Search

In recent years, increasingly more soils are getting contaminated with organic and inorganic toxins globally due to waste emissions. Among inorganic pollutants, heavy metal like chromium (Cr) is alarming to our environment, even though its environmental management is also ignored. As a result, Cr accumulates in plant tissues at toxic concentrations end up in the food chain. Therefore, pot experiment was conducted to investigate the effects of biochar and modified biochar application on the properties of Cr polluted soils and interaction of Cr with other soil nutrients. Two different biochar viz. rice stubble and saw dust were slow pyrolyzed (450 ± 50ºC) and modified with1M KOH. All biochars were applied at a rate of 20 t ha-1 on soils artificially polluted with Cr at the levels of 0, 100, 200 and 300 µg g-1. The biochars and modified biochars had significant effects (P

Chromium (Cr) is a potentially toxic metal occurring in the soil as a result of natural and anthropogenic activities and is mainly found in Cr

The deterioration of environmental quality due to wastes generated from tannery industries is an alarming global issue in Bangladesh. To assess this problem in an area adjacent to the recently shifted tannery industries at Hemayetpur, soil, water and plant samples are collected from upstream as control, secondary treatment ponds, main discharge station and downstream at 500, 1000, 2000 and 3000 m across the areas and are analyzed for environmental quality. The water samples of Dhaleswari river are slightly acidic to moderately alkaline pH from 6.55 to 10.60, high TDS from 176 to 10,433 mg/l, EC from 305 to 18,206 μS/cm, nitrate from 0.14 to 194 mg/l, sulfate from 10.72 to 8922 mg/l, moderate phosphate from 0.58 to 7.2 mg/l and low DO from 1.61 to 5.50 mg/l. It is clearly noticed that most of the water parameters exceeded WHO guideline values except pH and phosphate that indicates Dhaleswari river water quality is declining slowly. The available concentrations of nitrogen, phosphorus, potassium and sulfur in soil varies from 12 to 263, 1.19 to 38, 17 to 170, 251 to 680 mg/kg, respectively, whereas, the total concentration ranges from 0.03 to 0.14%, 0.090 to 0.14%, 0.12 to 0.48%, and 0.11 to 0.42%, respectively. In soil samples, total phosphorus and potassium concentrations are increased but sulfur decreased. The soils are found acidic in nature that have high EC 8.17 dS/m. A significant positive correlation is found with each other of nitrogen, phosphorus, potassium and sulfur concentrations in soil samples. The nutrients in plant samples have no deficiency those are within the optimum range. Dhaka Univ. J. Biol. Sci. 31(1): 29-43, 2022 (January)

The release of a large quantity of heavy metals into the Dhaleswari River from the tannery, dyeing, and other industrial setups and their subsequent transfer to food chains through fish consumption have been an alarming issue in Bangladesh. To study the pollution level, a total of seven fish species, namely Heteropneustes fossillis, Channa punctata, Nandus nandus, Chanda nama, Anabas testudineus, Mystus gulio, and Colisa fasciata, were collected in winter from the Dhaleswari River and the total concentrations of Cr, Pb, Ni, and Zn in head and body tissues were analyzed separately. The concentrations of Cr, Pb, and Zn were found 300, 20, and 10 times higher, respectively, than the guideline value of the Food and Agriculture Organization (FAO)/World Health Organization (WHO), indicating possible health risks to humans. In most cases, bioaccumulation factors (BAFs) exceeded the highest limit, expressing that most of the species, especially C. nama, A. testudineus, and C. fasciata, were in the highly bioaccumulative state. The health risks associated with fish consumption were determined in terms of estimated daily intake (EDI), non-carcinogenic risks (THQ), and carcinogenic risk (TR) factors. The THQs for Cr and Pb crossed the maximum value of 1 in all the fish species except Pb in Mystus gulio, which might cause different non-carcinogenic diseases upon consumption of these fishes. In all the fish species, the carcinogenic risk factor for Cr exceeded the standard value (10-4), indicating chronic cancer risk to humans. Although the estimated daily intake (EDI) values did not cross the permissible limit, continuous consumption of contaminated fish from the target area may cause serious health complications. This study revealed that consumption of these fishes exposed people to a higher risk of non-carcinogenic and carcinogenic consequences in terms of human health.

