Pol. J. Environ. Stud. Vol. 23, No. 5 (2014), 1491-1498 Originl Reserch Vermicomposting of Vegetble Wste Amended with Different Sources of Agro-Industril By-Product Using Lumbricus rubellus Azizi Abu Bkr 1, 2 *, Syrifh Nurul Afzn Syed Mohd Gwi 1, Noor Zlin Mhmood 1, 2, Noorlidh Abdullh 1, 2 1 Institute of Biologicl Sciences, 2 Mushroom Reserch Center, Fculty of Science, University of Mly, 50603 Kul Lumpur, Mlysi Received: 17 September 2013 Accepted: 4 My 2014 Abstrct Vermicomposting of vegetble wste (VW) spiked with multiple sources of gro-industril wste ws conducted in microcosms for 18 dys of pre-composting nd subsequent 70 dys (10 weeks) of vermicomposting by utilizing epigeic Lumbricus rubellus. Nutrient element nd hevy metl content in vermicompost produced were evluted by compring with different gro-industril wste s mended mterils. Erthworm multipliction nd growth showed the highest increment in 100% of spent mushroom compost (SMC) (+323.72% for biomss nd +38.10% for number). Significnt differences (P<0.05) between erthworm biomss nd number ws identified in tretment of 100% cow dung (CD), cow dung:vegetble wste I (CD:VW I), 100% of spent mushroom compost (SMC), nd spent mushroom compost:vegetble wste I (SMC:VW I). The highest nutrient element i.e. N, P, nd K content in vermicompost ws pddy strw:vegetble wste II (PS:VW II) 1.37±0.040, 0.37±0.057, nd 1.29±0.050 respectively nd the lowest C:N rtio in cow dung:vegetble wste I (CD:VW I) (19.62±0.11), which indictes n dvnced degree of compost mturity. Hevy metl, i.e. Cd, Cr, Pb, Cu, nd Zn content in vermicompost from ll vermibeds were lower compred to the compost limits set by the USA, Europen countries, nd the Mlysin Recommended Site Screening Levels for Contminted Lnd (SSLs). Thus, L. rubellus is fesible in bioconverting VW spiked with groindustril wste into vermicompost, nd the product possesses gronomic potentil s well s environmentlly sounding in contrst to synthesized chemicl fertilizer. Keywords: biofertilizer, erthworms, hevy metl, nutrient element, recycling, vermitechnology Introduction Out of 3,500 tons of wste in Mlysin lndfill, t lest 50% is orgnic wste. Vegetble wste (VW) is ctegorized s one of the orgnic wstes from the gro-industril sector, including livestock frming. Vegetble wste is *e-mil: ziexis@gmil.com zizi.bkr@um.edu.my esy to putrefy due to its nturl chrcteristics nd the putrefction period occurs in time of hrvesting, trnsporttion hndling, storge, mrketing, nd dditionl processes tht generting wste. Moreover, these vegetble processes ttrct flies, mosquitoes, cockroches, rts, nd other pests tht re disese vectors for humns nd could potentilly cuse pollution for the environment. A prcticl nd perspiccious method should be scertined on VW mngement so tht nutrient recovery cn be restored for humn benefits
1492 Azizi A. B., et l. Tble 1. Substrtes mixture in rtio for ech vermibed. Vermibed (Substrte mixture) Rtio (kg) Description CD (control) 3.5 Cow dung only CD:VW I 1.75:1.75 1 prt cow dung:1 prt vegetble wste CD:VW II 1.17:2.33 1 prt cow dung:2 prts vegetble wste VW (control) 3.5 Vegetble wste only PS:VW I 1.75:1.75 1 prt pddy strw:1 prt vegetble wste PS:VW II 1.17:2.33 1 prt pddy strw:2 prts vegetble wste SMC (control) 3.5 Spent mushroom compost only SMC:VW I 1.75:1.75 1 prt spent mushroom compost:1 prt vegetble wste SMC:VW II 1.75:2.33 1 prt spent mushroom compost:2 prts vegetble wste s well s for the environment. Since VW nd other orgnic wstes re recyclble, conversion into vlue-dded product by mens of composting or thermocomposting into nutritive compost is indeed environmentlly fesible due to its cost-effectiveness, nd