Particulate emission from agricultural waste fired boiler

In the current overview paper, particulate emissions from the combustion of agricultural residues are discussed. The influence of operating parameters and fuel quality was investigated. Studies on the mass concentration, number concentration and size distribution of particles emitted from agricultural waste fired boiler are presented. Mass concentrations of particles in the flue gas from small scale combustion appliances reported in the literature to be in the range of 8 - 2095 mg/Nm3, while particle number concentrations in the range of 7.0 x 10-2 to 1.8 x 108 particles/cm3. The dominating chemical compositions of the particle emissions were Ca followed by K, Mn and Mg. Organic Carbon (OC), Elemental carbon (EC), Elemental emission, Poly-cyclic Aromatic hydrocarbon (PAH) and emission of different size particles (PM?0.1 to PM10) were also reported. Combustion temperature is the most important factor in determining PAH composition

Characteristics of methanogens and methanotrophs in rice fields: a review

Methane is the second most important greenhouse gas after carbon dioxide (CO2) with a global warming potential 25 times more than CO2. Rice fields are one of the main anthropogenic sources for methane and responsible for approximately 15-20% of the annual global methane efflux. Methanogens and methanotrophs are two microbial communities which contribute to the biogeochemical methane cycle in soil by producing and oxidizing methane, respectively. In fact, the total methane emission from rice soil is the balance between methanogen and methanotroph activities. Methanogenic archaea are more active in highly reduced conditions and anoxic soils. However, methanotrophs are more active in oxic soils. These microorganisms have been studied frequently in different soils from natural wetlands to rice fields. This article has mainly focused on the characteristics of methanogens and methanotrophs in a rice soil ecosystem with the objective of deriving solutions the high level of methane emissions from paddy fields

Treatment of wastewater from rubber industry in Malaysia

Presently, Malaysia is the third largest rubber producer in the world, whereby the rubber industry is an economically and socially significant industry. Rubber industry consumes large volumes of water, uses chemicals and other utilities and produces enormous amounts of wastes and effluent. Discharge of untreated rubber effluent to waterways resulted in water pollution that affected the human health. With a new global trend towards a sustainable development, the industry needs to focus on cleaner production technology, waste minimization, utilization of waste, resource recovery and recycling of water. The present work aims at highlighting various technologies that currently have been used for treatment of rubber effluent in Malaysia. The work introduces the basis of these processes including their benefits and also problems. It also adheres to the future trends of rubber effluent treatment in Malaysia by reviewing various treatment technologies for natural rubber industry implemented by Thailand, the world largest rubber producer. These new and effective effluent treatment methods would minimize environmental pollution of rubber industry and bring it to become sustainable and environmental friendly

Biosorption of phenolic compounds from aqueous solutions using pine (Pinus densiflora Sieb) bark powder

The present study describes the development of a new bioadsorbent from lignocellulosic wastes of agricultural origin. The biosorption capacity of an agricultural solid waste, pine bark (Pinus densiflora Sieb.), to remove phenolic compounds (phenol, 2-chlorophenol (2-CPh), and 4- chlorophenol (4-CPh)) from aqueous solutions under batch equilibrium conditions was investigated. The morphological characteristics of the biosorbent were evaluated by BET surface area analysis, Fourier transform infrared spectroscopy (FTIR), elemental analysis, an X-ray diffractometer (XRD), and a scanning electron microscope (SEM). Batch experiments were conducted to investigate the effect of initial pH (2 to 10), contact time, initial concentration of adsorbate (50 to 200 mg/L), and biosorbent dosage. The biosorption of phenolic compounds decreased with increasing pH, and the highest biosorption capacity was achieved at a pH of 6.0. Biosorption equilibrium was established in 120 min. The biosorption equilibrium data were fitted and analyzed with Langmuir, Freundlich, and Dubinin-Radushkevich isotherm equations, as well as four adsorption kinetic models. The kinetics data fitted well into the pseudo-second-order kinetic model, with a correlation coefficient greater than 0.993. The maximum monolayer biosorption capacity of pine bark for phenol, 2-CPh, and 4-CPh was found to be 142.85, 204.08, and 263.15 mg/g, respectively, as calculated by the Langmuir model at 30 ± 1 °C. Pine bark could be used as a new effective, low-cost biosorbent material with good uptake capacity and rapid kinetics for the removal of phenolic compounds from aqueous media