In recent years, cadmium (Cd) contamination in agricultural soils and its subsequent transfer to crops is one of the high-priority environmental and public health issues of global concern, especially in densely populated developing countries like Bangladesh. However, no effective strategy has been introduced or implemented yet to manage Cd-contaminated soils in order to sustain agricultural production with no human health risks. In this study, agricultural soil samples were collected from 60 locations of 10 upazilas from Tangail district to assess the extent of soil Cd contamination. The Cd concentration ranged from 0.83 to 4.08 mg kg−1 with a mean of 2.17 mg kg−1 in topsoil (0–15 cm), and from 0.67 to 3.74 mg kg−1 with a mean of 2.10 mg kg−1 in subsoil (16–30 cm). The values of contamination factor (CF) indicated that all the sampling locations were found to be highly contaminated with Cd. Pot trials with the application of different doses of biochar and vermicompost in Cd-contaminated soil (0.8 mg kg−1 Cd) revealed that integrated application of biochar (5 t ha−1) and vermicompost (5 t ha−1) was the best treatment that significantly (p

The actual quantity of Soil Organic Carbon (SOC) stored in wetlands can only be estimated within a broad range of uncertainty. An accurate assessment of the size and distribution of the SOC storages in wetland resources is very difficult to obtain, therefore, the proposed research objective is to measure SOC storage and its pool on wetland soils of Arial beel in Bangladesh. Initial results of Arial beel soil profiles indicates SOC concentrations are high in surface soils ranges from 1.67 to 1.95% but its concentrations are decreasing with depth whereas SOC stock in kg C m-2 is increased with depth due to increse soil bulk density with depth. However, carbon in deeper layers may be more stable than that in surface soils due to difference in source, composition and environmental conditions. Soil organic C stored in the three different locations of wetlands soils to 1 m depth such as 16.47, 18.27 and 17.22 kg C m-2, respectively with an average of 17.32 kg C m-2. On the other hand, SOC stored in upland soils to 1m depth such as 11.24 kg C m-2, significantly less than the wetland soils, which indicates that wetland soils serve as a major source of SOC. However, this SOC act as a conditioner to enhance fertility status while combating with climatic extremes, not only that it is a vital component of soil with important effects on the functioning of terrestial ecosystems. For SOC pool, different extraction methods are used such as, highly labile fraction of SOC extracted with hot water (about 3-8% of toal SOC), water soluble fraction of SOC extracted with water (about 1% of total SOC), labile fraction is extracted using CaCl2 (about 1% of total SOC), moderately labile fraction extracted by pyrophosphate (about 4-10% of total SOC), polyaromatic SOC is extracted using toluene + methanol (trace amount of total SOC), microbial biomass C extracted by K2SO4 (about 2-5%) and the resistant fraction remaining after extraction. However, the SOC concentration is high in surface layer but with depth concentration decreases. In addition, soil bulk density and thickness values increase with depth, as a result deeper layers stored more carbon than surface layer in Arial beel soils. There is increasing evidence from the results that wetlands have an important and under-estimated role in carbon storage and its pool the regualation of greenhouse gas emission. Some types of wetlands play a particularly key role as C stores, these include forested wetlands and vegetated inter-tidal wetlands and hence, Sundarban mangrove forest and Tengarchar SOC stocks and pools measurement are an urgent issue for the Climate Change researchers and policy makers.

Cadmium (Cd) is a heavy metal which is not essential for human body. Cadmium enters into human body mainly through food consumption. Besides industrial wastes, phosphate fertilizers contain Cd which accumulates gradually in agricultural lands. To produce high quantity of food for about 160 million people of Bangladesh, agricultural lands need to be applied huge amount of fertilizes including TSP which add Cd to soils. It has been reported that in rice grains the cadmium concentrations were the highest in Bangladesh and Srilanka where the per capita rice intake is high, from a survey on four continents of 12 countries. The intake of these Cd containing foods may ultimately increase the Cd concentration in human kidneys and livers which might be related to the enhanced kidney patients in Bangladesh. There is lot of toxic effects of excess Cd on humans. The present review illustrates the urgency of further studies of Cd in Bangladesh. J. Environ. Sci. & Natural Resources, 11(1-2): 227-234 2018

A pot experiment was carried out with arsenic (As) viz. 0, 0.1, 1 and 2 mgL-1 as sodium arsenite and phosphorus viz, 0, 15 and 30 μgmL-1 as ammonium dihydrogen phosphate to evaluate their effects on dry matter yield and nutrients concentration in rice plants (Oryza sativa L.) in the net house. Arsenic toxicity caused more damage to root than to shoot. As reduced plant height and dry matter yields but lower level increased the same significantly. A maximum diminution of 26.70% shoot weight and 32.30% root weights were observed where 2 mgL-1As and 0 μgmL-1 P were applied. Micronutrients were found to be more strongly antagonized by arsenic than the macronutrients. Maximum and minimum accumulation of different nutrients was found at 30 μgmL-1 and 0 μgmL-1 P applications, respectively. The lowest concentration of most of the nutrients were found at 2 mgL-1As and 0 μgmL-1 P. Experiment revealed that the concentrations of nitrogen, potassium, sulphur, iron, copper, zinc and manganese in the root and shoot of rice plants showed an antagonistic effect with As and synergistic effect with P. J. Biodivers. Conserv. Bioresour. Manag. 2019, 5(1): 31-38