the process involved is chemiclly free. Even so, thermocomposting hs been dopted s bsic tool for on-site wste decomposition. Some disdvntges of trditionl thermocomposting methods include the long durtion of the process, frequent ertion required, loss of nutrients (e.g., grssing off nitrogen), nd heterogenous end product [1]. In nture, co-opertion between microbes, fungi, nd other detritivores such s detritusfeeder invertebrtes (i.e. erthworms) in decomposition of vriety orgnic wste termed s vermicomposting is more efficient in converting orgnic wste into vlue dded product, i.e. vermicompost. Vermicomposting is simple biotechnologicl process in which erthworms re employed to convert the orgnic wste mteril into vermicompost or excellent orgnic compost [2]. Moreover, vermicomposting emerges s one of the most fesible lterntive techniques compred to conventionl erobic composting. This process is not only rpid, esily controllble, cost effective, energy sving, nd zero wste, but lso ccomplishes the most efficient recycling of orgnic wste nd nutrients [3]. Vrious physicl nd biochemicl processes re ffected by erthworms. The physicl processes include substrte ertion, mixing, nd grinding. The biochemicl processes re ffected by microbil decomposition of substrtes in the intestine of the erthworm [4]. During the process, the importnt plnt nutrients in the mterils re relesed nd converted through microbil ction into forms tht re much more soluble nd vilble to plnts thn those in the prent compounds [5]. The vermicompost produced is n excellent soil conditioner tht hs higher nutrient vilbility for plnt growth, since it is homogenous, hs desirble esthetics, reducing levels of contmintion, nd tends to hold more nutrients over longer period [6]. However, previous work on vermicomposting of orgnic wste by Azizi et l. [7], 60-70% moisture content of feed mterils ws mintined during the process, but it is problemtic to implement such moisture content with VW nture chrcteristics (i.e. esily putrescible) unless substrte mendment is dded in the vermicomposting process. Therefore, the objective of this work is to convert VW into bioproduct spiked with gro-industril wste s mendment, viz., pddy strw, cow dung, nd spent mushroom compost by employing Lumbricus rubellus or red worms. In the mentime, to compre nutrient elements nd hevy metl content in the produced product (i.e. vermicompost) from different gro-industril wste s mended mterils in the vermicomposting process. Mterils nd Methods Substrte, Microcosm, nd Erthworm Preprtion Approximtely 47 kg of vegetble wste (VW), minly lefy vegetbles such s cbbge, lettuce, nd culiflower, were collected in gunny scks from dily-fresh mrket in Putrjy. Other types of VW, i.e. onion, grlic, peppers, tomto, potto, pes, chilies, nd citrus, were not collected since they would hve hindered the erthworms pltbility. The collected VW were dried for one dy under direct sunlight on newsppers. Foreign residues such s rubber bnds, plstic, nd wrpping pper were discrded prior to sun bthing. Cow dung (CD) ws collected from country cow frm in Serdng, Selngor, nd ws dried for 11 dys before stbiliztion in the pre-composting period. Menwhile, pddy strw (PS) nd swdust-bsed spent mushroom compost (SMC) were obtined from n griculturl frm in Jenderm Hulu, Selngor, nd the Mushroom House in the Institute of Biologicl Science, University of Mly, respectively. Erthworms utilized in this study were L. rubellus, which ws cultured in mixture of vriety of orgnic wste sources. Experiments were conducted in microcosm (360 mm 280 mm 200 mm) rtificilly designed with net (250 mm 100 mm) covering the center of the lid to llow ertion, to prevent ny interruption by pests, nd to provide microclimtic conditions [7-9]. All of
