Effect of struvite and organic acids on immobilization of copper and zinc in contaminated bio-retention filter media

Few studies have been carried out to connect nutrient recovery as struvite from wastewater and sustainable utilization of the recovered struvite for copper and zinc immobilization in contaminated soil. This study revealed the effect of struvite on Cu and Zn immobilization in contaminated bio-retention soil in the presence of commonly exuded plant organic acids. The research hypothesis was that the presence of both struvite and organic acids may influence the immobilization of Cu and Zn in soil. The outcome of this research confirmed that more than 99% of Cu and Zn was immobilized in bio-retention filter media by struvite application. Water-soluble Cu and Zn concentrations of struvite treated soil were less than 1.83 and 0.86 mg/kg respectively, and these concentrations were significantly lower compared to the total Cu and Zn content of 747.05 mg/kg in the contaminated soil. Application of struvite to Cu- and Zn-contaminated soil resulted in formation of compounds similar to zinc phosphate tetrahydrate (Zn₃(PO₄)₂?4H₂O) and amorphous Cu and Zn phases. Struvite was effective in heavy metal remediation in acidic soil regardless of the presence of Ca impurities in struvite and the presence of plant organic acids in soil. Overall, this study revealed that struvite recovered from wastewater treatment plants has potential for use as an amendment for heavy metal remediation in contaminated bio-retention soil.     

Effects of two sludge application on fractionation and phytotoxicity of zinc and copper in soil

The potential harm of heavy metals is a primary concern in application of sludge to the agricultural land.A pot experiment was conducted to evaluate the effect of two sludges on fractionation of Zn and Cu in soil and their phytotoxicity to pakchoi.The loamy soil was mixed with 0%,20%,40%,60% and 80%(by weight)of digested sewage sludge(SS)and composted sludge (SC).The additions of the both sludges caused a significant raise in all fractions,resulting in that exchangeable(EXCH)and organic matter(OM) became predominance for Zn and organic bound Cu occupied the largest portion.There was more available amount for Zn and Cu in SS treatments than SC treatments.During the pot experiment,the concentration of Zn in EXCH,carbonate(CAR)and OM and Cu in EXCH and OM fractions decreased in all treatments,so their bioavailability reduced.Germination rate and plant biomass decreased when the addition rate was high and the best yield appeared in 20% mixtures at the harvest of pakchoi.The two sludges increased tissue contents of Zn and Cu especially in the SS treatments.Zn in pakchoi was not only in relationship toΔEXCH andΔCAR forms but also inΔOM forms in the sludge-soil mixtures.Tissue content of Cu in pakchoi grown on SC-soils could not be predicted byΔEXCH. These correlation rates between Zn and Cu accumulation in pakchoi and variation of different fractions increased with time,which might indicate that sludges represented stronger impacts on the plant in long-term land application.     

Characteristics of sewage sludge and distribution of heavy metal in plants with amendment of sewage sludge

In order to better understand land application of sewage sludge, the characterization of heavy metals and organic pollutants were investigated in three different sewage sludges in Shanghai City, China. It was found that the total concentrations of Cd in all of sewage sludge and total concentrations of Zn in Jinshan sewage sludge, as well as those ofZn, Cu, and Ni in Taopu sludge are higher than Chinese regulation limit of pollutants for sludge to be used in agriculture. Leachability of rig in all of studied samples and that of Cd in Taopu sewage sludge exceed the limit values of waste solid extraction standard in China legislation. Based on the characteristics for three kinds of sewage sludge, a pot experiment was conducted to investigate the effect of soil amended with Quyang sewage sludge on the accumulation of heavy metalo.by Begonia semperfloreas-hybr; Ophiopogon japonicas （L.F.） Ker-Gaw; Loropetalum chindense-var, rubrum; Dendranthema morifolium; Viola tricolor; A ntirrhinum majas; Buxas radicans Sieb; Viburnum macrocephalum; Osmanthas fragrans Lour; Cinnamomum camphora siebold and Ligustrum lucidum ait. Results showed that 8 species of plant survived in the amended soil, and moreover they flourished as well as those cultivated in the control soil. The heavy metal concentration in plants varied with species, As, Pb, Cd and Cr concentration being the highest in the four herbaceous species studied, particularly in the roots of D. morifolium. These plants, however, did not show accumulator of As, Pb, Cd and Cr. The highest concentration of Ni and Hg was found in the roots ofD. morifolium, followed by the leaves ofB. semperflorens-hybr. Levels of Zn and Cu were much higher in D. morifolium than in the other plant species. D. morifolium accumulated Ni, Hg, Cu and Zn, which may contribute to the decrease of heavy metal contents in the amended soil. Treatment with sewage sludge did not significantly affect the uptake of heavy metals by the L. chindense-var, rubrum, however, it significantly affected the uptake of heavy metals by D. morifolium.     