The release of a large quantity of heavy metals into the Dhaleswari River from the tannery, dyeing, and other industrial setups and their subsequent transfer to food chains through fish consumption have been an alarming issue in Bangladesh. To study the pollution level, a total of seven fish species, namely Heteropneustes fossillis, Channa punctata, Nandus nandus, Chanda nama, Anabas testudineus, Mystus gulio, and Colisa fasciata, were collected in winter from the Dhaleswari River and the total concentrations of Cr, Pb, Ni, and Zn in head and body tissues were analyzed separately. The concentrations of Cr, Pb, and Zn were found 300, 20, and 10 times higher, respectively, than the guideline value of the Food and Agriculture Organization (FAO)/World Health Organization (WHO), indicating possible health risks to humans. In most cases, bioaccumulation factors (BAFs) exceeded the highest limit, expressing that most of the species, especially C. nama, A. testudineus, and C. fasciata, were in the highly bioaccumulative state. The health risks associated with fish consumption were determined in terms of estimated daily intake (EDI), non-carcinogenic risks (THQ), and carcinogenic risk (TR) factors. The THQs for Cr and Pb crossed the maximum value of 1 in all the fish species except Pb in Mystus gulio, which might cause different non-carcinogenic diseases upon consumption of these fishes. In all the fish species, the carcinogenic risk factor for Cr exceeded the standard value (10

Due to climate change biochar is recently recommended as a control approach to increase crop productivity and global warming reduction. As biochar application changes the soil pH towards alkalinity, this effects acid soils nutrient cycles the same as microbial abundance. This research was conducted to investigate the microbial abundance as affected by waste-derived biochar application in two different rates on acidic soil of Bangladesh. Slow pyrolyzed (500±50ºC) different waste-derived biochars viz. sewage sludge, sugarcane bagasse, potato peels, water hyacinth, and organic waste were applied at 10 tons ha-1 and 15 tons ha-1 on the acidic soil. An in-vitro incubation study was conducted on experimental soil applying all the biochar to understand how nutrient availability and carbon dynamics affect the microbial abundance of the acid soil. The incubation study was divided into two stages: submerged condition (up to 60 days) followed by a dry condition (61 to 120 days) and biochars were applied in two different rates such as 10 and 15 tons ha-1. The viable count of bacteria significantly (P

Five(5) different waste-derived biochar viz. animal bone, corn stover, wood chips, green coconut palms, and nutshells were slow pyrolyzed (500±50ºC) and further investigated to know their morphological characteristics and nutrient contents. Results produced the fact that corn stover biochar had the best nutrient status along with excellent physical properties like water holding capacity (525%) and CEC (251.85 Cmolc/kg) whilst coconut palm biochar was the second-best among all categories. The average particle size of WC biochar 0.82 (μm2) was the largest along with the maximum pore depth. Nonetheless, the region of this biochar was occupied by remarkably small particles, which was 47.42%. The corn stover biochar, on the other hand, had the smallest average particle size (0.18 μm2) and the lowest particle area (9.19%). WC biochar (51.3%) and CS biochar (46.2%) had the highest organic C value, while biochar nutshell had the lowest (15.31%), sequentially. Nutrient content can vary depending on the variation in the feedstock mostly N, P, K, and S in total content. Animal Bone biochar (3.89 percent) and biochar nutshells (3.32 percent) exhibited the highest total N content. In the interpretation, high phosphorus concentrations resulted in biochar derived from animal bone feedstock (8.44%), whereas other biochars were less than 1%. The CP biochar had higher total K content than other biochars. All the biochars exhibited equal total S concentration other than biochar derived from the animal bone (2.34%) had a higher percentage of total K compared with other biochar. Biochar related wastes showed a very low concentration of heavy metals such as Cr, Pb, Cd, and Ni. The overall amount of lead and cadmium in all of the biochar was below the detection mark. &nbsp