Effect of pretreatments on compost production from shredded oil palm empty fruit bunch with palm oil mill effluent anaerobic sludge and chicken manure

Rapid co-composting of lignocellulosic oil palm empty fruit bunch (OPEFB) and palm oil mill effluent (POME) is a cost-effective and sustainable way to eliminate biomass residues. In this study, suitable pre-treatments and co-substrates for an accelerated composting treatment process were investigated. A steam pre-treatment was performed prior to composting. The composting mixtures were placed in plastic drums under a roofed area. They were regularly turned for aeration and measured for temperature, oxygen, moisture content, bulk density, carbon to nitrogen (C/N) ratio, and fiber tensile strength. C/N ratio is the main parameter measured as a maturity indicator for the compost. The compost temperature was above 60 °C during the thermophilic phase after the steam pre-treatment, based on the heat produced by the microbes. Steam-treated OPEFB and untreated OPEFB co-composted with chicken manure achieved the same maximum temperature of 62 °C and C/N ratios of 8.76 and 9.58, respectively. Steam pretreatment did not have significant effect when the treated OPEFB was co-composted with POME anaerobic sludge due to insufficient steam pressure at 40 psi and 140 °C. Steam-treated OPEFB and untreated OPEFB co-composted with POME anaerobic sludge achieved 54 °C and 60 °C, respectively, while the C/N ratios were 12.41 and 10.14, respectively

Performance evaluation and characteristics of selected tube wells in the Coastal Alluvium Aquifer, Selangor

Alluvial aquifers can be found in most of the coastal areas of Peninsular Malaysia. Seven tube wells located in such aquifers in the west coast of Selangor state had their performance evaluated by carrying-out step drawdown tests. The performance of these wells was evaluated in terms of aquifer loss, well loss, specific capacity and well efficiency. The aquifer loss coefficient and well loss coefficient were found to be in the range of 0.0198 hrm-2 to 0.4014 hrm-2 and from 0.0001 hr2m-5 to 0.0410 hr2m-5, respectively. The drawdown in tube wells TW1 and TW7 is mainly influenced by well loss component as compared to the aquifer loss component, while in tube wells TW2, TW3, TW4, and TW5, the drawdown is mainly influenced by aquifer loss component. The drawdown in tube well TW6 is influenced by aquifer loss component at a low discharge rate, but at high discharge rate, it is influenced by well loss component. The specific capacity and efficiency of the tested tube wells varied from 1.329 m2hr-1 to 40.166 m2hr-1, and from 11% to 96%, respectively. Tube wells TW2 and TW4 are categorized as high productive wells, while tube wells TW1, TW3, TW5 and TW7 are categorized as moderate productive wells and tube well TW6 as low productive well

Strength assessment of mining soil treated with steel slag as liner material for retention pond

Clay soil has always been associated with low shear strength and high compression behavior due to the high content of organic matter. The limited amounts of clay available onsite and acid mine drainage (AMD) problems have necessitated the continuous search for the treatment technology potentials. Mining soils, obtained from Selinsing Gold Mine in Raub, Pahang were evaluated to determine their suitability for use as mining soil and steel slag mixtures as compacted retention pond liners for AMD treatment. The studied samples were subjected to classification, compaction, permeability and strength tests. The results indicated that the index properties of the samples met the minimum requirements for use as liners. The compaction test showed that the maximum dry density (MDD) and optimum moisture content (OMC) decreased and increased, respectively, for all studied samples. At OMC, hydraulic conductivities of the compacted soil-steel slag were in the order of ≤ 10-9 m/s. The results from unconfined compression strength (UCS) tests gave values of 204 kN/m2 and 61° for soil cohesion and soil internal friction angle, respectively. Furthermore, the influence of steel slag treatment on strength properties has generally shown an improvement of up to 15% steel slag which gives the acceptable results of stress-strain in respect of its usability as liner material

