Nasiman Sapari

Biochar efficiency in pesticides sorption as a function of production variables—a review

Biochar is a stabilized, carbon-rich by-product derived from pyrolysis of biomass. Recently, biochar has received extensive attentions because of its multi-functionality for agricultural and environmental applications. Biochar can contribute to sequestration of atmosphere carbon, improvement of soils quality, and mitigation of environmental contaminations. The capability of biochar for specific application is determined by its properties which are predominantly controlled by source material and pyrolysis route variables. The biochar sorption potential is a function of its surface area, pores volume, ash contents, and functional groups. The impacts of each production factors on these characteristics of biochar need to be well-understood to design efficient biochars for pesticides removal. The effects of biomass type on biochar sorptive properties are determined by relative amounts of its lingo-cellulosic compounds, minerals content, particles size, and structure. The highest treatment temperature is the most effective pyrolysis factor in the determination of biochar sorption behavior. The expansion of micro-porosity and surface area and also increase of biochar organic carbon content and hydrophobicity mostly happen by pyrolysis peak temperature rise. These changes make biochar suitable for immobilization of organic contaminants. Heating rate, gas pressure, and reaction retention time after the pyrolysis temperatures are sequentially important pyrolysis variables effective on biochar sorptive properties. This review compiles the available knowledge about the impacts of production variables on biochars sorptive properties and discusses the aging process as the main factor in post-pyrolysis alterations of biochars sorption capacity. The drawbacks of biochar application in the environment are summarized as well in the last section.

A Review on Phytoremediation of Crude Oil Spills

Changes in crude oil production and distribution have increased the incidence of oil spills throughout the world. Oil spills often cause destructive effects on aquatic and land ecosystems. The oil spill cleanup and recovery techniques are challenging and usually involve complex mechanical, chemical, and biological methods. Usually, mechanical removal of free oil is utilized as an effective strategy for cleanup in aquatic and terrestrial environments; however, they are expensive and need specialist personnel and equipment. The other commonly used method is the application of chemical materials such as dispersants, cleaners, demulsifiers, biosurfactants, and soil oxidizers. Nevertheless, these reagents can have potential harmful environmental impacts, which may limit their application. As an alternative, bioremediation can offer reduced environment risk; however, the limitations of microbial activity in the soil can make this option unsuitable. One area of bioremediation is phytoremediation, which offers potential for restoring large areas of contaminated ground. Plants are able to remove pollutants through processes such as biodegradation, phytovolatilization, accumulation, and metabolic transformation. This review presents the fate of crude oil spills in aquatic and land ecosystems and their environmental effects. Furthermore, the paper focuses on crude oil phytoremediation and its applications in polluted ecosystems.

Enhancing the hydrophobicity of mangrove bark by esterification for oil adsorption

Oil spills generally cause worldwide concern due to their detrimental effects on the environment and the economy. An assortment of commercial systems has been developed to control these spills, including the use of agricultural wastes as sorbents. This work deals with raw and modified mangrove barks (Rhizophora apiculata), an industrial lignocellulosic waste, as a low cost adsorbent for oil-product-spill cleanup in the aquatic environment. Mangrove bark was modified using fatty acids (oleic acid and palmitic acid) to improve its adsorption capacity. The oil sorption capacity of the modified bark was studied and compared with that of the raw bark. Kinetic tests were conducted with a series of contact times. The influence of particle size, oil dosage, pH and temperature on oil sorption capacity was investigated. The results showed that oleic acid treated bark has a higher sorption capacity (2,860.00 ± 2.00 mg/g) than untreated bark for Tapis crude oil. A correlation between surface functional groups, morphology and surface area of the adsorbent was studied by Fourier transform infrared spectrum, field emission scanning electron microscopy images and Brunauer-Emmett-Teller analysis. Isotherm study was conducted using the Langmuir and Freundlich isotherm models. The result showed that adsorption of crude oil on treated mangrove bark could be best described by the Langmuir model.

NOVEL CONFIGURATIONS OF SOLAR DISTILLATION SYSTEM FOR POTABLE WATER PRODUCTION

More and more surface water are polluted with toxic chemicals. Alternatively brackish and saline water are used as feed water to water treatment plants. Expensive desalination process via reverse osmosis or distillation is used in the plants. Thus, this conventional desalination is not suitable for low and medium income countries. A cheaper method is by solar distillation. However the rate of water production by this method is generally considered low. This research attempts to enhance water production of solar distillation by optimizing solar capture, evaporation and condensation processes. Solar radiation data was captured in several days in Perak, Malaysia. Three kinds of experiments were done by fabricating triangular solar distillation systems. First type was conventional solar still, second type was combined with 50 Watt solar photovoltaic panel and 40 Watt Dc heater, while third type was integrated with 12 Volt Solar battery and 40 Watt Dc heater. The present investigation showed that the productivity of second and third systems were 150% and 480% of the conventional still type, respectively. The finding of this research can be expected to have wide application in water supply particularly in areas where fresh surface water is limited.