In recent years, cadmium (Cd) contamination in agricultural soils and its subsequent transfer to crops is one of the high-priority environmental and public health issues of global concern, especially in densely populated developing countries like Bangladesh. However, no effective strategy has been introduced or implemented yet to manage Cd-contaminated soils in order to sustain agricultural production with no human health risks. In this study, agricultural soil samples were collected from 60 locations of 10 upazilas from Tangail district to assess the extent of soil Cd contamination. The Cd concentration ranged from 0.83 to 4.08 mg kg

An investigation was conducted to assess the impact of solid waste disposal on surrounding environment of Matuail landfill site of Dhaka city. Three different locations such as current dumping, abandoned and its surrounded agricultural areas of Matuail landfill were selected for soil and plant samples, leachate from active dumping and fish samples from treated leachate pond. The Cu, Zn and Pb concentrations were high in the dumping (360 µg g-1 Cu, 806 µg g-1 Zn and 382 µg g-1 Pb) and abandoned (199 µg g-1 Cu, 452 µg g-1 Zn and 519 µg g-1 Pb) areas that exceeded the permissible limits. The heavy metal concentrations in plant samples did not show any significant contamination except Cu, Zn and Pb that also exceeded the permissible limits. On the other side, the organic matter and nutrient concentrations such as N, P, K and S of both soil and plant samples are within desirable value in the studied area. The concentrations of DO, BOD, COD and TDS of the untreated leachate were found 1.34 mg L-1, 96 mg L-1, 1343 mg L-1 and 7120 mg L-1, respectively that exceeded inland surface water standard but after treatment the concentrations of DO, BOD and TDS in the treated leachate pond were found within the permissible limit. The presence of heavy metal in leachate is not contaminated as it is below the toxic limit. The bioaccumulation of fish from treated pond is extremely high of Fe, Mn, Pb and Ni that exceeded the WHOs permissible limit.

A study was conducted to determine the organic carbon fractions in the vertical sections of a benchmark wetland soil of Bangladesh (Arial Beel) and their dynamics that directly affect the biogeochemistry of soil, water and plant biomass ecosystem. Two distinctive soil series viz. Sara and Arial are characterized such as pH, moisture content, textural class, CEC, organic carbon (SOC), bulk density and total organic matter etc. Different extraction methods were used for the fractionation of dissolved organic carbon such as water-soluble Fraction (WSC), hot water extractable fraction (HWC; 80°C), labile fraction (CaCl2- extractable; LF), moderately labile fraction (Pyrophosphate-extractable; MLF), polyaromatic fraction (toluene + methanol extractable), Microbial Biomass C Fraction (MBF) and the remaining Resistant Fraction (RF). The total organic carbon content ranges from 0.72 to 1.95%; surface horizons had higher C than underneath horizons and prolonged inundation increased the C content mostly. Higher CEC of the soils had a positive correlation to HWC, MBC and RF. The DOC content particularly MLF was found higher in surface and substratum than subsurface horizons in most of the soils. The HWC and ML fraction had highly significant (p 1%) which is relatively resistant to further degradation and might be considered as sequestered C. Short inundated period and scope of winter Robi crops might have caused Sara soil to have relatively lower organic C and RF than Arial. Moreover, the amount of DOC fractions in Sara series was lower and that decreased with depth but in Arial series, fractions varied within the profile.

Six slow pyrolysis biochars viz. farmyard manure (FM), water hyacinth (WH), domestic organic waste (DW), quick compost (QC), corn cob (CC) and rice straw (RS) were analyzed for their physical and chemical properties. Biochar yielding capacity varied from 34 to 51%, depending on the used feedstock. Water hyacinth biochar exhibited the highest water holding capacity (495%), whereas corn cob biochar had the lowest (146%) regardless of its highest pore volume. Brunauer-Emmett-Teller (BET) specific surface area was found maximum among the plant derived biochars except corn cob. Rice straw biochar exhibited the least mean pore diameter while highest in domestic organic waste. All biochars possessed pH values more than 9. CEC of water hyacinth (WH) was highest, while lowest was in quick compost (QC) biochar. Smallest average particle size (0.54 ?m2) was exhibited by water hyacinth biochar. Organic carbon content ranged from 33 to 49%. Nutrient (N, P, K and S) status of biochar produced from domestic organic waste (DW) was found the maximum compared to the rest and corn cob (CC) biochar showed the lowest nutritional value.Bangladesh J. Sci. Res. 29(2): 111-122, December-2016