Vermicomposting of Vegetble Wste... 1493 the microcosms were kept in n erthworm reservoir (shed re) in the Institute of Biologicl Science, University of Mly, with identicl mbient conditions (room temperture 25±3ºC, reltive humidity 60-80%). Ech microcosm contined totl of 3.5 kg of substrtes mixture (Tble 1). Pre-Composting Period Pre-composting is the process of stbilizing the substrtes in terms of ph, temperture, nd moisture before vermicomposting. The pre-composting period is to void exposure of erthworms to high temperture during the initil thermophilic stge of microbil decomposition [10] nd provide pproprite conditions for erthworms in mss reduction, moisture mngement, nd pthogen reduction [11]. In this study, the mixtures of substrtes were stbilized in pre-composting period for 18 dys, strting from the first dy the substrtes were mixed. During the pre-composting period, ph nd temperture were monitored to ensure optimum level of ph 7±1, nd temperture of 27±1ºC ws chieved nd stbilized by mnul turning. Vermicomposting Process On dy 18 of pre-composting, 100 g (~30 g dry weight) smple ws tken from ech tretment for 0 week nutrient element nlysis. At the sme time s the substrtes ph, moisture content nd temperture were stble nd 35 clitelted L. rubellus were introduced into ech microcosm fter the biomss of the erthworms ws weighed. During the vermicomposting process, the moisture content of feed mterils ws mintined t 70±10% by periodic sprinkling of n dequte quntity of distilled wter using wsh bottles (80-160 ml per microcosm), together with mnul turning once every few dys to remove ny stgnnt wter nd odour nd to eliminte voltile gses tht re potentilly toxic to erthworms nd indirectly removing mmoni, odour, nd excess wter. No extr mixtures of feed mterils were dded during this experimentl stge. On dy 70 (week 10), the numbers of individul L. rubellus in ech microcosm were clculted by hnd sorting, nd its biomss weighed. 100 g (~30 g dry weight) smple of vermicompost from ech microcosm (totl 27 microcosms) ws hrvested in plstic vils (ir tight) for chemicl nlysis to determine the nutrient element nd hevy metl content in the vermicompost produced. The multipliction nd growth of erthworms ws clculted s: Lbortory Anlysis Totl orgnic crbon (TOC) ws determined by prtil oxidtion method [12]. Totl Kjeldhl nitrogen (TKN) ws estimted by Kjeldhl digestion with concentrted H 2 SO 4 (1:20, w/v) followed by distilltion [13]. Totl phosphorus (TP) ws detected by with the colorimetric method using mmonium molybdte in HCl [14]. Totl potssium (TK) nd hevy metls viz., Cr, Cu, Cd, Pb, nd Zn were mesured by the ignition method using Perkin Elmer model 3110 double bem tomic bsorption spectrophotometer, AAS fter digestion of the smple with concentrted HNO 3 :concentrted HClO 4 (4:1, v/v). [10]. C:N rtio nlyzed through clcultion. Sttisticl Anlysis Sttisticl nlysis ws crried out using SPSS for Windows version 16.0 (SPSS, Inc., Chichgo, IL, USA). One-wy nlysis of vrince (ANOVA) ws crried out to nlyze the significnt difference of the dt obtined between tretments during vermicomposting t 0.05% level of significnce. Pired smples t-test ws used to identify the significnt differences for ech microcosm between percentge of number nd biomss of erthworms during the vermicomposting process. Results nd Discussion Erthworm Multipliction nd Growth Erthworms multipliction nd growth during 70 dys (10 weeks) of vermicomposting re illustrted in Fig. 1. Fig. 1. Erthworm multipliction nd growth during vermicomposting.