Effects of vegetable oil residue after soil extraction on physical-chemical properties of sandy soil and plant growth

Vegetable oil has the ability to extract polycyclic aromatic hydrocarbons(PAHs)from contaminated sandy soil for a remediation purpose,with some of the oil remaining in the soil.Although most of the PAHs were removed,the risk of residue oil in the soil was not known.The objective of this study was to evaluate the effects of the vegetable oil residue on higher plant growth and sandy soil properties after soil extraction for a better understanding of the soil remediation.Addition of sunflower oil and column ex...     

Adsorption kinetics of the herbicide safeners, benoxacor and furilazole, to activated carbon and agricultural soils

Chloroacetamide herbicides, namely acetochlor and metolachlor, are common herbicides used on corn and soybean fields. Dichloroacetamide safeners, namely benoxacor and furilazole, are commonly used in formulations containing chloroacetamide herbicides. Extensive reports on adsorption of chloroacetamide herbicides are available, yet little information exists regarding adsorption potential of co-applied safeners. Herein, the adsorption and desorption characteristics of selected herbicide safeners to granular activated carbon (GAC) and in agricultural soils are reported. Further, soil column studies were performed to understand the leaching behaviour of the herbicide Dual II Magnum. Equilibrium sorption experiments of safeners to three agricultural soils and one GAC showed that adsorption was best fitted by the Freundlich isotherm. The Freundlich adsorption constant, K_f, for benoxacor and furilazole sorption onto three agricultural soils ranged from 0.1 to 0.27 and 0.1 to 0.13 (mg/g) × (mg/L)?(1/n), respectively. The K_f for benoxacor and furilazole to GAC was 6.4 and 3.4 (mg/g) × (mg/L)?(1/n), respectively, suggesting more favorable sorption of benoxacor to GAC than furilazole to GAC. The sorption to soils was reversible as almost 40%–90% of both safeners was desorbed from three soils. These results were validated in four replicated soil column studies, where S-metolachlor was shown to leach similarly to the safener benoxacor, originating from the herbicide formulation. The leaching of S-metolachlor and benoxacor was influenced by soil texture. Cumulatively, these results show that safeners will move through the environment to surface waters similarly to the active ingredients in herbicides, but may be removed during drinking water treatment via GAC.     

Bamboo charcoal addition enhanced the nitrogen removal of anammox granular sludge with COD: Performance, physicochemical characteristics and microbial community

The effects of different chemical oxygen demand (COD) concentrations on the anammox granular sludge with Bamboo Charcoal (BC) addition were evaluated in UASB reactor. The results showed that the average total nitrogen (TN) removal efficiency was reduced from 85.9% to 81.4% when COD concentration was increased from 50 to 150 mg/L. However, the TN removal efficiency of BC addition reactors was dramatically 3.1%–6.4% higher than that without BC under different COD concentrations. The average diameter of granular sludge was 0.13 mm higher than that without BC. The settling velocity was increased by elevated COD concentration, while the EPS and VSS/SS were increased with BC addition. The high-throughput Miseq sequencing analyses revealed that the bacterial diversity and richness were decreased under COD addition, and the Planctomycetes related to anammox bacteria were Candidatus Brocadia and Candidatus Kuenenia. The Metagenomic sequencing indicated that the abundance of denitrification related functional genes all increased with elevated COD, while the abundance of anammox related functional genes of decreased. The functional genes related to anammox was hydrazine synthase encoding genes (hzsA, hzsB and hzsB). The average relative abundance of hzs genes in the reactor with BC addition was higher than the control at COD concentrations of 50 mg/L and 150 mg/L. The functional genes of denitrification mediated by BC were higher than those without BC throughout the operation phase. It is interesting to note that BC addition greatly enriched the related functional genes of denitrification and anammox.     

