Post reclamation of acid sulphate soil due to extended tidal irrigation area in Palingkau, Central Kalimantan, Indonesia

The Palingkau Swamp Irrigation Scheme SP1 SP2 SP3 extends tidal irrigation between Kapuas Murung River and Kapuas River, which local peoples developed. The development of the new agricultural land behind the old tidal irrigation system creates oxidation of potential acid sulphate (FeS2) soil. The result of the leaching process polluted local’s agricultural area causes the decrease land productivity. The field observation recorded the water pH ranges between 3.9 - 5.3; 3.7 - 4.31 at the handil; 2.5 - 4 at the collector channels; and 2.8 - 3.6 at the primary channels. Good water management is needed to overcome these problems, both at the new irrigation system and handil. The HECRAS mathematical model is used to evaluate water circulation in the system and its reliability. The Efforts to normalize the handil impact increasing the amount of water entering the handil although it is not significant. Moreover, it still cannot meet the water demand for the leaching process in the network system by 2.06 million m3/day. It is necessary to increase the capacity of the channel to allow freshwater flow from the river for the leaching process in the network system.

Obtaining and Properties of a Photocatalytic Composite Material of the “SiO2–TiO2” System Based on Various Types of Silica Raw Materials

Compositions and technology for obtaining a photocatalytic composite material (PCM) by deposition of titanium dioxide particles synthesized by the sol–gel method on a silica support of various types (microsilica, gaize and diatomite) have been developed. The properties (chemical and mineral composition, dispersion, specific surface area, porosity, ζ-potential, acid–base properties, and microstructure) of microsilica, gaize and diatomite were studied to assess the effectiveness of using a photocatalytic agent as a carrier. In terms of specific viscosity (ηsp = 45), the concentration of the precursor (tetrabutoxytitanium—TBT) is set at 22 vol. % in a solvent (ethanol), at which it is possible to obtain the maximum amount of dissolved film oligomer without the formation of an aggregate-like precipitate. Modification of the reaction mixture (precursor: ethanol = 1:3) by replacing part of the solvent with a Span-60 surfactant/TBT = 1–1.1 made it possible to obtain polydisperse titanium dioxide particles with peak sizes of 43 nm and 690 nm according to laser granulometry data. Taking into account the interaction of titanium complexes with the surface of a silica support, a phenomenological model of the processes of structure formation of a photocatalytic composite material is proposed. By the value of the decomposition of rhodamine B, the photocatalytic activity of the developed composite materials was determined: PCM based on diatomite—86%; PCM based on microsilica—85%; PCM based on gaize—57%.

Study on Nutrient Balances of Newly Developed Lowland Rice Fields at Kleseleon Village, Malaka District, Nusa Tenggara Timur

The land allocated for newly opened lowland rice can be from ultisols, oxisols, inceptisols, and potential acid sulfate soils. The study was aimed to evaluate nitrogen (N), phosphorous (P), and potassium (K) inputs – outputs of newly developed lowland rice under different treatments and to validate the N, P, and K recommended applications rate according to N, P, and K balances. The study was conducted in Kleseleon village, Malaka District. Five treatments were tested namely T0: farmers practices, T1: NPK at recommendation rate + Rice straw compost, T2: NPK at recommendation rate + Smart + Rice straw compost, T3: ¾ NPK at recommendation rate + Smart + Rice straw compost, and T4: NPK at recommendation rate + Smart + Rice straw compost. The treatments were arranged in a randomized complete block design with three replications. The nutrient balances were constructed according to the difference between nutrient inputs and losses. The results indicated that there were surplus N, P, and K across the treatments and more than adequate to replace N, P, and K removed by harvest products. The suggested N, P, and K application rates were 100 kg urea, 100 kg SP-36, and 100 kg KCl with the addition of compost 3 Mg ha-1 season-1.

Influence of Medications Containing Acid Salts on Serum Bicarbonate in CKD

BackgroundMany medications are formulated with acid salts. Their effect on acid-base balance in CKD is unclear.MethodsWe calculated the acid load (meq/d) from medications prescribed to 74 United States veterans with diabetes and CKD to identify agents with high potential acid load. We also determined cross-sectional associations between the acid load from medications and acid-base parameters after adjusting for demographics, eGFR, protein intake, and other confounders.ResultsOf the 125 medications prescribed, 31 (25%) contained an acid salt. Metformin hydrochloride (15.4 meq/d at 2550 mg/d) and gabapentin hydrochloride (13.0 meq/d at 2700 mg/d) were identified as agents with a high potential acid load. Mean daily acid load from medications was 6.6 meq/d in the overall cohort, 14.2 meq/d in the high medication acid load group (≥7.7 meq/d, n=29), and 1.6 meq/d in the low medication acid load group (<7.7 meq/d, n=45). After adjusting for potential confounders, those in the high acid load group had 1.7 meq/L lower total carbon dioxide (CO2) and 2.2 meq/L higher anion gap than those in the low acid load group. Use of gabapentin alone was not associated with differences in total CO2 or anion gap. Use of metformin alone was associated with 0.7 meq/L lower total CO2 and 1.0 meq/L higher anion gap. Use of metformin with gabapentin was associated with 1.8 meq/L lower total CO2 and 2.4 meq/L higher anion gap. The higher anion gap was not explained by higher serum lactate levels. The acid load from medications was not associated with differences in urinary ammonium, titratable acid, or pH.ConclusionsMedications containing acid salts, particularly metformin hydrochloride and gabapentin hydrochloride, are sources of an exogenous acid load. These agents may influence serum total CO2 levels and serum anion gap in individuals with CKD.Clinical Trial registry name and registration numberInvestigations of the Optimum Serum Bicarbonate Level in Renal Disease, NCT01574157