1494 Azizi A. B., et l. Tble 2. Nutrient elements i.e. N, P, nd K content (mg kg -1 ) nd C:N rtio in vermibeds in week 0 nd vermicompost in week 10. Vermibed Week 0 Week 10 NPK content N P K N P K CD (control) 1.45 0.57 1.98 1.22±0.053 0.23±0.030 1.18±0.056 CD:VW I 1.22 0.43 1.65 1.25±0.040 0.24±0.015 1.27±0.082 CD:VW II 1.10 0.35 1.14 1.20±0.045 0.29±0.025 1.27±0.076 VW (control) 1.38 0.66 1.75 1.38±0.045 0.11±0.032 1.18±0.035 PS:VW I 1.18 0.67 1.24 1.30±0.080 0.37±0.050 1.29±0.075 PS:VW II 1.18 0.44 1.07 1.37±0.040 0.37±0.057 1.29±0.050 SMC (control) 1.19 0.67 1.22 1.18±0.032 0.29±0.040 1.08±0.047 SMC:VW I 1.15 0.48 1.22 1.18±0.020 0.27±0.020 1.31±0.031 SMC:VW II 1.23 0.37 1.13 1.31±0.031 0.30±0.070 1.23±0.056 C:N rtio CD (control) 30.24 26.87±2.79 CD:VW I 28.59 19.62±0.11 CD:VW II 15.68 27.17±0.95 VW (control) 27.14 24.66±2.67 PS:VW I 26.47 23.39±1.88 PS:VW II 22.05 21.26±1.25 SMC (control) 21.20 21.65±1.67 SMC:VW I 28.75 25.76±1.13 SMC:VW II 29.59 22.30±0.10 Vlues re men nd stndrd devition (men±sd; n = 3). Refer to Tble 1 for vermibed description. The highest biomss nd number increment ws in vermibed of 100% SMC with +323.72% nd +38.10%, respectively, wheres the lowest in biomss nd number ws in vermibed of 100% VW with -100% in both biomss nd number. In the pired smples t-test conducted for ll vermibeds between both biomss nd number, the result showed tht significnt difference (P<0.05) in vermibeds 100% of CD, CD:VW I, 100% SMC nd SMC:VW I. In fct, those significntly different vermibeds were only vermibeds yielding n increment percentge in both biomss nd number. It ws evidence tht the erthworms in 100% of VW recorded 100% mortlity strting from the first two weeks of the vermicomposting process nd grdul circumstnces of mortlity occurred for SMC:VW II, PS:VW I, CD:VW II, nd PS:VW II (in descending trend). Multipliction nd growth of erthworm biomss nd number re conditionl to erthworm pltbility on the feedstock mixture or vermibed qulity. Multiple increments in SMC vermibed (i.e. SMC:VW I nd 100% of SMC, Fig. 1) might be due to the presence of fungi in the forms of myceli, which provided nutritious food source for erthworms physiologicl development. Michel Bonkowski et l. [15] nlyzed the possible explntion for fungl preferences by erthworms to focus on the nutritionl vlue of the fungus, or the presence of ntibiotics or other deterrent metbolites in or round myceli. Hence, it cn be inferred tht fungi primrily function s indictors of food qulity to erthworms or other microbes/detritivores in soil. Aprt from tht, the SMC swdust bse used in this study cted s n bsorbent to VW relesing moisture content, thus reducing the mount of distilled wter utilized to moisten the feedstock mixture during the vermicomposting process. Mortlity of erthworms recorded possibly derived from the high moisture content of VW, which ws relesed during the intermedite period of the monitoring schedule. During tht period, the erthworms experienced sphyxite conditions, which led to lethl phse. A similr sitution occurred on PS vermibeds, i.e. PS:VW I nd PS:VW II, where the results reflect tht PS ws not ble to bsorb excess moisture content relesed by VW nd resulted in quick wter stgntion in the microcosms followed by erthworm mortlity. Moreover erthworm mortlity lso ws reported in vermibeds of more thn 50% of VW i.e. SMC:VW II, PS:VW II, CD:VW II nd 100% of VW, nd