Influence of biosurfactant on the diesel oil remediation in soil-water system

There were six high diesel oil degrading bacteria strains isolated from the oil contaminated soil that collected from Linzi City. The strain YI was able to produce biosurfactant rhanmolipid when cultivated on diesel oil as carbon source. The critical micelle concentrations （CMC） of rhanmolipid in water and in the soil were measured respectively according to the correlation between the surface tension of the medium and the added rhamnolipid concentration. The results showed that the CMC of rhanmolipid in water was 65 mg/L, and was 185 mg/L in soil. The tests on diesel oil biodegradation were conducted with the addition of different concentrations of rhamnolipid in water and in soil respectively. When 0.01% rhanmolipid was added to water, the diesel oil degradation was enhanced. On the contrary, when the same concentration of rhanmolipid was added to the soil, the degradation of diesel oil was inhibited. The results suggested that the rhamnolipid could enhance the diesel oil biodegradation, indicating that the concentration of rhamnolipid was higher than the corresponding CMC in the medium. Kinetics parameters for the diesel oil biodegradation parameters such as biodegradation constant （λ）, coefficient of correlation （r） and half life （t1/2） in both tests were numerically analyzed in this paper, indicating that the moderate concentration of rhamnolipid in the medium could not only enhance the extent of diesel oil biodegradation but also shorten the time for oil remediation.     

Effects of cadium, zinc and lead on soil enzyme activities

Heavy metal （HM） is a major hazard to the soil-plant system. This study investigated the combined effects of cadium （Cd）, zinc （Zn） and lead （Pb） on activities of four enzymes in soil, including calatase, urease, invertase and alkalin phosphatase. HM content in tops of canola and four enzymes activities in soil were analyzed at two months after the metal additions to the soil. Pb was not significantly inhibitory than the other heavy metals for the four enzyme activities and was shown to have a protective role on calatase activity in the combined presence of Cd, Zn and Pb; whereas Cd significantly inhibited the four enzyme activities, and Zn only inhibited urease and calatase activities. The inhibiting effect of Cd and Zn on urease and calatase activities can be intensified significantly by the additions of Zn and Cd. There was a negative synergistic inhibitory effect of Cd and Zn on the two enzymes in the presence of Cd, Zn and Pb. The urease activity was inhibited more by the HM combinations than by the metals alone and reduced approximately 20%--40% of urease activity. The intertase and alkaline phosphatase activities significantly decreased only with the increase of Cd concentration in the soil. It was shown that urease was much more sensitive to HM than the other enzymes. There was a obvious negative correlation between the ionic impulsion of HM in soil, the ionic impulsion of HM in canola plants tops and urease activity. It is concluded that the soil urease activity may be a sensitive tool for assessing additive toxic combination effect on soil biochemical parameters.     

