The traditional salt production in Indonesia was investigated to report the preparation and processing of salt, determine the characteristics of sea water and bittern as well as explore the potential of bittern management with appropriate technology. Field study and comprehensive analysis were performed so as to better understand the salt making, providing valuable information for the proposal of targeted management strategies in salt quality improvement and wastewater recovery. The results show that Na + , Cland Ca 2+ in East Java Province seawater were found greater than the majority of values found in the literature. The highest concentrations of Na + , Cland Ca 2+ were measured in Camplong-Sampang District. The highest concentrations of Mg 2+ and trace metals were recorded in Panceng-Gresik District. The trace metals found in sea water and bittern need particular concern to be removed without disposing of sea water minerals. The potential number of bittern in Indonesia promoted the development of the bittern management for magnesium recovery and achieving marine environment sustainability. High purified material recovery can be achieved by using crystallization technology.

As one of the basic human needs, water services should be sustainable. Researches related to the sustainability of water services have been conducted in several developing countries. However, there are no identical researches in Indonesia. This paper discusses the analysis of factors that contribute to sustainability of rural water supply systems in East Java, Indonesia. Data is collected by observing rural water supply facilities, interviewing water committees and water users, and taking documentation. The data is used to build a model, which was developed from theoretical or conceptual model. The model's development uses structural equation modeling (SEM). This model can show the factors that contribute to sustainability of rural water supply systems. The sustainability is influenced significantly by nine variables; they are selection of technology, water sources, investment cost, capability of operator, availability of spare parts, operation cost, technical operation, community participation, and institutional management.

Sebagian besar limbah cair hasil dari kegiatan manusia dibuang ke saluran. Sekitar 60% pencemaran KaliSurabaya berasal dari limbah domestik (Fatnasari dan Hermana, 2010). Padahal air Kali Surabaya memasoksekitar 96% kebutuhan air baku Perusahaan Daerah Air Minum (PDAM) Kota Surabaya (Herera dkk, 2013).Penelitian ini bertujuan untuk mengidentifikasi tingkat pencemaran dan menentukan prioritas strategipengendalian pencemaran air Kali Surabaya menggunakan AHP (Analitycal Hierarchy Processes).Pengumpulan data sekunder berupa data kualitas air Kali Surabaya yang terdiri dari temperatur, TSS, pH,BOD, COD, DO, nitrat, amonia, kromium, tembaga, nitrit, minyak, deterjen, fenol, total coli, dan faecal coliyang dibandingkan dengan baku mutu air kelas 2 berdasarkan Peraturan Pemerintah nomor 82 tahun 2001.Kemudian dilakukan penentuan status mutu air Kali Surabaya menggunakan metode indeks pencemaranberdasarkan Keputusan Menteri Lingkungan Hidup Nomor 115 tahun 2003. Analisis Strategi pengendalianpencemaran air Kali Surabaya didapat setelah dilakukan pembagian kuesioner kepada Badan LingkunganHidup Provinsi Jawa Timur, Dinas Pekerjaan Umum Pengairan, Perum Jasa Tirta, Dinas Perindustrian danPerdagangan, PDAM dan Tokoh Masyarakat. Hasil penelitian menunjukkan bahwa parameter pencemar airKali Surabaya adalah TSS, BOD, DO, nitrit, minyak, dan fenol. Selain itu, status mutu air Kali Surabayatermasuk tercemar ringan. Hasil running prgram AHP diketahui bahwa strategi pengendalian pencemaran airKali Surabaya lebih menitik beratkan pada ketegasan dalam menaati peraturan perundangan yang berlaku. The Surabaya River’s main problem currently was the wastewater resulted from human activities mostly being discharged into the river. About 60% of Surabaya River pollution originated from domestic wastewater (Fatnasari dan Hermana, 2010). Infact, about 96% of water Perusahaan Daerah Air Minum (PDAM) Surabaya take from this river (Herera dkk, 2013). This study aims for identification of pollution level and determination of strategy priority of water pollution control in Surabaya River using Analytical Hierarchy Processes (AHP). The study was begun from secondary data collection of water quality parameter of: temperature, TSS, pH, BOD, COD, DO, nitrate, nitrite, ammonia, chromium, copper, oil, detergent, phenol, total coli and faecal coli. The data would be compared with stream standard. Then quality status of Surabaya River water was determined by using pollution index method according to Ministry of Environment Decree N0. 115/2003. The analysis of strategy to control Surabaya River water was done by questionnaire and direct interview methods to Badan Lingkungan Hidup (BLH) of East Java Province, Dinas Pekerjaan Umum Pengairan, Perum Jasa Tirta I, Dinas Perindustrian dan Perdagangan, PDAM and several affectional peoples in society. The result of study shows that the polluting parameters of water in Surabaya River were TSS, BOD, DO, nitrite, oil and phenol. The water quality status of Surabaya River is categorized as low polluted. From the result of AHP the strategy of water pollution control in Surabaya River should be focused on social aspect which more focused firmness in keeping the existing regulations

The kinetics of crystallization of magnesium carbonate (nesquehonite) at room temperature (27°C) has been examined using an electrical conductivity method during process of nucleation. Magnesium carbonate hydrate from a reaction of magnesium chloride (MgCl2) and sodium carbonate (Na2CO3) in supersaturated condition was analyzed. Variations of batch reactor experimental are magnesium chloride initial concentration (500-3.000 mg/L) and operating pH (8-14). In this paper, we studied the crystallization kinetics of magnesium carbonate via an electrical conductivity method, a concentration monitoring method. By monitoring electrical conductivity during the solution reaction process, changes in [Mg2+] can be measured and an induction period of nucleation could be determined. Crystal has been formed was confirmed with powder X-ray Diffractometer (XRD) analyses. The results show that magnesium carbonate is formed during operating condition pH 10 with magnesium chloride initial concentration 3.000 mg/L. The nucleation process of magnesium carbonate crystallization can be represented by second-order reaction equation with R2 is 0.8. The induction period of magnesium carbonate crystallization is 50 second.

Objek penelitian ini adalah Kali Surabaya. Sungai ini dimanfaatkan sebagai sumber air minum dan untuk proses produksi industri. Sungai ini menerima beban pencemaran dari limbah domestik, limbah pertanian dan limbah industri. Kali Surabaya diperlukan perhitungan daya tampung untuk mengetahui batas maksimum air limbah yang boleh dibuang ke sungai. Wilayah titik pantau pada penelitian ini terdapat 5 segmen. Parameter kualitas air yang dianalisa adalah pH, suhu, DO, BOD, TSS, nitrat (NO3), ammonium (NH4) dan fosfat (PO4). Analisis data menggunakan aplikasi program QUAL2Kw untuk menghitung beban pencemaran yang masuk ke Kali Surabaya. Pemodelan data dilakukan dengan trial and error hingga diperoleh hasil model yang sesuai (mendekati) kondisi yang sebenarnya. Setelah itu modeldiverifikasi, sehingga model dapat digunakan untuk menghitung berbagai macam skenario yang sudah ditentukan. Nilai daya tampung Kali Surabaya adalah NH4 berkisar antara 100 kg/hari sampai 3563 kg/hari dan NO3 berkisar antara 976 kg/hari sampai 14306 kg/hari.