Vermicomposting of Vegetble Wste... 1495 Tble 3. Nutrient elements i.e. N, P, nd K content nd C:N rtio gin nd loss (%) in nine different vermibeds. Vermibed NPK content N P K C:N rtio CD (control) -15.86-59.65-40.40-11.14 CD:VW I +2.46-44.19-23.03-31.37 CD:VW II +9.09-17.14 +11.40 +73.28 VW (control) 0.00-83.33-32.57-9.14 PS:VW I +10.17-44.78 +4.03-11.64 PS:VW II +16.10-15.91 +20.56-3.58 SMC (control) -0.84-56.72-11.48 +2.12 SMC:VW I +2.61-43.75 +7.38-10.4 SMC:VW II +6.50-18.92 +8.85-24.64 + Denotes percentge gin of nutrient elements (NPK content) nd C:N rtio in the vermicomposting process. - Denotes percentge loss of nutrient elements (NPK content) nd C:N rtio in the vermicomposting process. Refer to Tble 1 for vermibed description. Tble 4. Hevy metl content (mg kg -1 ) in ech vermibed in week 10 of vermicomposting. Vermibed Cu Zn CD (control) 4.953±0.40 62.04±11.79 CD:VW I 7.500±3.62 60.59±2.06 CD:VW II 5.663±0.85 73.24±9.92 VW (control) 6.567±2.32 54.09±7.52 PS:VW I 0.001±0.00 28.27±8.71 PS:VW II 0.001±0.00 25.28±4.92 SMC (control) 0.001±0.00 8.03±4.34 SMC:VW I 5.910±6.15 24.52±3.33 SMC:VW II 6.671±11.55 19.30±0.94 Vlues re men nd stndrd devition (men±sd; n = 3). Cd, Cr, nd Pb content recorded similr content i.e. 0.001±0.00 mg kg -1, 0.0005±0.00 mg kg -1, nd 0.002±0.00 mg kg -1, respectively. Refer to Tble 1 for vermibed description. this conceivbly ws due to the high proportion of lignin complex structure in vermibeds tht lowered erthworm nutrition selection prior to deth. On the other hnd, CD provided in the vermibed of 100% CD, CD:VW I nd CD:VW II, funding the nutrient uptke for erthworm multipliction nd growth s evidenced by positive increments in 100% CD nd CD:VW I. Therefore, CD tretments except CD:VW II resulted in significnt differences (P<0.05) between erthworm biomss nd number during the vermicomposting process. Shhck-Gross [16] reported tht herbivore dung is composed of mcroscopic nd microscopic orgnic mterils (vegetl, bcteril, nd niml) of inorgnic microscopic minerls (dung spherulites, geogenic prticles, ditoms, sponge spicules, clciumoxltes, nd opl phytoliths) nd is enriched in P, 15 N nd lignin reltive to the ingested components. Thus, these enriched component constituents fvor erthworms in their diet nd reflect its pltbility. Furthermore, this is lso relted to the durtion of the nutrient-enriching process, which hs been stbilized in the long digestive process of the ruminnt. Nutrient Element Content Nutrient element content in vermibeds nd vermicompost re encpsulted in Tble 2. Totl N content in vermicompost on dy 70 resulted in increments compred on dy 0 in CD:VW I, CD:VW II, PS:VW I, PS:VW II, SMC:VW I, nd SMC:VW II. Vermibeds of 100% of CD nd 100% of SMC depicted decreses in totl N nd only 100% of VW showed either increment nor decrese of totl N content (Tble 3). A similr trend ws recorded for totl K in CD:VW II, PS:VW I, PS:VW II, SMC:VW I, nd SMC:VW II. Besides tht, vermibeds of 100% of CD, CD:VW I, 100% of VW, nd 100% of SMC resulted in decrese in totl K content. Totl P content showed reduction in ll vermibeds with the highest reduction i.e. 100% of VW (-83.33%) nd the lowest reduction i.e. PS:VW II (- 15.91%). C:N rtio in ll vermibeds re tbulted in Tble 2. The lowest C:N rtio clculted ws CD:VW I (19.62±0.11) nd the highest ws CD:VW II (27.17±0.95). C:N rtio gin nd loss in Tble 3 shown tht the gretest loss in C:N rtio ws in CD:VW I (-31.37%) wheres CD:VW II recorded the highest gin in C:N rtio (+73.28%). N, P, nd K re essentil mcronutrient elements in deliberting qulity of compost or vermicompost. In this work, there were mixture of increses nd decreses of nutrient element content fter 70 dys of vermicomposting. According to Plz et l. [17], N content of vermicompost incresed due to minerliztion of C-rich mteri-