Release and sedimentation behaviors of biochar colloids in soil solutions

The release of biochar colloids considerably affects the stability of biochar in environment. Currently, information on the release behavior and suspension stability of biochar colloids in real soil solutions is scarce. In this study, 20 soils were collected from different districts in China and the release behavior of biochar colloids and their suspension stability in soil solutions were systematically examined. The results showed that both pyrolysis temperature and biomass source had important effects on the formation of biochar colloids in soil solutions. The formation amount of biochar colloids from low pyrolysis temperatures (400 °C) (average amount of 9.33–16.41 mg/g) were significantly higher than those from high pyrolysis temperatures (700 °C) (average amount of less than 2 mg/g). The formation amount of wheat straw-derived biochar colloids were higher than those of rice straw-derived biochar colloids probably due to the higher O/C ratio in wheat-straw biochar. Further, biochar colloidal formation amount was negatively correlated with comprehensive effect of dissolved organic carbon, Fe and Al in soil solutions. The sedimentation curve of biochar colloids in soil solutions is well described by an exponential model and demonstrated high suspension stability. Around 40% of the biochar colloids were maintained in the suspension at the final sedimentation equilibrium. The settling efficiency of biochar colloids was positively correlated with comprehensive effect of the ionic strength and K, Ca, Na, and Mg contents in soil solutions. Our findings help promote a deeper understanding of biochar loss and stability in the soil-water environment.     

Changes in the sorption, desorption, distribution, and availability of copper, induced by application of sewage sludge on Chilean soils contaminated by mine tailings

The effect of mine tailings and sewage sludge was evaluated on sorption, desorption, availability and distribution of copper in two soils, one high (sandy soil) and one low in copper (clay soil). In both soils contaminated by mine tailings the copper sorption capacity and the affinity of the substrate for the metal decreased substantially compared to the uncontaminated soils, however, the sorption remained always high in the clay soil substrates. In the substrates with sandy soil, the high Cu content and lower clay content were determining factors in the lower magnitude of the sorption. Similarly, metal desorption was closely related to these two parameters, and it was higher in clay soil with lower pH. In general, the application of sewage sludge favored the sorption of Cu in soils contaminated and uncontaminated with mine tailings, and in all cases desorption decreased, an effect that remained for at least 30 days. Simple extraction of Cu with CaCl2 and diethylenetriaminepentaacetic acid gave contradictory results, so a careful choice of the procedure is required, depending on the level of metal in the soil and on the acting principle of the extracting agent. In that relation, more complete information on the changes in the metal forms was obtained by application of the sequential extraction procedure proposed by the European Community Bureau of Reference.     

壳聚糖对沉水植物轮叶黑藻抗污能力的影响

利用化学需氧量(CODCr)分别为318 mg·L-1、157 mg·L-1、30 mg·L-1的生活污水培养轮叶黑藻.在各浓度生活污水中添加浓度为0.1%的壳聚糖,同时设不添加壳聚糖的对照组.通过对轮叶黑藻生长指标和叶绿素、可溶性蛋白质含量及抗氧化酶活性的测定,研究壳聚糖对沉水植物轮叶黑藻抗污能力的影响.结果显示,壳聚糖可明显促进轮叶黑藻主茎、根、分枝的生长,添加壳聚糖的试验组植株的叶绿素、可溶性蛋白质的含量比对照组高,且差异显著.壳聚糖能诱导黑藻超氧化物歧化酶和过氧化物酶活性增高,减轻膜脂质过氧化反应.研究结果提示壳聚糖能够促进黑藻生长,提高黑藻的抗污能力.     

Prenatal diagnosis of metabolic diseases on chorionic villi obtained before the ninth week of pregnancy

Nine pregnancies at risk for various metabolic disorders were monitored by prenatal diagnosis on chorionic villi obtained between the sixth and ninth weeks of pregnancy. A diagnosis of an affected fetus was made in five cases (Sandhoff, Tay—Sachs (2), Pompe's, GMI), while metachromatic leukodystrophy, GM1 (2), and Pompe's were excluded in four cases. It is concluded that chorionic villi are a reliable tissue for prenatal diagnosis of metabolic disorders also when obtained before the ninth week.     

Microvillar enzyme assays in amniotic fluid and fetal tissues at different stages of development

A systematic study of microvillar enzyme activities in the amniotic fluid in correlation with their values in different fetal tissues during development has been undertaken. Microvillar enzymes appeared in the amniotic fluid at the time of disappearance of the anal membrane, 12–13 weeks, and declined from the 18th week until the 24th week. The study of fetal tissues and fluids has shown that gamma-glutamyltranspeptidase is mainly of liver origin. The significant decrease of the activities of these amniotic fluid enzymes has been the basis of prenatal diagnosis of cystic fibrosis. These assays may be useful for the diagnosis of certain digestive tract abnormalities at later stages of pregnancy.     