Assessment of the influence of continuous and intermittent irrigation on greenhouse gas emissions from paddy rice

The impact of two water management practises on Greenhouse Gases (GHGs) emissions from paddy rice fields was investigated. New Rice for Africa (NERICA 2) lowland variety was planted under intermittent irrigation (II) and continuous flooding (CF) water management practises. Two closed gas chambers (GCs) were developed and used for gas sampling from paddy fields and measurement was done conventionally in all the four growing stages of rice. Gas Chromatograph (GH200-9) was used analysing GHGs such as Methane (CH4), Nitrous oxide (N2O), Hydrogen Sulphide (H2S) and Oxygen (O2). Soil analyses were carried out to determine the presence of the following parameters viz: nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), Manganese (Mn) and calcium (Ca). Others are Organic Carbon (OC), Moisture Content (MC), Iron (Fe), Chloride (Cl) and Electrical conductivity (EC) using standard laboratory procedures and ascertain effects of their availability on GHGs concentration levels. From the study, no appreciable CH4 emissions was detected during the four growing stages and under the two water management practises but other GHGs emitted were higher in CF compared with II. Soil nutrients such as N, OC, K and P also contributed considerably to emissions recorded on the two rice fields. The detection of H2S was also an indication that other gases apart from the common GHGs were present in rice fields. Although, CH4 was not detected, other GHGs emitted were more in CF when compared with II which suggested that II be encouraged as a mitigation strategy for reducing impacts of its emissions

Prediction of groundwater contaminants from cattle farm using Visual MODFLOW

Livestock operation activities such as cleaning operation, feeding, milking and manure disposal are potential sources of contaminants into nearby surface and groundwater. In this study, the number of wastes generated from a cattle farm in Ladang 16 UPM, Serdang Selangor was estimated. Two monitoring wells were constructed at the site for groundwater quality monitoring assessment. The concentration of pollutants such as Potassium, Nitrate, and Copper was used in the simulation as an initial waste state. The simulation was conducted using Visual MODFLOW Software to predict the contaminants in groundwater. The aim was to predict the concentration of the pollutants distributed in groundwater and surface water sources in 365 days. Results of MODFLOW simulation showed that the flow of groundwater was in the direction towards the pond. The concentrations of Potassium, Nitrate, and Copper were predicted to accumulate in the groundwater to the pond within a year but the values were still below the drinking water standard. The groundwater contaminants could be due to seepage from the manure storage basin through subsoil into the shallow aquifer

The influence of pH on the removal of ammonia from a scheduled waste landfill leachate

Leachates are formed as the result of water or other liquid passing through the landfilled waste. These leachates contain high amounts of inorganic and organic matter such as ammonia which must be treated before being discharged into the environment. A pretreatment is required to increase the efficiency of the ammonia removal process. This paper presents the influence of pH on the removal of ammonia in leachate sample by lime precipitation. A raw leachate sample taken from a scheduled waste landfill was treated with different amount of lime (2, 4, 6, 8 and 10 g/L) to investigate the removal or release of ammonia. The removal of ammonia of raw leachate (average pH=9.43) was 26% and increases to the optimum dosage of 4 g/L with 54% removal at pH=12.39. However, addition of lime of more than 6 g/L does not show any significant effect on ammonia removal due to restabilization of colloids and re-dispersion of the colloidal particulates. An appropriate dosage of lime is an important factor that could save cost and time for the downstream secondary treatment