1496 Azizi A. B., et l. Tble 5. Comprison of hevy metls (mg kg -1 ) contined in vermicompost with EU, USA compost limits nd Mlysin site screening levels (SSLs). Mlysin Site Screening Levels (SSLs) c Hevy metl EU limit rnge USA biosolids limit b Vermicompost d Residentil soil Industril soil Cr 70-200 1,200 70 810 0.0005 Cd 0.7-10 39 280 14,000 0.001 Pb 70-1,000 300 400 800 0.002 Cu 70-600 1,500 3,100 41,000 0.001-7.50 Zn 210-4,000 2,800 23,000 310,000 8.03-73.24 b Limits set for compost pplied in Europen countries nd United Sttes [34]. c Recommended levels for Mlysin contminted site screening bsed on Contminted Lnd Mngement nd Control Guidelines No. 1 [35]. d Vermicompost from vermicomposting in week 10. ls nd N-fixing bcteri. Moreover, the erthworm itself hs its role in generting N content derived from mucus, nitrogenous excretory substnces, growing stimulting hormones, nd enzymes [18]. Aprt from tht, decying tissues of ded erthworms might contribute to the N content in the vermicompost produced, nd similr nlysis discussed by Suthr [19] pproved this suggestion. Decrese in N content is irregulrly reported in vermicomposting work, nd the occurrence from this study showed tht pltbility of erthworms on the mixture of the vermibeds hindered the cpbility of erthworms to fcilitte microclimtic condition for the N-fixing bcteri in enriching nutrient content. Moreover, the mortlity of erthworms lso prevented the secretion of erthworm mucus (polyscchride) to moisten its body surfce for supplementing vermibeds with N-fixer bcteri [20], nd consequently the microbil propgtion ws retrded. Prmnik et l. [21] hve reported tht cid production during orgnic mtter decomposition by the microorgnisms is the mjor mechnism for solubiliztion of insoluble P nd K, which subsequently results in n increse in P nd K contents in vermicompost. On common circumstnces of the vermicomposting process, the erthworms gut enzymes, i.e. cid phosphtses nd lkline phosphtses converted some P into more vilble forms in gut intestine [22] nd the possible ction from P-solubilizing microorgnisms present in vermicompost is the reson for the increse of P in vermicompost [23], lthough this study recorded decrese of P content. The decrese of P is similr scenrio s experienced by Orozco et l. [24], which recorded lower P content in coffee pulp wste fter vermicomposting. These differences in the P content fter vermicomposting cn be ttributed to the differences in the chemicl nture of the initil rw mterils [25], even though there is no possible leching of P by the excess wter tht drined through the microcosms. Further study is needed on determining the chemicl nture of the vegetble wste. Besides, the sitution cn possibly be due to prt of the N, P, K, nd micronutrients being removed from the vermicompost before nlysis nd ssimilted by the erthworms [26]. The decrese in nutrient element content is lso cused by the mortlity of erthworms tht ws supposedly performing the vermicomposting process. Indeed, modifiction onvermibeds mendment to correct erthworm pltbility is required in future study. The C:N rtio reflects the spectr of chnging C nd N concentrtions of the biowste during the composting/vermicomposting process [27]. According to Senesi [28], C:N rtio < 20 indictes n dvnced degree of orgnic mtter stbiliztion nd reflects stisfctory degree of orgnic wste mturity. Conversely, high C:N rtio reflects decrese in biologicl ctivity nd consequently slow degrdtion due to the mortlity of erthworms. In this study, mortlity of erthworms nd erthworm pltbility hs suspended the spectr of C:N rtio to chieve s low s <20, except for CD:VW I tretment. Nevertheless, ll tretments recorded C:N rtio below 30, which mesured s dequte C:N rtio becuse it is considered tht the microorgnisms require 30 prts of C per unit of N [29]. Hevy Metl Content Hevy metls content in vermicompost ws nlyzed on dy 70 (week 10) to investigte sfe utiliztion of the vermicompost in gronomic pplictions. Hevy metls content in ll vermibeds is shown in Tble 4. Cd, Cr, nd Pb content in ll vermibeds recorded similr content, i.e. 0.001 mg kg -1, 0.0005 mg kg -1, nd 0.002 mg kg -1, respectively. The highest contents for Cu were CD:VW I (7.50±3.62 mg kg -1 ) nd CD:VW II (73.24±9.92 mg kg -1 ) for Zn. The lowest Cu recorded for PS:VW I, PS:VW II nd 100% of SMC (0.001±0.00 mg kg -1 ), wheres Zn ws the lowest content recorded in 100% of SMC (8.03±4.34 mg kg -1 ). In smll mounts, mny of these elements (hevy metls) my be essentil for plnt growth; however, in higher concentrtions they re likely to hve detrimentl effects on plnt growth [30]. All concentrtions of hevy metls tbulted in the vermibeds were lower compred to the permissible limits of hevy metls content in compost set by the USA, Europen countries, nd the Mlysin Recommended Site Screening Levels for Contminted Lnd (SSLs) (Tble 5). Hence, the vermicompost produced