Comparative study of 15 lysosomal enzymes in chorionic villi and cultured amniotic fluid cells. Early prenatal diagnosis in seven pregnancies at risk for lysosomal storage diseases

A large number of chorionic villi samples obtained from women undergoing elective first trimester termination of pregnancy was analysed by enzyme assays similar to those applied to cultured amniotic cells. The levels of 15 lysosomal enzymes were compared to those observed in tissue cultures of amniotic cells obtained through amniocentesis at 16-18 weeks of pregnancy and the results were discussed in order to assess the usefulness of trophoblast biopsy for first trimester diagnosis of hereditary lysosomal diseases. The data suggest the applicability of this source of fetal cells for prenatal diagnosis of fifteen respective genetically determined enzyme deficiencies with the probable exception of α-L -iduronidase deficiency. Enzyme determinations were performed on chorionic villi samples of two pregnancies at risk for Tay-Sachs disease, three pregnancies for GM₁ gangliosidosis type 1, one for mucopolysaccharidosis type VI and one for Wolman's disease.     

Prenatal diagnosis of cystic fibrosis: I. Prospective study of 51 pregnancies

A prenatal diagnosis was performed in 51 pregnancies with a 1-in-4 risk of having a child with cystic fibrosis. The criteria for determining an affected fetus were based on the results of alkaline phosphatase (ALP) residual activity after inhibition by phenylalanine and by homoarginine, of total ALP activity, and of gamma-glutamyltranspeptidase (GGTP) activity in the amniotic fluid taken between 16 and 19 weeks of pregnancy. The chromosomal analysis of amniotic fluid cells showed trisomy 13 in one case which was excluded from the analysis of biochemical assays. The biochemical assays were in the normal ranges in the amniotic fluid of 35 pregnancies: 26 have reached term and a normal infant has been born, 9 are still in progress. A deficiency of the ALP phenylalanine-inhibitable form, depressed values of total ALP and GGTP were observed in the amniotic fluid of 15 pregnancies: one pregnancy went to term and the infant had CF, in 14 cases the pregnancy was terminated, and meconium ileus was observed in ten of these cases. It was observed that the changes towards abnormal values became more significant with advancing gestational age and that 18 weeks appeared to be the optimum time for diagnostic amniocentesis.     

Identification of naphthalene metabolism by white rot fungus Armillaria sp. F022

Armillaria sp. F022, a white rot fungus isolated from tropical rain forest (Samarinda, Indonesia) was used to biodegrade naphthalene in cultured medium. Transformation of naphthalene by Armillaria sp. F022 which is able to use naphthalene, a two ring-polycyclic aromatic hydrocarbon (PAH) as a source of carbon and energy was investigated. The metabolic pathway was elucidated by identifying metabolites, biotransformation studies and monitoring enzyme activities in cell-free extracts. The identification of metabolites suggests that Armillaria sp. F022 initiates its attack on naphthalene by dioxygenation at its C-1 and C-4 positions to give 1,4-naphthoquinone. The intermediate 2-hydroxybenzaldehyde and salicylic acid, and the characteristic of the meta-cleavage of the resulting diol were identified in the long-term incubation. A part from typical metabolites of naphthalene degradation known from mesophiles, benzoic acid was identified as the next intermediate for the naphthalene pathway of this Armillaria sp. F022. Neither phthalic acid, catechol and cis,cis-muconic acid metabolites were detected in culture extracts. Several enzymes (manganese peroxidase, lignin peroxidase, laccase, 1,2-dioxygenase and 2,3-dioxygenase) produced by Armillaria sp. F022 were detected during the incubation.     