A study was carried out to evaluate the effects of brick manufacturing on phosphorus (P) and sulfur (S) concentrations in soil and plant collected from different distances of brick kilns in four AEZs of Bangladesh. Forty eight composite soil samples (0 - 15 cm depth) were collected from 48 points in 12 different sites at 0 m, 300 m, 800 m and 1500 m from brick kilns, where most (site 2, site 3, site 5, site 6, site 7, site 9 and site 10) of the brick kilns used coal for brick burning purposes. Plant samples (rice straw and different vegetables) were also collected from the respective fields except 0 m distances. Significantly (p ? 0.05) lower organic matter, cation exchange capacity, clay content and soil pH were found at 0 m distances compared to other distances. Highest concentration of total P in soil were recorded at 0 m distances and these concentrations decreased with increasing distances from the brick kilns in most of the sites; whereas available P is significantly lower at 0 m distances than that of other distances. Total and available concentration of S in soil followed the trend 0 m>300 m>800 m>1500 m. Maximum accumulation of P (69.15 mg kg-1) and S (0.14%) in plant was found at 800 m away from the brick kiln.Bangladesh J. Sci. Res. 29(2): 123-131, December-2016

An investigation was carried out to assess the characteristics of leachate and its impact on surrounding agricultural land of the Matuail landfill site, Dhaka, Bangladesh. Leachate samples were collected from active dumping areas; soil and plant samples from three different sites of surrounding agricultural areas. Water quality parameters like pH, DO, BOD, COD, TDS were measured for leachate samples and heavy metals like Cu, Zn, Pb, Cd, Ni were analyzed for leachate, soil and plant samples. The results showed that untreated leachate concentrations of DO, BOD, COD and TDS were 1.34, 96, 1343 and 7120 mg/l, respectively that exceeded inland surface water standard but the concentrations of DO (7.49 mg/l), BOD (10 mg/l) and TDS (790/l) in the treated leachate pond were found within the permissible limits. The leachate samples are not contaminated with heavy metals as these are present below the toxic limits. The heavy metal concentrations in agricultural soils are below the permissible limits except Pb; but in plants the concentrations of Cu, Zn and Pb exceeded the critical limits.Bangladesh J. Sci. Res. 29(1): 31-39, June-2016

An investigation was conducted to determine the distribution and concentrations of different forms of Zn in the soils of Gazipur. Gerua, Kalma and Khilgaon soil series were identified in three land types, named as highland, medium high land and medium low land, respectively. Soil samples were collected from each soil series at three different depth such as surface (0 -15 cm), subsurface (15 -40 cm) and substratum (40 cm+) to determine soil characteristics and the distribution pattern of Zn fractions. Results indicated that amount of total Zn varied significantly, ranges from 14.99 to 36.11 ?g/g at different depth of different land types. Moreover, the purpose of the sequential extraction or fractionation was to find out the Zn in the exchangeable (Exch.), organic matter (Org.) bound, Mn oxide (Mn-O), amorphous Fe oxide (Am. Fe-O), crystalline Fe oxide (Crys. Fe-O) and residual (Res.) fractions. In Gerua, Kalma and Khilgaon soils, Zn concentrations predominated in Res. followed by Crys. Fe-O and Am. Fe-O fractions. Results reflected that soil properties influence the distribution of different Zn fractions in soils.Dhaka Univ. J. Biol. Sci. 25(1): 19-25, 2016

Experiment was carried out to assess the concentration of Zn, Cu, Pb, Fe and Mn in agricultural soil and plant near selected brick kilns. Soils and plants samples were collected from four points such as 250, 500, 1000 and 1500 m away from brick kilns. Three metals were found at elevated levels in the soils near brick kilns such as, Pb (92.5 to 214 mg/kg), Zn (86 to 156 mg/kg) and Cu (24.7 to 46.9 mg/kg). It may be caused due to burning of poor quality coal and fire woods. The uptake of heavy metals in the nearest areas (250 m) of the brick kilns was significantly higher than the areas far from the brick production and their concentrations range from 7 to 543 mg/kg for Pb, 23 to 101 mg/kg for Zn, 10 to 41 mg/kg for Cu, 35 to 1309 mg/kg for Fe and 26 to 126 mg/kg for Mn. Results indicated that soils and plants accumulated maximum amount of micronutrients within 500 to 1000 m distance from brick kilns significantly decreased with distance. Iron and manganese were not polluting the soils near brick kilns but affecting the plants. Therefore, it can be suggested that no agricultural crops should be grown within 1000 m distance from a brick kiln.Dhaka Univ. J. Biol. Sci. 25(1): 75-81, 2016