Vermicomposting of Vegetble Wste... 1497 is hrmless in the ppliction s soil stbilizer nd biofertilizer. Erlier work reported tht hevy metls content decresed in vermicompost nd ccumulted in erthworm tissue s it pssed through the limentry cnl of the erthworms, nd there were no holes beneth the microcosms tht could be the cuse of leching nd dringe of hevy metls or ctions [9]. Removl of the hevy metls were prllel to erthworm dietry uptke which bioccumulte the hevy metls long its limentry cnl equipped with microflorl simultion nd gut enzymes. Furthermore, Morgn nd Morris [31], who studied the ccumultion nd intrcellulr comprtmentliztion of metls in L. rubellus nd D. rubid from highly contminted soil identified from electron microprobe nlysis, the mjor chemicl constituents of the chlorgogenous tissue, especilly in chlorgosome grnules, were P, C, Zn, nd Pb, nd further confirmed in preliminry nlyses of cryosections the presence of Pb nd Zn (with C nd P), together with the bsence of Cd in the chlorgosomes ws high in L. rubellus compred to D. rubid. The lowest concentrtion of hevy metl content recorded in the vermicompost produced ws Cr (0.0005 mg kg -1 ) nd the highest ws Zn (73.24±9.92 mg kg -1 ) (Tble 4). This is due to the fct tht hevy metl removl rte during vermicomposting is directly relted to the initil hevy metl concentrtion tht increses hevy metls biovilbility to erthworms [32]. Nonetheless, this fctor depends on the interction of erthworms with locl edphic fctors i.e. ph, orgnic mtter content, etc. [33]. It hs been suggested by other reserchers to hve longer period of vermicomposting in order to remove greter mount of hevy metls from vermibeds, but it hs been discovered tht erthworm (i.e. L. rubellus) uptke cn rech equilibrium nd relese the hevy metls within the excretion period [9]. Conclusions This study represents the fesibility of VW with mendments of gro-industril wste in vermicomposting. SMCswdust bsed with mendment to 50% of VW proved the best mendment for vermiculture due to the multiple increse of erthworm biomss nd number. Aprt from tht, SMC-swdust bsed dvnced s wter bsorbent mteril nd t the end of the process produced homogenous, stbilized, good textured nd esthetic bioproduct. PS demonstrted 10 to 16% nd 4 to 20% of increments in N nd K content, respectively. Hence, PS is the credible mendment to increse the nutrient element content in vermicompost. In fct, the ddition of other mendments, djustments of mixture rtio, nd longer period of the process should be tken into considertion in future work. Cow dung (CD) with 50% of VW demonstrtes potentil combintion for providing vermicompost with dvnced degrees of stbiliztion. Moreover, hevy metl content in the vermicompost produced hs no dverse effects to the environment nd for humn ppliction s biofertilizer since its content ws 26.15 to 140,000-fold below the limits set. Concisely, this study provides new insight on utiliztion of L. rubellus in vermitechnology s potentil tool to convert VW nd gro-industril wste into vlue-dded mteril for sustinble living prctice. Acknowledgements Authors re thnkful to the Institute of Reserch Mngement nd Consultncy (IPPP), UM under UMRG (RG007/09AFR) mnged by Advnced Fundmentl Reserch Cluster, UM for finncil support. References 1. NAIR J., SEKIOZOIC V., ANDA M. Effect of pre-composting on vermicomposting of kitchen wste. 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