Effects of aeration on the suspended matter from a tropical and eutrophic estuary

A comprehensive understanding of the complex biogeochemical interactions between organic matter and persistent contaminants in the suspended matter is vital for ecoefficient estuary recovery. However, little is known regarding aeration effects in suspended particulate aggregates. Therefore, this study aimed to investigate the effects of aeration on the suspended matter from a Tropical and Eutrophic estuarine environment. Anoxic water with 60 g/L of suspended particulate matter(SPM) was collected from Guanabara Bay, Rio de Janeiro, Brazil, transferred to experimental boxes and aerated for 61 days. SPM aggregates monitoring included abiotic variables measurements and, determination of total organic matter(TOM), biopolymers composition, bacterial activity, trace metals, and polycyclic aromatic hydrocarbons(PAHs) concentrations. The aeration enhanced dissolved oxygen(DO) concentration and the redox potential(Eh). However, from days 0 to 61 the predominant bacterial activities were denitrification and fermentation. Electron transport system activity increased after day 10, and aerobic activity was detected after day 19. In summary, aeration increased aerobic bacterial activity, lipids(LIP) and trace metal concentrations, although diminished protein/carbohydrate ratio and PAH concentration.Trace metals concentration(Ni, Pb, Cu, Cr, Mn, and Fe) were the highest on day 19 when the p H was 5.9. Copper presented toxic values(Cu 20.0 μg/g). The p H showed a strong negative correlation with Eh(r =-0.94; p 0.001). Acidic environment(p H ≤ 5.9) in marine ecosystems with high loads of toxic trace metals is unsafe for biota. Therefore, managers must be aware of the environmental and biological risks of introducing the aeration technique into a eutrophic marine environment.     

臭氧和干旱交互作用对杨树叶片抗氧化酶活性的影响

地表臭氧(O_3)污染和干旱成为严重威胁植物正常生长的主要环境胁迫因子.本文研究3种O_3浓度(CF:过滤空气O_3;NF:未经过滤的环境空气;NF40:NF+40 nmol·mol-1O_3)和2种水分处理(充分灌溉;干旱,60%灌溉)及其交互作用对敏感性杨树品种‘546’(Populus deltoids cv.55/56×P.deltoides cv.Imperial)叶片饱和光合速率、抗氧化酶活性及可溶性蛋白含量的影响.结果表明,O_3浓度升高显著降低饱和光合速率,干旱处理对饱和光合速率的影响不显著,O_3和干旱的交互作用显著.干旱显著降低过氧化氢酶(CAT)和超氧化物歧化酶(SOD)活性,且随着处理时间的延长CAT和SOD活性降低显著.处理时间的延长也显著降低抗坏血酸过氧化物酶(APX)活性,增加了可溶性蛋白含量.过氧化物酶(POD)不受O_3、干旱及O_3与干旱交互作用的显著影响.O_3处理以及O_3与干旱的交互作用均未对抗氧化酶活性产生显著影响.该研究结果为应对环境变化背景下O_3浓度升高与干旱加剧对杨树的伤害提供科学依据.     

Nickel accumulation and its effect on biomass, protein content and antioxidative enzymes in roots and leaves of watercress (Nasturtium officinale R. Br.)

In order to understand its response towards nickel stress,watercress(Nasturtium officinale R.Br.) was exposed to nickel(1-25 mg/L) for 1,3,5 and 7 days.The accumulation and translocation of nickel were determined and the influence of nickel on biomass,protein content and enzymatic antioxidants was examined for both roots and leaves.It was determined that N.officinale could accumulate appreciable amounts of Ni in both roots and leaves.Nickel accumulated particularly in the roots of plants.Biomass increased at low nickel concentrations but certain measurable change was not found at high concentrations.Under stress conditions the antioxidant enzymes were up-regulated compared to control.An increase in protein content and enzyme activities was observed at moderate exposure conditions followed by a decline at both roots and leaves.The maximum enzyme activities were observed at different exposure conditions.Our results showed that N.officinale had the capacity to overcome nickel-induced stress especially at moderate nickel exposure.Therefore,N.officinale may be used as a phytoremediator in moderately polluted aquatic ecosystems.