Three different soil series such as Gerua, Kalma and Khilgaon were identified in three different land types (high, medium high and medium low land). Soil and plant samples were collected from each land type following a catena. Soil samples were collected from surface, subsurface and substratum in each soil series and plant samples were collected from each soil series to examine how the soil characteristics affect nutrient uptake by plants. The uptake of N, P, S and Zn increased from Gerua to Kalma soil and decreased to Khilgaon. K uptake increased from Gerua to Khilgaon soils. The concentration of Fe, Mn and Cu decreased at first and then increased that were opposite to the status of N, P, S and Zn. The uptake of P and Mn were positively correlated (r2 = 0.845**, r2 = 0.767*) and the uptake of K and Fe were negatively correlated (r2 = –0.951**, r2 = –0.676*) with the soil nutrients. This indicates the variation in nutrient concentration influenced by different factors in the catena. The uptake of nutrients by plants varied significantly within the catena. Macro and micronutrients were accumulated by the plants and the soils studied in the experiment did not show any nutrient deficiency or any metal contamination.Bangladesh J. Sci. Res. 28(2): 113-121, Dec-2015

A pot experiment was conducted to investigate the effect of irrigation water collected from different industrial areas on Red amaranth (Amaranthus tricolor L.) and tomato (Solanum lycopersicum L.). Collected water samples were analyzed for various parameters, which include pH, DO, BOD, COD, P, NH3-N, K, S, Zn, Cu, Pb and Cd. The results were compared with the irrigation water quality standards by the Department of Environment (DoE) of Bangladesh and many of them were found several-folds higher than the permissible limit. The deterioration trends of the water samples are as follows: Tejgaon canal > Rampura canal > Sitalakhya river. Dry matter of vegetables grown on Tejgaon soil was significantly (p ? 0.05) higher than that of agricultural soil. Both red amaranth and tomato grown in Tejgaon soil accumulate highest concentration of heavy metals followed by Rampura and Sitalakhya soil. The concentrations of zinc (Zn), lead (Pb) and cadmium (Cd) in edible portions of both vegetables were found several times higher than the WHO prescribed permissible limits. The concentration of heavy metals in vegetables were found in the order Zn > Cu > Pb > Cd.Bangladesh J. Sci. Res. 28(2): 151-159, Dec-2015

Cadmium is a trace element which is not essential for human being. High cadmium concentration in some rice samples in Bangladesh was reported than that of other countries. This study was carried out to find out the Cd concentration fertilizers, soils, rice and vegetables and along with other chemical properties of Karotia union, Tangail sadar upazila, Tangail. A total of 29 samples were collected among the 14 soils from 7 stations at 0-15 cm and 16-30 cm depth respectively, 5 vegetables, 5 rice and also 4 different countries TSP fertilizers from local market. The Cd concentration values of all soil samples were found between 0.97 to 1.73 mg/kg (0-15 cm) and 0.53 to 0.83 mg/kg (16-30 cm), respectively and the vegetable sample values were found between 0.053 mg/kg to 0.123 mg/kg (d.w.).The rice sample values were found between 0.05 mg/kg to 0.096 mg/kg (d.w.). The fertilizer sample values were found between 20.67 to 92.33 mg/kg. The soil pH values obtained 7.06 to 7.70 (0-15 cm) and 7.48 to 7.88 (16-30 cm) which indicated that the study area soils were neutral to moderately alkaline. The EC values of all soil samples were between 47.67 to 82.67dSm-1 (0-15cm) and 33.33 to 58.33dSm-1 (16-30 cm). The organic matter content of all soils ranged from 0.789 to 0.905% and 0.351 to 0.869% at (0-15 cm and 16-30 cm), respectively. The available sodium (Na) values of soils were found between 1.84 to 1.92 ppm (0-15 cm) and 1.83 to 1.90 ppm (16-30 cm), respectively. The available potassium values ranged from 1.81 to 1.96 ppm (0-15 cm) and 1.84 to 1.97 ppm (16-30cm), respectively. The available calcium values of all soil samples were 1.92 to 1.97 ppm (0-15 cm) and 1.91 to 1.96 ppm (16-30 cm), respectively.

A long term incubation study was carried out to ascertain the effects of basic slag on acid sulfate soil. Four treatment levels of basic slag (0, 30, 40 and 50 t/ha) were selected to find out their response on pH, EC, as well as on various water soluble and exchangeable cations (Na, K, Ca, Mg and Fe) with incubation period. In most of the cases, the results showed significant effects of basic slag on pH and cations. The highest pH and EC were recorded with the largest doses of basic slag at the final stage of incubation period. In addition, this research did not find any negative impacts concerning basic slag on the supplied soil and suggested that basic slag could be used on agricultural land. DOI: http://dx.doi.org/10.3329/bjsr.v26i1-2.20225 Bangladesh J. Sci. Res. 26(1-2): 1-9, December-2013