Investigation of Modified Mangrove Bark on the Sorption of Oil in Water

Today oil spills generally cause worldwide worry due to their damaging effects on environment. Use of agricultural wastes such as raw and modified mangrove barks (RhizophoraApiculata), as an abundant and low cost adsorbent for oil-products spill cleanup in aquatic systems, has been developed to control these spills. Sorption capacity can improve by modification of adsorbent. The modification significantly increased the hydrophobicity of the adsorbent. The raw mangrove bark was modified using fatty acid (Palmitic acid) to improve its adsorption capacity. Oil sorption capacity of the modified bark was studied and compared with the raw bark. Kinetic tests were conducted with a series of contact time. The kinetic studies show good correlation coefficients for a pseudo-first-order kinetic model. A correlation between surface functional groups of the adsorbent was studied by FTIR spectrum. The results gave the maximum adsorption capacity of 2640.00 ± 2.00 mg/g for Palmitic acid treated bark (PTB). The prepared adsorbent revealed the potential to use as a low-cost adsorbent in oil-spill clean-up.

Water Quality Assessment of Ex-Mining Lakes in Perak, Malaysia as Alternative Source of Water Supply

This study investigated the water quality of some of the ex-mining lakes in Perak State of Malaysia for possible use as alternative to water supply and compared them to water quality of some of the rivers used for intake of water treatment. A total of twelve (12) water samples were collected for analyses from selected sampling sites. These samples were analyzed for physico-chemical properties, heavy metals concentrations, and organic pollutants concentrations. The analyzed results indicated that average temperature varied from 28.1 oC to 34.1 oC, pH 6.2 to 9.0, EC 55 to 400 μs/cm ,turbidity 5.6 to 74.2 NTU, DO 3.21 to 9.56 mg/l, TDS 36.8 to 268 mg/l, F- 0.017 to 0.182 mg/l, Cl- 0.483 to 3.339 mg/l, Br- 0 to 0.392 mg/l, SO42- 0.051 to 15.307 mg/l, Mg 0.833 to 1.466 mg/l, Na 0.669 to 3.668 mg/l, and Ca 2.85 to 26.77 mg/l. Heavy metals concentrations (mg/l) were: Zn 0.04 to 0.057, Pb 0.019 to 0.075, Cd not detected, Ni 0.013 to 0.105, As not detected to 0.004, and Cu not detected while COD 4 to 51 mg/l. Analyses revealed that all the water samples were turbid and containing slightly high concentration of Pb. Generally, they had common water quality problem. Further work should carry out more tests on other water quality parameters particularly on heavy metals, chemical and biological pollutants at different seasons.

The Effects of Feedstock Sources and Pyrolytic Temperature on Biochars Sorptive Characteristics

Biochar addition to soil and water environments has been shown to be effective in sequestering contaminants. This study evaluated the effects of biomass type and the preparation temperatures of biochars on their properties as a sorbent. Rice husk and empty fruit bunches of oil palm were used as the source of biomass for the production of biochars by heating at 300, 500 and 700°C. The biochars properties including functional sites, elemental components and BET surface area were determined to assess the biochars sorption mechanisms. The biochars produced in low temperature were found to have more polar functional groups effective in sorption of polar molecules while the highest temperature increased biochars surface area which is effective in non-selective sorption of contaminations.

The Performance of Trapezoidal Glass Cover Solar still during Monsoon Period of Tropical Environment

Seawater or brackish water desalination process using Reverse Osmosis as one of the current treatment technologies is expensive. A cheaper alternative is by using solar still. The paper presented the performance of solar still under tropical environment during monsoon period. The solar still was constructed using black stainless steel basin. Measurement of temperatures, solar intensities and distillate produce were recorded in the month of November and December, 2013, between 8 am and 6 pm. It was found that the distillate production rates obtained varied from 1.88 kg/m2/d to 2.26 kg/m2/d with efficiency of 37.7 %.

Nutrients balance for improvement of phytoremediation ability of teak seedlings (Tectona grandis)

ABSTRACT As a green technique, plant-based remediation systems can be used to remove nitrogen (N) pollutants from N-rich wastewaters. However, the excess amount of N and shortage of other nutrients in this system limits the plant growth and affects the plant remediation efficiency. In this study, the effect of adding phosphorus (P) and potassium (K) to the N-enriched wastewater on growth and N-removal efficiency of teak seedlings (Tectona grandis) was evaluated. Twelve ratios of N:P:K were applied to teak seedlings and the related effects were compared with those in control solution containing only N. The results indicated that a ratio of 1N:0.5P:1K increased dry matter accumulation in teak seedlings by improving the balance of nutrients in plants. Teak seedlings grown in nutritionally-improved system eliminated 33.8% N more than those grown in only N solution. The water loss through plant uptake was also enhanced in the improved system up to 56%.

Treatment of urea manufacturing facility effluent by Hopea odorata and Khaya ivorensis

Phytoremediation is an environmentally friendly and sustainable alternative for treatment of nitrogen-enriched wastewaters. In this study, Ta-khian (Hopea odorata) and Lagos mahogany (Khaya ivorensis), two tropical timber plants, were investigated for their performances in treatment of urea manufacturing factory effluent with high nitrogen (N) content. Plant seedlings received four concentrations of N (190, 240, 290 and 340 mg/L N) in laboratory-scale constructed wetlands every 4 days for a duration of 8 weeks. The solution volumes supplied to each container, amount of N recovered by plants and plant growth characteristics were measured throughout the experiment. Results showed that Ta-khian plants were highly effective at reducing N concentration and volume of water. A maximum of 63.05% N recovery was obtained by Ta-khian plants grown in 290 mg/L N, which was assimilated in the chlorophyll molecule structure and shoot biomass. Significant positive correlations have been shown between N recovery percentages and plant growth parameters. Ta-Khian plants can be applied as suitable phytoremediators for mitigating N pollution in water sources.