed mediums 2.5 g of dried refuse concrete and cement powders together with 1.0 g (1–2 mm size) of waste paper were transferred and packed into the burette. Continuous filtration of 100 ml of waste samples was performed with different mediums under room temperature at a flow rate of 0.33 ml min1.
3739
one of the detrimental criteria in waste water treatment. In this study filtration of SS with the aforementioned mediums were conducted and treatment efficiencies are presented in Table 1. The reproducibility (R.S.D.) of this method was better than 15% for 3 repeated measurements. Filtration of SS with single medium varied within 42–100%, and with mixed mediums 55–91%. As in Fig. 1 with smaller particle diameter mediums filtration of SS increased in general, while in Fig. 2 filtration was lower with smaller and larger particle size mediums of refuse cement and refuse concrete, respectively, mixed with waste papers. The reason of this phenomenon is not clear. Presumably it may be due to the presence of dirt which arose from refuse cement. Consequently, best filtration of SS 99–100% was observed with charcoal, independent of particle size effect, as shown in Fig. 1. Phosphoric ions removal To remove phosphate from contaminated waste water both biological and physico–chemical processes have been extensively studied. In European Union using different biological or physico–chemical processes allowed to cope with discharge content of 1–2 mg l1 (Copper et al., 1994). Nevertheless, in
RESULTS AND DISCUSSION
Suspended substances (SS) Suspended substances play an important (and often underestimated) role in characterizing the treatability and hence the degree of contaminant removal in waste water. Therefore, removal of SS is
Fig. 1. SS removal in the waste water treatment with shell, nitrolite, limestone, charcoal and charcoal-bio at different particle sizes: (*), Shell, (4), Nitrolite, (*), Limestone, (&), Charcoal, (m), Charcoal-bio.
Table 1. Summary of treatment efficiency of different mediumsa Mediums Refuse cement and waste paper Refuse concrete and waste paper Shells Limestone Nitrolite Charcoal-bio Charcoal a
n ¼ 3.
SS
COD
PO4
NO3
NH4
62–91% 55–78% 42–88% 76–87% 72–91% 54–95% 99–100%
No removal 8–14% 42–65% 42–58% 30–61% 61–71% 85–88%
79–80% 33–54% 20–32% 13–27% 36–66% 18–32% 11–17%
14–23% 11–17% 17–37% 12–25% 7–22% 29–38% 15–19%
0–13% No removal 6–16% 7–12% 65–75% 31–62% 11–32%
3740
Shamim Ahsan et al.
Fig. 2. SS removal in the waste water treatment with waste paper-mixed refuse cement and refuse cement at different particle sizes: (*), Refuse cement mixed with waste paper, (*), Refuse concrete mixed with waste paper.
Fig. 3. PO4 ion removal in the waste water treatment with shell, nitrolite, limestone, charcoal and charcoal-bio at different particle sizes: (*), Shell, (4), Nitrolite, (*), Limestone, (&), Charcoal, (m), Charcoal-bio.
some regions, more stringent measures (0.8– 0.5 mg P l1) are applied to control eutrophication (Galarneau and Gehr, 1997; Matsche´, 1997). As shown in Fig. 3 that with single medium best removal was obtained with nitrolite i.e., in the range of 36–66%. Contrarily, Fig. 4 illustrates that, most significant adsorption of PO4 ion was observed with mixed medium of refuse cement and waste paper, regardless of any particle size effect. Alternatively, Figs 3 and 4 show that with other single and mixed mediums generally removal was better with smaller particle size grains. Nitric and ammonium ions removal In various treatment methods for nitrate removal, ion exchange have been found to be very efficient (Dahab and Lee, 1988). Chemical and biological
Fig. 4. PO4 ion removal in the waste water treatment with waste paper-mixed refuse cement and conerete at different particle sizes: (*), Refuse cement mixed with waste paper, (*), Refuse concrete mixed with waste paper.
Fig. 5. NH4 ion removal in the waste water treatment with shell, nitrolite, limestone, charcoal and charcoal-bio at different particle sizes: (*), Shell, (4), Nitrolite, (*), Limestone, (&), Charcoal, (m), Charcoal-bio.
treatment of NH4–N removal is widely used. In the case of high concentration of NH+ 4 –N (>3000 mg l1) in the waste, air stripping process is the most common method. However, these treatment process is relatively expensive. Therefore, waste and natural indigenous materials were applied to nitric and ammonium ions removal. Results are presented in Table 1. Removal of NO3 ion with both single and mixed medium were generally low, supposedly, due to lesser physical adsorption affinity of NO3 ion with partially charged ions. However, shell (37%) and charcoal-bio (38%) demonstrated slightly better removal than other mediums. As presented in Table 1, maximum NH4 ion removal (75%) was obtained with nitrolite. Reasonably good and moderate removal were achieved with charcoal-bio and charcoal, respectively, and other treatment mediums demonstrated poor removal. Earlier study (Ohta et al., 1998) reported 58% NH4
Waste water treatment by natural and waste materials
3741
ion removal was obtained with only refuse concrete, contrarily, in this investigation with refuse concrete mixed in waste paper no removal was recorded. Illustration in Fig. 5 shows that with smaller particle diameter size generally removal was better than larger size. However, maximum removal of NH4 ion with processed nitrolite (75%) and charcoal-bio (62%) was obtained with 0.3 and 0.4 mm particle size powders, respectively. Decrease in COD Various treatment technologies are been utilized for organic load removal in waste water expressed as COD or BOD. Nevertheless, yet there is need to ascertain alternative effective low cost treatment methods. Therefore, in this study potentials of waste and naturally available indigenous materials for COD removal was investigated. COD curve of Charcoal in Fig. 6 show that it has little effect of particle size, while with charcoal-bio there is
Fig. 6. Decrease in COD in the waste water treatment with shell, nitrolite, limestone, charcoal and charcoal-bio at different particle sizes: (*), Shell, (4), Nitrolite, (*), Limestone, (&), Charcoal, (m), Charcoal-bio.