A pot experiment was carried out to observe the effect of waste water irrigation on the growth and nutrient status of Kalmi (Ipomoea aquatica) in the nethouse of the Department of Soil, Water and Environment, University of Dhaka. The soil samples were collected from Tejgaon, Rampura, Sitalakhya and from the north?side of Rampura area, the latter is located at a distance from the polluted area and has been used as the control soil. The pots containing the first three soil samples were irrigated with wastewater collected from the adjacent industrial area and control pots were irrigated with tap water. The plants on Tejgaon soil produced the maximum biomass while the plants on Sitalakhya produced the least amount of biomass. The accumulation of toxic metal concentration was found to be the highest in Kalmi grown on Tejgaon followed by Rampura and Sitalakhya. The metal concentration in Kalmi (dry weight basis) ranged between 31 and 408 mg/kg for Zn, 27 to 45 mg/kg for Cu, 0.2 to 5.0 mg/kg for Pb and 0 to 2 mg/kg for Cd, respectively. The concentrations of heavy metals in the Kalmi were higher than the recommended standards in all the treatments except control.DOI: http://dx.doi.org/10.3329/dujbs.v23i1.19820Dhaka Univ. J. Biol. Sci. 23(1): 1?8, 2014

The study was carried out to observe the present status of heavy metals in water, sediment, soil and plant in the Tejgaon-Rampura-Shitalakhya water channel and the adjacent areas of the Dhaka city as well as to evaluate the heavy metal transfer in the water-soil-plant systems. Water, sediment, soil and plant samples were analyzed to know about lead, cadmium, copper and zinc contents. The findings show that heavy metal concentrations in water, sediment, soil and plant in the study area had the trend: Tejgaon Khal>Rampura canal>Shitalakhya river. Different water quality parameters such as pH, DO, BOD, COD, TDS, and NH3 shows that most of the values are higher than the DoE (Bangladesh) recommended irrigation water standards. The heavy metal concentrations in water varies and are well below the recommended values except for Cd and the trend follow the order Pb>Cd>Zn>Cu. The concentrations of the investigated heavy metals in sediment samples are found higher than the USEPA recommended sediment standards and follow the trend Zn>Cu>Pb>Cd. Similar trends are observed for the heavy metals in soil. The accumulation of heavy metals in plants followed the trend Zn>Pb>Cu>Cd in the Tejgaon and Rampura area while the trend are Zn>Cu>Pb>Cd in plants from Shitalakhya. In most of the cases the results of the tested parameters shows significant variations (at 1% level) from Tejgaon river samples with others.

An experiment was conducted to study the effects of sewage sludge on the response of Ipomoea aquatica to plant nutrients and heavy metals in soil at different soil pH. An incubation study was done for the selection of four individual pH levels, viz. , 4.7, 5.7, 6.6 and 7.8 to be used for the plant culture experiment. Yield of Ipomoea aquatica and concentration and uptake of N, P, K, Ca, Mg, Cd, Cu, Fe, Mn and Zn in the plant were evaluated. Application of sewage sludge in soil increased the concentration and uptake of the elements in Ipomoea . Slightly acidic to slightly alkaline pH was found to be better for amendment of soil with sewage sludge DOI: http://dx.doi.org/10.3329/bjsir.v47i1.10721 Bangladesh J. Sci. Ind. Res. 47(1) , 47-54, 2012

Ammonium sulphate at six concentrations in simulated precipitation has been applied weekly over two years to Calluna vulgaris growing in peat soil. The nitrogen deposition treatments were chosen to embrace and exceed critical load. The growth and composition of the Calluna and the changes over time in the chemistry of the peat soil and its soil solution were monitored. In spite of significant increases in foliar nitrogen concentration in new shoots, especially in the first year, growth did not increase significantly in response to nitrogen treatment. Several factors could be contributing to the lack of significant growth response. (1) Increasing ammonium input significantly acidified the soil solution, which could adversely effect growth directly. (2) Foliar calcium concentration was reduced significantly in both years by the ammonium sulphate treatments, and more calcium was undoubtedly lost from the rooting zone at higher nitrogen inputs. (3) Foliar phosphate declined significantly between the first and second year, so lack of growth response might also reflect a phosphorus limitation. There was a distinctly visible darkening of the leaves in response to increasing ammonium applications, especially for the first year's growth, and the chlorophyll a and b concentrations in leaves from new growth at the three highest nitrogen treatments were significantly (at P < 0.05) higher than those for the control. The pigment concentrations fell markedly by the end of the second season, and treatment effects were much less consistent. It is suggested that pigment analysis therefore probably has little diagnostic value for assessing damage from pollutant nitrogen effects.

