The quality of rainwater from a tile and a galvanized-iron type roof catchments were analysed over a period of 5 months. Examination of staggered I litre samples collected during a rainfall event showed that the concentration of various pollutants were high in the first litre but decreased in subsequent samples with few exceptions. Faecal coliform and total coliform counts ranged from 8-13 (tile roof) and 4-8 (iron roof) to 41-75 (tile roof) and 25-63 (iron roof) colonies per 100 ml, respectively. However, no faecal coliforms were detected in the fourth and fifth litre samples from both roofs. The pH of rainwater collected from the open was acidic but increased slightly after falling on the roofs. The average zinc concentrations in the run-off from the galvanized-iron roof was about 5-fold higher compared to the tile roof, indicating leaching action but was well below the WHO limits for drinking water quality. Lead concentrations remained consistently high in all samples collected and exceeded the WHO guidelines by a factor of 3.5. For the roof area studied, a "foul flush" volume of 51. would be the minimum to safeguard against microbiological contamination but the high metals content in the water indicate the need for some form of treatment. Rainfall intensity and the number of dry days preceeding a rainfall event significantly affects the quality of runoff water from the catchment systems.

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.

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.

Desalination of water can be achieved via the use of solar stills, especially as they are considered to be the cheapest option for potable water production in remote, arid and small communities with limited availability of freshwater. However, one very common challenge with water production via solar stills is that the amount of water produced is usually low. The aim of this work is to evaluate the productivity enhancement of solar stills using different heat storage materials in the basin. To conduct the experiments, three triangular solar stills were fabricated with similar shapes. In each solar still, a transparent polythene film and a stainless steel trough as cover and basin were used, respectively. Each basin had a length of 50 cm, width of 30 cm and depth of 8 cm. The solar still configurations differed based on inclusion of 2 cm depth of black soil or a layer of black paint in the basin. Experimental outputs indicated that there was significant increase in the amount of potable water produced using different heat storage materials under Malaysia tropical condition. Daily cumulative results of water production using these solar stills showed that the solar still with black-painted basin was more efficient; its level of productivity over the conventional solar still and the solar still with black soil in basin was 101 and 20 %, respectively. Some water quality parameters were also tested in the laboratory which indicated that the treated water met the WHO standard for drinking water.Keywords Solar distillation Á Stainless steel basin Á Black soil Á Black paint Á Potable water Nomenclature T w1 Temperature of water of solar still SS1 (°C) T w2 Temperature of water of solar still SS2 (°C) T w3 Temperature of water of solar still SS3 (°C) T a Temperature of ambient air (°C) T ic1 Temperature of inner cover of solar still SS1 (°C) T ic2 Temperature of inner cover of solar still SS2 (°C) T ic3 Temperature of inner cover of solar still SS3 (°C) I s Solar irradiance (W/m2) W h1 Hourly water production of solar still SS1 (L/m2) W h2 Hourly water production of solar still SS2 (L/m2) W h3 Hourly water production of solar still SS3 (L/m2) W c1 Cumulative water production of solar still SS1 (L/m2) W c2 Cumulative water production of solar still SS2 (L/m2) W c3 Cumulative water production of solar still SS3 (L/m2) V Wind speed (m/s)

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Biochar is the bio-solid material produced by pyrolysis. The biochar properties are controlled by feedstock and pyrolysis variables. In this study, the impacts of these production variables on biochar yield and physicochemical properties including pH, cation exchange capacity (CEC), total organic carbon (TOC) content, surface area, and pore volume and size were investigated. Rice husk (RH) and oil palm empty fruit bunches (EFB) were used as biomass. The biochars were produced at temperature range of 300 to 700 °C, heating rate of 3 to 10 °C/min and retention time of 1 to 3 h. The pyrolysis conditions were optimized using response surface methodology (RSM) technique to maximize the values of the responses. Analysis of variance (ANOVA) of the results demonstrated that the data fitted well to the linear and quadratic equations. Temperature was found to be the most effective parameter on the responses followed by retention time and heating rate, sequentially. CEC, TOC, surface area, and pore characteristics were evaluated as biochar properties determining their sorption potential. The optimum conditions for the maximum values of the properties were temperatures of 700 and 493.44 °C and time of 3 and 1 h for RH and EFB biochars, respectively. Heating rate at 3 °C/min was found to be the best rate for both biochars. The structure of EFB biomass was more sensitive to heating than rice husk. The biomass type and the production variables were demonstrated as the direct effective factors on biochar yield and physicochemical properties.

Removal of oil spillage from the environment is a global concern. Various methods, including the use of fibers as sorbents, have been developed for oil spill control. Oil palm empty fruit bunch (OPEFB) fiber is a plant biomass that may be acetylated by acetic anhydride using N-bromosuccinimide (NBS) as a catalyst; here, the extent of acetylation may be calculated in terms of weight percent gain (WPG). The modified fiber was used to remove Tapis and Arabian crude oils. The optimum time, temperature, and catalyst concentration were 4 h, 120 °C, and 3 %, respectively, and these parameters could achieve an 11.49 % increase in WPG. The optimized parameters improved the adsorption capacity of OPEFB fibers for crude oil removal. The acetylated OPEFB fibers were characterized by using Fourier transform infrared spectroscopy and field emission scanning electron microscopy to observe the functional groups available and morphology. Kinetic and isotherm studies were conducted using different contact times and oil/water ratios. The rate of oil sorption onto the OPEFB fibers can be adequately described by the pseudo-second-order equation. Adsorption studies revealed that adsorption of crude oil on treated OPEFB fiber could be best described by the Langmuir isotherm model.

A mixed plating rinse wastewater containing zinc, hexavalent chromium, trivalent chromium, and cyanide with total dissolved solids of 424 mg/1 was treated by a model consisting of a sand filter and ion exchange columns. A strongly acidic cation resin in hydrogen form and a strongly basic anion resin in hydroxide form were used in the columns as cationic and anionic exchangers, respectively. The cationic and anionic exchangers were regenerated by using 2% H2SO4 and 5% NaOH, respectively. A 100% removal of zinc, total chromium, hexavalent chromium and trivalent chromium was achieved in the studies. Very high removal of total dissolved solids, cyanide and hardness level was achieved at 98.9%, 99.9% and 96.5%, respectively. The conductivity of wastewater was reduced from an average of 358 μs/cm to 5 μs/cm. The case study has shown that treatment systems using cationic and anionic resin were able to treat a mixed plating bath effluent to comply with the standard discharge under the Malaysian Environmental Quality (Sewage and Industrial Effluents) Regulation, 1979.