3742
Shamim Ahsan et al.
depression of curve with larger size particle. Table 1 shows limestone served to remove 42–58% representing an oval shaped curve in Fig. 6, while with nitrolite and shell best removal was recorded with 0.4 mm diameter particle size powder. Most notable removal was observed with charcoal in the range of 85–88%, which is due to high organic matter adsorption capability of charcoal. In the earlier study (Ohta et al., 1998) with refuse cement and refuse concrete as independent treatment mediums COD removal of 24–30% and 36–53%, respectively. On the contrary, in this study refuse cement and refuse concrete mixed with waste paper have shown no removal and 8–14% removal, respectively, as noted in Table 1. This phenomenon presumably may have been contributed by the presence of organic matters in the waste papers or its less biomass retention capacity.
Possible treatment mechanism Rocks and refuse materials generally occur as silicate, aluminate, and calcium substrates in different forms. Therefore, using these naturally available materials the possible basic fundamental mechanisms for treatment are: filtration/settling, adsorption(physical) and ion exchange. Suspended substances were mostly removed by mechanical straining, filtration + and settling, while the PO3 4 , NO3 and NH4 were basically removed by ion exchange or by physical adsorption (Grimshaw and Harland, 1975). NH+ 4 ions were removed by cation exchange, while other anions removals likely were attributed by physical adsorption with partially charged ions. Furthermore, the weak chelating bond between metal elements and PO3 could occur in the treatment process. Exact 4 mechanism of holding organic matter by charcoal materials are not clearly known. However, presumably efficient removal of COD by charcoal and charcoal-bio have been attributed due to effective adsorption of organic matters in the large surface area of charcoal. Removal of organic matter by other treatment mediums is the possible result of higher affinity of carbon for silicate or aluminate substrates. The following hypothetical figures presented are based on the theoretical elucidation of ion exchange, dipole interaction and filtration which represents the possible ion exchange and some physical adsorption phenomenons presumably have taken place in the treatment of waste water (Grimshaw and Harland, 1975; Ohta et al., 1998):
CONCLUSIONS
Results of this fundamental study opened a new dimension on the utilization of waste and naturally occurring indigenous materials for the treatment of waste water. This also adds manifest on the use of cheap treatment mediums for a small scale waste treatment facilitates. Though in this investigation processed nitrolite, charcoal and charcoal-bio showed slightly better removal efficiency for some specific parameters than waste and indigenous materials, nevertheless, the most viable point in utilizing these refuse and indigenous treatment ingredients are: refuse concretes are abundant and easily available as waste materials. Moreover, utilization of these materials will definitely reduce environmental burdens as well as cost of treatment, so is the utilization of other naturally available indigenous rocks. Therefore, results obtained in the laboratory study proposes for field application of mixed mediums of refuse materials and rocks in a small scale treatment system, thus, allow an avenues to reduce treatment cost. Acknowledgements}This research work was supported by the Ministry of Education, Science and Culture of Japan and the Foundation of International Center for Environmental Technology Transfer, Japan.
REFERENCES
Copper P., Day M. and Thomas V. (1994) Process option for phosphorus and nitrogen removal from waste water. J. Int. Water Environ. Manag. 8, 84–92. Dahab M. F. and Lee Y. W. (1988) Nitrate removal from water supplies using biological denitrification. J. Water Pollut. Control. Fed. 60, 1670–1678. Galarneau E. and Gehr R. (1997) Phosphorus removal form waste water: experimental and theoretical support for alternative mechanisms. Water Res. 31, 328–338. Grimshaw R. W. and Harland C. E. (1975) Ion-exchange: Introduction to Theory and Practice. The Chemical Society, London, pp. 1–137. Matsche´ N. (1997) Phosphate removal from waste water-the situation in Austria. In La De´phosphatation des Eaux Use´es. CEDEBOC, Lie´ge, pp. 145–154. Matsumoto S. (1997) The conception and execution of improved river water quality using newly developed purification method: The Simanto-gawa system. UNEPIETC Newsletter, August, 3–6. Matsumoto S. (1999) Fundamentals and Practices of Soil Bioremediation. Soil Sci. Plant Nutr. 45(1), 237–251. Ohta K., Ahsan S., Kaneco S., Suzuki T., Mizuno T. and Kani K. (1998) Treatment of waste water with rocks (andesite, granite, marble), refuse concrete and refuse cement. Proceedings of Fourth Asian Symposium on Academic Activity for Waste Management and Resources. pp. 162–168.