Calluna vulgaris/peat microcosms have been used in an outdoor simulated acid rain experiment to test a series of hypotheses about sulphuric acid deposition effects upon the growth of Calluna on peat soil, namely: (1) Initially, enhanced acid input will enhance base cation and ammonium concentrations in soil solution. This may enhance uptake of these species, increasing foliar concentrations of base cations and nitrogen, and possibly foliar chlorophyll a and b concentrations. (2) If changes are induced in nutritional status, they may influence plant growth. (3) in the longer term, enhanced ammonium and base cation solubility occurring as a consequence of cation exchange reactions will lead, especially in winter months, to enhanced leaching losses. Hence any positive effects upon plant nutrition will not be sustainable. (4) the peat will acidify significantly over two years, in the shorter term primarily as a consequence of an enhanced mobile anion effect. (5) Acidification may reduce the rate of m...

As an empirical pseudo-science, soil chemistry was one of the oldest branches of chemistry, originating in pre-historic times. It continued in this low-key role until it evolved in the late nineteenth and early to mid twentieth centuries as a research discipline crucial to underpinning agriculture and the technical demands of increased food production. Over the past decade it has enjoyed a renaissance as its wider applications, especially in pollution science and hydrogeochemistry, and hence in strategic long-term environment planning, have been increasingly recognized.

An incubation study has been performed to investigate the rates of redistribution of 65 Zn from spiked sewage sludge into different soil fractions. The labeled zinc in soils amended with sludge was fractionated by operationally defined procedures at three different times (1, 7 and 30 days after incubation) into exchangeable, organically bound, amorphous iron oxide-bound, crystalline iron oxide-bound and residual fractions. The rates of redistribution of zinc from sewage sludge mainly depended on soil pH. In acid soils, most of the sludge-derived zinc (70–80%) went to the exchangeable pools, and was retained in this form at high concentration for at least a month. The effect of the time during digestion of the incorporation of a 65 Zn spike into sludge was also studied. Although the results were significantly effected by spike timing, the effects of the latter on subsequent zinc fractionation results were minor compared with the effect of soil pH.

A macrocosm study was carried out to assess the transfer of arsenic (As) from irrigation water and sludge of arsenic removal water filter to two varieties of Amaranthus and their effects on phosphorus (P), potassium (K), sulfur (S), calcium (Ca) and magnesium (Mg) uptake. P and K uptake in shoot and root were negatively affected by As that were not significant. However, a significant negative relationship was observed between As and S in shoot. A positive and significant relationship existed between As and Ca of green Amaranthus shoot but it was negative and insignificant in case of red Amaranthus . Mg content of shoot and root was positively affected by As in green Amaranthus . On the other hand, in the red Amaranthus the relation between As and Mg was positive in the shoot but negative in the root. DOI: http://dx.doi.org/10.3329/dujbs.v21i1.9748 DUJBS 2012 21(1): 87-96

Brick kiln is well known as one of the main sources of air pollution; however, the pollutants produced from it do not remain in the air, they ultimately fall down to the soil and pollute the surroundings, therefore, this study was carried out to assess the status of macro (N, P, K and S) and micro nutrients (Fe, Mn and Zn, Cu) in the agricultural environment near the brick kilns of Young Brahmaputra and Jamuna Floodplain soils. Composite soil and plant samples were collected from four distances such as 250 m, 500 m, 1000 m, and 1500 m in three different sites. Sulphur (2352–3378 mg kg−1), Zn (86–156 mg kg−1) and Cu (24.7–46.9 mg kg−1) are found in the elevated levels near brick kiln soils that is released due to burning of poor quality coal and fire woods. The alarming news is that plant uptake of S and micro nutrients in the nearest areas of the brick kilns are significantly higher than the areas far from the brick production and their concentration ranges from 23 mg kg−1 to 101 mg kg−1 for Zn, 10–41 mg kg−1 for Cu, 35–1309 mg kg−1 for Fe, 26–126 mg kg−1 for Mn and 2590–mg kg−1 for S. Data indicates both soil and plant received maximum amount of micronutrients and S concentrations within 500–1000 m distances from brick kilns. Iron and Mn concentrations vary within a permissible limit but the plant uptake is high. Nitrogen concentrations is increasing with the distance from the brick kilns in both soils and plants but no definite pattern of P and K accumulation was found. Research suggested avoiding agricultural practice nearby brick kiln soils due to micronutrient contamination in order to preserve adjoined agricultural environment.