SISTEM PENGOLAHAN AIR ASAM TAMBANG DARI MATERIAL WASTE DAN APLIKASI MODEL ENKAPSULASI PADA BENDUNGAN TSF DI TAMBANG EMAS MARTABE

ABSTRAK Indonesia adalah negara yang kaya akan sumber daya alam, baik berupa sumber daya alam pulih maupun yang tidak pulih. Industri pertambangan adalah salah satu aktivitas yang bergerak dalam mengolah sumber daya alam yang tidak pulih yang dapat memberikan dampak positif maupun negatif baik dari sisi sosial, ekonomi maupun lingkungan. Air asam tambang adalah salah satu dampak dari industri pertambangan yang harus ditangani secara serius yang terbentuk akibat reaksi mineral sulfida (pirit) dan logam berat yang terpapar ke media air dan udara yang berasal dari batuan yang terbuka pada saat aktivitas penambangan berlangsung. Sejak tahun 2013, tambang emas Martabe telah menerapkan manajemen air asam tambang (AAT) dalam konstruksi bendungan TSF dengan enkapsulasi sederhana yang dirancang dengan dua kategori utama batuan PAF (Potential Acid Forming) dan NAF (Non Acid Forming) sebagai bagian dari material tanggul TSF konstruksi hilir dan juga mengembangkan basis data karakteristik geokimia material waste di lokasi tambang emas Martabe. NAPP (Net Acid Production Potential) adalah metode standar industri yang digunakan untuk menentukan potensi untuk mengoksidasi dan menghasilkan bahan limbah asam, yang nantinya akan ditempatkan di bendungan TSF dengan metode enkapsulasi. Metode ini bertujuan untuk membungkus material sulfida beresiko tinggi yang sedang di tambang di Martabe dengan lapisan penyegel (sealing layer) dengan mengambil keuntungan dari iklim (curah hujan yang tinggi) dan sifat material ROM (run of mine). Konstruksi lapisan penyegelan dan penjadwalan material waste dilakukan dengan pengembangan strategi operasional pengelolaan limbah yang terperinci dan terintegrasi. Monitoring rutin dengan instrument WRSF (Waste Rock Storage Facility) untuk pengukuran oksigen dan juga dari pengukuran kualitas air menunjukkan kalau enkapsulasi material waste pada embakment TSF berhasil mencegah pembentukan air asam tambang. Kata kunci: material waste, air asam tambang, naf, paf, bendungan tailing, model enkapsulasi ABSTRACT Indonesia is a country that is rich in natural resources, both in renewable and non-renewable. The mining industry is one of the activities that is engaged in processing non-renewable natural resources that can have positive and negative impacts both in terms of social, economic and environmental aspects. Acid mine drainage is one of the impacts of the mining industry which must be dealt with seriously which is formed due to the reaction of sulfide minerals (pyrite) and heavy metals which is exposed with water and air from rocks during mining activities.Since 2013, the Martabe gold mine has implemented mine acid drainage management (AMD) in TSF dam construction with simple encapsulation designed, with two main categories of PAF (Potential Acid Forming) and NAF (Non Acid Forming) rocks as part of construction TSF embankment material downstream and also develop the geochemical characteristics database of waste material at the Martabe gold mine site. NAPP (Net Acid Production Potential) value is an industry standard method to determine the potential to oxidize and produce acid waste materials, which will be placed in the TSF dam by encapsulation model. This method aims to wrap the high risk sulfide material in a mine at Martabe sealing layer to take advantage of both the climate (high rai fall) and material properties of run of mine (ROM). The construction of sealing layer and scheduling of waste is made possible by the development a detailed and integrated operational waste management strategy. Routine monitoring with the WRSF (Waste Rock Storage Facility) instrument for measuring oxygen and also from measurements of water quality shows that the encapsulation of waste material in TSF embankments successfully prevents the formation of acid mine drainage. Key words: waste materials, acid mine drainage, naf, paf, tailing storage facility, encapsulation model

Prediksi Laju Pembentukan Air Asam Tambang dengan Metode Column Leaching Test

Prediction of Acid Mine Drainage Forming using Method of Column Leaching Test. One of the environmental problems in coal mining activities is the formation of acid mine drainage. Prediction of the formation of acid mine drainage is important as an effort to control environmental impacts. Acid mine water occurs with interactions between potentially acid-forming material with oxygen, bacteria and water. Objective of study is to analyze the potential for acid mine drainage forming based on material characteristics. The research method was carried out using static and kinetic tests. The static test method classifies materials according to the ability to produce clean acids with observed parameters such as paste pH, total sulfur, Acid Neutralizing Capacity (ANC), Net Acid Generation (NAG), Maximum Potential Acid (MPA), and Net Acid Producing Potential (NAPP). The Kinetic test method predicts the rate of acid-forming of a material. The kinetic test uses the Column Leaching Test Method by using material with composition designed to represent field condition. The kinetic method parameters are pH, electrical conductivity, acidity, alkalinity, sulfate content, and dissolved metal content (Fe, Mn, and Cd). Results of the static test classified the material into NAF Non-Acid Forming (NAF), Potential Acid Forming (PAF) and Uncertain (UC) material categories. The results of the Column Leaching Method classified the material into categories of potential and no potential to form acid mine water. The columns that have the potential to form acid mine drainage occur in columns with large amounts of tonnage of PAF material or those in the upper layer so that it reacts with oxygen. The columns that have no potential to produce acid mine drainage in columns with PAF material are in the middle layer or mixed with NAF material.